Surface Soil Salinity and Soluble Salts after 15 Applications of Composted or Stockpiled Manure with Straw or Wood-Chips

The influence of 15 annual applications of composted (CM) or stockpiled (SM) beef feedlot manure with straw (ST) or wood-chip (WD) bedding on electrical conductivity (EC), soluble cations and anions (Na, K, Ca, Mg, SO₄-S, Cl), sodium adsorption ratio (SAR), potassium adsorption ratio (PAR), and pH of a clay loam soil (0–15 cm) in southern Alberta was examined in an irrigated barley silage cropping system. Manure type (CM versus SM) had a significant effect on certain soil salinity parameters. Calcium, Mg, Na, K, and SO₄-S were significantly (p ≤ 0.05) greater for SM- than CM-amended soils for certain bedding materials and rates. Electrical conductivity, concentration of soluble cations and anions (Na, K, SO₄-S, Cl), SAR, PAR, and pH in the surface soil were greater for ST than WD bedding. Two exceptions were Ca and Mg, where soil concentrations were generally greater for WD than ST. Salinity parameters were greater with increased application rate, and greater for amended than unamended soils. Overall, bedding had considerably more significant effects on soil salinity parameters compared to manure type. Wood-chip bedding may be a management tool for feedlots to lower EC, soluble cations and anions, and pH of surface soils.     

缓释肥等氮替代尿素对坡耕地径流氮素流失和青贮玉米生长的影响

为比较单施尿素与尿素和缓释肥配施对云南坡耕地径流氮流失、土壤养分及青贮饲用玉米生长的影响作用。通过自然降雨下的径流槽试验,在等氮条件下按云南常规施肥量设置单施尿素(CK)、添加硝化抑制剂速溶诺泰克^®21等氮替代40%的尿素+60%普通尿素(处理I)和聚谷氨酸增效3代等氮替代40%的尿素+60%普通尿素(处理Ⅱ)3个处理。结果表明:生育期内尿素配施缓释肥的处理I和处理Ⅱ与单施尿素CK处理相比,总氮、铵态氮和硝态氮流失浓度削减量最高分别为2.59,1.60,1.42 mg/L和1.61,1.38,1.25 mg/L;累计流失量与CK相比,处理I、处理Ⅱ的总氮、铵态氮和硝态氮累计流失量分别削减18.56%,16.19%,24.31%和10.75%,8.73%,17.08%。在青贮玉米生育期内,配施缓释肥处理土壤较CK处理铵态氮含量分别显著提高13.94%~45.04%和9.63%~22.39%,硝态氮含量分别显著降低3.70%~29.91%,8.61%~12.55%,土壤微生物生物量氮含量分别显著提高22.13%~31.76%,11.80%~22.81%。尿素配施缓释肥也可以显著提高青贮玉米产量和植株氮吸收量,并通过显著提高植株粗蛋白和粗脂肪含量,降低粗灰分和洗涤纤维含量来提高其品质性状。相关性分析可知,径流氮流失与土壤氮含量、青贮玉米产量和植株吸氮量呈负相关关系,土壤氮素与产量和植株氮吸收均呈正相关关系,产量与植株氮吸收呈极显著正相关关系。综上所述,与单施尿素相比,尿素配施缓释氮肥能够减缓土壤氮素的硝化过程,显著增强土壤的固氮能力,维持土壤高氮素水平,进而提高青贮饲用玉米的产量和品质,为红壤坡耕地青贮玉米种植的施肥提供科学理论依据。     

Silage Dry‐Matter Yield and Nitrogen Response following Land Application of Spent Timber Residue from Out‐Wintering Pads to Irish Grassland

Abstract

Out‐wintering pads are a cattle housing system, consisting of a layer of timber residue over an artificially drained surface. Residues from out‐wintering pads that require management include liquid effluent and spent timber residue (timber soiled with manure). In Ireland, the current management strategy for these materials is to apply them to grassland for the production of silage. The main objective of this study was to determine the dry‐matter yield and nitrogen (N) response of first and residual cut silage to spent timber residue at three rates (10, 30 and 50 t ha^?1). No silage yield or N response was observed from application of spent timber residue. A secondary objective was to determine the impact of dry timber residue (i.e., not soiled with manure) on silage yield and N response for first, second, and third cut silage. A significant negative response was observed for first cut silage yield in response to dry timber residue. However, no effect was observed for the second and third cut silage yield.     

麦秸还田及水稻氮肥配施技术研究

通过麦秸直接还田和水稻氮肥配施技术的研究表明 :经过三熟作物秸秆连续还田 ,土壤有机质、全氮、速效钾显著地增加 ;秸秆全量还田 ,水稻产量随秸秆还田量增加而提高 ,秸秆还田量 5 4 0 0 kg/ hm2 的产量比不还田的增产 6 .6 % ;全生育期氮肥配比以前∶中∶后期为 6 .5∶0 .5∶ 3为最佳。     

Soil, Water and Yield Relationships in developing Strategies for the Precision Application of Nitrogen Fertiliser to Winter Barley

To investigate on-farm strategies for the site-specific application of nitrogen fertiliser, two hypotheses were tested: that maximum economic output is either obtained by applying more nitrogen to the historically highest yielding soil and less to the lowest yielding soil, or by the reverse strategy.Field experiments were conducted in 1997, 1998 and 1999 on a commercially managed field of winter barley (Hordeum vulgare), comprising a clay loam and a sandy loam, in Cambridgeshire, UK. The experiments were carried out in a strip-based design using on-farm equipment. In all 3 yr, at typical application rates of 100–200 kg[N] ha⁻¹, there were significant differences between the yield of the clay loam and the sandy loam soil. When rainfall in the February to July period of the growing season was higher than average, the sandy loam soil yielded significantly higher than the clay loam soil and the reverse occurred when the rainfall was lower.Despite the above factors, analysis showed that the maximum of the yield response curve for each soil, occurred at the same application rate in each growing season. Given this relationship, there was no economic benefit from variable rate application of nitrogen to different soil units based upon historic yield, or any other form of information.