ALBERT

Notes: Effects of sowing date, fungicide seed treatments, and the head smut fungus Ustilago bullata Berk, on establishment, herbage, and seed production of prairie grass cv. Grasslands Matua (Bromus willdenowii Kunth) were measured in autumn- and spring-sown field trials in New Zealand.Autumn seedling establishment from thiram-treated seed relative to untreated seed was increased by 27% from the earliest sowing (early March), and by 65% from the latest sowing 8 weeks later. Infestation of seed with ustilospores of U. bullata reduced seedling establishment at all but the latest autumn sowing. Fungicide seed treatments had little effect on spring seedling establishment, but V. bullata infestation of seed reduced establishment compared with healthy seed, particularly after late sowings (early November).Herbage production was greater from early than from late sowings in both autumn and spring, and was less in plants grown from U. bullata infested seed than in plants from healthy seed. Enhanced autumn establishment from thiram-treated seed led to improved herbage production when plants were young, but this effect disappeared about 18 weeks after late autumn sowing. Overall herbage production from spring sowing was more than twice that from autumn sowing.A 6-week delay in autumn sowing led to a 58% reduction in seed production the following summer.Early autumn and spring sowings, together with adequate control of seedling diseases, are likely to give optimum herbage and seed production from prairie grass.

Notes: Herbage production and quality of swards of brome grass (Bromus carinatus. Hook and Am) were compared with other commonly sown grasses at two sites in Scotland. At Ayr, the comparison was with perennial ryegrass (Lolium perenne L.), cocksfoot (Dactylis glomerata L.) and timothy (Phleum pratense L.) under 6-cut (experiment 1) and 4-cut (experiment 2) regimes over 3 years with 360 kg ha−1 fertilizer N applied annually in each experiment. At Edinburgh, brome grass was compared over 3 years with perennial ryegrass and cocksfoot under a 7-cut system given 3(X)-35O kg N ha−1 year−1 (experiment 3) and with perennial ryegrass, cocksfoot and Italian ryegrass (Lolium multiflorum Lam.) under a 4-cut system given 250–325 kg N ha−1 annually (experiment 4).Over the 3 years, brome grass gave 1.18, 6.19 and 1.3% less dry matter (DM) production than the other grasses in experiments 1, 2 and 3 respectively; in experiment 4, it was 1 % less productive than Italian ryegrass but 1.2% more productive than the other grasses. The organic matter digestibility (OMD) of brome grass was lower than that of perennial ryegrass but higher than timothy at Ayr, similar to perennial and Italian ryegrasses at Edinburgh but markedly superior to cocksfoot at both sites. N concentrations in brome grass were higher than in the ryegrasses but lower than in cocksfoot. Mineral composition data showed brome grass to be high in P and K, low in Ca and Mg and very low in Na compared with corresponding concentrations in the other grasses.The variable performance of this brome grass species (B. carinatus) against commonly used grasses in the reported experiments, together with similar evidence from the literature, leads to the conclusion that it is unlikely to be suitable for widespread use in the UK; nevertheless, it has shown some promise in drought-prone situations.

Notes: Book reviews in this article: Advances in Nitrogen Cycling in Agricultural Ecosystems Edited by J.R. Wilson Ruminant nutrition. Recommended allowances & feed tables Edited by R. Jarrige Soil Husbandry Tom Batey Evaluation of straws in ruminant feeding Edited by M. Chenost and P. Reiniger

Notes: An experiment was conducted to examine the effect of concentrate supplementation on the performance of suckling lambs while grazing at variable levels of herbage allowance. Twenty-four ewes suckling twin lambs were allocated 55 d after lambing between four grazing treatments (two levels of herbage allowance × two levels of supplementation) in a 2×2 factorial design. The sward consisted of Tall Fescue and was grazed rotationally.Daily herbage organic matter (OM) allowances were 57.0 (H) and 38.5 (L) g OM kg LW−1 above 1·5 cm cutting height. Lambs were either supplemented (S) ad libitum with high-moisture whole maize grain or unsupplemented (U).Supplement intake during the 60-d grazing period was 16 kg DM and 17.5 kg DM respectively for LS and HS lambs. The effect of supplementation on lamb growth rate differed significantly between allowances: at the low allowance level, supplementation increased growth rate (287 g d−1 vs 226 g d−1), whereas it had no effect at the high level (277 g d−1 vs 276 g d−1). Growth rate of unsupplemented lambs was significantly reduced at the low level of allowance compared to the high level (226 g d−1 vs 276 g d−1). The effect of sward height on time spent grazing by unsupplemented lambs is described during the defoliation of a plot.

Notes: This study evaluated the relationships between legume proportion and dry matter (DM) yield, N yield, and herbage N concentration for three binary legume-grass mixtures In Uruguay. Two identical trials were established, one in 1983 (Trial 1) and another in 1984 (Trial 2) and were evaluated for 2 years. Treatments were white clover (Trifolium repens L.) (WC), red clover (Trifolium pratense L.) (RC), and birds-foot trefoil (Lotus corniculatus L.) (BT), each grown with tall fescue (Festuca arundinacea Schreb.) (TF) at four legume proportions, plus pure stands of TF. In Trial 1, annual DM yields of RC-TF were greater than yields of WC-TF or BT-TF and in Trial 2 RC-TF and BT-TF yielded more than WC-TF. The N concentration of either the legume or TF components usually was greater for WC-TF than other mixtures in both trials. Annual DM yields in Trial 1 were optimized by legume proportions of 47 to 59% for WC, 62 to 67% for RC-TF, and 57 to 100% for BT-TF; and N yields were optimized by 70% of WC or RC, and by 100% BT. In Trial 2, which had greater soil-N availability than Trial 1, optimum DM or N yields were achieved at lower WC proportions than in Trial 1. Changes in legume proportion did not affect legume N concentrations, but N concentration of TF in mixture was always positively and linearly related with legume proportion. It is concluded that DM yields for the first 2 years after seeding were greater for RC-TF and BT-TF than for WC-based mixtures. Herbage DM and N yields of WC-TF were optimized by lower legume proportions than for RC-TF and BT-TF. The N concentration of TF increased linearly with increasing proportions of any of the three legumes.

Notes: The numbers of lactic acid bacteria (LAB), as measured by Rogosa SL agar, on lucerne (Medicago sativa) chopped for ensiling were predicted using two methods. The first prediction method consisted of regression equations developed from two previous harvesting seasons and required inputs of wilting time between mowing and chopping, average wilting temperature and moisture content of the lucerne at chopping. The second method simulated the growth of LAB on the lucerne during wilting and needed similar inputs. The former method predicted LAB counts within one order of magnitude more than 95% of the time except for lucerne samples drier than 60% dry matter. The prediction of the simulation model had more variation than those of the regression equations, but the simulation model was applicable over a wider range of conditions. These results, together with earlier studies, provide a preliminary basis for determining when a silage inoculant containing LAB will be most beneficial.

Notes: The occurrence of Listeria spp. in pasture grass and grass silage made with various additives and preservation techniques is reported. Silage samples were collected three times (in November, February and May) from eighty dairy farms. The prevalence of Listeria spp. in pasture grass samples was 0.647 and in silage samples 0.227. Only two species, L. monocytogenes and L. innocua were observed. Listeria spp. Were isolated from the silage at least once at thirtynine farms (0.488), and L. monocytogenes at twenty-seven farms (0.338). The occurrence of Listeria was highest among the silage samples collected in November (0.288). Silages preserved with acids had the lowest prevalence of Listeria (0.194). Silages preserved in tower silos were most often free of Listeria, only 0.056 being positive. The highest prevalence of the Listeria spp. (0.324) was detected in clamp silage. The results of chemical analyses of silage statistically reflect the frequency of Listeria.

Notes: An ultrasonic rangefinder (sonic sward stick) was developed for rapidly measuring and recording the undisturbed surface height of swards. HFRO and ultrasonic sward stick measurements of undisturbed sward height over continuously grazed pasture were closely related. The measurements obtained with both instruments were related to the sward mass; the distribution of that mass between leaf, stem and dead material had little effect.

Notes: A mathematical model is presented that predicts the time-course of aerobic deterioration in grass and whole-crop maize silages. The model predicts the stability of the silage taking into account the buffering capacity of the silage, the initial contents of organic acids and ethanol, pH, the initial temperature and the initial populations of the microorganisms. The specific processes simulated include the growth of yeast and acetic acid bacteria, the oxidation of fermentation products, the consumption of oxygen and the production of carbon dioxide, the rise in temperature. and the increase in pH.The deterioration of silage is seen to be initiated by acetic acid bacteria or by yeast, or by both groups together. The factors that determine which groups will prevail are the dry matter contents and the chemical composition of the silage. The output of the model is validated by comparison of the simulated data with data from published work on the deterioration of silage.

