Nutrient Management Strategies for Sloping Lands in Guizhou
IPNI-1999-CHN-GZ11
12 Jan 2005
2004 Annual Interpretive Summary
Nutrient Management Strategies for Sloping Lands in Guizhou, 2004
Previously supported research finds alley cropping to be an effective means of reducing soil erosion, and specifically, soil potassium (K) loss...both major agronomic concerns for developing sustainable crop production technologies on sloping lands. The integration of balanced fertilization (BF) substantially improves crop yields and further reduces soil erosion. Day lily+Chinese prickly ash (D+C) and polygonum cymosum trev + plum tree (P+P) were selected as two hedgerow cropping patterns to be compared against traditional engineered terraces (ET). Farmers' fertilization practice (FP) of applying 270-105-0 kg nitrogen (N)-phosphorus (P2O5)-K2O/ha was compared with the BF treatment of 270-105-105 kg/ha plus 6 kg zinc sulfate (ZnSO4)/ha. In 2004, the objective of this project was to better understand the mechanisms that alley cropping and balanced fertilization use to reduce soil erosion.
In the fifth year, soil erosion under each BF treatment was dramatically lower (15.7 to 22.7 t/ha) than under FP. More specifically, compared to FP, soil erosion under the BF, BF+(D+C), and BF+(P+P) treatments was 9.7 t/ha (- 62%), 2.7 t/ha (- 89%), and 2.9 t/ha (- 88%), respectively. Lower soil erosion under BF is attributed to increased plant growth and land coverage (22% higher than FP in July). Integrating BF with alley cropping further increased land coverage by 15% compared to BF alone.
The effect of BF, alone or in combination with alley cropping, significantly increased corn yield, showing a trend similar to the previous year. Hedgerow cash crops are producing considerable economic returns for farmers. BF+(P+P) and BF+(D+C) treatments returned a net income of US$1,438/ha and US$1,448/ha, respectively, or 262% and 266% higher than FP. Large-scale demonstration and extension of this technology continues under provincial government sponsorship. Guizhou-NMS03