ALBERT

Notes: Interest in the use of adjustment models has recently increased as analysts have come to see the value of these models in the study of regional growth processes. Adjustment models are especially useful in clarifying the nature and direction of population-employment interactions. However, other models of regional growth suggest that employment should not be treated as a single homogeneous variable, as is the usual assumption in regional adjustment models. This paper looks at the issue of employment disaggregation, and suggests that adjustment models can be alternatively specified by making use of economic base theory to separate employment into at least two broad sectors. Alternative economic base specifications are tested using data for the nonmetropolitan counties (n=254) of the US. Rocky Mountain West during a recent time period. The results show that an economic base version of the adjustment model provides insights to regional change that are not available from the traditional version of the model.

Notes: Book review in this article:East Asian Development: Will the East Asian Growth Miracle Survive? Edited by F. Gerald Adams and Shinichi Ichimura.Regional Change in Industrializing Asia. Edited by Leo van Grunsven.Black Powe/White Power in Public Education, by Ralph Edwards and Charles V. Willie.

Notes: Fiscal devolution fiom federal to state jurisdictions gives states more authority but also more responsibility for redistributing and stabilizing income. Both the revenue and expenditure sides of a state's budget are affected. This paper describes a social accounting matrix approach to documenting multi-regional, multi-jurisdiction fiscal accounts, called a fiscal SAM. Two of the many potential uses of a fiscal SAM are demonstrated. First, a fiscal SAM of rural, urban, and metro areas of Iowa is used directly to describe and compare the benchmark net fiscal situations of interdependent regions. Second, it is used to analyze the impacts of an economic downturn under a block-grant welfare system.Substate regions are relatively more specialized than state or national economies. Thus, for example, shocks to agriculture will directly affect agriculture-dependent counties more than other types of counties. Substate regions are also more interdependent than states, as well as more open than the nation as a whole. This means that indirect and spatial spillover effects of fiscal and other exogenous changes can be surprisingly large between counties. Here, analysis of fhe multipliers highlights the relative intensities of within and across-region effects of changes in the form of intergovernmental transfers. The multiplier simulation estimates the relative impacts and spillover effects of economic shocks under the new regime.

Notes: Many counties in the mountainous areas of the western U.S. are experiencing rapid growth in population and income, even though extractive industries that served historically as their primary economic base are in decline. The purpose of this paper is to establish statistically the spatial determinants of population, employment, and income densities in 86 rural mountain counties and any changes in those determinants between 1985 and 1994. The results of this analysis indicate that densities are oriented to regional metropolitan centers and critical amenities such as ski areas, national parks, and universities or colleges. Negatively sloped density gradients with respect to distance from regional metropolitan centers suggest that the densities of settlement patterns beyond metropolitan boundaries are analogous to those within metropolitan areas relative to urban centers. In short, a tension apparently exists in locational choice; residents of the Mountain West desire to live near the beauties and amenities of the mountain landscape but do not want to entirely sever their urban ties. Because amenities are the primary attraction of mountain counties rather than employment in locationally dependent industries, at least some migrants must have relatively footloose forms of income.

Notes: Book review in this article:The California Cauldron: Immigration and the Changing Fortunes of Local. Communities. By William A.V. Clark.Structural Economics, by Faye Dunchin.

Notes: This paper takes seriously the idea that international trade has played an important role in explaining both some convergence between developed economies as well as rising inequalities at the personal level. Previous studies used traditional trade theory as a reference framework. The empirical consensus is now that differences in factor endowment explain at best a small fraction of rising wage inequalities. This argument, by contrast, builds on labor specialization and increasing returns. Deeper economic integration allows trade in differentiated intermediate goods and primary tasks, thus transforming local increasing returns into global increasing returns. This pushes towards geographical equalization. At the same time, deeper integration also increases the size of the pool of available skilled workers. This may lead them to a‘technological secession’as it makes more skill-demanding technologies more profitable. Technological secession in turn fosters wage inequalities at the personal level.

Notes: Foreign exports are claiming growing shares of US. state economic production. While growth of foreign exports is often cited as a driving force for state economic growth, little attention has been paid in prior research to the issue of Granger causality between foreign exports and economic performance at the state level. This study examines Granger causality between foreign manufacturing export growth and state manufacturing performance during the period from 1980 to 1991. Results indicate that, at the aggregate level, there is a bi-directional Granger causal relationship between foreign exports and state manufacturing activity. Among the individual industrial sectors, results are more mixed, however, with sectors displaying either export-led growth, reverse Granger causality, or in some instances, negative Granger causality.

Notes: A modification of the Boamet model of local economic change is developed that links the growth of urban nodes in functional economic regions to employment and population change in the rural hinterlands of these regions. The two-equation model uses labor market and residential zone observations that are consistent with commuter fields around each rural community in the regions studied. The model parameters are estimated for 204 Danish rural municipalities, for 3515 rural communes in six regions of Eastern France, and for 268 rural census tracts in South Carolina. Results indicate that urban nodal spread effects are often significant and tend to dominate urban backwash impacts on rural communities. Accordingly, rural communities need to be concerned with the economic fortunes of their urban nodes and with policies that affect the pattern of urban growth between urban center and the urban fringe.

Notes: This paper examines the competitive characteristics of small and medium-sized manufacturing firms (SMFs) in a Canada-U.S. crossborder region (the Niagara Frontier). Particular attention is given to the innovation and business performance of comparably-sized firms on both sides of the border. The results of two firm-level surveys are presented. A comparative analysis of the two groups suggests that Canadian Sh4Fs exhibit significantly stronger export and innovation performance than their US. counterparts. The results also suggest that U.S. firms face tougher competitive difficulties arising fiom specific national and regional circumstances, including shortages of skilled labor, higher corporate tax rates, rising import competition, and a more complex regulatory environment. The implications of the empirical results are discussed in the context of policy options for regional economic development in crossborder zones such as the Niagara Frontier

Notes: Several empirical studies have estimated the value of agricultural land as open space to local residents. An important goup of individuals that may be affected by the loss of agricultural land are visitors to a region. The value of ranchland to tourists visiting a resort town in the Rocky Mountains is estimated through a travel cost model that combines information on observed behavior data from actual trips with contingent behavior data on intended current visitation if the resource were converted to urban and resort uses. The value of ranch open space to tourists is the gain or loss in consumer surplus derived from a visit to the study area attributable to the resource. A random effects Poisson regression model is estimated because of the panel nature of the data, accounting for the correlation of the multiple responses from heterogeneous individuals. Twenty-five percent of the sample would reduce visitation and 23 percent of the sample would increase visitation if ranch open space were converted to urban and resort uses. The overall effect of converting ranch open space to resort and urban uses is no net change in average consumer surplus per trip for summer tourists in general.

Notes: The welfare effects of public versus private waste disposal with and without flow controls are analyzed. The pricing of private waste disposal services is modeled as being bounded above by the public entity's average disposal cost, but constrained by potential entry of private competitors. It is found that once a publicly owned disposal facility has been built, waste generators are almost always better off if their local government has flow control authority. This results from the necessity of covering the fixed costs of the public facility once it has been built, in conjunction with the expected pricing behavior of private firms.

Notes: The effects of state public capital investment on economic growth is an important question that has been the focus of a recent substantial research effort. But the majority of this research has ignored these investments’influence on the intra-state pattern of economic activity. Yet if external agglomeration economies are important determinants of growth, then investments may indirectly affect growth by fostering or discouraging agglomeration. This paper discusses the effect of state infrastructure investments on the distribution of employment within states and the implications of these spatial effects for aggregate state employment growth. Preliminary empirical results suggest that state infrastructure investments tend to redistribute growth from areas of dense employment to other parts of the state. This redistribution may diminish agglomeration benefits offered by cities, which has the potential to reduce state growth. The paper concludes with a discussion of implications of the work for research and policy.

Notes: This article examines diverse transnational corporations’(TNC) strategies in response to labor shock and specific conditions that enhance TNCs’local embedding in export processing zones (EPZs). The goal of this paper is to understand the rationale behind TNCs’choice between spatial differentiation (mobility) and spatial fmity (immobility). Based on field research and data analysis from the Masan Free Export Zone (MAFEZ) in South Korea, it is argued that TNCs do not always withdraw from EPZs in reaction to wage costs and growing labor militancy. Higher labor costs can be overridden by other advantages: existing physicalkocial inhstructure, tax benefits, fured assets, localized labor skills and technology, cultural proximity, and advantages from geographical proximity to market, raw materials, and TNCs’headquarters. This paper criticizes the overly simplistic view of capital mobility. However, TNCs that choose to remain in the EPZs use both upgrading and cheapening strategies, and their remaining does not necessarily result in upgrading labor skills or improving labor conditions. This article raises a critical question of the firm-centered view of the global enterprise literature and the local embeddedness literature of TNCs on workers’welfare. It emphasizes the important role of firms and of unions in training workers for purposes of technology and skill upgrading.

