| The land is the non-renewable resources, uses the advanced technical method and scientific management, sustainable using the land resource always is the hot topic which the various countries' government and the correlation researcher pays attention. The farming is in the land the primary production most important resources, the farming soil fertility quality directly affects the agricultural production development. With our country reform and open policy thoroughly, the cultivated area and the mass variation safely constituted the stern challenge to the grain, receives the party and the government as well as researcher's daily attention.This research used the GIS technology in 2005 the area farming soil main agriculture character to carry on the investigation to Hannan of Wuhan, and carried on the comparison and the analysis with 1980 second soil general survey result, area farming soil available nutrient vicissitude has carried on the overall appraisal to Hannan. In order to apply fertilizer rationally, protects the farming,enhances the grain yield, guarantees the grain security, produced thegreen product to provide the scientific basis. The main findings include:1 Investigated thoroughly the farming quality present situationThe research has gathered Hannan 301cultivated land soils sample, through to the sampling soil attributeanalysis and the appraisal, investigated thoroughly this area soil available nutrient present situation. The research discovered that, this area majority of farming soil assumes the neutral leaning alkali, The pH mean value 7.3, in which is in 7.5～8.0 sectors the alkalescency soil to account for the investigation total area 46.8%,the pH value accounts for the total area between the 7.0～7.5 neutral soil 43.6%. The available K is situated between 80～120 mg/kg,occupies 61.3% of total investigation area; Some 36.0% farming available K is bigger than 120 mg/kg;Some 2.7% fanning available K is only smaller than 80 mg/kg; The available P horizontal overall is lower, 80.6% cultivated land available P content is smaller than 10.0 mg/kg, including 14.0% to be lower than 5.0 mg/kg; between 10.0～20.0 mg/kg cultivated land occupies the investigation area 18.5%; Only has the few cultivated land available P to be bigger than 20 mg/kg.Farming soil organic matter aggregate level moderate to superior, the mean value is 22.56 g/kg. 88.2% farming organic matter content above 15 g/kg,in which is bigger than 20 g/kg, occupies the investigation area 44.9%, only some 11.8% farming organic matter content between 10～15 g/kg. Present situation reflection, in the area overall the P insufficient supply, Lacks the P the land parcel to be more, moreover between the different land parcel the P content difference is big. The K level medium is high, majority of land parcels K content richer, between the land parcel the variation is smaller. Organic matter content considerable, between the land parcel the difference is also smaller. The majority of soils still assumed the alkalescency, few assumed the alkalinity.2 Analysis of the trendThe findings indicated that, the area of Hannan soil pH overall change is not big, but presents two to the middle development tendency, 25 years ago soil main pH is situated between 6.7～8.0, the mean value is 7.4; At present pH is situated between 6.6～8.0,the mean value is 7.3. After 25 years cultivation, the area of Hannan soil pH value has situated between 7.0～7.5 the area to increase 8 percentage points,the pH value has been situated between 6.5～7.0 the area to reduce 2.4percentage points, but the pH value was bigger than 7.5 soils toreduce 5.6 percentage points. The soil available K remarkably reduces, 25 years ago the soil available K mean value is 146.03 mg/kg; Now the mean value is 108.08 mg/kg, equally drops nearly 40 mg/kg, the drop scope achieves 27.4%. The soil available P slightly has the rise, 25 years ago the area of Hannan soil available P average contentis 7.37 mg/kg, now the soil available P mean value is 8.62mg/kg, the majority of soils still lacked the phosphorus. It is extrapolation that farmland soil nutrient change through 25 years around, K fertilizer investment relative insufficiency, originally the rich soil K element massively is consumed,should bring to the attention; The P element deficient and the soil pH value is high always is limits this area agricultural development the important barrier factor. Must improve the soil P nutrition condition, besides increases executes the P fertilizer, must simultaneously improve the alkali soil.3 The principle of fertilizer recommendationsThrough obtains to the Hannan farming soil present situation and 25 years change trend analysis, the Hanana farming soil organic matter aggregate level considerable, add organic fertilizer Appropriately, use of the existing resources of organic fertilizer Reasonably; The wuhan most soils are the calcareous moisture soil, therefore best selects the acidic fertilizer; General increase in the amount of P fertilize, choice acidity stronger calcium superphosphate or double superphosphate variety; The Hannan most soils K element level dropped from 25 years agorich level to the present medium level, partially even presents the latent deficient condition. Therefore to these cultivated land must suitably supplement the K fertilizer, especially must take the cotton, the hemp as well as the industrial crop K element supplement.Sandy soils in the region more, pH value high, these soils preserve and supply fertility for fatability worse, is easy to cause the many kinds of elements fixed and the loss, gradually promote higher levels of phosphorus fertilizer. Therefore, Hannan will have to continue in next several year to add organic fertilizer, steadily will execute the N fertilizer, again will execute the P fertilizer, suitably will execute the K fertilizer, will make up middle element and trace element, will select the acidic fertilizer as far as possible in the fertilizer variety, and will coordinate other measure improvement alkali soils.4 Established a spatial databaseIt has Digitized the soil map and the present land-use map of Hannan as a spatial database of maps,also has took the whole understanding of soil distribution and using the present situation of Hannan.The findings demonstrated through 10 special maps show, let theresult be more direct-viewing. The research has also established this area farming resources and available nutrient the spatial database. Have laid the foundation for the later further research and the application. |
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