Dynamic Changes Of Main Nutrient Elements In Different Paddy Soils In Xinchang County

In China,the terrain is complex and the climate is diverse,especially in rural areas,the soil types are diversified,and the soil fertility and crop fertilization level are quite different.Although there are many researches study on the soil nutrient level and fertilizer utilization rate,there is no conclusion based on the analysis of soil nutrient changes in a region in past few decades.On the basis of consulting and classifying the rock types and parent materials of soil formation in Xinchang County and statistic analysis of the data results from the soil survey in 1984,the pH value and the contents of organic matter,total nitrogen,available phosphorus,rapidly available potassium,and micronutrients such as iron,manganese,copper,zinc and boron in three paddy soil in Xinchang County during year 2008 to 2013 were measured and analyzed.Comparing the basic physical-chemical properties and micronutrients level of the soil samples during year 1984 to 2013,we noticed these three types of soil were acidic and showed a downward trend.Althoug the levels of organic and total nitrogen were slightly increased,the overall level were not high enough.The available phosphorus content was greatly increased,and about one order of magnitude higher than the data of year 1984,the mean value was about 10.05 to 34.71 mg kg-1.Except the Brown mud soil,the rapid available potassium of Yellow mud soil and Yellow sand soil increased about 58.2%and 21.4%respectively.Based on the measurement results of year 1984 to 2013,we proposed suitable fertilization recommendations for these three types of soil.Include using organic matter to replace chemical fertilizer and using appropriate amout of lime to retard the soil acidification trend.Through soil testing and fertilizer recommendation,we changed the proportion of different nutrients and add appropriate amout of micronutrients to meet the needs of plants,finally raise the fertilizer utilization rate.