ALBERT

Description: A 7-yr study was conducted to determine the effects of repeated annual applications of manure containing softwood shavings (M + S) at 50 t ha−1 on the soil and its productivity, relative to manure without shavings (M) at 50 t ha−1 and nitrogen fertilizer (F) at 67 kg ha−1. The EC, OM, total N and C:N ratio of the soil of the M + S and M + S + F plots to 60-cm depth were not significantly greater than those from the M plots, and in some instances they were significantly less. The NO3-N and total N and available P contents of the soil from the M + S treatment were significantly lower than those from the M treatment. Immobilization of N in the M + S and M + S + F treatments was indicated. Barley (Hordeum vulgare L. 'Gait') straw and grain yields and protein content of the grain were generally greater under the M than under the M + S treatment. When N fertilizer was included in the M + S treatment (M + S + F) the yields were similar to those of M, and the protein content increased. If manure with shavings is used for fertilizer, supplemental N should be applied to offset N immobilization. Key words: Manure disposal, manure, manure with wood shavings, nitrogen, crop yields

Description: In an 8-yr experiment on an irrigated Dark Brown Chernozemic soil, four rates of N (0, 34, 67 and 101 kg ha−1), applied annually with 45 t ha−1 of manure containing softwood shavings (avg. of 46% dry wt) produced a linear yield response (from 3.5 with the check to 4.3 t ha−1 at the highest rate) of barley grain (Hordeum vulgare L. 'Galt'). There were large differences in yields among years, which could be attributed to weather factors, but there was no significant N × year response. Protein content increased linearly (from 11.2 to 13.5%), and both kernel weights and "test weights" (kg hL−1) decreased slightly but significantly with N applications. There was a pronounced "residual" effect of N rates on both grain yield (from 3.8 to 6.3 t ha−1) and protein content (from 10 to 13%) in the first year after applications of manure and N fertilizer ceased. These effects decreased rapidly and had practically disappeared by the end of the 3rd yr, although yields of all treatments remained high (about 5 t ha−1). Organic matter and N contents of the soil were increased by 70 and 41%, respectively, from the cumulative applications of shavings manure. It is concluded that application of manure containing large quantities of softwood shavings has a negligible effect on the N fertilizer requirements of the crop being grown. Beneficial residual effects of N fertilizer applied with the manure may result because of buildup of NO3-N throughout the soil profile, and likely also because of N release from readily mineralized organic compounds or microbial biomass. However, this effect was not reflected in soil tests for readily mineralizable N by NO3 incubation or KCl digestion methods and the effects were practically dissipated after 3 yr. The recovery of applied N fertilizer by the crops was high at all rates (61–79%), and essentially all of the N applied (fertilizer + manure) was accounted for by crop removal + increased soil N. Key words: Mineralizable-N soil tests, Chernozemic soil, repeated fertilizer applications, residual effects

Description: The rates of change of several soil chemical properties in response to repeated annual applications of cattle feedlot manure, in a long-term experiment, were determined from 1974 to 1984. Manure was applied at 0, 30, 60 and 90 Mg ha−1 and 0, 60, 120 and 180 Mg ha−1 (wet weight) to nonirrigated and irrigated Dark Brown Chernozemic soils, respectively, using three tillage methods of incorporation. Soil acidity (pH), estimate of soluble salts (EC), sodium adsorption ratio (SAR), and accumulation of Na, Ca + Mg, SO4 and Cl in the soil were determined annually. Regression analyses were used to determine the rates of accumulation of these parameters with time. The rates of change with time were mostly linear and varied with the level of manure applied and irrigation regime. The soil became more acidic with time. Soluble Na and Cl increased at rates similar to or less than those applied, and soluble Ca + Mg increased at rates greater than those applied. Changes in the soluble SO4 were poorly correlated with time. Regression analyses from 1974 to 1977 and 1978 to 1984, under irrigated conditions, indicated that the rates of change were generally less in the latter period. Thus, the losses of applied constituents were higher in the second period than in the first period under irrigation. However, various soluble constituents from the annually applied manure accumulated in the soil even at the recommended rate. These findings indicate that sustained agricultural production of this land with annual application of manure is in question, and the potential for problems due to leaching of various soluble salts and nutrients to groundwater is increased. Key words: EC, soluble salts, leaching, salinization, pH

