| Paddy soil fertility and basic soil productivity had a decisive effect on rice yield and fertilizer dosage and utilization. Therefore, it has very important significance to safeguard the stability of rice production and sustained growth that researching and clarifying the dynamic evolution of paddy soil fertility and basis, which is the premise and foundation of guiding paddy soil management and manuring scientifically and reasonably. In the past, studies failed to proceed from the big perspective of time and space to explore the spatial and temporal evolution characteristics, especially, there wasn’t any quantitative comparative analysis of variation between different regions; and most rice research has focused on the early and late rice and single cropping of rice while few studies focused on middle rice. Therefore, relying on the USDA National paddy soil monitoring data, this study uses the value analysis method to explore the past 25 years(1988-2012 years) dynamic evolution characteristics of paddy soil nutrients, and various fertility indicators and weighting factor using numerical normalization, then combining integrated soil fertility index model and foundation soil fertility index model to analyze the temporal evolution of soil fertility and basic soil fertility between different regions of the country: and discussed the "gone" effect of basic farmland soil fertility improvement across the country at the same time. And the main conclusions are summarized as follows:(1) Through proven, it is reasonable to use the F value, P value and BPI values to characterize integrated soil fertility, soil productivity and soil fertility.(2) From 1988 to 2012, basically it showed an upward trend under the conditions of the farmers habitual fertilization that the content of paddy soil organic matter(SOM), total nitrogen(TN), nitrogen(AN), available phosphorus(AP) and potassium(AK) in our major grain producing areas(the Yangtze River region, the Northeast, Southwest Region, Southern Region), but soil p H decreased(Northeast After checking the long-term trial data showed that the p H is also slightly downward trend), and has shown some acidification trend especially in the Yangtze River, Southwest and South paddy fields.(3) Under customary peasant farming and management conditions, the Yangtze River, Southwest, South and Northeast Fourth District paddy integrated soil fertility index(FI value) over time for both the upward trend was significant(p <0.01), which shows that there have improved overall paddy soil fertility in major grain producing areas nearly 25 years. And increase over time, integrated soil fertility can be reached "saturation", which is equal to the relative equilibrium(FI value of the maximum threshold).(4) From the overall change of view, in the Yangtze River area, the evolution state of integrated paddy soil fertility was earlier than in the Southwest Region, Southern Region and the Northeast region in time series. Thus, compared to the Yangtze River area, areas showed more integrated soil fertility for improvement in southwest, south and northeast; the remaining three districts will be more pronounced than the effect of the Yangtze River region when through scientific and rational fertilization to improve integrated soil fertility.(5) Through differences of the Yangtze River region’s soil fertility in the evolution of the different principal component, analysis can be drawn that, soil potassium and phosphorus are still important factors of ongoing paddy production and sustainable development of agriculture in the area from a perspective of nutrient Balance, potassium and phosphorus inputs and supplements need to be strengthened in the future management of the process of fertilization, but the amount of nitrogen fertilizer required reasonable control.(6) Changes in fertilizer nutrient balance and changing the type of fertilizer, especially nitrogen, phosphorus and potassium balance fluctuations are the main factors leading integrated paddy soil fertility variation.(7) There has shown an overall upward trend of major grain producing areas in paddy basic soil productivity for nearly 25 years under customary farmer fertilizer management. And the basic soil productivity level of the Yangtze River area was significantly higher than the other three areas, Southwest was the lowest level fertility basis, there was no significant difference between Northeast and South China, namely the Yangtze River area> Northeast ≥ Southern Region> Southwest.(8) The soil productivity of paddy in major grain producing areas improved over time from 1988 to 2012, and basic soil productivity(BPI values) and soil productivity(PI value) showed a significant positive correlation(p <0.01). Thus explained that soil productivity could be improved with the enhancing of basic soil productivity, which is equal to the "Corresponding Rise" effect.(9) Integrated Soil Fertility four(FI value) and basic fertility(BPI value) of the dynamic evolution of the trend can be seen that soil fertility and basic soil productivity of China’s major grain producing areas all have a huge room for improvement, which is an important way to enhance the productivity of paddy.
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