Nutrient Management Strategies for Sloping Lands in Guizhou

The project aims to quantify the effectiveness of alley-cropping in reducing soil and potassium (K) loss and to develop a balanced fertilization (BF) program for the erosive soils and landscapes in southwest China. Daylily + Chinese prickly ash (D+C) and Polygonum cymosum trev. + pear tree (P+P) were selected as the two patterns of hedgerow crops, and an engineered terrace (ET) was used as comparison treatment. The study is also examining the relative effectiveness of balanced fertilization [270-105-105-6 kg nitrogen (N)-P₂O₅-K₂O-zinc sulfate (ZnSO₄)/ha] versus farmer practice (270-105-0-0) on soil erosion.

Balanced fertilization (BF) alone or in combination with the two patterns of alley-cropping significantly increased corn yield by 980 to 1,150 kg/ha (19 to 23 percent) compared to farmer practice. Soil erosion for BF, BF+(D+C), and BF+(P+P) was dramatically reduced from 2,920 to 1,170 kg/ha, 157 kg/ha, and 165 kg/ha, and 60, 95 and 94 percent, respectively. Subsequent effects of the different soil conservation treatments were greater than the first year of measurement due to increased hedgerow crop growth. The ET treatment reduced soil loss by 1,910 kg/ha (65 percent) compared to the balanced fertilization alone, and crop yield was reduced by 816 kg/ha (16 percent) due to a reduction in the cropping area after construction of the terraces.

This technology can be applied to about 90,300 hectares (ha) of sloping lands in Guizhou province. GUIZHOU-NMS03