Tillage and Manure Effects on Soil and Aggregate-Associated Carbon and Nitrogen
Tillage and Manure Effects on Soil and Aggregate-Associated Carbon and Nitrogen
复制标题
DOI：
10.2136/sssaj2004.8090
复制
发表时间：
2004-05
影响因子：
2.9
通讯作者：
M. Mikha;C. Rice
中科院分区：
文献类型：
--
作者：
M. Mikha;C. Rice
在农业系统中，维持土壤有机质（SOM）一直被认为是减少土壤退化的一种策略。免耕和改肥是可以增加土壤有机质含量和改善土壤团聚性的管理措施。研究了不同耕作制度和氮素来源对10年土壤团聚体大小分布和团聚体相关碳氮的影响。主小区处理为免耕（免耕），常规耕作（免耕），次小区处理为氮源处理（有机肥、有机肥、氮肥、有机肥）。本试验于1990年在肯纳贝克中等排水良好的粉砂壤土（细粉质、混合、超活性的中粒混和单粒混和土）上进行，土壤中有连续玉米（Zea mays L.）。1999年，从田间处理中收集土壤样品（0 ~ 5 cm深度），通过湿筛法将其分为4个团聚体大小等级（>2000、250 ~ 2000、53 ~ 250和20 ~ 53 μm）。利用完整和破碎的团聚体的28 d实验室孵育，测量了所有团聚体大小的组分的活性C和N含量。免耕和施M处理显著提高了全碳和全氮含量，促进了大团聚体的形成。与NT相比，传统耕作显著减少了大团聚体，团聚体向微团聚体的重新分布显著。大团聚体（>2000和250 ~ 2000 μm）的保护活性碳和氮显著高于小团聚体（53 ~ 250和20 ~ 53 μm）。M大于F，表明在大团聚体中对活性碳有物理保护作用。免耕和单独施肥均显著提高了土壤团聚体和团聚体相关的碳氮；而氮肥和氮肥的共同作用进一步改善了土壤团聚体和团聚体保护型碳氮。
In agricultural systems, maintenance of soil organic matter (SOM) has long been recognized as a strategy to reduce soil degradation. No-tillage and manure amendments are management practices that can increase SOM content and improve soil aggregation. We investigated the effects of 10-yr of different tillage systems and N sources on soil aggregate-size distribution and aggregate-associated C and N. The study was a split-plot design replicated four times. The main plot treatment was tillage (no-tillage, NT; conventional tillage, CT) and the subplot treatment was N source (manure, M; NH 4 NO 3 fertilizer, F). The experiment was established in 1990 on a moderately welldrained Kennebec silt loam (Fine-silty, mixed, superactive mesic Cumulic Hapludll) with continuous corn (Zea mays L.). In 1999, soil samples were collected (0- to 5-cm depth) from the field treatments and separated into four aggregate-size classes (>2000, 250-2000, 53-250, and 20-53 μm) by wet sieving. Labile C and N content of all aggregate-size fractions were measured using 28-d laboratory incubations of intact and crushed aggregates. No-tillage and M treatments significantly increased total C and N and the formation of macroaggregates. Conventional tillage in comparison with NT significantly reduced macroaggregates with a significant redistribution of aggregates into microaggregates. Aggregate protected labile C and N were significantly greater for macroaggregates, (>2000 and 250-2000 μm) than microaggregates (53-250 and 20-53 μm). and greater for M than F indicating physical protection of labile C within macroaggregates. Notillage and M a lone each significantly increased soil aggregation and aggregate-associated C and N; however, NT and M together further improved soil aggregation and aggregate-protected C and N.