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Research and Extension of Ag-lime Application in Sichuan

IPNI-1999-CHN-SC15

Overview Related Interpretive Summary
30 May 2001

1999 Annual Interpretive Summary


Research and extension of ag-lime application in agriculture in Sichuan province, 1999

This project was aimed at studying the limiting factors of acid soils in Sichuan province. The province has 491,000 ha of unlimed acid soils with pH values below 5.5. The research is designed to identify the relationship between soil acidity and lime requirement and determine the optimal rates, timing, and placement of aglime. Seven soil samples from two major acid soil types were analyzed for their nutrient and acidity status. All soil samples were found to be deficient in K, Ca and Mg and most were lacking in boron (B) and molybdenum (Mo). The lime requirement (LR) was determined for each soil and an incubation study was designed to verify LR values. A field trial was also conducted on wheat to further test the LR values on a field-scale. Liming in combination with balanced fertilizers is estimated to increase potential P and K fertilizer use on acid soils by about 90 and 200 kg/ha, respectively. SICHUAN-15