Study On The Balanced Fertilization Of Soybean On Black Soil In BaiQuan County

Heilongjiang province is China's main soybean production area with a seeded area accountingfor about 35 % of China's total soybean seeded area and a total production accounting for 38 % ofChina's total soybean production. The total soybean amount flowed out from Heilongjiang provinceaccounts for 80 % of China's trading soybean amount. But low yield per unit of area, low qualityand weak competence have been the main problem limiting Heilongjiang's soybean production. Yet,optimizing the fertilizer application would be the best way to increase soybean yield and improvesoybean kernels' quality.Balanced fertilization means to determine the rate of fertilizer, fertilizer ratio and applicationtimes according to nutrients supplying capacity of soil, nutrients' uptake mechanism, characters offertilizer and efficiency of fertilizer to optimize the crop's fertilizer response. Balanced fertilizationseeks a higher yield. Yet, based on the "ecological balanced fertilization theory," the ecologicalbalanced fertilization is a way of fertilization to attain multi-goals (economical, ecological andsocial goals) by means of "ecological balanced fertilization" with "ecological type of fertilizer" ascarrier.Field experiments of fertilizer were carried out in BaiQuan County of Heilongjiang provincein 2006. It was found that the peak of nitrogen uptake was from flowering stage to seed stage, thatthe peak of phosphorus uptake was from flowering stage to pod stage, and that the peak ofpotassium uptake was from seedling stage to flowering stage. The results also showed thatapplication of nitrogen may stimulate the uptake of phosphorus and potassium, that application ofphosphorus may stimulate the uptake of nitrogen and potassium and that application of potassiummay stimulate the uptake of nitrogen and phosphorus. In certain ranges, soybean yield increasedwith fertilizer rate.In the entire growing season, cumulative dry-matter weight of soybean was positivelycorrelated with the cumulative weight of nitrogen, phosphorus and potassium respectively. Nitrogen,phosphorus and potassium cumulative quantities increased with the cumulative weight of soybeandry-matter.Specific parameters of balanced fertilization and fertilizer response equations were obtainedby analyzing the relationship between the soybean yields and the application rates of N, P, K andthe ratio between them. The F test showed that this equation may be used in BaiQuan County. The ecological balanced fertilization abandoned the two central parameters of traditionalbalanced fertilization: the efficiency of fertilizer and the efficiency of nutrients from soil byintroducing "the lower limit of available nutrients of soil after the growing season W_min" and theupper limit of available nutrients of soil after the growing season W_max", two parameters specific toecological balanced fertilization model.As the controlling parameter, W_min Can strictly control the negative impacts of increased inputand on the environment caused by overuse of fertilizer. According to the results of fieldexperiments, W_n+m specific parameter model was obtained by simulating the available nutrients ofsoil after the growing season and the yield.â–³W is a characteristic parameter carrying connotations of influx and effiux of availablenutrients.â–³W characteristic parameter model was obtained by regressing rate of fertilizer andyield.Regional nitrogen fertilizer application model, Regional phosphorus fertilizer applicationmodel, field nitrogen fertilizer application model and field nitrogen fertilizer application modelwere obtained by ordinary model and characteristic parameters of seasonal available nutrientsbalance.By Snedecor's F statistic calculation, the above models were proven practical and can beapplied to the soybean production region of BaiQuan County to guide application of fertilizer.Compared to the application rate of fertilizer recommended by traditional fertilization model, theapplication rate of fertilizer recommended by ecological balanced fertilization model was 10%lower, economizing the input and reducing the non site specific pollution caused by fertilization.