Nutrient Management Strategies for Sloping Lands in Guizhou
IPNI-1999-CHN-GZ11
16 Jan 2006
2005 Annual Interpretive Summary
Effect of Different Cash Crop Hedgerows and Land Use Patterns on Soil Conservation of Sloping Lands in Guizhou, 2005
The purpose of the study is to monitor and evaluate various patterns of established cash crop hedgerows in Guizhou in order to select and extend optimal land use practices for sloping lands in the region. Field experiments were upgraded to 10 treatments based on results from 2004. Treatments included: alley cropping (corn-soybean-sweet potato-rape), grain crops interplanted with forage (corn-alfalfa), fruit trees (plum), engineered terraces with corn, cash crop hedgerow (day lily+corn), cash crop hedgerow (buckwheat+plum tree), grass (grass+chicory), contour cultivation with corn, downslope cultivation with corn, and bare land.
Soil erosion was highly correlated with rainfall quantity prior to July and reached its peak value (R=0.98) in June. Water run-off formed two peak values, one in June (R=0.91) and one in August (R=0.88). The degree of land coverage significantly affected soil erosion. Land use patterns had a dramatic effect on soil erosion, which ranged from 9.7 to 69.9 t/ha under the following treatment order: grass < grain crop interplanting forage < fruit trees < hedgerow (day lily+corn) < engineering terrace < alley cropping < hedgerow (buckwheat + plum tree) < contour cultivation < downslope cultivation < bare land. Of course, the bare land treatment provided the worst protection against soil erosion (6,440 t/ha), which was followed by the traditional practice of downslope cultivation with 69.9 t/ha in soil erosion and 1,730 t/ha in run-off (equivalent to about 200 mm in lost rainwater).
The integration of balanced fertilization and hedgerow (day lily+corn) and contour cultivation substantially improved crop yields and greatly reduced soil erosion on sloping lands. The net income gain for 2005 was US$995/ha, which is nearly 14 times the expected earnings from common farmer practice of US$72/ha. Guizhou-NMS03