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Studies on the soil nutrient limiting factors in east Sichuan province

IPNI-1995-CHN-SC11

Overview Related Interpretive Summary
28 May 2001

1998 Annual Interpretive Summary


Studies on the soil nutrient limiting factors in east Sichuan province, 1998

A systematic study of the soil nutrient limiting factors in east Sichuan province (now part of Chongqing) has indicated that most soils are deficient in P, N, Zn, Mg, B, and K. As an example, the +P treatment increased corn and potato yields by 23.5 and 25.4 percent, respectively. Optimum P application rates were determined to be 105 kin/ha for corn and 60 kg/ha potato. Purple soils in Sichuan province have traditionally been considered sufficient in K. However, regional awareness towards K deficiency and significant crop response to K are increasing. The +K treatment increased corn and potato yields by 7.5 and 43.8 percent, respectively. The optimum K application rates were 405 kg/ha for corn and 225 kg/ha for potato. Application of K to turnip after corn increased turnip yield, vitamin C, and water-extractable amino acids by 10.1, 22.9 and 202 percent, respectively, and reduced nitrate NO3- content in turnip by 11.5 percent. These demonstrations along with technology transfer efforts continue to expand P and K consumption in the region. SICHUAN-11