Author : Latief Mahir Rachman

Summary : Field and laboratory studies were conducted to evaluate the sustainability of alley cropping systems (with and without mulching) and farmer's practice as well as to improve the existing cropping systems for more sustainable agriculture. Runoff, soil erosion, and nutrient loss; some soil biological, physical, and chemical properties; concentration of nutrients in soil solution; and grain yield were determined during the 1995 wet cropping after six years of cropping experiement. Together with data from the six-year cropping experiment, the results were used to evaluate soil productivity, soil quality, and sustainability potential of the three cropping treatments. Alley cropping with mulching was the best among the cropping systems studied and considered the most promising alternative for sustainable upland crop production systems for sloping agricultural lands. It also reduced runoff, soil erosion, and nutrient loss. It prevented the rapid deterioration of soil quality and provided better nutrient cycling, promoted biodiversity, produced higher crop yield, and was less dependent on external inputs (inorganic fertilizer) than the traditional farmer's practice. Soil loss under alley cropping with mulch was 9.6 ton/ha, which was much lower than loss due to farmers' practice (117.0 ton/ha) and alley cropping without mulching (42.2 ton/ha). Nutrient losses due to soil erosion and runoff was minimized. Alley cropping with mulch had the highest soil quality for crop or soil productivity and soil quality for crop productivity and environmental stability as compared with the farmers' practice. Also, only one limiting factor was noted for crop productivity in this cropping system as compared to four limiting factors in the farmers' practice. In alley cropping with mulch, nine tons dry matter of green manure was produced during corn cropping season. Since these were used as mulch or organic fertilizer, it provided 192 kg nitrogen (N), 16 kg phosphorus (P), and 168 kg potassium (K) per hectare. This recycled biomas.