Notes: In experiment 1, a mixture of perennial ryegrass and white clover (176 g DM kg−1) was ensiled with no addition, or with the application of Lactobacillus plantarum, 3 × 106(g fresh weight of herbage)−1 or enterobacteria, 3 × 106 (g fresh weight of herbage)−1 or both of these inoculants. Silos were incubated at either 18°C or 26°C for 7 d and sealing of half of the silos was delayed for 48 h. In experiment 2, cocksfoot (247 g DM kg−1) was ensiled with no additive, with the application of L. plantarum, 4 × 106 (g fresh weight of herbage)−1 enterobacteria, 4 × 106 (g fresh weight of herbage)−1 or ammonium nitrate, 5 g (kg herbage)−1. Silos were incubated at 18°C and sealing was delayed for 48 h.In neither experiment were the untreated silages of satisfactory quality after 35 d ensilage, having pH's of 4·3 and 6·4. and ammonia-N concentrations of 139 and 209 g N (kg total N)−1 in experiments 1 and 2 respectively. The poorer fermentation in experiment 2 reflected the lower water-soluble carbohydrate (WSC) content of the ensiled herbage (136 and 53 g WSC (kg DM)−1 in experiments 1 and 2 respectively). Inoculation with L. plantarum significantly reduced silage pH and the concentrations of ammonia-N (experiment 1 only) and ethanol and increased lactic acid concentrations. Inoculation with enterobacteria had only minor effects in each experiment.In experiment 1, incubation at 26°C increased the rate of fermentation in the silos as pH was significantly lower after 7d incubation at 26°C than at 18°C, but this effect had largely disappeared after 35 d incubation. When sealing of the silos was delayed for 48 h, the resulting silages had significantly higher pH and ammonia-N contents than silages from silos that had been sealed immediately after filling.In experiment 2, addition of ammonium nitrate significantly reduced the concentrations of ethanol and acetic acid in silages opened after 7 d. After 35 d the concentrations of ethanol were significantly reduced and those of ammonia-N increased by the addition of ammonium nitrate. There were marked increases in silage pH between 7 and 35 d ensilage and in the concentrations of ammonia-N and acetic acid in the silages that had been inoculated with ammonium nitrate at ensilage.

Notes: An examination was made of the effects of different spring treatments on the growth of white clover in a ryegrass/white clover sward. Plots were either cut once (in February, March or April) or twice (in February and April) or left uncut. Nitrogen was applied to half of the plots in each instance. The clover was sampled at intervals of approximately 3 weeks from February to June to determine numbers of leaves and growing points and weights of plant parts. Rates of leaf appearance were also observed and estimates were made of total herbage mass from ground-level cuts.Percentages of white clover in the herbage were higher in unfertilized than in fertilized plots and in defoliated than in undefoliated plots. The percentage increases that followed defoliation were usually maintained into later regrowth, showing that clover content was not automatically reduced as herbage mass increased. Increases in growing points were recorded after the beginning of April in defoliated unfertilized plots but not in undefoliated fertilized plots or in plots fertilized and defoliated twice during the spring period, in which numbers fell substantially.Inverse relationships were found between rates of leaf appearance, or the number of green leaves retained per stolon, and herbage mass, whereas heights of clover and grass leaves and the percentage of dry matter allocated to petiole rather than leaf in the clover increased with increasing herbage mass.We suggest that the observed differences between spring treatments in clover percentage result primarily from their differential effects on the formation and death of tillers and growing points in the early stages of regrowth.

Notes: Forage production based on summer annual crops is a common agricultural practice in many areas of the world where the growing season is favourable.0An investigation was conducted over 3 years to compare the dry matter (DM) yield and quality of four annual crops; maize (Zea mays L.), sunflower (Helianthus annus L.), sudangrass (Sorghum bicolor L. Moensch) and sorghum (Sorghum bicolor L. Moensch) x sudangrass; in two rainfed locations with different summer temperatures in north-west Spain (Galicia). The crops were compared at three harvest dates; first weeks of August and September and, except for sunflower, at a later silage stage.The comparative forage yields of each crop varied depending on location and harvesting date, reflecting their suitability for the climate of the location.At Mabegondo, with relatively mild summer temperatures (16.5 °C), maize throughout summer and sunflower until September produced higher DM yields than sudangrass and sorghum × sundangrass. At this location the silage DM yields for maize, sorghum × sudangrass and sundangrass were respectively 15.2, 9.92 and 7.79 t ha−1. At Puebla de Brollón, where the average temperature from June to September was about 2 °C higher than at Mabegondo, the DM production of the sudan-type crops were similar to maize, while sunflower was significantly lower at the September harvest. The silage DM yields were: maize 14.07 t ha−1 sorghum x sudangrass, 14.05 t ha−1, sudangrass 12–26 t ha−1.The in vitro dry matter digestibility (IVDMD) of maize was always higher than that of the other crops, with an average value of 700 g kg−1.It is concluded that, in north-west Spain, maize is the most suitable summer crop for maximum yield of good quality forage from the first week of August through to the normal silage stage in October.

Notes: An experiment was carried out during 1984 to study the effect of treating grass at ensiling with three commercially available inoculant-type additives (H/M Inoculant, Grass Sile and Siron), formic acid (850 g kg−1; Add-F) or no additive on grass preservation, in-silo loss, intake and animal performance. Primary growth grass ensiled from 28–29 May into concrete-walled covered silos was of high dry matter (DM, 234 g kg−1), water-soluble carbohydrate content (WSC. 212 g kg DM−1) and digestibility (MADF, 250 g kg DM−1).The untreated silage displayed good preservation and with the exception of the Sirontreated silage which showed significantly lower buffering capacity (Be) and volatile fatty acid (VFA) contents than the untreated silage, the application of inoculant-type additives did not improve silage preservation or decrease in-silo DM losses. The formic acid-treated silage displayed significantly lower Be, water-soluble carbohydrate, ash, ammonia nitrogen (g kg total N−1) and lactate contents than the untreated silage.After a 133 d storage period, silages were offered to finishing beef cattle for an 84-d period. Cattle offered the silages displayed similar and non-significant daily DM intakes, daily liveweight gains, dressing proportions and daily carcass gains. From this experiment it appears unlikely that any of the additives evaluated will improve animal performance relative to a well-preserved untreated silage.

Notes: In two field experiments acetylene (C2H2) reduction by white clover in mixed swards was compared to N2-fixed measured by 15N dilution. In both experiments, samples for C2H2 reduction were 7.5 cm diameter turves taken from plots within which microplots of 24 cm diameter were delimited and to which 15N was applied as ammonium sulphate (15NH4)2SO4). C2H2 reduction was assayed every 6–7 d. The rate of C2H2 reduction per unit length of stolon was applied to the estimated stolon length within the appropriate microplot at the time of assay, and the amount of C2H2 that would have been reduced within the microplot was estimated by integration.In experiment 1, turves taken from grass/clover swards to which 0, 1·5, 3·0, 4·5 or 6·0 g N m−2 had been applied were incubated in sealed chambers (10% C2H2, 90% air). The mean ratio of C2H2 reduced to N2 fixed during 5 weeks was 0.74:1. Application of N fertilizer lowered the proportion of assimilated N derived from N2 fixation from 95% in unfertilized swards to 83% in those receiving 6 g N m−2 (60 kg N ha−1). In experiment 2, clover roots and stolons from plots that previously had been grazed were dissected from turves and incubated in a stream of C2H2 and air (i.e. the open system). The maximum rate of ethylene (C2H4) produced during the first 12 min was taken as a measure of true nitrogenase activity. The relationship between C2H2 reduced and N2 fixed was significant (r=0.80**). The mole ratio was 0.55:1 for the 6 weeks duration of the experiment, the low ratio possibly being due to disturbance of the nodules adversely affecting acetylene reduction. Mole ratios from both experiments were well short of the theoretical 4·3:1. Using the open system does not, therefore, overcome the shortcomings of the acetylene reduction technique for measuring N2 fixation of white clover in mixed swards.

Notes: A second cut of lucerne was wilted to 500 g DM kg−1 and either left untreated (control) or treated with formic acid (4.5 1 fresh forage t−1) or with a commercial inoculum of lactic acid bacteria (105 colony forming units (cfu) g forage−1). The forages were ensiled in 2-t capacity silos for 8 months, and later fed to six lambs (mean initial weight 27.7 ±1.60 kg) in a 3x3 duplicated Latin square with 27-d periods. Portions of the untreated and additive-treated forages were also ensiled in laboratory silos at 25 ° C for intervals up to 42 d. Results from the laboratory silos showed that the major increase in ammonia-N in silage occurred between 40 h and 7 d of fermentation; during this period, both formic acid and the inoculant produced a smaller increase in ammonia-N, than did the control. The pH of inoculated silage declined from 5.74 to 4.57 in 7 d, but it took 14 d for the pH of the control silage to fall below 5.0. Formic acid treatment immediately reduced the silage pH from 5.74 to 5.10 (P 〈 0·01); the pH then remained unchanged until 21 d, after which it decreased slightly. When compared with control, lambs fed formic acid-treated silage consumed more (P 〈 0·05) digestible organic matter; the response was associated with a trend towards decreased concentration of ammonia in plasma. Inoculation of lucerne silage did not (P 〈 0·05) affect voluntary intake but increased (P〈0.05) apparent digestibility of fibre and tended to increase N retention.