Description: Two soils from a large depressional area, one with (AL) and one without (NL) a volcanic-ash layer, were investigated to determine the effect of the ash layer on soil properties. The soil parent materials, including the ash layer, were deposited in a lacustrine environment. Both soils had well-developed A and B horizons with secondary salinity. The AL soil contained less Na in the B horizon than the NL soil, resulting in a soil classification of salinized Gleyed Solonetzic Dark Brown Chernozem at the AL site and salinized Gleyed Dark Brown Solonetz at the NL location. Saturated hydraulic conductivity and moisture retention values indicated that the volcanic-ash layer enhanced the depth of effective drainage. This was supported by greater rooting depth, weaker B horizon structure, lower salinity, and dominance of different ions in the upper solum of the AL than in the NL soil. The distribution of soluble ions in the profiles indicated that the ash layer had negligible impact on the height of capillary rise. Lower soluble ion contents in the lower profile of the AL than the NL soil were attributed to the presence of an indurated or cemented layer between the water table and the ash layer in the AL soil. Key words: Soil properties, volcanic-ash, water movement, soluble salt movement, indurated horizon

Description: A method for calculating the fractions of water leached through the profile (leaching factor) in irrigated soils high in gypsum was developed. The method requires data on long-term changes in the salinity status of the soil profile, and is based on the principle that water moving through gypsum-rich soils becomes saturated with gypsum. The average total soluble salt content of two soils to a depth of 180 cm has decreased logarithmically since 1917. The average Ca content has decreased linearly at rates of 0.091 and 0.097 meq∙100 g−1∙yr−1 in a clay and clay loam soil, respectively. A leaching fraction 0.16, as obtained by our method, is similar to that calculated from a water balance procedure. However, the latter method required accurate information on the annual rate of irrigation and precipitation and consumptive water use by the crops grown. The results indicate that irrigation management at the two sites has provided sufficient leaching water to reduce the total soluble salts and to actually improve the suitability of the sites for crop production.

Description: Saturated hydraulic conductivity (Ks) and drainable porosity (f) determined by different methods and for different depths were compared with those determined from the performance of drainage systems installed at two locations. These comparisons were made to determine which methods are suitable for use in subsurface drainage design. Auger hole and constant-head well permeameter Ks were 140 and 110%, respectively, of Ks determined from subsurface drains. Agreement of horizontal or vertical Ks, from in situ falling-head permeameters; to other methods was satisfactory providing sample numbers were large. Ks by Tempe cells was only 3–10% of drain Ks and in one instance was significantly lower than Ks determined by all other methods. At one site a profile-averaged value of f determined from the soil moisture characteristic curve (0–5 kPa) of semidisturbed cores agreed with that determined from drainage trials. At the other site, a satisfactory value of f was found only when the zone in which the water table fluctuated was considered. Results indicate that Ks determined by the auger hole and constant-head well permeameter methods, and f determined from the soil moisture characteristic curve of semidisturbed cores, are sufficiently reliable and practical for subsurface drainage design. Key words: Subsurface drainage, hydraulic conductivity, drainable porosity

Description: Nineteen years of soil moisture content data at Lethbridge and two locations near Turin (Turin 1 and Turin 2) in southern Alberta were examined to evaluate the efficiency of follow for conserving moisture, and to calculate the long-term mean amount of water recharge during growing and nongrowing seasons under a fallow-cereal, 2-yr rotation and a continuous cropping system. Soil samples were taken annually from 1969 to 1987 to a depth of 120 cm in 30-cm intervals in the spring (early May) and fall (late September). A method for testing differences of means between nonstandard data using localized uncertainty associated with sliding polynomial smoothing was used to test for differences in the soil moisture contents due to cultural practices. The available soil moisture content of the soil to 120-cm depth was at least 50% of available water-holding capacity (AWHC) of the profile for the fallow treatment at Lethbridge and Turin 2, and, except in some years, at Turin 1. At seeding time, there was an average of 69 mm more available water (AW) in the fallow field than in the continuous cropping field at Lethbridge and 30, 35 and 27 mm more AW in the fallow field than in the fresh stubble field of a fallow-cereal, 2-yr rotation for Lethbridge, Turin 1 and Turin 2, respectively. The overall mean precipitation conserved as soil moisture for the fallow-cereal rotation practice was 23, 29 and 23% for Lethbridge, Turin 1 and Turin 2, respectively. The significantly higher soil water content at the 90- to 120-cm depth for the fallow field than for other fields during various periods of time indicates that the soil water recharge from precipitation might be deeper in the fallow field than in continuous cropping and fresh stubble of fallow-cereal rotation fields. The deeper soil water recharge could increase the available soil moisture for crop production and it could also contribute to ground water recharge. Key words: Soil water, available water content, continuous cropping, summerfallow