Notes: Overall total inequality for state per capita personal income as well as total inequality for nonmetropolitan and metropolitan areas are examined for the period 1969 to 1995. In each case, the total inequality was partitioned into between-and within-region variations. Statistical testing shows no perceptible differences between the major categories, nonmetropolitan and metropolitan. Further, this study uses a model to test for narrowing of income gaps within these categories. It was found that for both nonmetropolitan and metropolitan, a general trend toward equality was evidenced during the early 1970s decade. In that decade, the nonmetropolitan areas’incomes approached the metropolitan areas’incomes but showed significant divergences in the 1980s, followed again by a narrowing of the gaps in the 1990s.

Notes: Abstract. The effect of increasing rates of nitrogen (N) fertilizer on the yield response of 3 or 4 consecutive winter cereal crops after ploughing out grass was investigated at six field sites on commercial farms in England and Wales. Amounts of N required for an economically optimum yield (〉3 kg of grain for each kg of fertilizer N applied) ranged from 0 to 265 kg ha−1 and were dependent on soil N supply, but not on crop yield. Optimum N rates were large (mean 197 kg N ha−1) at three sites: two sites where cereals followed 2-year grass leys receiving low N inputs (〈200 kg N ha−1), and at one site where a cut and grazed 4-year ley had received c. 315 kg N ha−1 of fertilizer N annually. At the other three sites where 4 and 5-year grass leys had received large regular amounts of organic manures (20–30 t or m3 ha−1) plus fertilizer N (c. 300 kg ha−1 each year), optimum N rates were low (mean 93 kg N ha−1) and consistently over-estimated by the farmer by an average of 107 kg N ha−1. Optimum N rates generally increased in successive years after ploughing as the N supply from the soil declined. Determination of soil C:N ratio and mineral N (NO3N+NH4N) to 90 cm depth in autumn were helpful in assessing fertilizer N need. The results suggest there is scope to improve current fertilizer recommendations for cereals after grass by removing crop yield as a determinant and including an assessment of soil mineralizable N during the growing season.

Notes: Abstract. Soils, of clay texture, were taken from two crop rotations in a long term trial, (i) maize - spring oats - maize, (ii) maize - spring oats - autumn oats - red clover, and from an adjacent uncropped fenceline. Wet sieving was preceded by wetting under vacuum, wetting under tension or by direct immersion. The undisturbed soil was the most stable; the inclusion of clover in the rotation improved aggregate stability. Direct immersion was most disruptive in disintegrating aggregates followed by vacuum and pre-wetting under tension.

Notes: Abstract. A decision support system to predict the plant availability of nitrogen (N) following organic manure applications to land has been developed, drawing together the latest UK research information on factors affecting manure N availability and losses. The ADAS MANure Nitrogen Evaluation Routine (MANNER) accounts for manure N analysis, ammonia volatilization, nitrate leaching and mineralization of manure organic N. Only a few easily available inputs are required to predict the amount of N volatilized or leached, and the fertilizer N value for the next crop grown. Predictions from MANNER have been evaluated by comparison with independently collected data from a range of experimental studies where pig, cattle and poultry manures were applied to arable crops. Good agreement was found (r2 60–79%, P〈0.001), confirming that MANNER can provide a reliable estimate of the fertilizer N value of farm manures spread to arable land under a range of conditions.

Notes: Abstract. The structure of soils in areas of rain forest cleared for pasture is often compacted due to trampling by animals. When pasture is abandoned, regeneration of forest cover may be achieved from natural seed sources nearby.However, the regeneration of soil structure is also important for local hydrology and successful establishment of some plant species. In this study we investigated changes in soil structure and hydraulic properties in a series of plots on volcanic soils in the San Luis Valley, Costa Rica. The plots were current pasture, 15- and 20-year-old regenerating forest, and primary rain forest.Infiltration rate increased with increasing forest age and the water release characteristic reverted gradually from one with greater water retention at all matric potentials in the pasture plot towards that found in the primary forest. Compaction and low porosity were features of both the current pasture and 15-year-old regenerating forest in comparison to the primary forest.

Notes: Abstract. Over 170 countries have ratified the UN Framework Convention on Climate Change (UNFCCC) which aims at ‘the stabilisation of greenhouse gases in the atmosphere at a level that will prevent dangerous anthropogenic interference with the climate system’. The Kyoto Protocol, signed in 1997, commits the developed (‘Annex 1′) countries to a reduction in gaseous emissions. The global increase in atmospheric CO2, the main greenhouse gas, comes mainly from fossil fuels (6.5 Gt C yr−1), together with about 1.6 Gt C yr−1 from deforestation. The atmospheric increase is only 3.4 Gt C yr−1, however, due to a net sink in terrestrial ecosystems of about 2 Gt C yr−1, and another in the oceans. Increasing net carbon sequestration by afforestation of previously non-forested land is one way of reducing net national emissions of CO2 that is permitted under the Kyoto Protocol. Future modifications may also allow the inclusion of carbon sequestration brought about by other forestry and agricultural land management practices. However, associated changes in net fluxes of two other greenhouse gases identified in the Protocol — nitrous oxide (N2O) and methane (CH4) — will have to be taken into account. Growth of biomass crops can increase N2O emissions, and drainage of wetlands for forestry or agriculture also increases them, as well as emissions of CO2, while decreasing those of CH4. The problems of how to quantify these soil sources and sinks, to maximize soil C sequestration, and to minimize soil emissions of CH4 and N2O, will present a major scientific challenge over the next few years — one in which the soil science community will have a significant part to play.

Notes: Abstract. A lysimeter study from April 1993 to June 1997 assessed the effects of winter cover crops and unfertilized grass on both the volume of water draining over winter and the amounts of nitrate leached. There were three to five replicates of each treatment in a fully randomized design. The lysimeters were undisturbed monoliths of loamy medium sand, 1.2 m deep and 0.8 m diameter.There were six treatments: sown cover before spring-sown crops (SC), natural regeneration (‘tumbledown’) before spring-sown crops (T), unfertilized grass (UG), bare soil permanent fallow, (PF), winter barley (WB) and conventional overwinter fallow before spring-sown crops (WF). Sugarbeet replaced cereals in 1996 as a disease break, and in consequence no cover was established in SC and T in autumn 1996. Of the four years of the study, two were above-average rainfall, while two were of less than average rainfall. Results are only quoted if statistically significantly different from WB (P=0.10).Over the first winter, NO3―N losses were similar under UG (26 kg ha−1) and PF (29 kg ha−1), due to the slow establishment and growth of the grass. In the following three winters NO3―N losses under UG were small (c. 6 kg ha−1), giving an overall mean of c. 11 kg ha−1. Sown cover crops and T gave means of c. 16 and 22 kg ha−1 respectively, compared with c. 27–31 kg ha−1 under PF, WB and WF.Mean NO3―N concentrations were smallest under UG (4.4 mg l−1) and SC (10.6 mg l−1), although both T (13.7 mg l−1) and PF (12.4 mg l−1) were less than under WB and WF (15.8–18.7 mg l−1). Overwinter drainage was greatest from UG and PF, at 239 and 247 mm respectively. In the three winters that cover crops were grown, drainage was decreased by, on average, 30 mm year−1 compared with WF. However, there were large differences in effects between years, with significant decreases in only one year.We conclude that the widespread adoption of cover crops before spring-sown crops will reduce overwinter drainage in UK Nitrate Vulnerable Zones by no more than c. 2%, compared with no cover before spring-sown crops.

Notes: Abstract. The effectiveness of Festuca ovina and Poa pratensis as contour grass strips for erosion control was examined in a laboratory experiment for an crodible sandy loam soil on 21, 25 and 29% slopes. No significant differences P〈0.05 were observed in runoff between the plots with grass strips and bare soil but significant differences in soil loss were recorded. Both grasses reduced crosion in the early part of the simulated storms by ponding water behind the barrier, filtering sediment and causing deposition within the ponded area. The P. pratensis barrier was less rigid and became flattened under submergence in the later part of the storms. Runoff flowed over the grass strip forming rills on the slope below, which then cut back and undermined the barrier. These barriers resulted in as much soil loss as bare soil towards the end of the storms on all three slopes. The F. ovina was effective in controlling erosion on the 21% and 25% slopes but not on the 29% slope.

Notes: Abstract. The recommended method of reducing the emission of NH3 while spreading manure is to plough or harrow the manure into the soil. This in turn increases the possibility of N2O emission. At two sites in southern Sweden emissions of NH3 and N2O were measured after spreading pig slurry by broadcasting and band spreading. The band spreading technique can be used in growing crops i.e. when nitrogen is most needed, and it is thought that the NH3 emission is smaller with this technique compared to broadcasting. The average NH3 loss was 50% of applied NH4+ during warm/dry conditions and 10% during cold/wet conditions. The N2O emission was always less than 1% of applied NH4+. When the NH3 emission decreased, the direct N2O emission increased. However, when taking into account the indirect N2O emission due to deposition of NH3 outside the field, the spreading techniques all produced similar total N2O emissions. The ammonia emission was not much lower for the band spreading technique compared to broadcasting, when compared on seven occasions.

