长期免耕与施用有机肥对土壤微生物生物量碳、氮、磷的影响

EFFECTS OF ZERO-TILLAGE AND APPLICATION OF MANURE ON SOIL MICROBIAL BIOMASS C,N,AND P AFTER SIXTEEN YEARS OF CROPPING

通过设置在江苏省句容农科所的田间定位试验研究长期免耕及施用有机肥料对土壤微生物生物量碳、氮、磷的影响。结果表明 :经过 1 6年 32茬稻—麦水旱轮作后 ,表土层 ( 0～ 5cm)土壤微生物生物量碳、氮、磷含量比亚表层 ( 5～ 1 0cm)分别高 2 7.5 %、43.6%和1 1 %。与常规耕翻相比长期免耕处理表土层土壤微生物生物量碳、氮含量分别增加了2 5 .4%和 45 .4% ,而微生物生物量磷无明显变化规律 ;亚表层的土壤微生物生物量碳、氮、磷免耕与耕翻两种耕作方式间的差异不显著。尽管各施肥处理施用的氮、磷、钾数量完全相等 ,但土壤微生物生物量碳、氮、磷的含量却因肥料种类的不同而异。综合 0～ 5和 5～ 1 0cm土层 ,微生物生物量碳、磷为 :猪粪 +化肥 >秸秆 +化肥 >绿肥 +化肥 >化肥 >不施肥 ,微生物生物量氮则为 :猪粪 +化肥 >绿肥 +化肥 >秸秆 +化肥 >化肥 >不施肥。相关分析结果显示 ,土壤微生物生物量碳、氮与土壤有机碳、土壤全氮和土壤碱解氮之间均呈极显著的正相关 ,表明其与土壤肥力关系密切 。

The effects of tillage and manure application on soil microbial biomass carbon (MBC),microbial biomass nitrogen (MBN),and microbial biomass phosphorus (MBP) were investigated in a field experiment,which consisted of two main treatments of conventional tillage and zero tillage and five sub treatments of control(no fertilizers),chemical fertilizers,chemical fertilizers plus straw,chemical fertilizers plus green manure,and chemical fertilizers plus pig manure and had continued for 16 years at the farm of Jurong Agricultural Science Institute. The crop rotation of the experiment was summer rice (?Oryza Sativa ?L.)and winter wheat (?Triticum aestivum?). The results showed that MBC and MBN in zero tillage treatment increased by 25.4% and 45.4%?1/4HT?1/2,respectively compared to those in conventional tillage treatment in 0?5cm depth layer after 16 years. However,there were no significant differences of MBC,MBN,and MBP in subsoil (5?10cm) between conventional tillage and zero tillage. Although the application rate of N,P,and K in each sub treatment were equal,the contents of MBC,MBN,and MBP in 0?5cm and 5?10cm depth layer followed the order in the treatments:fertilizers plus pig manure>fertilizers plus straw>fertilizers plus green manure>chemical fertilizers>control.\;