| Miyi is the important base of modern agriculture in the southwest of Sichuan Province,also is the important region of agricultural production in the lower reaches of the Anning River.Based on the results of the testing soil for formulated fertilization,sampling analysis,field trial and examples,this study built the assessment indicator system of farmland productivity in the Miyi,which included soil parent material,topographic position,slope,surface slope,soil thickness,soil texture,p H,organic matter,available phosphorus and available potassium,tillage characters bedding factor,and so on.Combined the administrative map,soil strip map and present landuse map of Miyi,according the linear regression and analytic hierarchy process,the Integrated Fertility Index was calculated by addition method in the county cultivated land resource management information system.Then the farmland fertility grade was determined according to cumulative frequency curve method,and the distribution map of cultivated land fertility grade was drawn.In addition,this study put forward some suggestions for the sustainable utilization of cultivated land resources according to the establishment of county cultivated land resource management information system and evaluation results.The main achievements of this study are as follows:(1)The results of soil testing in Miyi showed that the farmland soil texture was divided into loam and clay,which was given priority to with loam accounted for 85.51% of its arable land.And the soil of the county was dominated by weak acid accounted for 79.14%,and the distribution of p H was between 4.5～7.5,the content of soil organic was between 20～30 g/kg accounted for 85.51%,the content of soil total nitrogen was between 1.0～1.5 g/kg accounted for 44.73%,the content of soil available nitrogen was between 120～150 mg/kg accounted for 30.70%,the content of soil available phosphorus was between 10～20 mg/kg accounted for 52.81%,the content of soilrapidly available potassium was between 50～100 mg/kg accounted for 65.34%.(2)Miyi County cultivated land fertility evaluation results from the overall,cultivated land in Miyi county was divided into seven grades.The fifth and the sixth grades accounted for the largest proportion,and accounted for 19.85% and 23.53% of the total area of the arable land respectively.Secondly,the forth and the seventh grades accounted for 12.36% and 17.26%,the third grades accounted for 13.84% of the total area of the arable land respectively.At last,the first and the second grades accounted for the minimum proportion,and just accounted for 5.25 % and 7.92%.(3)Based on the results of Miyi County Formula Fertilization Recommended,for the rice,the formulas of High-nitrogen,medium-phosphorus and high-potassium were mainly suitable for the south and southwest of Midi County,and the formulas of Low-nitrogen-low-phosphorus and medium-or low-potassium were mainly suitable for northeast,north and western regiones of Miyi County.For the rapeseed,the formulae of High-nitrogen and medium-phosphorus potassium were mainly suitable for the southwest part of the middle of Miyi County,and the formulas of medium-nitrogen high-phosphorus and high-potassium were mainly suitable for the northeast,central and southwest regions,and the formulas of low-nitrogen and low-phosphorus potassium were mainly suitable for the northeastern,northern and western parts of Miyi County.For the wheat,the formula of Medium or high nitrogen combined with medium-phosphorus high-potassium was mainly suitable for the southwest of central Miyi County.The medium or low nitrogen was mainly formulated with medium or low phosphorus and low potassium,which suitable for the northeast,central and southwest regions.For the corn,the high nitrogen combined with medium or high phosphorus and high potassium formula was mainly suitable for the southwest of Midi County,and the low nitrogen,low phosphorus,low potassium was mainly suitable for the north and west of Miyi County.Local area. |
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