Notes: The percentage of clover in a mixture of Huia white clover and Melle perennial ryegrass decreased during each of three winters. In the most severe winter, both grass and clover suffered a net loss of weight, clover losing two–thirds of its maximum weight while grass lost about one–third. In the mildest winter, grass continued to gain weight throughout, while clover lost weight. Such losses, when combined with conditions such as the use of nitrogen fertilizer, which prevent a recovery of clover percentage during summer, will lead to a long–term decrease in the clover content of a sward.The losses from the clover were contributed to by all plant parts especially leaf, which lost between 60% and 95% of lamina weight. The change from autumn to winter caused a greater decrease in the number of live leaves per shoot. and in the area and weight of individual leaves, in clover than in grass. Other work has shown that there is a greater decrease in photosynthesis in clover than in grass, probably owing to changes in canopy structure; this is one cause of clover's poor performance, though differences between the two species in the effect of winter on the distribution of the carbon fixed in photosynthesis and in losses of weight in respiration and tissue death may also be involved.

Notes: Seedlings of Rumex obtusifolius L. were grown in gaps (11 cm diameter) in an established sward at Lolium perenne L., Root competition from the surrounding sward was controlled by PVC tubes and shoot competition was controlled by cutting the sward frequently. All combinations, with and without root competition and with and without shoot competition, were used.Plants received either 40 or 80 kg N ha−1 month−1 and 0 or 300 kg K2O ha−1 and were harvested 39 d after emergence; a second harvest was made 12 d later, after shading to 20% of full sunlight.The shoot dry weight per plant of R. obtusifolius was much more affected by root competition than by shoot competition, especially at low nitrogen applications. Potassium supply had no effect.More dry matter was allocated to the leaf petioles under shaded conditions and the specific leaf area was greater. This morphological plasticity enabled R. obtusifolius to grow well under shading and to be affected only slightly by shoot competition from L. perenne.The results suggest that competition for nitrogen was the main factor limiting the initial grown of R. obtusifolius in a ryegrass sward and that the morphological characteristics of R. obtusifolius make it less susceptible to competition for light in the early stages of its development.

Notes: Five experiments were carried out in the years 1980-1983 and 1986 to study the effect of treating grass at ensiling with sulphuric acid (850 g kg−1) and formic acid (850 g kg−1) additives alone, and in mixtures with or without formalin on the preservation of grass, in vivo digestibility in sheep, in-silo loss, intake and performance of finishing cattle.Primary growth grass was ensiled in experiments 1 (3–4 June 1980), 2 (12-15 June 1981) and 3 (31 May-2 June 1982), primary regrowth grass in experiment 4 (1-2 August 1983) and secondary regrowth grass in experiment 5 (7-10 October 1986). During the ensiling period within each experiment, approximately 60 t of unwilted, double-chopped, additive-treated or untreated grass was packed into covered concrete-walled 60-t capacity silos. The dry matter (DM) contents of the ensiled grass in experiments 1, 2 and 5 ranged from 155-180 g kg−1 and were lower than those recorded in experiments 3 and 4 (214 g kg−1). With the exception of grass ensiled in experiment 2, where water-soluble carbohydrate (WSC) contents were low, at 104 g kg−1 DM, grass in all other experiments contained relatively high WSC contents ranging from 140-154 g kg−1 DM.In experiments 1, 3 and 4 all silages were well-preserved. However, in experiment 2 the 450 g kg−1 sulphuric acid-treated and formic acid-treated silages displayed significantly lower pH, buffering capacity (Bc) and ammonia nitrogen contents than the untreated silage. In experiment 5, the sulphuric acid-treated and formic acid-treated silages displayed significantly lower pH, Bc, ammonia nitrogen, butyrate and volatile fatty acid (VFA) contents than the untreated silage.Each of the silages was offered daily with various levels of a supplementary concentrate for approximately 70-d periods to twelve animals of mixed breed in experiments 1, 3, 4 and 5 and to fifteen animals in experiment 2. All animals weighed between 380-470 kg at the start of the experiments.In experiments 1, 2 and 3 there were no significant differences between silages for any of the intake or animal performance parameters. In experiment 4, cattle fed the formic acid-treated silage displayed significantly higher silage DM intakes and daily liveweight gains than those fed the sulphuric acid-treated and untreated silages; in experiment 5, cattle fed the formic acid-treated silage displayed significantly higher silage DM intakes than those fed the untreated silage. It was concluded that formic acid was a more effective silage additive than sulphuric acid.Increasing the level of supplementation significantly decreased silage DM intakes in cattle in experiments 3 and 4, and significantly increased daily liveweight gains and daily carcass in cattle in experiments 1, 3 and 4.

Notes: Rates of N accumulation were studied on sheep grazed grass swards maintained at a constant height of 5 cm for two growing seasons (1985 and 1986) and receiving no N fertilizer using a tiller tissue turnover technique. Grazing with normal excretal returns resulted in an 85-105% increase in the estimated rates of N accumulation by laminae compared with similarly grazed swards where excretal returns were prevented. Generally, increases in tiller numbers in plots receiving excreta were mainly responsible for the increased rates of N accumulation, rather than increased rates of N accumulation per tiller. Rates of N remobilization from laminae and senescence (flux of N to standing-dead litter pool) per tiller, and rates of leaf extension and leaf appearance/disappearance were unaffected by excretal returns, in urine patches increased tiller numbers and increased rates of accumulation per tiller both resulted in greater estimates of N accumulation compared with tillers not visibly affected by excreta. However, at any one time only about 11% of the plot area was affected by excreta and increases in N accumulation in excreta patches could not account for the overall plot increases in rates of N accumulation.The increased tillering in plots receiving excreta may have increased exploitation of the soil N. With an average stocking rate of 15 sheep ha−1, soil nitrate-N, but not total N (Kjeldahl) nor bulk density, was increased during the winter of the second year as a result of excretal returns.

Notes: Over a 24-week period during the 1986 summer, three groups of January- to March-calving dairy cows were either grazed conventionally (G) or grazed between morning and afternoon milkings and housed overnight and offered grass silage (Si) or a straw/concentrate mixture (St) ad libitum. The straw/concentrate mixture contained proportionately, 0-33 long barley straw, 0·28 ground barley, 0·12 soya bean meal, 0·25 molaferm and 0·22 minerals. The metabolizable energy (ME) and crude protein (CP) contents of the silage fed in weeks 1-8 and weeks 9-24 were 9-5 and 10−6 MJ kg MD−1 and 160 and 191 g kg DM−1 respectively. The straw mix had an ME content of 10−1 MJ kg DM−1 and CP content of 134 g kg DM−1. Partial storage feeding with silage or a straw/concentrate mixture led to a decrease in estimated herbage DM intake. The feeding of the straw/concentrate mixture increased total DM intake, but the estimated total ME intake was similar for treatments G and St. The intakes (kg DM d−1) for treatments G, Si and St were respectively, herbage 11·7,6·8,4·1; total l3·5,13·6,15·0; total ME intake (MJd−1) 163, 155, 163.Animal performance was, for treatments G, Si and St respectively: milk yield (kg d−1) 19·2, 17·5, 19·1 (s.e.d. 0-87); milk fat content (g kg−1) 36·9, 37·6, 37.1 (s.e.d. 1.22); milk protein content (g kg−1) 35·3, 32·9, 33·4 (s.e.d. 0·76).

Notes: Grassland in Britain is a plagioclimax vegetation type. All lies on land originally cleared from forest and, without some form of management, would revert to forest through a process of natural succession. Traditionally managed, unsown grasslands nonetheless resemble more natural grasslands in other parts of the world and contain a substantial proportion of our native flora and fauna. They are also often important for recreational activities. Agricultural intensification over a long period has led to a loss in their extent, species and amenity. Reconciling agricultural and environmental objectives in grassland management is very difficult because increased fertility and production invariably leads to species loss. Current overcapacity in the agricultural industry is leading to the switching of some agricultural support from food production to countryside management. As a result some arable and intensively managed grass is being managed more extensively. However future production technologies may be so efficient that very many fewer stock are required with the result that much marginal grassland may revert once again to forest.

Notes: Herbage quality, yields, tiller and plant populations of ‘Grasslands Matua’ prairie grass and ‘Caramba’ tetraploid Westerwolds ryegrass were investigated in a 2-year field trial on a sandy soil. Plots were either harvested frequently (five to six cuts per year) or infrequently (four cuts). During the first year, herbage was separated into leaf, vegetative and reproductive pseudostem, and analysed separately.With very mild winters and adequate water supply, swards had good persistence and production for 2 years. Total yield in the first year (10.5 t DM ha−1) was similar for both species. Yields in the second year were (t DM ha−1) 13.4 and 18 for Matua and 11.1 and 13 for Caramba under frequent and infrequent cutting respectively. Leaf contributed 58% to yields and reproductive pseudostem 35%. Infrequently cut plots had: 23% higher dry matter yields, primarily due to higher yields of reproductive pseudostem; higher yields of most chemical components and higher contents of water-soluble carbohydrates and cell walls; lower digestibility and nitrogen content. Cell wall content was consistently higher in Matua but otherwise herbage quality was similar for the two species. It is suggested that prairie grass should be considered as a replacement for spring-sown Westerwolds ryegrass on sandy soils in The Netherlands.

