Study And Application Of Soil Testing And Formulating Fertilization For Rice In Jianyang City

Rice is very important to national food production. Fertilizer application is an important way to improve the output per hectare paddy field. Soil testing and formulating fertilization is an effective fertilizer application method. It bases on determining the composition of soil and testing the effects of various fertilizers in paddy field. According to composition of soil, the demand law of crops for nutrient, the effects of various fertilizers and the nature conditions in different areas, we can reckon the optimum quantity and proportion for nitrogenous fertilizers, phosphate fertilizers and potash fertilizers and so on. Furthermore we can choose suitable kinds of fertilizers, the time and way that fertilizers are applied. With the help of DPS data process system, this thesis processes and analysis the data that come from 3987 soil examples and 30"3414"field fertilizer experiments. The thesis also discusses the fertility of the soil in Jianyang City; analysis the effects of nitrogenous fertilizers, phosphate fertilizers and potash fertilizers in this area in view of the demand law of rice; works out an application model for nitrogenous fertilizers, phosphate fertilizers and potash fertilizers; raises the optimum quantity and proportion of these fertilizers. Then a technician plan of large-scale fertilizers application is devised and promoted in Jianyang City.The experiment results show: the average pH of soil in Jianyang City is 5.20±0.29, which shows the soil in Jianyang City is slightly acid; the organic substance of the soil in this area,34.91±6.36g/kg, is relatively rich; the alkaline hydrolysis nitrogen in this area is 185.92±55.85mg/kg;the Olsen-P is 18.85±9.3mg/kg;quick-acting potassium is 89.19±52.38mg/kg. Comparing with soil testing and formulating fertilization indices that made by a group of experts, the alkaline hydrolysis nitrogen in 23.0% experiment soil examples, the Olsen-P in 19.4% experiment soil examples and quick-acting potassium in 26.3% experiment soil examples are rich.The nitrogenous fertilizers, phosphate fertilizers and potash fertilizers effect experiments (data from 30 early rice, middle-season rice and late rice) show:the yield contribution rate of soil is 69.92±13.3% and there is an increase of 22.67% brought by the nitrogenous fertilizers, an increase of 3.82% brought by phosphate fertilizers and an increase of 12.96% brought by potash fertilizers. So the order of increase production effects likes this:nitrogenous fertilizers>potash phosphate fertilizers> phosphate fertilizers. The nitrogenous fertilizers, phosphate fertilizers and potash fertilizers increase production effects in infertile land are higher than those in fertile land. The net increase income by applying more nitrogenous fertilizers, phosphate fertilizers and potash fertilizers are 4048.0 yuan per hectare,560.0 yuan per hectare and 1931.0 yuan per hectare respectively. The increase rice yields are 12.89kg per kg nitrogen,4.41kg per kg P2O5 and 8.81kg per kg K2O respectively. The output-input ratios of nitrogenous fertilizers, phosphate fertilizers and potash fertilizers are 5.99,1.76 and 4.41. Regardless of net income, the increase yields per kg or the output-input ratios, the effect of nitrogenous fertilizers is always best, the effect of potash fertilizers comes second and the effect of phosphate fertilizers is relatively poor. Testing of plant samples shows:the absorption ratio of nitrogenous fertilizers is 38.1%, the absorption ratio of phosphate fertilizers is 10.5% and the absorption ratio of potash fertilizers is 46.1%. According to experiment results, the ternary quadratic polynomial models of fertilizers application about early rice, middle-season rice and late rice are founded respectively. The results show regression equations are all significant in statistics. Recommended plan of fertilizers application shows:the optimum quantities and proportions of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer for the early rice, the middle-season rice and late rice, which grow in various fields, are somewhat different, because both the yields and the capacities of the soil for fertilizers are different. Averagely, the optimum quantities of three crucial components for early rice are 129.69kg/hm2,25.02 kg/hm2 and 102.64 kg/hm2; the proportion of them is 1:0.19:0.79. The optimum quantities of three crucial components for middle-season rice are 149.43 kg/hm2,48.18 kg/hm2and 124.53 kg/hm2; the proportion of them is 1:0.32:0.83.The optimum quantities of three crucial components for late rice are 127.13kg/hm2,41.09 kg/hm2and 111.20 kg/hm2;the proportion of them is 1:0.32:0.87.On this basis, the author considers the optimum quantities and proportions of three crucial components in different fertilizer-level soil in Jianyang City, also considers the determination results of quick-acting nitrogen, phosphorus and potassium of every soil sample taken from every village in the city and the yield levels of years. An idea, i.e. macro-prescription and micro-adjustment, is implemented to make and recommend a fertilizer plan for early rice, middle-season rice and late rice in various village. And this plan is promoted in more villages. This technical plan has been promoted in 27,000 hectares paddy field in Jianyang City. The average yield is 7454kg/hm2, which increases rice production 496kg/hm2 comparing with traditional fertilizer application way. Increase production rate is 7.1%. This plan offers 992yuan per hectare additional output. Therefore this plan brings good economic result.