| Improving the Unit Area Production is a main approach to increase agricultural production, and appropriate fertilization can increase the Unit Area Production. Therefore, it is essential to strongly extending the technology of soil testing and formulated fertilization for steadily increasing the Unit Area Production and the income of farmers, decreasing the production cost and this has far-reaching influence on the increase of fertilizer utilizing rate, the protection of agricultural environment, the safety of farm products and the agricultural sustained development. At the beginning of2005, it was proposed explicitly in the First Document of Central Government that the’Balanced Fertilization’is the first important technology which should be promoted in the whole China. Since then, balanced fertilization has been paid more attention by the whole society. Since2007, the technology of the "Balanced Fertilization" has been promoted in Taixing City. It stimulates the changes of the farmers’ conception by widely advertising and setting up demonstration bases. But there are still many problems which slow down the development of the project. To solve these problems, a detailed investigation of the current situation of the fertilization, and the implementation and extension of soil testing and formulated fertilization in Taixing was carried out. The results were listed as follows:(1) During the year from1989to2005, the contents of organic matter (OM), total nitrogen (TN) and available phosphate (AP) of soils in basic farmland conservation area were all increased. The average contents of OM, TN and AP of the years from2001to2005were22.81%,21.62%and38.76%higher respectively than those of the years of1989and1990. However, the content of available potassium of soil first decreased then increased.(2) During the year from1989to2005, the application rates of N, P and K were increased gradually. The average application rates of N, P and K of the years from2001to2005were39.45%,37.12%and91.92%higher respectively than those of the years of1989 and1990. However, some problems were showed up. Firstly, the cost for nutrient input were enhanced; Secondly, the suitable N:P:K rate for rice and wheat is1:0.5:1-2, however, the rate was1:0.27:0.29at2005in Taixing city, the low ratio of P and K was a soft spot in increasing N utilization efficacy. Moreover, the application ratio of organic N to inorganic N was reduced year by year.(3) According to the soil nutrient grading standard in the farmland in Jiangsu, the contents of OM (10-30g/kg), TN (0.75-1.5g/kg), AP (5-20mg/kg) and AK (50-150) in more than90%farmland soil in Taixing were at level III and IV. With respect to the content of available silicon,44%was at level Ⅱ (201-250mg/kg) and43%was level III (151-200mg/kg). According to the grading standard for soil available microelement, the contents of available Fe (>20mg/kg) and Cu (>1.8mg/kg) were at level V, and available Mn (5-15mg/kg) and Zn (1.0-3.0mg/kg) were at level III and IV, respectively.(4) The results of the "3414" field trails showed that, along with the increased application rates of N, P and K, the rice yield changes in the high sandy soil and miry soil areas had a similar tendency:first increased fast, and then slowed down and finally fell down. Single factor analysis with the "3414" analyzer showed that, The fertilizing amounts to get the maximum grain yields in the high sandy soil and miry soil areas were26.21kg N/667m2and23.25kg N/667m2,5.44kg P/667m2and4.88kg P/667m2, and9.90kg K/667m2and9.74kg K/667m2, respectively; and the most economical fertilizing amounts were22.93kg N/667m2and21.20kg/667m2,4.41kg P/667m2and3.99kg/667m2, and6.74kg K/667m2and6.77kg K/667m2, respectively.(5) With the "3414" analyzer, fertilizer response equations for high sandy soil and miry soil were obtained. The response equation for high sandy soil is Y=265.9615+11.6466X1+21.9397X2+12.9582X3-0.3723X12-1.8316X22-0.5461X32+0.7683XiX2+0.3867XiX3-2.1712X2X3(R=0.9975**F=174.62**). According to fertilizer response equation, the optimum yield (526.31kg/667m2) will be reached when N, P2O5and K20application rate was21.88kg/667m2,5.46kg/667m2and7.32kg/667m2, respectively; the highest yield (548.45kg/667m2) will be reached when N, P2O5and K2O application rate was26.71kg/667m2,5.86kg/667m2and9.66kg/667m2, respectively. The response equation for miry soil is Y=322.1771+16.419X1+21.1857X2+15.0223X3-0.5458X12-2.2022X22-0.7578X32+0.9614X1X2+0.4747X1X3-2.2506X2X3(R=0.9932**F=65.3347**). According to fertilizer response equation, the optimum yield (619.01kg/667m2) will be reached when N, P2O5and K2O application rate was20.44kg/667m2,5.32kg/667m2and6.69kg/667m2, respectively; the highest yield644.04kg/667m2) will be reached when N, P2O5and K2O application rate was23.67kg/667m2,4.66kg/667m2and10.41kg/667m2, respectively. |
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