Present Status of Soil Fertility and Fertilization Suggestions of Cultivated Land in Nanjing County

In order to get a more comprehensive understanding of the status quo of farmland soil fertility in Nanjing county, the pH value and the contents of organic matter, total nitrogen, available phosphorus and available potassium of 411 representative soil samples from paddy fields and dry lands in Nanjing county were measured in 2009, and then evaluated by the second national census classification standard. The results showed that the soil pH value was 5.11±0.21, the content of organic matter was 24.59±5.71 g·kg^-1, and the contents of total nitrogen, available phosphorus and available potassium were 1.16±0.28 g·kg^-1、62.12±32.25 mg·kg^-1和110.90±34.62 mg·kg^-1, respectively. Compared with the second soil survey in 1982, the pH value of cultivated soil increased by 0.16 and the content of organic matter increased by 1.91 g·kg^-1, and the distribution frequency of deficiency grades in soil nitrogen, phosphorus and potassium decreased by 1.45, 48.27 and 45.22 percentage points respectively, showing a trend of soil nutrition is developing to medium and rich grades, but partial acid and low nutrient content still exist in some soils. At the same time, the measures of soil improvement and fertilization for cultivated land in Nanjing County were put forward.