Notes: Book reviewed in this article: Soil Erosion at Multiple Scales: Principles and Methods for Assessing Causes and Impacts Edited by F. W. T. Penning de Yries, F. Agus & J. Kerr

Notes: It is increasingly acknowledged that the financial structure of a firm is an important determinant of its production costs. This paper argues that the use of a firm's liabilities should be seen as a separate input in the production process. At the same time, the input of non-financial assets is limited to the value that is used up during the reference period. The paper elaborates on these ideas and shows their use in empirical work. It is concluded that the approach set out in this paper establishes a much closer relationship of general economic accounting and analysis to business economics.

Notes: This paper uses a series of cross-section surveys to measure how wealth accumulation and active saving rates varied across cohort-groups during the early and mid 1990s. Our estimated rates of saving and wealth change across cohorts show a somewhat more dramatic life-cycle pattern than found in previous studies, in part because we use a new technique, and in part because the cross-section wealth surveys we use oversample the wealthiest families whose behavior dominates aggregate changes. Adjusting the wealth-change rates for bequests and subtracting out the capital gains component of wealth change move the estimates in the direction of results from previous studies, but the biggest changes in that direction result from excluding the top of the wealth distribution in each year.

Notes: The main purpose of this paper is to relate the empirical attempt of measuring output from the education sector to theoretical results about the welfare significance of an extended net national product (NNP) measure. We show that economic theory provides a more focused way of interpreting such output estimates, which has not been recognized in previous studies. The paper also contains new estimates of the output from the Swedish education sector.

Notes: This paper analyses the treatments proposed by Chapter XIX (Annex B) of the 1993 SNA and the manual Inflation Accounting published by the OECD (Peter Hill) as alternatives to the traditional recording of nominal interest. Real interest and interest prime (annex B) are relevant for different purposes. Their amounts are not the same to the extent that actual compensation and full required compensation for inflation differ. The recording of negative real interest is not compatible with the exclusion of holding gains/losses from the SNA current accounts. The accounting treatments in Inflation Accounting (capital transfers, additional lending/borrowing, no nominal holding gains/losses) and Annex B (nominal holding gains/losses, no capital transfers, no new lending/borrowing) are contrasted.

Notes: Using data from the German Socio-Economic Panel, we compare income mobility of persons from the eastern and western states of Germany between 1990 and 1995. We consider income mobility between consecutive years and between the first and the final year of this time period. We find that gross individual labor income mobility was much higher in the east than in the west during the first years after reunification, but that this difference has become much smaller until 1995. Changing to measures that reflect economic well-being more accurately, we observe that gross equivalent labor income mobility and net equivalent income mobility initially were also much higher in the eastern states than in the western states, but converged over time as well. This convergence has been particularly strong for net equivalent income mobility, suggesting that the social protection system has greatly reduced mobility risks associated with the transformation process in the eastern states of Germany.

Notes: The precautionary saving literature shows that income uncertainty increases savings and wealth. To estimate the magnitude of this effect, we need a measure of income uncertainty. This paper empirically analyzes subjective income uncertainty in The Netherlands. Data come from a large Dutch household survey. We measure income uncertainty by asking questions on expected household income in the next twelve months. First, we describe the data and investigate the relationship between the measure of income uncertainty and a number of household characteristics. Controlling for information on expected income changes, we find strong relationships between labor-market characteristics and the subjective income uncertainty as reported by the heads of the households. Second, we compare income uncertainty in The Netherlands with income uncertainty in the U.S. and Italy. It becomes evident that perceived income uncertainty is smaller in The Netherlands than it is in the U.S.

Notes: Precautionary savings models suggest that wealth should rise with income risk. Risk is reduced by means-tested transfers, however, which implies that transfer programs should discourage private wealth accumulation. We offer a comprehensive empirical assessment based on variation across states in the generosity of a number of programs, specifically unemployment insurance and means-tested transfers (Aid to Families with Dependent Children and Food Stamps). We use monthly data on married couples from the Survey of Income and Program Participation (SIPP) to regress wealth on income, income risk, and various measures of transfer generosity. The results support the precaution-ary savings model and reveal moderate negative wealth effects of both unemployment insurance and means-tested transfers, with an elasticity of about −0.18.

Notes: A simple regression of personal income per capita for the U.S. states is estimated from cross-section data for the years 1929, 1950, 1970 and 1990 with each state's distance from the equator as the regressor. While proximity to the equator is noted to have a sizable adverse effect on income, elasticity of personal income per capita with respect to “tropicality” shows a steady and somewhat dramatic decline during this 60-year period. The estimates indicate that the disadvantage of tropicality is not immutable, and need not imply a developmental determinism.

Notes: U.K. employment and self-employment income inequality are analysed over 1979–94/95. Robust inequality decompositions reveal occupation to be a relatively important and hitherto neglected determinant of earnings inequality. In contrast, self-employment income inequality is harder to explain, although occupation is also the most important single factor in the mid-1990s. The paper also provides a novel implementation of a decomposition of changes in Kolm's inequality index.

Notes: We measure the effective assistance to 24 Norwegian private industries in 1989 and 1991 from government budgetary subsidies, indirect commodity taxes, import protection through nominal tariffs and non-tariff barriers, and electricity market distortions. The assistance effects are measured by the change in the net-of-tax value added price due to a removal of the policy measures considered. Most industries were effectively assisted, but the effective assistance differs widely between industries, indicating the overall distortive effect on the industry structure. Agriculture, Food Processing and Manufacture of Beverages and Tobacco stand out as the most assisted industries. Budgetary subsidies and non-tariff barriers had the strongest effective assistance effect.

Notes: We examine the sensitivity of U.K.-Spanish poverty comparisons to variations in the dependence of equivalence scales on household size and composition, using evidence from national household budget surveys. We sum up these comparisons using subjective confidence levels. Taking into account the dissimilarities in the distribution of incomes and needs across countries, we find, inter alia, that although the poor are typically more numerous in Spain than in Britain, the actual headcount differences may vary by up to 10 percent of the population when needs allowances are altered, even when kept the same across the two countries. Comparisons of poverty composition across the two countries are also very sensitive to the choice of equivalence scale parameters. Generally, however, the proportion of single adults among the poor is much less important in Spain than in Britain, the reverse being true for households with three or more adults.

Notes: Abstract. The Pilot Nitrate Sensitive Areas Scheme was set up in England in 1990 to test measures aimed at reducing nitrate losses from agricultural land. Ten groundwater catchments were chosen to typify the geology and farming of areas where nitrate concentrations in abstracted water were high. Voluntary and compensated controls on farming, based on recent research, were introduced. Scheme membership was for 5 years from 1990 or 1991, and 86% of the agricultural land entered the Scheme. On all farms entering the Scheme, manure and fertilizer use were restricted and green cover crops were required over winter (Basic Scheme). Additional payments were available for conversion of arable land to zero or low-input grassland (Premium Scheme). Intensive pig and poultry farmers were assisted with the costs of transporting manure for spreading over a wider area. The most effective changes were improved management of livestock manures, especially of the very large local quantities from housed pig or poultry units; conversion of arable land to low-input grassland; and use of cover crops. There were no indications of reduced crop yields but some requirements increased costs and management complexities. Estimates based on both model calculations and measurements indicated that nitrate losses from agricultural land decreased by about 30%, with considerable variation between areas.

Notes: Book reviewed in this article: SOILpak for Cotton Growers. Third edition 1998. Edited by David C. McKenzie.

Notes: Abstract. Preferential flow has been increasingly recognised as a major component of water movement in many soils, particularly clays. This paper reviews problems in the measurement of solute fluxes in these soils, and discusses the solutions that have been adopted in UK studies of cracking clay soils. The estimation of solute fluxes is subject to many sources of error, which are best reduced by replicated measurements, such as those available in multi-plot experiments.

Notes: Abstract. Soil cores from river marginal wetlands from three sites in the UK (Torridge and Severn catchments), sampled and restrained in PVC piping, were flooded with dilute aqueous potassium nitrate. Half of the cores were sterilized prior to flooding to destroy the denitrifying bacteria. The change in nitrate concentration in the flood-water was measured over time. It is argued that the observed nitrate depletion rates (from 1.2 to 4.7 kg ha−1 d−1) is the result of microbially-mediated denitrification. The results show the method to be a simple and direct procedure for the assessment of spatial variation in nitrate-sink capacity. The depth of the denitrifying layer at the soil–water interface was confirmed to be of the order of a few mm only. A one-dimensional model for the diffusive flux in the flooded soil was developed which, on differentiation, gave a predictive expression for denitrification rate in terms of the effective soil diffusion coefficient for nitrate, the flood-water depth and concentration, and the thickness of the microbially active zone.

Notes: Book reviewed in this article: The Soils and Land Use Potential of the Southern and Eastern Slopes of Kilimanjaro, Tanzania.

