Research On Soil Testing And Fertilizer Recommendation Technology At Village And Town Level

Smallholder farmers are the main part of agricultural production system in China,but the scattered field management mode and complex planting types increase the difficulty of the application of soil testing and fertilization technology?STFRT?for smallholder farmers.In order to explore suitable for smallholder farmers'plots use of STFRT,this paper took Xin'an town,Xin'an village and Yangong village as the research area.On the base of geographic information system?GIS?the variation characteristics of nutrients at village and town level were researched.At the same time,works about exploring the interpolation and soil samples collecting method which suitable for spatial variation of soil nutrients and developing the technology of designing fertilizer formula for the research area were carried out.After that,the feasibility of the technology was verified through field comparative experiments,and finally a whole technical system of recommended fertilization for soil formula measured at village and town level was formed.The main results are as follows:?1?The content of soil nitrate in Xin'an town and Xin'an village was low,and the content of organic matter,available phosphorus and available potassium was in the middle level.The soil organic matter and nitrate nitrogen content in Yangong village were low,while the available phosphorus and available potassium content were not too high or too low.The variation coefficients of four soil nutrients in the three study areas were all of moderate variation intensity.Among them,the variation coefficients of nitrate nitrogen and available phosphorous in the three study areas were relatively high?around50%?.The variation coefficient of organic matter was the lowest?below 23%?.?2?Eight interpolation methods were used for spatial interpolation of four soil nutrients in the research area.It is found that the radial basis function interpolation method?RBF?,inverse distance weight method?IDW?,ordinary kriging interpolation method?OK?and universal kriging interpolation method?UK?are effective in spatial prediction of organic matter,and the coincidence degree is above 90%.RBF method was the best method for spatial prediction of soil available phosphorus and available potassium,and the degree of conformity were all over 90%in the research areas.Through eight interpolation methods interpolating the spatial variation of soil nitrate nitrogen,the result showed that the interpolation accuracy was low,the correlation coefficients were all less than 0.2 and the coincidence degree was all below 85%.?3?With the decrease of the interpolation samples,the image information became simple and the coincidence degree of sample points gradually decreased,while the cross validation results and correlation were not significantly affected by the variation of soil nutrients.Making spatial prediction according to the organic matter,available phosphorus and available potassium content,the town level and village should ensure a soil sample of13.3 and 6.7 hm²,respectively.However,in all the sampling schemes,Due to the instability of nitrate nitrogen and the different fertilization habits of farmers,the coincidence degree of nitrate nitrogen was low.?4?Soil texture and crop planting types have certain influence on soil nutrient spatial variation.In terms of soil texture,the average content of organic matter,nitrate nitrogen and available potassium in different soil texture forms were as follows:Loam>Sandy loam>Sandy soil,and the variation coefficient of the three nutrients in sandy soil was the largest.The effect of soil texture on organic matter,nitrate nitrogen,available phosphorus and available potassium is:Available potassium>Organic matter>Nitrate nitrogen>Available phosphorus.In regard to planting types,the variation coefficient of the four nutrients in wheat-maize planting system was lower than that of other planting types.The variation degree of nitrate nitrogen and available phosphorus was relatively larger,which indicated that nitrate nitrogen and available phosphorus were more affected by planting types than organic matter and available potassium.?5?When the formula was formed,the target yield was determined according to soil texture and boundary line method on the basis of previous peasant household surveys.Nitrogen fertilizer recommendation amount uses the target yield and nitrogen partial factor productivity?PFPN?.Phosphorus and potassium fertilizer application amount were recommended by constant monitoring technology based on soil nutrient map.Finally,the local main crops fertilizer formula were obtained and drawn into the formula maps at village and town level.Farmers can find a suitable formula from the finished map according to the location of the field.The results of 22 field comparison experiments in Xin'an town showed that the formula fertilizer treatment increased maize yield by16.3%,increased PFP_N,PFP_P and PFP_K by 1.2%,56.5%and 23.2%,respectively.The results of 11 comparative tests in Yangong village showed that compared with the farmer practice treatment,the formula fertilizer treatment increased yield and PFP_N by 10.8%and 28.5%in winter wheat season.The treatment of formulated fertilizer in the summer maize season increased yield and PFP_N by 10.3%and 16.9%,respectively.Soil testing and fertilization recommendation technology could achieve the aim of increasing yield and fertilizer use efficiency of winter wheat and summer maize.In conclusion,the prediction accuracy of soil nutrients can be improved by optimizing the interpolation method and sampling technology when the variation of soil nutrients in the village and town level is large.In addition,the formula technology based on GIS was used to recommend fertilization on smallholder farmers'field,which had a significant effect on increasing crop yield and nutrients utilization efficiency.At the same time it can solve the difficult problem of application of STFRT method on smallholder farmers.The STFRT at village and town level can provide technical support for the whole system promote of smallholder farmers.