Nutrient Management Strategies for Sloping Lands in Guizhou
IPNI-1999-CHN-GZ11
30 Jan 2007
2006 Annual Interpretive Summary
Effect of Different Cash Crop Hedgerows and Land Use Patterns on Soil Conservation of Sloping Lands in Guizhou, 2006
This study was initiated in 2004 to monitor and evaluate various patterns of land use with or without established hedgerows in order to select and extend optimal land use practices for sloping lands in the region. Field experiments consisted of nine treatments including: alley cropping (corn - soybean - sweet potato - rape), grain crops interplanted with forage (corn - alfalfa), fruit trees (plum), engineered terraces with corn, two cash crop hedgerow systems (HR1 = daylily + corn) or (HR2 = Polygonum cymosum Trev + plum tree + corn), grass (grass + chicory), contour cultivation with corn, and down slope cultivation with corn.
Data obtained in 2006 showed trends similar to those observed in 2005. Soil erosion and water runoff were highly correlated with rainfall quantity from March to October, forming two peak values, one in June and one in August. Of the two peaks of soil and water losses, June was the most significant. The degree of land coverage significantly affected soil erosion. Land use patterns had a dramatic effect on soil erosion, which ranged from 13.4 to 70.4 t/ha under the following treatment order: grass < grain crop interplanting forage < fruit trees < HR1 < engineering terrace < alley cropping < HR2 < contour cultivation < down slope cultivation. Water losses from different treatments followed an order of grain crop interplanting forage < grass < HR1 < engineering terrace < HR2 < contour cultivation < fruit trees < alley cropping < down slope cultivation.
After further in-depth analysis of the effectiveness of these different patterns on soil erosion, contour cultivation and down slope cultivation can be classified as highly-erosive cultivation patterns, and all the others can be considered as highly effective means of controlling soil erosion. In terms of runoff control, the treatments including down slope cultivation, alley cropping, contour cultivation, and fruit trees fell into the ineffective group, while all others were considered highly effective. The results are very helpful in screening out the practices suitable for use under the more erosive conditions or for soils more prone to runoff. The integration of balanced fertilization and daylily + corn (HR1) substantially improved crop yields and greatly reduced soil erosion on sloping lands. The net income gain for 2006 was US$1,275/ha, which is nearly 15 times the expected earnings from common farmer practice of US$85/ha. Guizhou-NMS-03