Microbial Biomass Dynamics in a Tropical Agroecosystem： Influence of Herbicide and Soil Amendments  

作　　者：Alka SINGH Mahesh Kumar SINGH Nandita GHOSHAL 

机构地区：[1]Centre of Advanced Study in Botany, Department of Botany, Banaras Hindu University, Varanasi 221005 India

出　　处：《Pedosphere》2016年第2期257-264,共8页土壤圈（英文版）

基　　金：financially supported by University Grants Commission,New Delhi,India in form of a major research project(No.SR36-32 2008) and University Research Fellowships to Ms.Alka Singh and Mr.Mahesh Kumar Singh

摘　　要：The influences of herbicide alone and in combination with the soil amendments with contrasting resource qualities on dynamics of soil microbial biomass C （MBC）, N （MBN）, and P （MBP） were studied through two annual cycles in rice-wheat-summer fallow crop sequence in a tropical dryland agroecosystem. The experiment included application of herbicide （butachlor） alone or in combination with various soil amendments having equivalent amount of N in the forms of chemical fertilizer, wheat straw, Sesbania aculeata, and farm yard manure （FYM）. Soil microbial biomass showed distinct temporal variations in both crop cycles, decreased from vegetative to grain-forming stage, and then increased to maximum at crop maturity stage. Soil MBC was the highest in herbicide ＋ Sesbania aculeata treatment followed by herbicide ＋ FYM, herbicide ＋ wheat straw, herbicide ＋ chemical fertilizer, and herbicide alone treatments in decreasing order during the rice-growing period. During wheat-growing period and summer fallow, soil MBC attained maximum for herbicide ＋ wheat straw treatment whereas herbicide ＋ FYM, herbicide ＋ Sesbania, and herbicide ＋ chemical fertilizer treatments showed similar levels. The overall trend of soil MBN was similar to those of soil MBC and MBP except that soil MBN was higher in herbicide ＋ chemical fertilizer treatment over the herbicide ＋ wheat straw treatment during rice-growing period. In spite of the addition of equivalent amount of N through exogenous soil amendments in combination with the herbicide, soil microbial biomass responded differentially to the treatments. The resource quality of the amendments had more pronounced impact on the dynamics of soil microbial biomass, which may have implications for long-term sustainability of rainfed agroecosystems in dry tropics.除草剂的影响独自并且在有有在土壤的动力学上对比资源质量的土壤修正案的联合，微生物引起的生物资源 C (MBC ) ， N (MBN ) ，和 P (MBP ) 在热带 dryland agroecosystem 在 rice-wheat-summer 休闲庄稼顺序通过二个年度周期被学习。实验与有 N in the forms of 化肥，小麦稻草， Sesbania aculeata，和农场院子粪肥(FYM ) 的相等的数量的各种各样的土壤修正案独自或在联合包括了除草剂(butachlor ) 的申请。微生物引起的生物资源显示出的土壤在两个庄稼周期的不同时间的变化，减少了从对形成谷物的舞台植物，然后在庄稼成熟舞台增加了到最大值。土壤 MBC 在处理由在减少的独自一个的处理在成长大米的时期期间订的除草剂 + FYM，除草剂 + 小麦稻草，除草剂 + 化肥，和除草剂跟随了的除草剂 + Sesbania aculeata 是最高的。在成长小麦的时期和夏天休闲期间，而除草剂 + FYM，除草剂 + Sesbania，和除草剂 + 化肥治疗显示出类似的层次，土壤 MBC 为除草剂 + 小麦稻草治疗达到了最大值。除了土壤 MBN 在成长大米的时期期间在在除草剂 + 小麦稻草处理上的除草剂 + 化肥处理是更高的之外，土壤 MBN 的全面趋势类似于土壤 MBC 和 MBP 的那些。尽管有通过在有除草剂的联合的外长的土壤修正案的 N 的相等的数量的增加，玷污微生物引起的生物资源回答差别到处理。修正案的资源质量更多在动力学上读了影响玷污微生物引起的生物资源，它可以在干燥热带为 rainfed agroecosystems 的长期的可持续性有含意。

关 键 词：chemical fertilizer farmyard manure organic amendment Sesbania aculeata wheat straw 

分 类 号：S156.2[农业科学—土壤学] X144[农业科学—农业基础科学]