Notes: White clover, (cv. Haifa) and subterranean clover (cv. Seaton Park) were grown in binary replacement series mixtures in the field at proportions of 100:0, 90:10, 50:50. 10:90 and 0:100, and cut every four weeks over three growing seasons from 1985 to 1987 at Scone, New South Wales (NSW) (32°S).Relatively low plant densities minimized competition in 1985, but in subsequent seasons Haifa and Seaton Park competed vigorously for the same resource;.; usually having relative crowding coefficients greater than 1.0, and relative yield totals greater than 1.0 in spring of 1986 and 1987, and autumn 1987. This over-yielding appeared to be due to some complementarity of leaf morphology and canopy architecture.Haifa severely depressed seed production of Seaton Park in mixtures. Haifa regenerated as an annual in 1986, but as a perennial, from surviving stolons, in 1987 owing to lower maximum temperatures and better rainfall distribution in late summer and autumn of 1987.It is concluded that white clover can survive severe competition from subterranean clover as a seedling, and if moisture allows, may severely depress seed production from subterranean clover, regardless of whether plants are annual or perennial in origin. Spatial separation may minimize competition in average years but competition effects may be severe in seasons with sufficient summer rainfall for perennation of white clover, and seasonal autumn rainfall for germination of subterranean clover.

Notes: Small swards of white clover and perennial ryegrass were established in Perlite in a heated glasshouse, as either monocultures or mixtures of equal plant numbers. On 26th March, 1984 the swards were moved outside and their growth studied over the period to 29th May. All swards received a basal level of nitrate N to simulate soil mineralization and two-thirds received additionally the equivalent of 80 kg N ha−1. Over the experimental period (26th March-29th May) clover maintained its proportion of total mixture dry weight In swards given ‘fertilizer’-N and increased its proportion in those given only ‘basal’ N, However, clover declined as a percentage of total mixture dry weight during the first period of the experiment when total leaf area index (LAI) and ambient temperatures were low, and increased its percentage later when temperature and LAI had risen. Changes in tiller and stolon growing point numbers were not good indicators of changes in dry weight. Relative yields and relative replacement rates also were not good indicators of relative performance in mixture. Where ‘fertilizer’-N was applied, clover derived less of its nitrogen from that source than grass although their uptakes per unit shoot dry weight were similar.

Notes: A field plot experiment was carried out on an established grassland sward from 1983–88 inclusive to examine the effects of time of application, chemical form of nitrogen (N) and cattle slurry dry matter (DM) content on yield and efficiency of N use. Four forms of fertilizer N (a semi-organic fertilizer, a combined 2.1:1 (w/w) semi-organic/calcium ammonium nitrate (CAN) fertilizer, CAN and urea, each supplying 300 kg N ha−1 year−1, were applied with or without unseparated or separated cattle slurry at 93 and 73 g kg−1 DM respectively, both supplying approximately 150 kg N ha−1 year−1. All fertilizers and slurries were applied in three equal dressings (February/March, May/June and July/August). The efficiency of use of fertilizer and slurry N was evaluated by measuring DM yield, N uptake and apparent recovery of N in herbage at all harvests during each growing season.Fertilizer N application significantly increased (P〈0.001) the mean yields of herbage at each harvest in all years. The form of fertilizer N had no significant effect (P〉0.05) on first harvest and total herbage yields, nor on N uptakes by herbage at the first harvest in any year. The performance of urea and of CAN was more variable at the second and third harvests relative to that of the semi-organic or combined 2.2:1 (w/w) semi-organic/CAN sources which had similar efficiencies of N use. Lower DM production was associated with reduced uptake of N. Values for mean overall apparent recovery of N ranged from 57.9 ± 2.67% for the semi-organic fertilizer to 50.2±3.05% for CAN.Unseparated cattle slurry and separated cattle slurry produced similar herbage yields and N responses that were lower and more variable than with fertilizer N. The overall mean apparent recovery of N from unseparated cattle slurry was 25.5 ± 5.03% compared to 5.0 ± 4.74% for separated cattle slurry. Efficiency of N use was highest with spring applications and least with mid-season applications. Recoveries ranged from −29% for separated cattle slurry applied in June 1984 to 56% for unseparated and separated cattle slurry applied in February 1988 and June 1987 respectively. No interactions were recorded between cattle slurry and fertilizer N in terms of DM production or N uptake by herbage.The results of this study support the use of a fertilizer N source, selected on a least-cost basis, in combination with slurry to promote spring herbage production. For subsequent production, N should be supplied in fertilizer form only. The use of urea is risky under low rainfall conditions. Mechanical separation did not improve the efficiency of use of slurry N.

Notes: A total of 1009 samples of silage made in bunker silos on commercial farms between 1972 and 1978 was analysed to investigate the effect of herbage water-soluble carbohydrate content (WSC) and weather conditions at ensilage on fermentation as measured by ammonia-N concentration and pH of first-cut grass silages.Silage dry matter (DM) content had the major effect on fermentation. Factors influencing silage DM were rainfall and hours of sunshine during silage making, and DM content of the grass cut. WSC content of herbage ensiled also had a significant effect on subsequent fermentation. The major influences on herbage WSC were hours of sunshine and rainfall during the growing season.The effect of chemical additives, albeit at poorly defined and often inadequate rates, was small in comparison to that of silage DM.The minimum DM necessary to produce well-fermented silage without additive was approximately 260 g kg−1. Use of formic acid significantly reduced this requirement to 240 g kg−1 and to 252 g kg−1 for sulphuric add + formalin. The results indicate that the minimum herbage WSC necessary to prevent a clostridial fermentation developing in silage with a DM content of 230 g kg−1 is approximately 37 g kg−1 without additive and 30 g kg−1 with formic acid.It is concluded that on commercial farms, weather conditions i.e. amount of rainfall and sunshine prior to and at ensilage, have a greater effect on subsequent silage fermentation than additive use.

Notes: Little bluestem (Schizachyrium scoparium (Michaux) Nash), a perennial bunchgrass, is a potentially valuable species for use in restoring ground cover in shallow range sites that are subject to drought. However, there are no data on the nutritive quality of the diverse phenotypes of little bluestem found in the north central USA and south central Canada, and there are no cultivars of little bluestem that are adapted to these areas. The objectives of this study were to measure the nutritive quality of little bluestem clones sampled on different dates and to determine whether clones differed sufficiently to facilitate selection efforts to improve forage quality. Whole plant samples of little bluestem were clipped on 8 August and 8 September 1983 and 5 July and 6 August 1984 from a field nursery at Mandan, North Dakota, containing plants originating from Minnesota and North and South Dakota in the USA. Significant differences between sampling dates were found each year for in vitro digestible organic matter (IVDOM), crude protein, lignin, calcium, phosphorus (P) and potassium (K). In order to minimize the effects of maturity on chemical composition, data were statistically evaluated for clonal differences, using only the August sampling dates. Clones were further separated into north and southeast groups according to stage of maturity and latitude and moisture conditions where the clones originated. Clones were significantly different with respect to IVDOM and P in both the north and southeast groups for the August 1983–1984 data. IVDOM and P among clones averaged over years for the August sampling date ranged from 374to 521 g kg−1 and from O-9to l-6g kg−1, respectively, for the north group and from 456 to 538 g kg−1 and from 1–2 to 2–0 g kg−1, respectively, for the southeast group. The range in IVDOM and P suggests that selection to improve little bluestem quality components, especially later in the season, may be warranted. However, it is important that these results be corroborated under conditions where the effects of maturity are further diminished.

Notes: The potential productivity of perennial ryegrass/ white clover swards (GC) under continuous stocking management was assessed by comparing their performance, when grazed by sheep at sward surface heights of 3, 6 and 9 cm, with that of an all–grass sward (G) maintained at 6 cm and fertilized with 420 kg N ha–1 The grass/clover swards received no nitrogen fertilizer. The different grazing treatments had a marked effect on animal performance. In the first year for example, for treatments GC3, GC6, GC9 and G6–420 respectively, mean stocking rates to weaning were 19–7, 14–3, 8–9 and 18–4 ewes ha–1 (plus twin lambs); lamb growth rates were 223, 268, 295 and 260 g d–1and so total lamb live weight gain was 1054, 920, 630 and 1148 kg h a–1. The relative performance of the treatments was similar in all three years. All three grazing treatments had a similar effect on the composition of the grass/clover swards. Clover content increased in 1985, and was sustained in 1986 and 1987 during the main grazing season, although a marked decline in clover content during the winter led to a progressive long–term decline in both the proportion and the amount of clover.It is suggested that a management based on maintaining a sward surface height close to 6 cm (as in all–grass swards) leads to optimum performance in grass/white clover swards grazed using continuous stocking with sheep. Despite the presence of a small and declining clover content, the output of the mixed grass/clover sward managed in this way was 80%, 80% and 82% of that of a grass sward supplied with 420 kg N ha–1 in 1985, 1986, and 1987 respectively and, similarly, 83% of the output in 1987 of a grass sward receiving 210 kg N ha–1.