Notes: Abstract. Gross N mineralization and nitrification rates were measured in soils treated with dairy shed effluent (DSE) (i.e. effluent from the dairy milking shed, comprising dung, urine and water) or ammonium fertilizer (NH4Cl) under field conditions, by injecting 15N-solution into intact soil cores. The relationships between gross mineralization rate, microbial biomass C and N and extracellular enzyme activities (protease, deaminase and urease) as affected by the application of DSE and NH4Cl were also determined. During the first 16 days, gross mineralization rate in the DSE treated soil (4.3–6.1 μg N g−1 soil day−1) were significantly (P 14;〈 14;0.05) higher than those in the NH4Cl treated soil (2.6–3.4 μg N g−1 soil day−1). The higher mineralization rate was probably due to the presence of readily mineralizable organic substrates in the DSE, accompanied by stimulated microbial and extracellular enzyme activities. The stable organic N compounds in the DSE were slow to mineralize and contributed little to the mineral N pool during the period of the experiment. Nitrification rates during the first 16 days were higher in the NH4Cl treated soil (1.7–1.2 μg N g−1 soil day−1) compared to the DSE treated soil (0.97–1.5 μg N g−1 soil day−1). Soil microbial biomass C and N and extracellular enzyme activities (protease, deaminase and urease) increased after the application of the DSE due to the organic substrates and nutrients applied, but declined with time, probably because of the exhaustion of the readily available substrates. The NH4Cl application did not result in any significant increases in microbial biomass C, protease or urease activities due to the lack of carbonaceous materials in the ammonium fertilizer. However, it did increase microbial biomass N and deaminase activity. Significant positive correlations were found between gross N mineralization rate and soil microbial biomass, protease, deaminase and urease activities. Nitrification rate was significantly correlated to biomass N but not to the microbial biomass C or the enzyme activities. Stepwise regression analysis showed that the variations of gross N mineralization rate was best described by the microbial biomass C and N.

Notes: Abstract. Sustaining soil fertility under agricultural intensification and expansion onto marginal lands is a significant challenge in the Nepalese Middle Mountains. In a detailed watershed study it was shown that the overall soil fertility is poor, forest soils display the poorest conditions as a result of biomass removal, and sustaining agriculture is questionable due to the transformation from traditional to multiple cropping systems. Parent material is a significant factor influencing low phosphorus status while insufficient inputs create deficiencies in total carbon, nitrogen and bases. A nutrient budget model was developed to assess inputs, redistribution and losses relative to soil fertility. Yield, input and management data obtained from farm interviews, and soil analysis data were used in the calculation of nutrient budgets. Results from modelling indicate declining soil fertility under rainfed agriculture, forest and rangelands, and marginal conditions under irrigated agriculture subject to intensive cultivation. Nutrient deficits were relatively low for irrigated rice-wheat systems, which benefit from nutrient inputs via sediments and irrigation waters, but the introduction of triple cropping showed greater deficits. Nutrient balances were most critical under rainfed maize production where 94% of the farms were in deficit. Current shortages of organic matter make elimination of nutrient deficits problematic but improvement of composting, biological N-fixation and fertilizer efficiency and reducing erosion were found to be potential options.

Notes: Abstract. Deterministic leaching models are used to estimate regional losses of nitrate from agricultural land to the environment. The estimated leaching losses are associated with uncertainty arising from uncertainty in the input data used. In the present case study we have assessed this uncertainty by use of Monte Carlo analysis, using the Latin hypercube sampling technique. Input data have preferably been adopted from publicly available data. Data which could not be retrieved from the databases was assessed by guided estimates or based on local data. The estimated annual leaching loss from the study region was around 106 kg N ha−1, which is in agreement with previous findings. The uncertainty in the leaching expressed in terms of coefficients of variation (CV) depended on the agricultural practices. CV's for arable farm rotations, cattle farm rotations, and pig farm rotations were around 20, 30 and 40%, respectively. Breakdown of the total uncertainty into contributions of different error sources did not isolate one single all important source.

Notes: Abstract. The nitrogen (N) conserving effects of Italian ryegrass (Lolium multiflorum L.) undersown as a nitrate catch crop in spring barley (Hordeum vulgare L.) were evaluated over a ten-year period in outdoor lysimeters (1.5 m deep, diam. 1 m) with sandy loam soil. Spring barley grown every year received 11.0 or 16.5 g N m−2 before planting or was kept unfertilized. The N was given either as calcium ammonium nitrate or as ammoniacal N in pig slurry. From 1985 to 1989, ryegrass was undersown in the barley in half of the lysimeters while barley was grown alone in the remaining lysimeters. The grass sward was left uncut after barley harvest and incorporated in late winter/early spring. From 1990 to 1994 all lysimeters were in barley only.Barley dry matter yields and crop N offtakes were not affected by the presence of undersown ryegrass, although grain yields appeared to be slightly reduced. After termination of ryegrass growing, N offtake in barley (grain+straw) was higher in lysimeters in which catch crops had been grown previously.The loss of nitrate by leaching increased with N addition rate. Regardless of N dressing, ryegrass catch crops halved the total nitrate loss during 1985–1989, corresponding to a mean annual reduction in nitrate leaching of 2.0–3.5 g N m−2. From 1990 to 1994, lysimeters previously undersown with ryegrass lost more nitrate than lysimeters with no history of ryegrass. The extra loss of nitrate accounted for 30% of the N retained by ryegrass catch crops during 1985–1989.It is concluded that a substantial proportion of the N saved from leaching by ryegrass catch crops is readily mineralized and available for crop offtake as well as leaching as nitrate. To maximize benefits from ryegrass catch crops, the cropping system must be adjusted to exploit the extra N mineralization derived from the turnover of N incorporated in ryegrass biomass.

Notes: Abstract. Escherichia coli serotype O157 is a virulent human pathogen the global incidence of which has increased. It has been demonstrated that cattle are the primary reservoir of this pathogen. This has serious implications for the land-based disposal of organic wastes such as cattle manure, cattle slurry and abattoir waste. Further, it also has serious ramifications for the protection of surface and groundwater drinking supplies and public access to pasture land. However, while soil and vegetation can be expected to directly influence the survival of this pathogen, there is a paucity of information concerning the behaviour and survival of E. coli O157 in agricultural environments. It appears that E. coli O157 presently contaminates between 1 to 15% of UK cattle herds, depending on region, and that faecal excretion of the bacterium shows a distinct seasonality which also reflects the incidence of human infections. E. coli O157 can remain viable in soil for greater than 4 months and appears to be a highly resilient pathogen possessing the capability to adapt easily to environmental stresses. While most human cases of E. coli O157 related food poisoning have been associated with the consumption of contaminated meat and dairy products, there is also evidence that human infection has occurred through the ingestion of contaminated soil, fruit and vegetables and drinking water. In this review the potential threat to human health posed by the application of contaminated organic wastes to soil and possible strategies for reducing the amount of pathogen entering the food chain are highlighted.

Notes: Abstract. A lysimeter experiment showed a decrease in maximum concentrations and total losses of the herbicide isoproturon leached from a heavy clay soil where the topsoil had a finer, deeper tilth than with a standard agricultural tilth. Volumes of leachate for the first flow event of the season were also smaller and leaching of bromide was slower. The isoproturon was radiolabelled so that its movement could be assessed using a novel radio-scanning technique. Bypass flow began close to the surface as a scan at 8 cm depth showed that only 0.5% of the total soil area had an activity more than four times the nominal background level. At depths of 10–20 cm, isoproturon was preferentially retained within areas of very fine aggregates. No radioactivity was detected in the scans below 20 cm depth, suggesting little or no retention of isoproturon during transport through the subsoil to the bottom of the lysimeter. Rhodamine-B dye injected to the base of the topsoil (approximately 20 cm depth) was also used to assess flow pathways through the subsoil. The dye spread laterally across the interface between topsoil and subsoil and then penetrated the subsoil through cracks and fissures. Even within cracks, transport of dye frequently occurred through only a very small proportion of the total crack area. The macropore flow model MACRO 4.0 was used to simulate results from the lysimeter experiment. The fourfold decrease in maximum concentrations of herbicide from the finer tilth lysimeter could be predicted by varying only a parameter describing aggregate sizes at depths of 6–24 cm, suggesting that transfer of herbicide between macropore and micropore regions was faster in the finer tilth. Differences in concentrations of bromide could be simulated only by adjusting the soil hydraulic parameters for the fine tilth to reflect a slight decrease in the predominance of bypass flow relative to matrix flow.

