Fertilizer Use on Different Upland Cropping Systems for Soil Conservation in Yunnan
IPNI-1997-CHN-YN9
30 Jan 2007
2006 Annual Interpretive Summary
Sloping Land Management Using Balanced Fertilization and Cash Crop Hedgerows in Yunnan, 2006
In 2004 and 2005, this sloping lands study focused on monitoring soil conservation, soil properties, crop yields, and farmers’ income as affected by the combined effect of balanced fertilization (BF) plus alley cropping using cash crop hedgerows. As the hedgerow crops grow bigger, their effects from shading, root system proliferation, and competition for moisture and nutrients on in-field crops have become evident, especially for the woody species of hedge plants. Therefore, the objective of this project was to assess the degree of hedgerow impact on annual crop yields and to further improve the fertilizer program for these sloping lands.
Compared to farmers’ practice (FP), most other improved practices boosted corn yield by 23 to 30%. The combination of FP plus Chinese prickly ash hedgerows (FP+A), reduced corn yield by about 5%. Among all treatments, the balanced fertilization (BF) treatment produced the maximum corn yield. The BF treatment produced 3% more yield than the balanced fertilization + hedgerows (BF+H) treatment. The yield reduction under BF+H could be attributed to hedgerow occupation of land and its competition with corn for nutrients, as evidenced by smaller corn plants near hedgerow locations. However, when the income generated from the cash crop hedgerows is considered, the BF+H treatment still turns out to be more beneficial than the BF treatment alone. Net income under BF+H was US$137/ha more than BF, and US$339/ha higher than FP. The adverse effect of hedgerows on in-field corn yield can be, at least partly, overcome by proper fertilization of the hedgerow crops. Cash crop hedgerows have formed permanent ridges with deeply anchored roots and dense aboveground portions which effectively block soil from washing down from the upper plots to the lower plots. With time, these firm bunds now function as ‘natural’ terraces. Because 2006 was a relatively dry year, there was no soil erosion measured from the BF+A treatment. However, the amount of soil erosion recorded in the BF alone was 688 kg/ha and 1,640 kg/ha from the FP treatment. Yunnan-09