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

In 2005, this sloping lands study continued to monitor soil conservation, soil properties, crop yields, and farmers’ income resulting from the combined effect of balanced fertilization (BF) plus alley cropping using cash crop hedgerows.

Soil erosion continued to be positively correlated with rainfalls from May to June when corn plants were establishing and the field was evolving from erosive bare soil to increasing crop coverage. No obvious relationship between rainfall and erosion was observed after mid-July as the field was fully covered by the corn canopy. No soil erosion was recorded for the BF+hedgerow treatment. All treatments without cash crop hedgerows produced negative net income ranging from -US$3.2/ha (BF alone) to -US$81.9/ha [farmers’ practice (FP)]. The two hedgerow treatments produced net incomes of US$117/ha (FP+HR) and US$223/ha (BF+hedgerows). Cash crop hedgerows have formed permanent ridges with deeply anchored roots and dense aboveground portions which effectively block soil from washing down. After 5 years, these firm bunds now function as 'natural' terraces. This integrated technology has also increased soil profile moisture during the growing season, which helps to protect crop growth against minor drought. Yunnan-09