连续免耕对中稻产量及土壤理化性质的影响

Effect of continuous tillage-free practice on the grain yield of semilate rice and soil physicochemical property

采用免耕剂进行两种不同免耕栽培方式 3a定点试验。结果表明 ,免耕直播、直插水稻产量 ,除了第 3a直插比对照 (翻耕 )减产 6.7%外 ,其余都比对照增产 ,增幅为 8.0 %～ 2 0 .9% ;免耕田的经济效益比对照田有大幅度的提高 ,其增幅为 37.7%～ 12 6.2 % ;经过 3a免耕栽培后 ,免耕田土壤表层总孔隙度比对照田增加 4 .7～ 6.2个百分点 ,0 .0 1mm、 0 .0 5mm、 0 .2 5mm粒径的团聚体比对照增加 3.1%～ 12 .3% ,土壤有机质及全量氮、磷、钾有所积累 ,而对照田则有所矿化 ;土壤酸碱度和速效养分没有明显变化。免耕直播方式栽培中稻可连续 3a以上免耕 ;建议免耕直插栽培要 3～ 4 a进行

Two tillage\|free methods using two kinds of tillage\|free reagents were tested in a fixed site for three years.The results showed that,the grain yields using direct sowing or direct transplating were increased by 8 0%-20 9% to compare with CK treatment(tillage),except the treatment of direct transplanting at the third year which was decreased by 6 7%.The economical benefit of tillage\|free treatments was also improved by 37 7%-126 2%.After a 3\|year tillage\|free cultivation,the total porosity of treated plots in soil upper layer was increased by 4 7%-6 2%, the aggregates with 0 01 mm,0 05 mm,0 25 mm diameters were increased by 3 1%-12 3%.The contents of O.M,total N,P and K in soil were also improved. However,the soil pH and available N,P,K have no significant variation.It was suggested that,the tillage\|free method with direct sowing can be applied to grow semilate rice for continously 3 years;and the tillage\|free method with direct transplanting needs to be cultured in rotation after 3-4 year.