Notes: Abstract. A database of 1065 fields in all parts of Finland, two soil profiles (augerhole borings) per field, was screened for acid sulfate (a.s.) soils. Each field represented 2100 14;ha of cultivated land. Soil pH and redox potential were determined in the field, at intervals of 10 14;cm, to a depth of 200 14;cm. Of the maximum of 124 profiles considered as a.s. soils according to the Soil Taxonomy and ILRI (International Institute of Land Reclamation and Improvement) systems, 46 profiles exhibited pH 〈3.5. These represented 48 14;000 14;ha of land. More than half of these severely acidic soils were associated with reduced subsoils and probably contained actively oxidizing sulfidic materials within 150 14;cm of the soil surface, while the remaining profiles were oxidized at least down to 150 14;cm. Using Soil Taxonomy criteria, the total area of cultivated a.s. soils was 67 14;000–130 14;000 14;ha. The minimum estimates exclude soils that may be leached or too low in sulfide to meet the criteria of a.s. soils. Application of the ILRI system produced an estimate of 61 14;000–130 14;000 14;ha. In the maximum estimate, 27% of the profiles were raw, 61% ripe and 12% potential a.s. soils. According to the FAO/UNESCO system, the area of cultivated a.s. soils (pH 〈3.5 or assumed sulfidic materials) is considerably less: 43 14;000–78 14;000 14;ha. All these estimates are only a fraction of the area considered to be covered by a.s. soils by established Finnish criteria. The choice of estimate has important economic implications for liming subsidies and planning regulations for the drainage of a.s. soils.

Notes: Inequality comparisons require equivalence scales to account for differences in household size and composition. The multiplicity of equivalence scale models makes the sensitivity of the inequality calculations to the scale used a significant policy issue. Such an investigation based on unit records of two adult households from Italy, Australia, South Africa, Thailand, Peru, Philippines, India and Tanzania was our principal motivation. The equivalence scale varies across countries and between different types of children. Inequality rankings of countries, though not the inequality decomposition between households of different composition, are robust to the equivalence scale used.

Notes: This paper, for the anniversary session on Milestones in Measurement, covers the years of the International Association for Research in Income and Wealth (IARIW) through the sixth General Conference in 1959. The first section of the paper describes the setting in which the Association was established and attempts to give a sense of the early years by identifying the people who were active in the Association and the topics that were being discussed. The second section identifies four milestones among the papers published in Income and Wealth, the volumes that brought together a selection of the papers from the General Conferences of this early period.

Notes: Abstract. Solutions collected from lysimeters of acid soils can show pH values close to or even above neutral. Laboratory experiments on an acid soil from Burundi were planned to test if denitrification or CO2 degassing might explain such a paradox. In the first experiment, soil profiles were reconstituted in columns and leached with 55 μm Ca(NO3)2 solutions at 30 °C and 4 °C. Two drainage regimes were applied: intermittent suction or no suction at the bottom of the columns. In the second experiment, pH values were measured in solutions drained from different horizons at 30 °C, before and after equilibration with ambient air. Sterilized soil was also tested in the same way. Results from experiment 1 showed that despite the accumulation of water in the bottom of soil profiles when no suction was applied, aeration still existed so that reduction reactions, namely denitrification, are not expected to affect greatly the percolate composition. Indeed nitrate concentration was similar in both drainage regimes and was close to the input value. The pH values in percolates were close to 7 at 30 °C and they dropped to about 5.5 when the columns were at 4 °C. In experiment 2, equilibration of percolates with ambient air resulted in pH increase which was greater for the top horizon (C-rich) but negligible when the soil was first sterilized. These convergent results illustrate the very important effect of CO2 degassing on pH of drained solutions when microbial activity is stimulated at high temperatures, in C-rich soil. This is of prime importance when interpreting results from lysimeter experiments. By chance, this study also showed that large quantities of nitrate can be produced in soil at low temperatures.

Notes: Abstract. As leaching of nutrients and agrochemicals can occur readily in cracking clay soils, which are important to UK agriculture, it is essential to identify management systems for them that can minimize the risk of contaminants reaching surface waters. The long-term Brimstone Farm study has provided considerable evidence on the movement of water and solutes through such soils and offers a unique opportunity to determine the factors influencing these processes. Management procedures, such as subsurface drainage and tillage, which are widely used for the production of cereals in these soil types, greatly influence the risk of contamination. At Brimstone Farm, tillage has been shown to change the hydrology in terms of both water table control and the route of water movement, and to increase the mineralization of nitrogen and the consequent risk of nitrate leaching. Drainage, essential in these soils, also creates a risk of solute losses, especially pesticides. Ways to retain effective drainage yet decrease losses to surface waters are discussed.

Notes: Abstract. The efficient use of biologically fixed N in agriculture is important in organic farming and when N fertilizers are either expensive or unavailable. The aim of the study was to determine the effects of cultivation and sowing dates on the efficiency of use of biologically fixed N built up during a period of grass/clover ley by subsequently sown ryegrass. Dates of cultivation in two field experiments conducted in consecutive years (1994/95 and 1995/96) ranged from August to October and sowing was carried out either immediately after cultivation or after a delay of one month. Nitrate-N losses through leaching, herbage yields and N offtake by ryegrass were measured from 1994 to 1996. A laboratory experiment was carried out to assess net N mineralization and nitrification in the soil of the field experiment under different conditions.The utilization of mineralized N ranged from 30 to 100 kg ha−1 in both field experiments. Herbage yield and recovery of mineralized N by ryegrass was greater when sowing was carried out immediately after cultivation than when it was delayed for one month. Cultivation in late October was inferior to cultivation in August or September but the optimum date (August to September) differed between the two years (1994/95 and 1995/96) due to differences in weather, especially rainfall, affecting N leaching during the germination and early growth phases. Indeed the main differences in the efficiency of utilization of mineralized N between treatments could be attributed to differences in NO3–N leaching losses during the autumn establishment period. Decreases in soil temperature during autumn resulted in a modest decrease in net N mineralization but a much more substantial decrease in the rate of nitrification, which has implications for NO3–N leaching. The optimum time for cultivation cannot be refined to a particular calendar date but reasonably accurate long-term rainfall forecasts in conjunction with data on soil moisture deficit would provide the means to set an optimum cultivation date.

Notes: Abstract. During three consecutive years (1993–1995) a split-plot design with three replications was used to study the biological and physical role of mulch in the improvement of crusted soil water balance and its productivity in the north of Burkina Faso. The main treatment was the use of an insecticide, to obtain plots with and without soil fauna (SF and NSF). The subsidiary treatment consisted of four mulch types randomly applied on subplots. These were straw of Pennisetum pedicellatum applied at 3 t ha−1, woody material of Pterocarpus lucens applied at 6 t ha−1 and composite (woody material and straw) treatments applied at 4 t ha−1. In addition there was a control, with no mulch (bare plot). Data on soil faunal activity, runoff, sediment accumulation from wind blown soil, vegetation cover and vegetation dry matter yield were collected on all plots.The biological activity (mainly termites) in mulched plots was the key element in the efficacy of mulching to rehabilitate crusted soil. Water infiltration and dry matter yield were statistically lower on NSF plots than on SF plots and runoff and dry matter yield were not different from the values obtained on bare plots. A significant correlation was found between runoff, all vegetation data and termite-voids. Sediment accumulation due to the physical barrier of the mulch was not found to be a significant factor in the improvement of vegetation performance and the reduction of runoff.

Notes: Abstract. Ammonia volatilization with and without gypsum incorporation was measured in Gujranwala soil (Udic Haplustalf) in an incubation study using different nitrogen fertilizers e.g. urea, ammonium sulphate (AS), calcium ammonium nitrate (CAN), and urea nitrophos (UNP). Nitrogen from different fertilizers was applied at the rate of 200 mg N kg−1 to two sets of soils in plastic bags (1.0 kg soil) and plastic jars (0.5 kg soil). Soil moisture was maintained at field capacity. Application of urea increased soil pH to 9, three hours after its addition. Ammonium sulphate and calcium ammonium nitrate had little effect on soil pH. Ammonium volatilization losses from fertilizers were related to the increase in soil pH caused by the fertilizers. Consequently maximum losses were recorded due to application of urea. Losses through ammonia volatilization were significantly lower with AS, CAN and UNP in descending order. Gypsum incorporation significantly reduced the losses. Therefore, application of gypsum to soil before urea may substantially improve N use efficiency for crop production by reducing N losses.

Notes: Abstract. Precision farming is the process of adjusting husbandry practices within a field according to measured spatial variability. In this review, we explore the prospects for precision farming using the principles that underly conventional soil management and agronomy.The cost-effectiveness of precision farming is determined by the cost of defining zones within fields, the stability of zones through time, the difference in treatment between zones in terms of cost, and the responsiveness of the crop in terms of yield and quality to changes in treatment. Cost-effective precision farming is most likely where prior knowledge indicates large heterogeneity and where treatment zones can be predicted, for example from soil type or field history.Soil related factors are likely to provide the main basis for precision farming because they tend to be stable through time and influence crop performance. In particular, soil mapping may usefully indicate the moisture available for crop growth, organic matter maps may be utilized for precision application of fertilizers and soil acting herbicides, and variation in soil pH can be mapped and used as a basis for variable lime application. However, comprehensive nutrient mapping is less likely to be economic with existing techniques of chemical analysis. The value of yield mapping lies in identifying zones which are sufficiently stable to be of use in determining future practices. Maps of grain quality and nutrient content would significantly augment the value of yield maps in guiding marketing decisions and future agronomy. Interactions between soil differences and seasonal weather are large, so yield maps show considerable differences from season to season. Interpretation of such maps needs to follow a careful, informed, analytical process.Extensive and thorough field experimentation by crop scientists over many years has shown that yield variation arises as a result of a large and complex range of factors. It is highly improbable that simple explanations will be appropriate for much in-field yield variation. However, the capacity to sense yield variability within fields as opposed to between fields, where there are many confounding differences, provides an opportunity for the industry to improve its understanding of soil-based effects on crop performance. This should support its decision taking, whether through precision farming or through field-by-field agronomy.The main obstacle to the adoption of precision farming is the lack of appropriate sensors. Optimal sensor configurations that will measure the specific needs identified by end-users need to be developed.The conclusions reached in this paper probably apply to farming throughout northern Europe.

