Research and Extension of Ag-lime Application in Sichuan

This project was initiated in 1999 and is aimed at determining the optimal rates, timing and placement of aglime for Sichuan province through a thorough study on the relationship between soil acidity and lime requirement.

Initial experimentation found the traditional method used for determining the lime requirement was inefficient. A new approach was developed that could accurately raise the pH of an acid soil to any desirable level. The optimum pH range for wheat growth appeared to be 5.5 to 7.5, while corn was not as sensitive under experimental conditions. Compared to the check, balanced fertilization increased wheat yield by 186 kg/ha or 4.0 percent, while liming the acid soil to the target pH 5.5 in combination with balanced fertilization increased yield by 1,340 kg/ha or 28.8 percent. Using the same treatments, corn yield only increased by 105 kg/ha or 1.2 percent and 330 kg/ha or 4.1 percent, respectively. Application of aglime with balanced fertilization proved to be an effective measure in promoting growth and preventing diseases in vegetables grown on the Chengdu plain.

This technique can be applicable to large areas of acid soils in southwest China including, Sichuan, Chongqing, Yunnan, and Guizhou. The increased potential for P and K in combination with aglime is substantial. SICHUAN-15