Status, Change and Evaluation of Soil Nutrient of Cultivated Land in Longde County

3 950 soil samples were collected in 13 townships in Longde county during 2007 to 2009 and testing and analysis were made on these samples. The result showed that the status of soil nutrient in Longde county was as follows: the contents of organic matter, total nitrogen, alkali-hydrolyzable nitrogen and rapidly-available potassium were higher than the average level of Ningxia, they were 15.77 g/kg, 1.03 g/kg, 74.39 mg/kg and 176.60 mg/kg respectively. The effective phosphorus content was 22.29 mg/kg, lower than the average level of Ningxia. Since the second soil census in 1984, the trend of change of the soil nutrient was: the organic matter did not changed significantly, the contents of total nitrogen, effective phosphorus and available potassium increased, the content of alkali-hydrolyzable nitrogen was on the decline The overall evaluation of the farmland soil nutrients is that the contents of the soil organic matter, total nitrogen, alkali-hydrolyzable nitrogen and available phosphorus are common as a whole and the content of rapidly-available potassium is high as a whole.