Nitrogen mineralization and availability of mixed leguminous and non-leguminous cover crop residues in soil
Nitrogen mineralization and availability of mixed leguminous and non-leguminous cover crop residues in soil
复制标题
土壤中豆科和非豆科混合覆盖作物残留物的氮矿化和有效性
DOI：
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复制
发表时间：
1998
影响因子：
6.5
通讯作者：
U. Sainju
中科院分区：
文献类型：
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作者：
S. Kuo;U. Sainju
摘要非豆科覆盖作物如黑麦或多花黑麦草能减少雨季氮素淋失，而豆科覆盖作物如毛叶野豌豆则能提高土壤氮素肥力。以豆科牧草混播为覆盖作物，可以达到减少氮素淋失，同时增加土壤氮素有效性的目的。本研究探讨了净氮矿化的土壤处理与毛豌豆残留物混合的谷物黑麦或一年生黑麦草和这些混合物对生长和N吸收谷物黑麦的影响。黑麦和一年生黑麦草的全氮含量较低，但水溶性碳和碳水化合物含量较高。减少毛箭舌豌豆的比例减少净氮矿化，黑麦植物生长和氮吸收的混合残留物，但增加了交叉时间（时间时，净氮矿化的残留物修正的土壤等于非修正的控制）所需的净氮矿化发生。当紫云英含量降低到40%或更低时，培养第一周的净N固定量显著增加。氮素残留量与黑麦生物量（r=0.81，P<0.01）和氮素吸收量（r=0.83，P<0.001）呈显著正相关，但与黑麦生物量（r=0.93，P<0.001）和氮素吸收量（r=0.99，P<0.001）的潜在初始氮矿化速率的相关性更高。从混合秸秆对黑麦氮素浓度和氮素吸收的影响来看，要提高氮素利用率，混合秸秆中黑麦或一年生黑麦草的比例不宜超过60%。需要进一步的研究，以检查不同的混合物的毛箭舌豌豆和黑麦或一年生黑麦草对土壤中的N淋溶的影响。
Abstract Whereas non-leguminous cover crops such as cereal rye (Secale cereale) or annual ryegrass (Lolium multiflorium) are capable of reducing nitrogen (N) leaching during wet seasons, leguminous cover crops such as hairy vetch (Vicia villosa) improve soil N fertility for succeeding crops. With mixtures of grasses and legumes as cover crop, the goal of reducing N leaching while increasing soil N availability for crop production could be attainable. This study examined net N mineralization of soil treated with hairy vetch residues mixed with either cereal rye or annual ryegrass and the effect of these mixtures on growth and N uptake by cereal rye. Both cereal rye and annual ryegrass contained low total N, but high water-soluble carbon and carbohydrate, compared with hairy vetch. Decreasing the proportion of hairy vetch in the mixed residues decreased net N mineralization, rye plant growth and N uptake, but increased the crossover time (the time when the amount of net N mineralized in the residue-amended soil equalled that of the non-amended control) required for net N mineralization to occur. When the hairy vetch content was decreased to 40% or lower, net N immobilization in the first week of incubation increased markedly. Residue N was significantly correlated with rye biomass (r=0.81, P<0.01) and N uptake (r=0.83, P<0.001), although the correlation was much higher between residue N and the potential initial N mineralization rate for rye biomass (r=0.93, P<0.001) and N uptake (r=0.99, P<0.001). Judging from the effects of the mixed residues on rye N Concentration and N uptake, the proportion of rye or annual ryegrass when mixed with residues of hairy vetch should not exceed 60% if the residues are to increase N availability. Further study is needed to examine the influence of various mixtures of hairy vetch and rye or annual ryegrass on N leaching in soil.