The Evaluation Of Paddy Soil Fertility And Land Productivity In Eastern Hunan

This article have the paddy soil in hilly red soil region of eastern Hunan as the study object, through massive sampling investigation and soil fertility location monitoring field test, in which representative soil nutrient of paddy field district in Liuyang, Liling were analyzed, and the evaluation of paddy soil quality in representative areas of eastern hunan, analysis the main restrictive factors, clear the breach of the soil quality improvement.The main results are as follows:1.The paddy soil of eastern Hunan was acidity (the probablity of soil pH on acidity and slight acidity soil was respectively 46.67% and 47.5%), the organic matter was rich (the probablity of organic matter of proper, rich and very rich was respectively 48.33%?43.33% and 4.17%), the total N was rich (the probablity of total N of proper,rich and very rich was respectively 43.33%?34.17% and 9.17%), the alkali-hydrolyzable N was very rich (the probablity of alkali-hydrolyzable N of rich and very rich was respectively 23.33% and 70.83%), the total P was proper (the probablity of total P of proper was respectively 50.83%), the available P was proper or rich (the probablity of available P of proper or rich was respectively 49.16% and 45.84%), the total K was lack (the probablity of total K of lack and very lack was respectively 25% and 73.33%), the available K was proper (the probablity of available K of proper was respectively 44.17%).2. Compared with the second soil census, the soil fertility of rice in Liuyang and Liling had obvious changes:total N?P?K decreased, alkali-hydrolyzable N, available P and K were improved, especially for the available P. Compared with the treatments of winter fallow, green manure-rice-rice and rapeseed-rice patterns could increase the accumulation of soil organic matter, the alkali-hydrolyzable N and available P significantly increased at the early rice harvest in green manure-rice-rice, but at the late rice harvest, soil nutrient contents were lower than that before planting rice, especially available K.3.It was significantly correlation between different soil fertility factor in eastern Hunan, both total N and alkali-hydrolyzable N had a significant positive correlation with organic matter, total P and available P was the same; In addition, pH had a significant negative correlation with organic matter in Liuyang, a significant positive correlation with total P and K. The theoretical yield had a significant positive correlation with total N, organic matter and alkali-hydrolyzable N in middle-season rice of Liuyang and Liling, early rice in Liling; The correlations between grain number per panicle and total P, available P were positive in late rice of Liuyang, effective panicles and theoretical yield had a significant positive correlation with alkali-hydrolyzable N; The correlations between grain number per panicle,1 000-kernel-weight, effective panicles and total K were positive in early rice of Lingling, grain number per panicle, theoretical yield and organic matter were positive in late rice of Liling.4.The rice yield of high fertility level field was significantly higher than that in low fertility level field, the rice yield of fertilization treatments were significantly higher than those in no fertilizer control, and primarily by affecting grain number per panicle and effective panicles on yield. Under low fertility conditions, pure fertilizer area processing production effect was obvious, while middle or highe fertility was 40% organic fertilizer area.40% organic manure treatment had obvious role in promoting the increase of the content of soil nutrient while pure fertilizer area was poor in soil improvement.