Notes: Book reviewed in this article: Gaseous Nitrogen Emissions from Grasslands Edited by S.C. Jarvis & B.F. Pain.

Notes: Abstract. Growing cover crops during the winter before spring-planted crops is often suggested as an effective method to decrease nitrate leaching. A four-course crop rotation (potatoes-cereal-sugarbeet-cereal) was followed through two rotations on a sandy soil in the English Midlands. Three management systems were imposed on the rotation to test their effects on nitrate loss. The effects of cover crops on nitrate leaching and crop yields were compared with the more conventional practice of over-winter bare fallow before potatoes and sugarbeet.Cover crop N uptake was variable between years, averaging 25 kg ha−1, which is typical of their performance on sandy soils in the UK. The cover crops usually decreased nitrate leaching but their effectiveness depended on good establishment before the start of drainage. Over 7 years, cover crops decreased the average N concentration in the drainage from 24 to 11 mg l−1. Potato yield and tuber N offtake increased after cover crops. Ware tuber yield increased by an average of c. 8%; this was unlikely to be due to additional N mineralization from the cover crop because the potatoes received 220–250 kg fertilizer N ha−1, and non-N effects are therefore implicated. Sugar yield was not increased following a cover crop.After 8 years of nitrate-retentive practices, there were no measurable differences in soil organic matter. However, plots that had received only half of the N fertilizer each year contained, on average, 0.14% less organic matter at the end of the experiment.

Notes: Abstract. Degradation of isoproturon in a heavy clay soil followed first-order reaction kinetics with half-lives at 15 °C of 27 and 208 days in the topsoil and subsoil, respectively. Adsorption when shaken with 3 mm sieved samples of the soil fitted the empirical Freundlich relationship with k values of 3.25 in the topsoil and 1.06 in the subsoil. Adsorption in a static system with different sized aggregates of soil did not reach equilibrium, even after 24 hours contact, and the rate of adsorption was slower with larger aggregates. Following an adsorption period of 24 hours, desorption equilibrium was reached more rapidly with larger (6–10 mm) than with smaller (〈3 mm) aggregates. Adsorption isotherms measured in a static system with a soil:water ratio typical of field conditions in winter also indicated less adsorption than that measured in shaken, laboratory systems with low soil:water ratios. The rate of change in water extractable residues of the herbicide was more rapid than that of total extract-able residues following application of isoproturon to the heavy clay soil in the field. The implications of the results for isoproturon leaching under field conditions are discussed.

Notes: Book reviewed in this article: Land Resources: Now and for the future By A. Young.

Notes: Abstract. In order to optimize the management of the N-fertilizer inputs with drip fertigation on sandy-silt soil under apple tree orchard cultivation, we observed in situ: (i) the N and water soil transfers, (ii) the N levels in all leaves, fruits and annual shoots, and (iii) the root distribution. Then we used a mechanistic one-dimensional model (WAVE, Vanclooster et al., 1994) to quantify the annual parameters of the water and nitrogen balance on a daily basis. The horizontal heterogeneity along the row of the tree-soil-dripper system has been treated with two adjacent compartments: one under the dripper and receiving fertigation and the other outside this zone. N transfers in the tree make it impossible to estimate directly N uptake by roots over time.The simulated N losses were due to equal amounts of N leaching below 0.9 m deep (9 g N tree−1year−1 and denitrification (7 g N tree−1year−1. The simulated losses of gaseous N were localized predominantly in the compartment under the dripper and showed a higher rate of leaching during the period of N input when the wet conditions and the high NO3− concentrations were favourable to denitrification. The N-leaching at 0.9 m depth was greatest outside the growing season and was caused by the extension of the N-inputs after the harvest date. This practice, based on the objective to store nitrogen before the period of dormancy does not seem to be justified.

Notes: Abstract. People in the Southern Highlands of Papua New Guinea cultivate some land semi-continuously within a regime of shifting cultivation; the staple crop is sweet potato (Ipomoea batatas). The fertility of Tropepts, variably affected by falls of volcanic ash, was investigated to give further understanding of how subsistence farmers avoid the soil constraints that commonly prompt abandonment. While organic matter, N and K all decrease significantly with time under cultivation, they do not reach critical levels. Phosphorus also decreases significantly over time, although contents are small throughout. Other nutrients show no significant variation with period of use or abandonment. These findings comply with the diversity of crops cultivated early in the life of ‘gardens’, followed by sweet potato, cultivated as a virtual monocrop in long established ‘gardens’. It continues yielding adequately regardless of decrease in nutrient availabilities, notably because nutrient ratios remain favourable for tuberisation and because of sweet potato's tolerance of small phosphorus concentrations. It appears that burning of vegetation significantly increases available minerals and helps maintain a supply which is adequate for longterm sweet potato monoculture. Similar situations are postulated for other areas of less-weathered soils within the tropics.

Notes: Abstract. The mean extractable sulphur (S) concentration in 315 upland topsoil samples collected in 1988/89 from beneath pasture in NE Scotland was 13 μg S g−1 (range 2–77 μg S g−1). More than two thirds of the samples had S concentrations less than that acceptable for productive soils. Continued decreases in atmospheric S inputs may have increased this proportion subsequently. The analysis of herbage S also indicated that two-thirds of the samples were below 0.2% S. A ‘respirometric index’, namely CO2 produced during cellulose decomposition without added S as a percentage of that produced with added S, was significantly less than 100% in a quarter of the soils. Results of three different extraction procedures suggested that sulphate in the soils was present mainly as free plus adsorbed rather than precipitated forms. Soil extraction identified a significant non-sulphate S fraction, presumably organic S. The variability in extractable S stemmed from a combination of geographical, depositional and local site and soil factors. Extractable S was significantly correlated with soil organic matter content and inversely with soil pH and together these factors explained 37% of the variability. While significant differences in mean concentrations between geographical area, soil association and drainage status were evident, no trends could be observed between the major soil subgroups or with altitude.

Notes: Abstract. We investigated whether a polyacrylate polymer could be used to remediate a soil which had been contaminated with copper for many years. Perennial ryegrass was grown in a loamy sand containing 230 mg ammonium-acetate-EDTA extractable Cu kg−1 and amended with 0, 0.1 and 0.2% of polymer. Growth of perennial ryegrass was stimulated in the polymer-amended soil, especially in the soil with 0.1% of polymer. After plant growth for 177 days, the amount of water extractable copper present in the unamended soil was 17 times that of the original soil. In the soil amended with 0.1% of polymer the level of copper after plant growth was only 0.11 times the amount present in the unamended soil. When the soil was incubated with polymer in the absence of plants, the level of water extractable copper was not reduced. The polymer seems to compete with plants for copper, and to prevent the increase of copper in soil solution brought about by root exudates.

Notes: Abstract. Soils developed on volcanic parent materials have many intrinsic qualities favourable to cropping. However, fertility decreases dramatically when they are badly managed. A short review and case studies from Réunion and Guadeloupe highlight the special characteristics of these soils, and their response to management.The interplay of cropping systems and physical characteristics of Andisols is first considered through the example of Pelargonium and food crop systems in Réunion. Progressive decrease in production and cropping potential shows in falling yields as well as in the overall decline of the system. The example of banana production in Guadeloupe highlights the increase in inputs needed to realise the land's potential and to maintain yields, in particular more tillage and pest treatment.In both cases, these trends are connected to the co-evolution of soil characteristics and cropping systems. They lead to an increase of risks with less security and less scope in the choice of cropping systems. Technical solutions in the form of erosion-control measures, rotation and planting techniques have been developed and prove to be relevant and consistent in their benefit.

