Aglime application for amelioration of acid yellow-red soil in South Anhui

There are about 1.2 million hectares (ha) of yellow-red soil in Anhui province, and it is widely scattered throughout southern China. The soil pH ranges between 4.5 to 5.3. The soil is not suitable for cultivation. Dolomite is a locally made, cost effective material, and its application to the area would bring the land into production and increase crop yields.

Rapeseed and soybean were planted at a fixed site in order to study the residual effects of previously applied dolomite on ameliorating acidic soils. Five rates (0 to 2,500 kg/ha) of dolomite were applied in 1998. Nitrogen (N), phosphorus (P), and potassium (K) were applied to rapeseed at 180-90-120 kg N-P₂O₅-K₂O/ha and at 40-90-120 kg N-P₂O₅-K₂O/ha for soybean. Rapeseed yield increased with higher rates of dolomite application. The highest rapeseed yield (2,170 kg/ha) was obtained with 1,600 kg dolomite/ha, which was 27 percent higher than the control. Dolomite application at 600, 1,100, and 2,500 kg/ha increased yield by 12, 22, and 19 percent, respectively, over the control. Net incomes from rapeseed with dolomite was US$48 to US$105/ha higher than the control. Net income from appying 1,600 kg dolomite/ha was US$494/ha. Soybean plots experienced drought stress; however, yields with dolomite were 7 to 30 percent higher than the control. The best treatment provided a net income that was US$143/ha over the control.

Lower rates of dolomite application became ineffective two years after application. However, the moderate and high rates still had positive impacts after two years. This experiment will be continued to determine the duration of crop response to residual dolomite and the required rate and frequency for its application. ANHUI-09