The Variation Of Farmland Productivity Of Alluvia Soil In Plain Area

Arable land,one of the inportant agricultural resources, which is to keep the societyand national economic sustainable development of the resources. Good farmlandproductivity level and reasonable use of regional agriculture which realize theregional agriculture and the sustainable social-economic development,are importantbasis and necessary conditions. Therefore, grasping the quantity, quality, and changesof the arable land resources has great significance for planning, using and effectivelyprotecting arable land.First, in order to analyze the spatio-temporal variability of farmland productivityabout alluvial soil in plain area from1982to2009，enhance the cultivated landutilization efficiency, and realize agricultural sustainable development. The authorresearched the changes and influencing factors of the Farmland productivity ofMinquan county in2009and1982in Henan Province by usingstatistics, geostatisticsand geographical information system (GIS). The results judging from the spaceshowed that the content of soil organic matter gradually reduced from east to west in1982, and the content of soil organic matter generally rose to a level in2009compared with the1982, and the most raising place lied in the centre of the studyingarea. In1982, the soil nitrogen content mainly concentrated in the I and II levels, andthe III level was less in the area. In2009, the soil nitrogen content was based on III、IV level, at the same time, the IV level was larger. In1982, the available phosphoruscontent was distributed in each town. Ihe available phosphorus content increasedmore in2009compared with the1982, which was mainly gathered in III、IV level,and the II level scattered in some townships. In1982, the content of potassiumgenerally based on III、IV level, and the V level mainly lies in the east of the area. Therange of the III level of potassium increased largely in2009compared with the1982,and the range of IV、V level were less.Judging from the time, along with the improvement of fertilization, the rationalizationof planting structure, and the increase of water utilization ratio, the soil organic mattercontent of this study area generally increased from1982to2009. The average valueof the soil organic matter content increased from6.42g/kg to13.19g/kg, increasingby105.45%. The average value of the soil nitrogen content increased from0.43mg/kg to0.83mg/kg,increasing by93.02%. The average value of the available phosphoruscontent increased from0.93mg/kg to17.99mg/kg, increasing by18.34%. The averagevalue of potassium content reduced from116.03mg/kg to91.85mg/kg, reducing by20.84%. It can be seen that the soil organic matter、the soil nitrogen content and thethe available phosphorus content had a large increase, but the content of the potassiumreduced.Second, Comprehensive changes in farmland productivity by using AHP, FuzzyEvaluation and Delphology: Arable land distribution of Minquan county wasconcentrated in the third-class and forth-class in1982, and the area of them were67440.15Ha、24122.75Ha. Which accounted for83.68%、29.93%in the totalcultivated area. In2009, arable land of Minquan county was mainly distributed infirst-class and second-class, and the third-class、forth-class were less. Their areas were21469.64Ha、38838.42Ha、19706.72Ha、574.28Ha, which accounted for26.64%、48.19%、24.45%、0.71%in the total cultivated area. Judging from the absolute changeof them: The first-class of the arable land increased by21469.64Ha; The second-classincreased by18784.92Ha; The third-class reduced by47733.33Ha; The forth-classalso reduced23548.47Ha. Judging from the changes in the relative amount of: Thefirst-class of the arable land increased by26.64%; The second-class increased by23.31%; The third-class reduced by59.23%,and the forth-class reducced by29.22%.In order to increase effective cultivated land, to improve the quality of cultivated land and toprovide efficency reference, I study the changes of cultivated land productivty. At the same time,optimizing reasonable fertilization, increasing soil nutrients and realizing the sustainabledevelopment of cultivated land resources are available through this reaserch..