Notes: Abstract. Soil classification is a tool for stratifying and generalizing information on soil resources but most systems are tailored to handle only slightly disturbed soil. We tested the applicability of the legend of the FAO-Unesco Soil Map of the World and the new World Reference Base for Soil Resources by classifying at the highest order 831 profiles from a nationwide 7 km grid survey in Denmark, where soils are developed in Quaternary glacial and marine sediments and intensively farmed. Comparison of the variability of pH and % clay +% silt of the master horizons (A, E, B, and C) within and between the major well-drained soil groupings shows that liming, fertilizing and ploughing have produced significantly deeper A-horizons with higher pH, lower % humus and C:N ratios on the two-thirds of the country that is cultivated. ‘Anthropogenic’ mollic and umbric horizons are a common result but the liming causes a random final classification of these surface horizons and, hence, random allocation of the soils in both systems. It separates cultivated soils and their undisturbed equivalents, and results in considerable within-group variation in soil texture. Grouping of cultivated and undisturbed soils, on the other hand, results in wide within-horizon pH ranges for most groups, again compromising the advantage of making useful general statements on the basis of classification.We propose that anthropogenic mollic and umbric horizons should be allowed in any soil group and that ‘anthric properties’ should be used to distinguish between profoundly changed cultivated soils and largely undisturbed soils, hereby constructing a two-tier system within each highest-order soil group. We classified the soils according to this proposal. The results show generally narrower ranges for both pH and % clay +% silt. We evaluated the within-group homogeneity by multivariate analysis of variance of pH, % clay +% silt, % clay, % humus, C:N ratio, exchangeable cations, and CEC. The results (Wilks's Lamda) show a higher degree of group compactness compared to the original FAO and World Reference Base systems.

Notes: Abstract. In dairy farming systems the risk of nitrate leaching is increased by mixed rotations (pasture/arable) and the use of organic manure. We investigated the effect of four organic farming systems with different livestock densities and different types of organic manure on crop yields, nitrate leaching and N balance in an organic dairy/crop rotation (barley–grass-clover–grass-clover–barley/pea–winter wheat–fodder beet) from 1994 to 1998. Nitrate concentrations in soil water extracted by ceramic suction cups ranged from below 1 mg NO3-N l−1 in 1st year grass-clover to 20–50 mg NO3-N l−1 in the winter following barley/pea and winter wheat. Peaks of high nitrate concentrations were observed in 2nd year grass-clover, probably due to urination by grazing cattle. Nitrate leaching was affected by climatic conditions (drainage volume), livestock density and time since ploughing in of grass-clover. No difference in nitrate leaching was observed between the use of slurry alone and farmyard manure from deep litter housing in combination with slurry. Increasing the total-N input to the rotation by 40 kg N ha−1 year−1 (from 0.9 to 1.4 livestock units ha−1) only increased leaching by 6 kg NO3-N ha−1. Nitrate leaching was highest in the second winter (after winter wheat) following ploughing in of the grass-clover (61 kg NO3-N ha−1). Leaching losses were lowest in 1st year grass-clover (20 kg NO3-N ha−1). Averaged over the four years, nitrate concentration in drainage water was 57 mg l−1. Minimizing leaching losses requires improved utilization of organic N accumulated in grazed grass-clover pastures. The N balance for the crop rotation as a whole indicated that accumulation of N in soil organic matter in the fields of these systems was small.

Notes: Abstract. Eight lysimeters, each with a surface area of 0.5 m2 and a length of 60 cm, were taken over mole drains from a Denchworth soil and divided into two groups with either a standard agricultural tilth or a finer, deeper topsoil tilth. They were variously instrumented to measure soil moisture content at three depths and losses of nitrate, a bromide tracer and radiolabelled isoproturon, all of which were followed over a year. Leaching of isoproturon was initiated by artificial irrigation either 1 or 39 days after application. The finer tilth seemed to increase the water-holding capacity of the topsoil, and this resulted in slower wetting of the subsoil, decreased flow volumes from the first events of the season and a delay of approximately four weeks in the time to the maximum concentration of the bromide tracer in leachate. The finer topsoil tilth also decreased maximum concentrations of isoproturon from 29 to 15 μg l−1 following irrigation 1 day after treatment and from 43 to 9 μg l−1 following irrigation 39 days after treatment. Total losses of isoproturon were three times larger with the standard agricultural tilth. Differences were attributed to a decrease in bypass flow through the topsoil with the finer tilth, particularly during events early in the season. There was a small decrease in total losses of nitrate in leachate from the finer tilth compared to that from the standard tilth.

Notes: Abstract. The effects of afforestation on potential nitrification, nitrification and ammonification rates were studied at an experimental site in NE Scotland 4½ years after afforestation of former arable land. The site had been planted with three tree species (Sitka spruce, sycamore and hybrid larch) at three different planting densities, with half the plots treated with inorganic NPK fertilizer. Laboratory measurements of potential nitrification, nitrification and ammonification rates, measured using a perfusion system, were compared between the unforested control and combinations of the various treatments. Differences in soil pH and soil moisture content were also investigated.Potential nitrification rates measured in plantation soils were significantly lower than in the unplanted control soil. Nitrification and ammonification rates were also consistently lower, although these differences were only significant in a few of the treatments. Soils planted with a normal tree density had a tendency to show higher nitrification rates compared to soils planted with a high tree density.The results suggest that afforestation of former agricultural soils may cause changes in important parts of the soil N cycle soon after planting. At this early stage in the life of the plantation this appears to be unrelated to changes in soil pH or moisture content, even though soils beneath the trees are drier. The apparent change may be the result of differences in the soil microbial community associated with the type of organic matter substrate present in the unplanted and planted soils.

Notes: Abstract. Increasing concerns for the financial and environmental impact of the use of broadcast fertilizer by the UK horticultural industry is leading to the development of alternative application techniques, which aim to reduce inputs through improved efficiency. One such technique, ‘starter’ fertilizer, was investigated with drilled and transplanted crisp lettuce (Lactuca sativa) on two fertile peaty soils. Starter fertilizers injected below the seed of the drilled crop, or as spot applications around the planting module, were tested alone and in various combinations with different rates of broadcast fertilizer. The work extended previous findings, based largely on mineral soils, and demonstrated that high yields of iceberg quality lettuce can be achieved with reduced inputs of broadcast fertilizer, and that there can be additional benefits of earlier maturity and improved quality. It is concluded that starter fertilizer can contribute to the development of environmentally beneficial farming practices whilst maintaining the productivity and competitiveness of the horticultural industry.

Notes: Abstract. Ancient forests which have never been under agriculture often have larger ecological and pedological value than later established forests. We made a reconstruction of the land use history of the Meerdaal forest complex in central Belgium since 1759. Soil profiles of 33 recent forest sites and of contiguous forest parcels were examined morphologically by augering to 120 cm depth. pHKC1 was determined on samples from every horizon. The data were analysed by Principal Component Analysis, and the axes were used as a basis for derivation of horizon parameters. Former agricultural land use since 1759 can still be recognized in three soil morphological characteristics: colour of the eluviation horizon, intactness of the horizon containing illuviated clay and thickness of the organic layer. These parameters were combined into a ‘naturalness index’, which differs significantly between ancient and recent forest and can be easily and cost-effectively obtained to assess the degree of man-made disturbance of forests on loess-derived soils.

Notes: Abstract. A long-term lysimeter experiment with undisturbed monoliths studied leaching behaviour and balances of phosphorus (P), potassium (K) and nitrogen (N) during a seven year crop rotation on four types of soil receiving inorganic fertilizers, manure and grass compost respectively. It was shown that application of manure did not lead to any direct change in nutrient leaching, unlike the application of fertilizers to soils of normal fertility. However, soil type considerably affected the nutrient concentrations in the drainage water.Manure applied in amounts equal to the maximum animal density allowed by Swedish legislation slightly oversupplied P and N (0.5–3.5 and 18–38 kg ha−1 y−1 respectively) compared to the crop requirement and leaching losses for most of the soils. The relationship between lactate-soluble P in the topsoil and the concentrations of dissolved P in the drainage water was very strong. However the strength of this relationship was dependent on just one or two soils. P losses from a fertile sandy soil were large (1–11 kg ha−1 y−1) throughout the crop rotation and average crop removal (13 kg ha−1 y−1) plus the leaching losses were not balanced (average deficit 3–6 kg ha−1 y−1) by the addition of fertilizer, manure or grass compost. No decreasing trend was found in the P losses during seven years. However, the K deficit (average 26 kg ha−1 y−1) led to a significant reduction in the leaching trend from this soil. The other soils that had a smaller K deficit showed no significant reduction in the leaching of K.

Notes: Abstract. Guizhou province has one of the most severe soil erosion problems in China, with 44% of its total area affected. Within the province, Bijie prefecture is the most severely eroded with 63% of the total area affected. In recent decades this erosion is mainly caused by man's agricultural and industrial development. Not only is erosion restricting crop production, it is the cause of disastrous floods which recur with a frequency far greater than in the past. Reduced infiltration of rain has led to a third of the wells and a fifth of the streams running dry, depriving people and livestock of drinking water.This unsustainable use of land can only be corrected by a combination of population control, prevention of slash and burn cultivation and return of steeply sloping land to forest and grassland. Greater appreciation of the need for soil and water conservation is an essential part of this process.

