Investigation on Soil Fertility of Newly Increased Cultivated Land after Wasteland Improvement in Loess Hilly Region-a Case Study in Ganquan County, Shaanxi Province

Through sampling analysis, field method and weighted sum evaluation method were used to study and analyze the fertility index of newly-increased cultivated land after wasteland land consolidation in loess hilly region. The fertility level, the biggest limiting factors and the comprehensive fertility index of newly-increased cultivated land were discussed, and reasonable fertilization strategies were put forward. The results show that: (1) the soil fertility content of newly-increased cultivated land in the loess hilly region is at a relatively low level after wasteland improvement. The average content of organic matter is 5.95 g / kg, the average content of total nitrogen is 0.52 g / kg, the average content of available phosphorus is 8.80 mg / kg, and the average content of available potassium is 183 mg / kg. (2) The soil fertility index of the newly-increased cultivated land in the study area ranged from 61.5 to 73.0 points, with an average score of 66.3 points. The project area with a score of 65 to 71 accounted for the majority, accounting for about 60 % of the total. (3) Soil organic matter and total nitrogen are the biggest control factors of the newly increased cultivated land fertility index after wasteland improvement in the loess hilly region. Increasing soil organic matter and total nitrogen is the most direct way to improve the comprehensive index of new cultivated land fertility.