Effects Of Long-Term Different Tillage Methods On Properties Of Paddy Soil And Formation Of Double-cropping Rice Yield

In order to exploring the effect on paddy soil properties and the formation of the yield of the double-cropping rice under four different tillage methods(l.No Tillage(NT).2.Little Tillage(early rice no tillage.late rice tractor-ploughing,LT),3.Tractor-Ploughing(early and late rice tractor-ploughing.TP),4.Cattle-Ploughing(early and late rice cattle-ploughing,CP),we took an experiment on the north east experiment base of the Jiangxi Agriculture Academy of Sciences in the year2011, this experiment had been lasted for5years since the year2006. The main results were showed as follows:1. Continuous using different tillage methods had influence on paddy soil properties. Compared with the year2006, the soil bulk density of NT and LT of the early and late rice of the year2011incresed, while the TP and CP decreased, the order of the soil bulk density was NT>LT>TP>CP; The avalible nutrients of the paddy soil increased first and then decreasd during the whole rice growing stage,it reaches the maxium at the tillering stage, the order of the soil bulk density was TP>CP>LT>NT at the same growing stage. the order of the soil organic matter was CP>TP>LT>NT; At the same soil layer,the order of the soil organic matter was NT、LT more than TP and CP.while the order of other nutrients were TP>CP>LT>NT,the soil fertility decreased along with the increasing of the depth of the soil layer.Compared with the other treatments.the NT treatment drop to be the quickest,the nutrient obviously accumulated on the soil surface.2. Continuous using different tillage methods also had influence on the growth of the double-cropping rice. the yield of the TP and CP was basically stable while the yield of the NT and LT decreased after successive years of rice planting.especially the NT. The yield of the NT drops significantly at the no-tillage season, while close to TP and CP at the tractor-tillage season. The order of the number of ears.the number of grains,1000-grain weight as well as the yield of the year2011was TP>CP>LT>NT,while the order of grain filling rate was the opposite.The LAI of the early and late rice showed a trend of first ascendent and then desendent.it reached the maximum value at the full-heading stage,while the dry matter weight assumes the escalation trend during the whole growing stage. the order of the LAI,the dry matter weight and the order of the SPAD value of three top leaves were TP>CP>LT>NT at the same growing stage. The order of the ear length.the number of the primary and secondly branchs,the number of the grains were also TP>CP>LT> NT,while the order of grain filling rate was on the contrary. The order of the leaf length.leaf width.leaf area, internode length,plant height,sheath length,stem width were TP>CP>LT>NT.The absorption amount of the Nitrogen, phosphorus and the potassium of rice plant increased gradually during the entire growing period. The order of the nutrient content and the absorption amount in the leaf,stem,sheath and the ear as well as the whole rice plant were TP>CP>LT>NT. The order of the stem bleeding intensity of the full-heading stage and maturity were the same. The order of the the total dry root weight and dry root weight at the same soil layer were TP>CP>LT>NT. the dry root weight decreased when the depth of the soil layer increased.the root of the NT distributed mainly in the0-7cm layer of soil,very little in the deep soil layers.