Abstract:

The present experiment was conducted to study soil nutrient status of four kinds of purple soil that developed in Jurassic period Mesozoic era in Chongqing District by fuzzy synthetic estimation. The results showed that: the soil fertility in Chongqing District was at secondary level, among which 22.6% was better, 58.5% was middling and 18.9% was worse. The content of organic matter, total nitrogen, available nitrogen and available manganese are low. Total phosphor, available phosphor, available potassium, available zinc and cation exchange capacity were at intermediate level. Total potassium, slowly release potassium, available cuprum were at rich level. And it was severely short of available boron. The main factors that decide the soil fertility were available nitrogen, organic matter, total nitrogen, available phosphor and available potassium. And the contribution rate of main factors were available nitrogen>organic matter>total nitrogen>available phosphor>available potassium.