Notes: Intensive grazing of pastures may cause drastic and rapid changes in swards which have major effects on ingestive behaviour and diet. Twelve adult Angus cows (Bos Taurus), mean live weight of 482±19 kg, were allowed to graze on swards of lucerne (Medicago sativa L.) that were not grazed (TO), or had been grazed previously for 1 h (T1), or 2 h (T2) in a balanced changeover design. Herbage dry ma er (DM) masses (〉5 cm) were 2611, 1895 and 1441 kg ha−1; leaf fractions were 0-48, 0-29 and 0-14; and herbage DM allowances per animal were 10·6, 7·9 and 6·0 kg h−1 for TO, T1 and T2, respectively. During a 1 h measured grazing session that followed an overnight fast, cows ingested 2-93, 1·71 and 0·66 kg DM h−1 with herbage DM intakes per bite of 1·6, 0·9 and 0·4 g for T0, T1. and T2, respectively. Rates of biting did not respond to sward treatment and averaged 30 bites min−1. Intake of leaf DM was estimated at 98, 70 and 6% of total DM intake for the same treatment sequence. Utilization of herbage allowance was 0·29, 0·23 and 0·12, for TO, T1 and T2, respectively. Metabolzable energy (ME) intake per animal was 30, 17 and 5 MJ h−1 and ME intake per bite was 16, 9 and 3 KJ for TO, T1 and T2, respectively. Data show that grazing-induced differences in sward characteristics moderate both ingestive behaviour and diet.

Notes: Harvesting techniques, which involve simultaneously preserving and upgrading mature crops of whole cereals using an alkali, have been developed. When treated crops have been fed to sheep and cattle, satisfactory intakes and growth rates have been observed. With the possibility of falling cereal prices, such an end-use for grain crops may be attractive in the future. Accordingly, a mathematical model of the production, harvesting and utilization of whole-crop wheat and grass silage has been developed to examine the economic implications. Using the model, the comparative costs of growing and feeding alkali-treated whole-crop wheat in place of grass silage for winter milk production have been examined.A milk production system based on whole-crop wheat rather than grass silage is estimated to improve profits by up to £130 per cow. However, the improvement in profitability is very sensitive to assumptions about the uses for surplus land or silage arising from such a switch. Furthermore, for physiological reasons it may be prudent to restrict the quantity of whole-crop wheat fed to about 50% of the total forage intake. Thus, whole-crop cereals may best be seen as a complement to rather than a substitute for grass silage. However, in the absence of data on feeding dairy cows with treated wheat silage, research is required before the computer simulations can be corroborated.

Notes: Respiration losses, effect of sugar content, formic acid addition and inoculation were evaluated in relation to initial fermentation and silage quality in three experiments. Changes in the content of fermentable substrate during post–harvest respiration and initial fermentation were studied in the laboratory. Soluble carbohydrates were estimated as glucose, fructose, sucrose, fructans and starch by an enzymatic method.About 70% of the sugars remained after 30 h of conventional wilting, as opposed to less than 50% in a chopped sample kept in the dark. During the first days of fermentation the metabolic activity was very intensive. Sugars, which accounted for 10% of the dry matter, were fermented within 4 d. There were indications, mainly in clover silages, that substances other than water-soluble carbohydrates were used as energy sources.Low-sugar crops were obtained by shading the fields. After 3 d the sugar in the grass had decreased to half of the original content. This effect was less pronounced in clover. The amount of available substrate and dry matter (DM) content had a major influence on silage quality. In an unwilted crop at least 25 g of water-soluble carbohydrate was needed per kg of fresh material to obtain an acceptable silage quality in the controls, while 20 g was sufficient in inoculated silage. Formic acid addition makes the fermentation less sensitive to water–soluble carbohydrate content. Inoculation of willed silage increased lactic acid production and decreased the pH. There was also less variation in silage quality.

Notes: A total of eighty-nine big-bale (BB) silages made on commercial farms in South Wales during the autumn in 1983-87 were analysed to discern the effect of dry matter (DM) content on fermentation. Silages were made predominantly in late September, during fine weather from permanent pasture or perennial ryegrass pastures, which had not been grazed for 9 weeks. On average 7·8 ha of pasture were cut; most farmers attempted to pre-wilt grass for an average of 36 h prior to ensilage in individual plastic bags. Silage making was usually completed within 4 d of starting to cut. Silage ammonia-N content was inversely correlated with DM content. The results indicated that a DM content of about 280 g kg−1 was needed to produce well-preserved silage with an ammonia-N content of 100 g (kg total N)−1. Silages were, therefore, generally poorly preserved because the DM increase from wilting was only 2·3 g kg−1 h−1.

Notes: Red fescue (Festuca rubra L.) cvs Reptans, Dawson and Ruby, perennial ryegrass (Lolium perenne L.) cvs Perma and Sprinter, crested dogstail (Cynosurus cristatus L.) cv. Southlands, smooth meadow-grass (Poa pratensis L.) cvs Parade and Arena, Yorkshire fog (Holcus lanatus L.) commercial types I and II, creeping bent (Agrostis stolonifera L.) cv. Penncross and rough meadow-grass (Poa trivialis L.) cvs Omega Øtofte, Dasas and Sabre were each sown with white clover (Trifolium repens L.) cv. Donna and the productivity of the fourteen mixtures assessed under simulated grazing (six harvests per year) for 3 years. A single fertilizer-N rate (50 kg ha−1) in early spring was applied to all treatments each year.Over the 3 years, mean annual dry matter (DM) production of the swards ranged from 5·25 t ha−1 (creeping bent) to 8·71 t ha−1 (red fescue cv. Reptans), with the species ranking order of: red fescue 〉 perennial ryegrass 〉 crested dogstail 〉 smooth meadow-grass 〉 Yorkshire fog 〉 creeping bent. Rough meadow-grass only persisted over the first harvest year. Mean annual organic matter digestibility (OMD) values of the swards ranged from 0·712 (creeping bent) to 0·782 (ryegrass cv. Sprinter). Mixtures with the lowest proportion of grass (crested dogstail and smooth meadow-grass) generally gave the highest proportions of white clover. The creeping bent mixture had exceptionally low production of both components.Red fescue, crested dogstail and smooth meadow-grass showed compatibility with clover and, therefore, have potential for use in grass/clover swards. Yorkshire fog had lower compatability with clover. Some breeding effort to improve selected characteristics of promising species, e.g. improvement of low OMD in red fescue, seems warranted.

Notes: The influence of N in slurry or in mineral fertilizers on herbage yield and nitrogen fixation by white clover grown in mixed swards was investigated. Two levels of N in cattle slurry were compared with a range of mineral N fertilization. The percentage of N derived from symbiosis (% Nsym) was measured by the 15N-isotope dilution method. The measurements were made in spring 1987 in two 4-year-old field trials, and included two out of five harvests.The % Nsym was approximately 90% without N fertilization. It decreased in response to both mineral N and N in slurry but did not fall below 63%. The sum of two harvests revealed that 51·2 kg N ha−1 were fixed in the absence of N fertilization. With 75 kg mineral N ha−1 or 50 m3 cattle slurry ha−1, the yield of fixed N decreased to 17·2 and 24·9 kg ha−1, respectively. When compared on the basis of the fertilizer effect on dry matter yield and N concentration of perennial ryegrass, the decrease in yield of N fixed due to treatment with cattle slurry was less than that due to mineral N fertilizer. This was owing to the smaller extent of the depression in the proportion of white clover in the sward when the same amount of N was applied in cattle slurry, as compared with mineral fertilizer, although % Nsym responded similarly to both types of N fertilization.

Notes: Land Use and the European Environment Edited by M. Whitby and J. Ollerenshaw

Notes: A small-plot cutting trial was carried out 1983-85 at North Wyke Research Station, Devon to compare the dry matter (DM) production and response to nitrogen (N) of a naturally occurring Agrostis stolonifera-dominant sward, developed under low fertility conditions on a poorly structured soil. and a sward of Lotium perenne cv. Melle, direct-drilled in 1982 at the same site. All plots received standard inputs of P. and graded inputs of K, related to the four annual N treatments (0, 200, 400 and 800 kg ha−1, in seven equal applications). All plots were cut six times each year, except in 1983; DM yield, herbage digestibility, herbage N concentration, response to applied N, apparent recovery of applied N. and botanical composition of the swards were recorded.On average, A. stolonifera gave 69% of the DM yield of L. perenne. A. stolonifera did not out-yield L. perenne at the low N levels (0 or 200 kg N ha−1 a−1), or in mid-season. and yielded significantly (P〈0-001) less in drought conditions in 1984 (4-4 t DM ha−1 and 6-9 t DM ha−1, s.e.d.±0-22). Average digestibility of A. stolonifera was 3 units of D-value lower (P〈0-001) than L. perenne, but N concentrations were higher (3-01% and 2-53%, s.e.d. ±0-074). However, total yields of N from A. stolonifera were lower. Responses in DM production per kg N applied were lower in A. Stolonifera than in L. perenne for all N increments, except the highest, (400-800 kg N ha−1). Fitted response curves allowed interpolation of the values of DM yield (Y10) and N input (N10) where the response was 10 kg DM (kg N)−1. Values of Y10 for A. stolonifera and L. perenne averaged 7-1 t DM ha−1 and 12-9 t DM ha−1respectively. and values of Mo averaged 460 kg N ha−1 and 570 kg N ha−1, which further indicated the lower responsiveness of A. stolonifera to applied N. Apparent recovery of applied N was generally low, with significantly higher values (P〈0-001) for L. perenne in 1983 and 1984, but not in 1985. The botanical composition of L. perenne swards with no applied N showed a steady and rapid decline in ground cover by the sown species. AH L. perenne swards showed an abrupt decrease of L. perenne cover in late 1985, with invasion by A. stolonifera at all but the highest N level (800 kg N ha−1). A. stolonifera treatments receiving 400 or 800 kg N ha−1 showed initial expansion of their native L. perenne populations; however, these declined after the drought in 1984. Only low levels of L. perenne cover remained in the A. stolonifera swards at the end of the trial; these were unaffected by N level. It was concluded that under the conditions of this trial, A. stolonifera had lower DM productivity and efficiency of N use than L. perenne.

