摘要
A tillage method of combining ridge with no-tillage(RNT)was employed in lowland rice-based cropping system to study the long-term effects of RNT on soil profile pattern,soil water stable aggregate distribution,nutrients stratification and yields of rice and post-rice crops.After flooded paddy field(FPF)was practiced with RNT for a long time,soil profile changed from G to A-P-G,and horizon G was shifted to a deeper position in the profile.Also the proportion of macroaggregate(>2 mm)increased,whereas the proportion of silt and clay(<0.053 mm)decreased under RNT,indicating a better soil structure that will prevent erosion.RNT helped to control leaching and significantly improved total N,P,K and organic matter in soil.The highest crop yields were found under RNT system every year,and total crop yields were higher under conventional paddy-upland rotation tillage(CR)than under FPF,except in 2003 and 2006 when serious drought occurred.RNT was proven to be a better tillage method for lowland rice-based cropping system.
基金
Project supported by the National Natural Science Foundation of China(No.40501033)
the National Key Technologies R&D Program for the 11th Five-Year Plan of China(No.2007BAD87B10)
