Fertilizer Use on Different Upland Cropping Systems for Soil Conservation in Yunnan

Balanced fertilization (BF) with nitrogen (N), phosphorus (P), and potassium (K) plus alley cropping, a system using hedgerow cash crops, is a profitable and effective new alternative to engineered terraces. This project introduced the technology, by transfer and subsequent adaptation of the Sichuan model, to erosion prone regions (Xiangyun and Fuming counties) in Yunnan.

Xiangyun: The BF treatment was 150-120-90 kg N-P₂O₅-K₂O/ha plus 1.4 kg zinc (Zn) and 1.0 kg boron (B)/ha, while farmer fertilization practice was 180-120-0 kg/ha. Compared to: (1) farmer practice, treatments using down-slope cultivation plus BF; (2) contour cultivation plus BF; and (3) contour cultivation plus BF and hedgerows, the corn yields were respectively increased by 477 kg/ha, 1,059 kg/ha, and 1,244 kg/ha. Soil loss was reduced by 9.1 t/ha (18%), 39.6 t/ha (79%), and 44.9 t/ha (90%) for the three improved treatments. Under common farmer practice, soil loss was 50.2 t/ha.

Fuming: The BF treatment was 150-150-60 kg/ha plus 1.5 kg B/ha, while farmer practice was 180-100-0 kg/ha. Compared to farmer practice, treatments (1), (2), and (3) increased corn yield by 538 kg/ha, 990 kg/ha, and 878 kg/ha, respectively. Soil loss was reduced by 1.5 t/ha (63%), 1.8 t/ha (76%), and 2.1 t/ha (90%) for the three improved treatments. Soil loss with common practice amounted to 2.3 t/ha.

Net income for the best treatment, contour cultivation plus BF plus hedgerows, was US$815/ha at Xiangyun and US$481 at Fuming. This integrated technology also increased soil moisture by 1 to 4% during the growing season, which improved crop resistance to minor drought. Benefits of this technology are being disseminated through a continuing demonstration and extension program in the province. Yunnan-09