Notes: Populations of Aberystwyth S23 and S24 ryegrass tillers were individually labelled and harvested at intervals to follow their life histories and productivity in response to the effect of infection with crown rust at two levels of nitrogen fertilization.The number of tillers in a population was reduced as a result of infection with crown rust. Increased rates of tiller death due to the pathogen occurred throughout the population age-range and were most pronounced in the youngest tillers. Population changes were evident following infection and continued to be apparent in the following spring. The disease caused alterations in sward age structure, leading both to a higher proportion of older tillers in the more rust-damaged treatments and to a decrease in the weight of the herbage produced. It is concluded that rust infection of a sward may lead to changes in population structure with long-term yield effects, in addition to the immediate direct yield reductions commonly reported. The significance of these results to the ecological and agronomic balance of grassland is discussed.

Notes: The productivity of permanent swards of mixed species composition was compared with that of sown Lolium perenne, cv. Melle at five fertilizer-N rates (0, 150, 300, 450 and 900 kg N ha−1) and with L. perenne/Trifolium repens, cv. Grasslands Huia at 0 kg N ha−1. The investigation was conducted under two cutting frequencies at sixteen sites in England and Wales, representing a range of grassland environments.Annual total herbage dry matter (DM) production from both permanent and reseeded swards increased with successive increments of fertilizer-N up to 450 kg N ha−1. Herbage DM production from reseeded swards in the first year after sowing was signficantly higher than from the permanent swards, at all fertilizer-N treatments. In subsequent years the production advantage of the L. perenne reseeds was maintained only at the higher N rates, though sown L. perenne/T. repens was the most productive sward type at 0 N. Average differences in modified acid-detergent fibre suggested small advantages in herbage quality to the reseeded swards.It is concluded that, while reseeded swards are more productive in the year after sowing, many permanent swards are capable of high levels of production and that reseeding to a L. perenne sward cannot always be justified, particularly for grassland receiving low or moderate inputs of fertilizer-N.

Notes: The drying rates of grasses and lucerne, following treatment with 1% formic acid, were compared with those of untreated crops. Material was fully exposed to a flow of air in a ventilated laboratory oven set at 23 °C. Treatment with formic acid initially enhanced the rate of drying of grass, but this was followed by retardation. This reduction in the rate of drying was caused by the rapid desiccation of laminae, which reduced their effectiveness in providing a pathway for water loss from the stem. The rate of water loss directly from the stem surface was not increased by formic acid treatment, probably because the enveloping leaf sheaths acted as a protective layer. In contrast, formic acid increased drying rate in lucerne. whose stems have no such protective layer. The results suggest that chemical desiccants. which have a contact action are unlikely to have any application in making hay from grass.

Notes: In a pot experiment the pH of a hill peaty soil was adjusted to cover the range 3.8 to 6.8 with Ca(OH)2. Yield and N content of the harvested plant material was greatest at pH 6.8 in pots sown with only Lolium perenne, and greatest at soil pH 6.1 in pots sown with Trifolium repens and L. perenne. T. repens established only at soil pH between 4·3 and 6·1. A small reduction in sward yield and a large and highly significant decrease in total N recovered by the harvested material, which occurred with increase in soil pH from 3·8 to 4·3, was attributed to a combination of increased N immobilization in the soil microbial biomass and to the poor performance of both sown and self-propagating indigenous species around pH 4·3.

Notes: SPOT high-resolution visible (HRV) multispectral data were used to estimate the biomass of an improved pasture near Clare in South Australia. The study examined the effects of trees, senescent vegetation, surface wetness, herbage composition and management practices including the age of the pasture and stocking rate, on reflectance. This was undertaken by a comparison of spectral responses and through the use of partial correlation analyses. Changes in biomass had the greatest influence on reflectance, though the presence of trees and senescent vegetation influenced reflectance significantly in all wavebands. These areas were excluded from the model developed to estimate pasture biomass. The regression model was inverted and applied to a normalized difference SPOT HRV image. The accuracy of the biomass estimation was 43–81% at the 95% confidence level, or ±57.0 gm−2 of dry grass. This technique provides resource managers with a tool for routinely assessing pasture condition over large areas.

Notes: The use of brine in plastic pipes inserted into the ground is now an established technique for sampling leatherjackets in grassland. Three sequential sampling plans were compared with a standard twelve-pipe sample for the probability of a recommendation to spray and the number of sample units necessary before a decision over a range of population densities. Data derived from field studies showed a good fit with the expected outcomes. All four plan models were applied to leatherjacket distribution data from Northern Ireland, This shows the number of samples required before a decision was reduced with sequential sampling and that the use of single sequential samples would increase the risk of error. The results are discussed in the context of the physical limitations of the brine sampling procedure and it is concluded that a sequential scheme based upon groups of four pipes would reduce average sampling time by 36% without increasing error.

Notes: Small plots of a Festuca-Agrostis upland sward on a peaty gley podsol were strip-seeded during late June 1986 with white clover cvs Aberystwyth S184 or Menna at 4 kg ha−1 and defoliated early (20 August) or late (3 September) and then frequently or infrequently (every 2 weeks or 4 weeks) until the end of September. All plots were defoliated in early November, at 3-weekly intervals during the growing season in 1987 and then grazed rotationally during 1988.Satisfactory seedling establishment, representing 46% emergence, was achieved 5 weeks after sowing. The differential defoliation regimes had no persistent significant effects on clover development. S184 soon produced more leaves per seedling than Menna and a smaller proportion of its leaf number and weight were removed at each defoliation. Following large losses of leaves over the 1986–87 winter, SI84 had significantly more leaves per stolon than Menna; subsequently it also colonized the sward at a quicker rate. During 1987 amounts of herbage harvested (6.1 t ha−1) were similar with the two clover cultivars, with S184 contributing 47% and Menna 44% of this respectively. SI84 made a larger contribution to yield during May and June but Menna was more productive during September and October. During 1988 clover populations were maintained with rotational grazing without additional fertilizer inputs.The results show that, despite initial soil and climatic contraints, both small and medium-leaved clovers can be strip-seeded into upland swards with large subsequent benefits to yield and herbage quality. However, they also indicate the need for further experiments to determine the influence of sward morphology and defoliation regime on stolon branching rates and accumulation of growing points which, in turn, govern sward colonization.

Notes: Permanently marked tillers of five perennial grasses, native to the mixed-grass prairie of North America, were monitored to determine patterns of defoliation, architectural attributes influencing probabilities of defoliation. and post-defoliation responses. Frequency of tiller defoliation was greatest for one of the dominant midgrasses, intermediate for the remaining midgrass and two dominant shortgrasses. and least for the subdominant midgrass. Midgrass species, including the infrequently grazed subordinate species, were consistently grazed more intensively than the shortgrass species. However, the relative intensity of defoliation did not vary among species or grazing periods indicating that intensity of defoliation was primarily a function of pre-defoliation tiller height. Tiller architecture, including height, lamina number and the presence of reproductive culms, did not significantly influence frequency or intensity of defoliation within a species. The lack of evidence supporting tiller architecture as a selection criterion within a species suggests that animals were selecting on vegetation parameters at higher levels of vegetation organization than individual tillers. Grazed tillers of the three midgrasses exhibited greater relative rates of tiller elongation between grazing periods than non-grazed tillers, particularly early in the season when environmental conditions for growth were most favourable. The patterns of interspecific tiller defoliation observed in this study parallel the long-term patterns of grazing-induced species replacement observed in this grassland.

Notes: Approaches for analyzing employment stability with aggregated data for SICs in large regions or major metropolitan areas are misleading indicators of the impact of manufacturing growth in rural areas. Performance of moderate-sized individual establishments seriously impact total employment variation in small-employment-sized rural communities, requiring analysis of the determinants of employment stability of these establishments. Aggregate SIC performance and most conventional criteria for judging probable stability appear to provide very limited predictability for individual firm performance. However, manufacturing development appears generally to have desirable effects on community-wide employment stability.

Notes: Information-intensive producer services, which constitute one of the fastest growing components of the U.S. economy, have been identified as a potential contributor to economic development in rural areas. This issue is examined in a case study of a community in rural Washington State. The findings indicate that producer services have not been decentralizing to rural Washington, and that opportunities for producer services development in rural communities are limited because of the inaccessibility of markets, smaller pools of skilled labor, and the lack of agglomeration economies. Opportunities for producer services are greatest in large rural communities with high-quality telecommunications systems. Although the quality of telecommunications systems is important to the economic health of communities, advances in telecommunications can be a two-way street for rural America. While telecommunications improvements increase a rural community's access to information and make it possible for rural businesses to more easily serve non-local markets, they can also make it easier for firms located in urban areas to serve rural markets via branch offices or through the telecommunications system.

Notes: Numerous studies have focused on national and regional manufacturing decline in the U.S., but far less attention has been placed on decline in substate areas. This oversight is troublesome because manufacturing decline in substate areas, particularly in the Midwest, has been severe and prolonged. This paper, therefore, examines the causes of manufacturing decline at the substate level. Specifically, I evaluate whether the impact of factors influencing decline varies according to the size and location of medium- and small-sized cities in Illinois. Survey data and loglinear modeling methods are used for the empirical analysis. The results indicate that the impact of technology lags in substate areas varies significantly by the size of cities. The effects of technology, the regional shift of manufacturing, and federal trade policies are influenced by the relative location of cities.

