Study On Spatial Characteristics Of Soil Nutrients Fertility In Weihe Plain County Farmland

The region of Weihe plain is characterized with Flat, mild climate, lower altitude andalmost no the phenomenon that water loss and soil erosion.The effects of soil fertility ismainly affected by the content of soil nutrient. Thus, making a full understanding about thespatial distribution, and the further research on soil fertility status.Taking Xingping Countylocated in the Weihe plain as the research site, Geostatistics,the research results of "3414"experiments and Fuzzy comprehensive evaluation methods combined with GeographicalInformation System (GIS) are employed in this paper to establish the best semi-variancetheory model, applied to study the spatial variability and distribution pattern of soil fertilityincluding OM, TN, AN, AP, AK, Fe, Mn, Cu, Zn, B, Mo and C/N, N/P in the farmland. Thestudy on mapping the spatial distribution of soil nutrients, analyzing the influence factors andstatus of nutrients as well as evaluating the fertility of the soil nutrient so as to providescientific guidance and theoretical basis for the regional balanced fertilization, farmlandmaintenance, agricultural production and reducing the cost of agriculture production. Mainresults are as follows:(1)At present,Soil nutrient content of Xingping farmland is shown as:The variationcoefficient of thirteen kinds of soil nutrients are from23.56%to74.87%, belonge to medium-variability.The average content of OM,TN,AN,AP,AK is respectively14.54g kg-1、1.04gkg-1、38.38mg kg-1、27.13mg kg-1�'�202.07mg kg-1.while the average content ofFe,Mn,Gu,Zn,B and Mo is respectively6.60mg kg-1、16.71mg kg-1、1.72mg kg-1、2.65mgkg-1、0.78mg kg-1and0.416mg kg-1.C/N and N/P are9.77and1.99. In terms of availablenutrient abundant-deficiency, available nitrogen content is in the "low" level, it is hard to meetthe growth of the crops, available phosphorus and available potassium content are rich, canbasically meet the needs of the crop.(2) In geostatistics: Optimal half variance theory model of soil nutrients exceptMn,Gu,Zn,B and Mo are for the spherical model, the remaining six kinds of soil nutrients areexponential model.The nugget of eleven kinds of soil nutrients are from0.486to0.970.Spatial correlation of OM, AN, AP, AK, Mn, Cu, Zn and Mo belonge to weak spatialdependence, mainly affected by human factors with fertilization,cropping systems,etc.Spatial correlation of TN, Fe and B belonge to moderate spatial dependence, mainly affected by bothnatural factors and human factors. The best theory model of soil Mn, Cu, Zn, B and Mo areSp-model, others are Ex-model.(3)There is a significant difference in the spatial distribution of the soil nutrients. traceelements (except Cu and B)and AK decrease gradually from north to south.The trends haveobviously change, lower level distributes in the Weihe basin located in the south and southeastof Xingping County. At the same time, other soil nutrients show a trend that decrease aroundthe central. In terms of available nutrient level status, AN content has an obviously decline,AN can’t meet the growth of the crops because of the low level; At the same time AP and AKis rich enough to basically meet the need of crops.(4) Compared with the1980s, OM increased by34.63%and the growth increased fromall-around to the central region.AN decreased by27.45%and the reduction rate increasedfrom east to west, south to north; AP increased by107.10%and the increasing rate increasedfrom south to north; AK content generally increased while increased in the north anddecreased in the south;at the same time, soil available N/P ratio in the whole decreased thatincreased in the south and decreased in the north, and had reversal distribution trend.Spatialand temporal variability of available nutrients have a consistent regularity: Low-value areasgrew faster, but slower in high-value areas.(5) Soil fertility showed reduction from the central region to all-around, the lowestcontent is located in the Southeast of Xingping County. Soil fertility are mainly in thesecondary level, so the situation showed overall a relatively good condition. Based on theevaluation results, from the soil fertility considerations, both Tian Fu and Fu Zhai along theWeihe plain should actively increase the application of nutrient, especially OM and N.Meanwhile, alluvial soil and silt soil account for a large proportion at Tian Fu and Fu Zhaialong the Weihe plain according to soil type. Recommend measures to be taken to mix withsilt and increase green manure so as to actively improve soil texture and structure, andimprove the ability of soil water with fertilizer.The northern plateau region of the study areashould be combined with the lack-abundance of status and crop yields, precision fertilization,supplement of nitrogen and efficient utilization of soil.