Notes: Many central statistical offices use indirect time series disaggregation methods to produce quarterly national accounts estimates or other high frequency variables. This paper investigates the relation existing between the statistical properties of indirectly estimated time series and the contemporaneous aggregation level at which estimation is carried out, when a version of the Chow-Lin (1971, 1976) method is used to evaluate quarterly time series. It is shown that estimation at the lowest possible level of contemporaneous aggregation is not always optimal. In order to choose the level of contemporaneous aggregation at which time series disaggregation should be carried out, the use of formal econometric tests is suggested.

Notes: Several different approaches to international comparison of Total Factor Productivity (TFP) have now emerged. Among these are the time-series approach, the panel approach, and the cross-section approach. This paper compares methodologies of these different approaches and results that have been obtained from their application. The comparison of results is conducted in the context of two samples, namely the sample of G7 countries and a large sample that includes developing nations. It is found that while there are broad agreements in results, there exist considerable differences too. The analysis shows how these differences can be related, in part, to differences in methodology. The paper also shows how these different approaches to international TFP-comparison can play a complementary role in enhancing our understanding of such important phenomena as technological diffusion and TFP-convergence.

Notes: This paper first shows, with data from fourteen countries, the potential of time-use studies for measuring, in comparable physical quantities, labour inputs in SNA and in non-SNA production. It then presents the monetary valuations of unpaid household labour and of households' non-market product achieved on the basis of time-use data in a few of these countries. Further elaboration of these valuations illustrates the contribution of households' non-SNA production to extended private consumption. The conclusion suggests desirable future developments.

Notes: In a recent issue of this journal, M. Luisa Ferriera, Reuben C. Buse, and Jan-Paul Chavas argue that the equivalence scales implicit in the official U.S. poverty line and in public welfare programs overcompensate parents for their children, with resulting negative distributional and incentive effects. We show that their analysis is based on a very particular, and ethically unappealing, assumption about the importance of children's well-being.

Notes: The first set of hours of work estimates constructed for Canada and its regions for the 1880–1930 period is presented in this article. These estimates suggest a trend decline in hours of work, especially following First World War. In addition, these estimates suggest that the decline in hours of work came at no or little cost in terms of real weekly income. The trends uncovered for Canada are found to be similar to those revealed for the U.S. In effect, by the early twentieth century workers were realizing their long expressed preferences for a shorter workweek at no loss in real income.

Notes: Researchers know relatively little about the beginnings of wealth accumulation. This paper analyzes the wealth of young baby boomers, individuals born from 1957 to 1964, using a previously ignored wealth data set, the National Longitudinal Survey of Youth 1979 (NLSY79). First, a detailed data quality evaluation is performed. Findings suggest that not cleaning NLSY79 wealth data causes nonsensical results, but there are no other serious problems. Analyzing the cleaned wealth data quantifies many stylized facts. For example, the typical baby boomer's wealth holdings increase by more than $2,000 a year. Married females hold more wealth than either married or unmarried males. Finally, while young boomers start with a majority of their wealth in illiquid holdings such as automobiles and possessions, they rapidly shift their wealth holdings into homes as they grow older.

Notes: Estimates using survey data are determined by two factors: the data collected and the survey weights. This paper discusses the design and calculation of a set of consistent weights for the Surveys of Consumer Finances. Taking both these weights and the multiply-imputed survey data, we look at estimates of changes in the distribution of wealth over the first half of the 1990s.

Notes: We use 1990 U.S. Census of Population data to calculate what poverty rates would have been if cohabitors were treated in the same manner as married couples. We find that the official treatment of cohabiting partners as separate family units overstated the extent of poverty in 1989 among all children by about three percent. Only about 11 percent of the observed rise in child poverty between 1969 and 1989 would be eliminated if the Census Bureau made this change in its definition of the family. We estimate a logistic regression model of the likelihood that poor, cohabiting families with children would be reclassified as non-poor if the cohabitor's income were included in family income.

Notes: The international System of National Accounts 1993 (1993 SNA) was implemented in Canada in November 1997, but with some modifications. Our occasional departures from the 1993 SNA affect the overall GDP only marginally and are primarily in the sector details. This paper provides a brief description of some of the most important differences still remaining between the 1997 Canadian System of National Accounts and the 1993 SNA. It will be very useful Lo know if other countries have faced or are facing similar problems in their implementation of the 1993 SNA. A collection of such reports from many countries will provide us very useful and rich source material for possible changes in the future version of the international SNA.

Notes: This paper investigates the effects of varying consumption patterns for families with and without children on measured trends in child poverty. We first use data from consumer expenditure surveys to calculate price indices by family type. We next examine the effect of using these group-specific price indices on measured trends in child poverty. Although we find that, all else equal, children increase the cost of living, our calculations indicate that on average families with children experienced relatively lower inflation rates than families without children during the 1968 to 1987 period. While this result suggests that estimates of child poverty rates calculated using an average price index may have over-stated secular increases in child poverty, we find that child poverty rates calculated using a price index specific lo families with children are not substantively different from those calculated using an average index for all families.

Notes: Additivity is an important property for the aggregation methods used in constructing purchasing power parities. For a practical definition of additivity, this paper categorises all aditive methods. First of all, a generalisation of the Geary-Khamis method of aggregation is defined: this is called the Generalised Geary-Khamis, (GGK), approach. The key result proved is that, within a broad class of possible aggregation methods, the set of additive methods is precisely equivalent to the set of GGK indices. Some implications of this categorisation of additive methods are considered, both in the multilateral and bilateral cases. For example, in the multilateral case, the Iklé index is set in context as another special case of the GGK approach. In the bilateral case, it is shown that there always exists a GGK, (and therefore additive), equivalent to the Fisher Index.

Notes: National accounting issues related to forest resources have attracted much attention recently. The net-depletion method, the most popular method for estimating aggregate changes in the value of timber stocks, tends to overstate both the depreciation of mature forests due to harvests and the appreciation of immature forests due to growth. Alternative, correct methods, which I term the net-price and El Serafy variations, can be derived from an asset valuation model that takes forest age into account. An empirical example indicates that estimates from the net-depletion method can deviate from actual values by up to 40 percent for some age classes.

Notes: The paper conducts an empirical analysis of the importance of entrepreneurship for wealth concentration and mobility using data from the Panel Study of Income Dynamics. The data shows a marked concentration of wealth in the hands of entrepreneurs which is not merely a consequence of their higher incomes. The higher saving rates among entrepreneurs is one of the possible explanations for their higher asset holdings and this hypothesis is supported by the statistical tests conducted in the paper. The data also shows that entrepreneurs experience greater upward mobility in that they have a greater probability of moving to higher wealth classes, and this is not only a consequence of their higher incomes.

Notes: This paper provides two extensions to the group decomposition of the Gini index by Yitzhaki and Lerman. First, within group, stratification, and between group inequality are analyzed along several dimensions at once. This provides for a better understanding of the determinants of inequality. Second, the impact on the Gini of marginal changes in income or consumption by group is derived. This can be used to evaluate targeted redistributive policies or assess the impact of exogenous shocks by group. The analysis is applied to data from Bangladesh with a focus on the impact of land ownership, education, and occupation on inequality.

Notes: The importance of adjusting for quality changes in the measurement of consumer prices, and the role hedonic regressions can play in achieving this, is well recognised. However, the use of such regressions can take different forms, including (i) adjustments by statistical offices for non-comparable substitutions via the matched models method, (ii) direct estimates from the coefficients on dummy variables for time, and (iii) exact hedonic and superlative indices corresponding to a constant utility formulation from an economic theoretic approach. The literature on these approaches generally deals with each in isolation; the purpose of this paper is to outline and evaluate them in order to draw conclusions as to their practical suitability for the compilation of quality-adjusted consumer prices indexes. The case is argued for a move towards the last of these approaches, which developments in electronic data retrieval (scanner data) now make feasible. The paper concludes with the results of some empirical work comparing the results of the direct method with those from the exact, superlative, approach.

Notes: In this paper I estimate the age-wealth profile under two different identification assumptions about age, cohort and time effects. According to the life-cycle model, the two sets of assumptions should yield similar age-wealth profiles. Using the 1984–93 Italian Survey of Household Income and Wealth, the estimated average annual rate of wealth decumulation in old age is found to be between 3 and 6 percent. As in the life-cycle model, the cohort effect increases with year of birth. However, the results also uncover considerable population heterogeneity: the rates of wealth decumulation are much lower for rich households and households headed by individuals with higher education.

Notes: The dynein ATPases are a family of motor enzymes that drive microtubule sliding in cilia and flagella and contribute to microtubule-based transport inside cells. the multi-dynein hypothesis makes two predictions: 1) Axonemes contain multiple dynein heavy chain (DHC) isoforms, each encoded by a different gene; 2) Each isoform performs a specific role in ciliary beating. We used PCR-based techniques to clone thirteen different DHC sequences from Tetrahymena genomic DNA. All thirteen genes appeared to be expressed in growing cells. Comparisons of the deduced amino acid sequences of the thirteen DHCs with other known DHCs suggested that we have cloned three outer arm DHCs. two cytoplasmic DHCs, and eight inner arm DHCs.