Notes: The Japanese presence in U.S. banking markets is of particular significance. Japanese represent slightly over one-half of the total foreign banking presence in the U.S., concentrated in two states (California and New York). The growth of Japanese direct investment in the U.S. and the yen/dollar exchange rate appear to be the two most important economic factors influencing this rising Japanese banking presence. Japanese legislation liberalizing the flow of investment in and out of Japan, beginning in 1980, is a very important factor. Also, the International Banking Act of 1978 may be important in explaining the recent growth of Japanese bank branches in California.

Notes: Many economists expect that new business survival rates in rural areas ought to be low because of inherent disadvantages of rural economies (e.g. small markets). What little evidence there is in support of this expectation is based on data which is biased toward rural areas. Using unemployment insurance tax records (ES202) for Arkansas, Maine, and North Dakota, the authors calculate and analyze new firm survival rates. Results show that new business survival rates are as high in rural areas as they are in urban areas. Further, survival rates in different industrial sectors are comparable, even when level of urbanization is taken into account. The authors conclude that economists may be overstating the inviability of rural in relation to urban economies.

Notes: National preferences for the development of regional and environmental policy are dependent on the competitive resolution of priorities emanating from four national centers of preference formation, namely: (a) national opinion leaders, (b) society at large, (c) state political institutions, and (d) the private business sector. The viability of national policies for regional development and environmental protection is assumed to be a function of the degree of systemic concordance among these four competing loci of preference formation. The paper explores differences between developed and developing countries in the formation of national preferences and analyzes the process by which competing preferences for regional development and environmental protection are ultimately resolved. It demonstrates that MDCs enjoy a high degree of harmony among their more autonomous centers of preference formation to achieve regional development goals, whereas LDCs are constrained by the dominant and coercive role of the state apparatus.

Notes: Book reviews in this article: Immigration Michael C. LeMay, ed. City Finance Helen F. Ladd and John Yinger. The Impact of Impact Assessment Robert V. Bartlett, ed. Status: Professional vs. Capitalist Tom Bottomore and Robert J. Bryn, eds.

Notes: Standardized features dominate the retail landscape of the United States and are the physical components of retail districts. This study tests the hypothesis that standardized building blocks have failed to produce the same retail structure in all metropolitan statistical areas (MSAs). Ninety-two medium-sized MS As are analyzed to determine if the arrangement and strength of their retail districts differ. The relationship between functional and spatial aspects of retail structure in central place theory provides a basis for testing the hypothesis of diversity. Christaller's separation principle provides a plausible conceptual framework for diverse retail structure if each MSA is analyzed as an isolated region. Five types of retail structure are analyzed using data obtained from the Census of Population and the Census of Retail Trade. The types are identified by performing a serial iterative partition cluster procedure on prioritized metropolitan sales variables. The statistical significance of the types is tested with Mann-Whitney U-tests of functional variables not used in the cluster analysis. Verification confirms five distinctive types. Monocentric and polycentric retail structures exist but decentralized retail structure is even more common in medium-sized MSAs. The distribution of types of retail structure follows regional pattern that indicate historical and political factors as contributing causes.

Notes: The paper introduces the concept of labour equivalence and determines the index of the intensity of labour use in its terms. The measure thus defined is shown to be analogous to the predefined labour multiplier with the necessary incorporation of prices and wages. The explicit inclusion of price-wage parameters gives it the advantage of being a more efficient planning tool.

Notes: Book reviews in this article: Industrial Change International G J.R. Linge and G.A. van der Knaap, eds., Labor, Environment and Industrial Change. Internal Colonies C. Matthew Snipp, ed. Public Policy Impacts on American Indian Economic Development. Do People Choose in Government Service Markets? The Competitive City: The Political Economy of Suburbia. Stimulating Business-The State as EntrepreneurPeter K. Eisinger. The Rise of the Entrepreneurial State: State and Local Economic Development Policy in the United States. Alternative Service Delivery: One View John A. Rehfuss. Contracting Out in Government: A Guide to Working with Outside Contractors to Supply Public Services. Alternative Service Delivery: Another View Lawrence K. Finley ed., Public Sector Privatization: Alternative Approaches to Service Delivery. Changes: United States and Australia Lay James Gibson and Robert J. Stimson eds., Regional Structural Change: Experience and Prospects in Two Mature Economies.

Notes: The purpose of this paper is to explain changes in regional attractiveness as measured by the competitive component of the shift-share model. This is done by applying the shift-share model to the manufacturing sector in the province of Quebec and using time series data for twenty two-digit industries as the basis of analysis. The study concludes that shift-share is useful for analyzing historical employment patterns and identifying their causes through regression analysis. However, the inherent structural instability limits the predictive potential of the model.

Notes: Book reviews in this article: Trends in Urban Change Examined Michael G. H. McGeary and Laurence E. Lynn, Jr. eds., Urban Change and Poverry. Swedes and Norwegians Briant Lindsay Lowell. Scandinavian Exodus: Demography and Social Development of 19th Century Rural Communities. Environmental Management Joseph M. Petulla. Environmental Protection in the United States: Industries, Agencies, Environmentalists.

Notes: This article shows the pivotal role, played by the German system of vocational education and training, in the emergence of a new manufacturing policy. It offers a critique of recent changes in British training policy and practice and suggests further radical revisions in that area, in order to break out of the vicious circle of low training effort–low technology–low competitiveness.

Notes: Absence studies often pay little attention to institutional settings. This study of a large hospital looks at factors affecting absence, and worker attitudes to time off. It reveals a highly committed workforce, but one with low morale, deeply distrustful of a management initiating rapid changes.

Notes: In the context of the NUM's decision to seek a merger, this article examines the financial impact of the 1984–85 strike. In conducting the strike, its federal structure is shown to have provided the union leadership with flexibility. But it has limited the capacity to recover afterwards and has consequences for merger prospects with other unions.

Notes: This article traces the number of legal cases concerning gender, race and other forms of discrimination in the US, Canada and Britain where there is now up to a quarter of a century's experience. Substantial differences in the extent to which the legislation is used across countries and by different groups within each country are revealed.

Notes: A trade union's constitution is intended to produce its leaders in a democratic and even-handed manner, but the reality for women is one of inequality. They remain almost invisible in senior positions in British unions. The social processes by which women do or do not progress in a union's career structure are investigated through a case study of SOGAT ‘82.

Notes: France has had a Socialist President since 1981, and yet support for French trade unions has declined markedly. This article assesses the nature of this decline and examines the role of government, changes in the labour market, employer policies and trade union strategies, in order to explain this apparent paradox.

Notes: The Crisis of Labour: Industrial Relations and the State in Contemporary Britain David Coates Philip Allan Manufacturing Change: Industrial Relations and Restructuring Stephanie Tailby and Colin Whitston The Competitiveness of European Industry Arthur Francis and P. K. M. Tharakan Routledge Managing People at Work Peter Makin, Cary Cooper and Charles Cox Strikes Richard Hyman Macmillan The Seamen—a history of the National Union of Seamen Arthur Marsh and Victoria Ryan Malthouse Crisis in the French Labour Movement: A Grassroot's Perspective W. Rand Smith Macmillan Individual Employment Law Barry Titman and Peter Camp

Notes: In 1988 public sector steelmaking in Britain was extinguished by the sale of all shares in British Steel plc. Given the politicised history of steel, the ease with which the company floated is surprising. This article suggests explanations which lie in the character of the principal industrial actors and the main political parties.

Notes: Book Reviewed in this Article: Pay Determination and Industrial Prosperity Alan A. Carruth and Andrew J. Oswald The State as Employer: Labour Law in the Public Services Sandra Fredman and Gillian S. Morris Employment Disputes and the Third Party Pat Lowry Homework, Conditions of Work Digest, Volume 8, Number 2 Michele B. Jankanish (ed.) New Technologies and Work: Capitalist & Socialist Perspectives A. Francis & P. Grootings (eds.) Managerial Strategy for New Technology Wendy Currie Innovation in Technology and Organisation Peter Clark and Neil Staunton Managing Innovations: A Study of British and Japanese Factories D. H. Whittaker Innovation Marathon: Lessons from High Technology Firms Mariann Jelinek and Claudia Bird Schoonhoven Labour under the Marshall Plan: The politics of productivity and the marketing of management science Anthony Carew American Labor and Postwar Italy, 1943–1953: A study of Cold War politics Ronald L. Filippelli Labor Divided: Austerity and Working-Class Politics in Contemporary Italy. Miriam Golden Industrial Relations Strategies M. W. Nuttall

Notes: This article attempts to examine the changes taking place in the Yugoslav ‘self-management’ and industrial relations system. It looks at the emerging roles of both management and labour in the context of moves to give market factors greater prominence in the economy.

Notes: While there is widespread agreement that tripartite industrial tribunals are the most appropriate way of handling individual rights at work, the case for extending the system to embrace collective labour law is much more controversial and complex. Nevertheless, despite the problems and risks involved, the author favours moves in this direction.

Notes: In recent years increased attention has been focused on the factors that influence member commitment to union. However, little attention has been paid to the role grievance procedures play in this commitment. Here the authors examine the relationship between member attitudes toward the grievance procedure and commitment to an American union.

Notes: Here the author examines the locational strategy of Japanese car manufacturers and their component part suppliers in the US at both the regional and local scale. This is compared briefly with the strategy pursued by Japanese investors in the UK auto industry

Notes: Governments, Managers and Industrial Relations. Public Enterprises and their Political Environment Anthony Ferner Information and Government Studies in the Dynamics of Policy-Making Roger Davidson and Phil White (Eds.) When Public Sector Workers Unionize Richard Freeman and Casey Ichniowski (Eds.) Making Mondragon W. Foote Whyte and K. King Whyte Worker Co-operatives in Theory and Practice M. Mellor, J. Hannah, J. Stirling Developing Successful Worker Co-operatives C. Cornforth, A. Thomas, J. Lewis and R. Spear The Origins of Economic Democracy—Profit Sharing and Employee-Shareholding Schemes Michael Poole People's Capitalism? A Critical Analysis of Profit-Sharing and Employee Share Ownership Lesley Baddon, Laurie Hunter, Jeff Hyman, John Leopold, and Harvie Ramsay The Third Way—The Promise of Industrial Democracy Dennis Lawrence The Search for Labour Market Flexibility R. Boyer (Ed.) The Changing Ideas of a Teachers Union C. T. Kerchner and D. E. Mitchell Safety at Work: the Limits of Self-regulation S. Dawson, P. Willman, M. Bamford and A. Clinton Shopfloor Politics and Job Controls: the post-war engineering industry Michael Terry and P. K. Edwards (Eds.)

Notes: Book reviews in this article: Environmental Watchdogs James A. Tober. Native Americans C. Matthew Who Owns the Subsurface? Ronald T. Libby. Middle East Michael Bar-Zohar. A Green World S. Frederick

Notes: This article examines the question of whether the traditional view of a complementary relationship between universities and local businesses is still appropriate or whether auxiliary activities and other competitive elements have changed this relationship. Cross-sectional data on over 3100 counties and 3300 institutions are used to analyze the effects of university enrollment and auxiliary activities on county-level employment in the retail, financial, and service sectors. Findings indicate that the negative effects of university auxiliary activities are confined to relatively small counties, are small in magnitude, and are more than offset by the positive effects of spending by universities and students. The overall impact is positive, is more pronounced in more populous counties, and has increased over time.

Notes: Employment in tourism has grown substantially in recent years and has been the subject of considerable policy interest. This article reviews some of the key issues in estimating tourism employment and provides clarification of the relationship between various estimates which have been presented in different studies.

Notes: Industrial conflict on the docks was for many years attributed to casual forms of employment. Consequently, the instigation of a more permanent employment relationship in 1967 was expected to bring industrial peace on the waterfront. However, empirical investigation reveals that ‘permanent’ employment has had little, if any, effect on strike activity.

Notes: The Employee Development and Assistance Programme (EDAP) is a unique new initiative launched jointly by the management and unions at Ford. Here the author outlines the scheme which provides a significant ‘model’ for adult and continuing education within commercial enterprises. It is attracting widespread interest and imitators.

Notes: While a number of surveys have identified a trend towards decentralised bargaining, this article is one of the first to examine the process of decentralisation. The decision of Coats Viyella PLC to decentralise bargaining in its apparel division is examined in detail and the outcomes of the first round of decentralised negotiations are analysed.

Notes: This article examines the law relating to claims by women employees that their work is of value equal to that performed by men. It focuses on several recent case-law authorities, considers difficulties with the legislation, and the possible non-compliance of UK law with EEC standards.

Notes: This article describes the development of political and economic reform in Hungary since 1956 and considers the recent emergence of independent trade unionism, particularly the new Democratic Union of Scientific Workers (TDDSZ). The author assesses the prospects for independent trade unionism in general as well as the reform of the official trade union movement (SZOT) in a rapidly changing political climate.

Notes: The extensive range of far-reaching managerial initiatives which are constantly reported might seem to signal a transformation to a totally new order of human resource management. This article examines some entrenched structural features of the British context which can help explain the limits to this pattern of change

Notes: Three variations in regional policy distinguish the conduct of the nationalized British coal industry—social industry, state industry, and state commerce. Each variation takes a distinct approach to natural and human resource development in chronically depressed regions such as the peripheral coal fields in Britain or the Appalachian coal fields in the United States. Central to the variation are recognition of the factor of decline that E. F. Schumacher analyzed in the 1950s and the mitigation of social welfare consequences of shifts in production and investment. Schumacher's analysis raised policy issues of social welfare, resource development, and energy. These emerged again in the British coalminers'strike of 1984–85. Broad issues like these are likely to surface in regions where employment is concentrated in a declining industry facing new and severe competition.

Notes: This paper analyzes the Sengstock typology of annexation laws for predictive power. Cities were found to annex at different rates when categorized according to the Sengstock typology. Cities allowed to annex land areas under municipal determination provisions were found to annex at higher rates than cities that annexed under predominantly under other types of laws. Cities that annexed under judicial determination provisions were found to annex land areas at lower rates than cities that annexed under other types of laws.

Notes: Rankings of economics departments nationwide and in the South are calculated using numbers of pages published in three of the most highly ranked journals for the periods 1978–83, 1983–88, and 1978–88. Changes in the rankings between the 1978–83 and 1983–88 time periods are examined, and the results are compared to those obtained in previous studies. While the Spearman rank correlation coefficient between our nationwide 1978–83 and 1983–88 rankings is .80, there are a number of cases of substantial movements by individual schools either up or down in the rankings.

Notes: This paper utilizes newly available industry-specific historical measures of Gross Regional Product to highlight the changing regional structure of the U.S. economy between 1963 and 1986. During this period, the percentage of U.S. output produced in the eight different regions changed significantly. The largest changes occurred in the Great Lakes (−3.65 percent), Mideast (−3.32 percent), and Southeast (+3.64 percent).Four major industry sectors (Agriculture, Mining, Construction, and Government) declined in relative importance in all eight regions. Five major industry sectors (TCPU, Retail Trade, Wholesale Trade, FIRE, and Services) expanded in relative importance. Somewhat surprisingly, Manufacturing output expanded for the U.S. as a whole and for six of the eight regions. The perception of decline in the relative importance of manufacturing in the U.S. is clearly based on the dramatic declines in the once dominant manufacturing base of the Mideast and Great Lakes regions.

Notes: The purpose of this paper is to construct monthly manufacturing output indexes for a metropolitan area, employing a method used by the Federal Reserve Banks to construct regional manufacturing indexes. The Tulsa metropolitan area is the region considered. The index of total manufacturing output is included in a vector autoregression model of the Tulsa economy. The results indicate that the linkages between manufacturing activity and non-manufacturing employment differ from the linkages between employment in those sectors, and that since the early 1980s both sectors have become less sensitive to changes in the price of oil.

Notes: One solution that has been proposed for the fiscal disparities in fragmented metropolitan areas is the sharing of taxes generated by commercial and industrial property. A criticism of this proposal is that it distorts the efficient pattern of business locations resulting when an implicit market for business locations is allowed to develop through the independent fiscal behavior of communities and the optimizing location behavior of businesses. Critics recognize that the efficiency argument against sharing a metropolitan area's business tax base must be qualified to the extent that local governments possess location advantages which enable them to extract rents from business firms. This paper presents an empirical analysis which permits a partition of the local property tax payments from industrial firms into accessibility location rents and compensation payments to the community for the negative externalities of industrial development. The empirical analysis suggests that approximately 40 percent of the industrial taxes received by communities in this analysis represents accessibility location rents. It is concluded that these receipts could be redistributed through a metropolitan area tax base sharing program without affecting the efficiency of the implicit market for business locations.

Notes: What follows is a comment on Noel D. Uri's “The Structure of Agricultural Unemployment in the United States,” published in Growth and Change in Summer 1989. Uri's reply appears after the comment.

Notes: The ability of small rural governments to provide local public goods in a Pareto-efficient manner is examined. A test developed by Brueckner (1982) is used to examine the efficiency of a sample of town governments in rural Maine. The empirical results suggest that local property values are maximized, which implies that local public goods are provided in a Pareto-efficient manner.

Notes: Year in and year out, flooding causes greater dollar losses than any other natural hazard. To cope with that problem, more than 17,000 communities across the US have adopted riverine floodplain management programs to reduce the amount of urban development at risk from flooding and flood-related damage. This article examines the extent to which floodplain management programs influence the investment and predevelopment decisions of owners of vacant floodplain land in ten selected cities. Such public programs are found to alleviate investment and development pressure in flood hazard areas. Community-wide factors such as the availability of non-floodplain buildable land, however, can magnify or depress this effect of public policy on investment activity. Further, landowner perceptions of the flood hazard itself have an important influence on anticipated property appreciation and investment activity.

Notes: In this paper we estimate alternative models of the growth rate of real housing investment for Japan, Korea, Taiwan, and the U.S. Pure time series models generally provide superior fit to these growth rate data both within and out of the sample period. These time series models are then used to forecast investment growth rates in other countries. The results indicate that such time series models can be used to provide reasonable accurate forecasts for other countries.