Quality and Crop Yield Potential of Moderately Degraded Alfisols Under Different Nutrient Inputs and Cropping Patterns

【摘要】 Crop performance on degraded soil needs special management practices to overcome soil quality limitations. In a 2-year（from summer 2006 to winter 2007–2008） field trial on a moderately degraded Alfisol in Swabi District（34°7′12′′N, 72°28′20′′E）, Pakistan,the effects of three cropping patterns, cereal-cereal（CC）, cereal-legume（CL）, and cereal-cereal and legume intercrop（CLI）, were tested in main plots under four fertilization treatments in sub-plots, including no fertilization（control）, farmers’ practice(FP, 60:45 kg ha^-1 N:P₂O₅), recommended dose(RD, 120:90:60 kg ha^-1 N:P₂O₅:K₂O), and integrated nutrient management(INM, 20 t ha^-1 farmyard manure integrated with 50% N, 100% P, and K of recommended dose), using a split-plot randomized complete block design. The performance of CL was superior than CC in plant height, leaf area index（LAI）, cob length, grain yield, biological yield, and grain protein（8%, 26%, 8%, 5%, 10%, and 8% increases, respectively）, while CLI confirmed significant improvement only in LAI（25%） over CC. Response to nutrient inputs from all sources was in the order of INM > RD > FP > control, and the maximum net economic return by INM（23% and 2.5 times higher than RD and FP, respectively） indicated severe deficiency of both macro-and micro-nutrients in the soil as well as degraded physical properties. Increases in soil organic matter, total N, total mineral N, available P and K, total porosity, and available water-holding capacity by 6%, 34%, 24%, 50%, 13%, 5%, and 7%, respectively, and decrease in soil bulk density by 4% after four crop seasons indicated optimistic changes in soil quality as a result of the combined effects of fertilization from organic and inorganic sources and legumes within crop rotation. This study suggests that keeping the soil covered under cereal-legume rotation crops all year round and treatment with INM（50% N from organic source and 50% from inorganic source） are the best management practice for sustained production on degraded Alfisols.更多还原

【Abstract】 Crop performance on degraded soil needs special management practices to overcome soil quality limitations. In a 2-year（from summer 2006 to winter 2007–2008） field trial on a moderately degraded Alfisol in Swabi District（34°7′12′′N, 72°28′20′′E）, Pakistan,the effects of three cropping patterns, cereal-cereal（CC）, cereal-legume（CL）, and cereal-cereal and legume intercrop（CLI）, were tested in main plots under four fertilization treatments in sub-plots, including no fertilization（control）, farmers’ practice(FP, 60:45 kg ha^-1 N:P₂O₅), recommended dose(RD, 120:90:60 kg ha^-1 N:P₂O₅:K₂O), and integrated nutrient management(INM, 20 t ha^-1 farmyard manure integrated with 50% N, 100% P, and K of recommended dose), using a split-plot randomized complete block design. The performance of CL was superior than CC in plant height, leaf area index（LAI）, cob length, grain yield, biological yield, and grain protein（8%, 26%, 8%, 5%, 10%, and 8% increases, respectively）, while CLI confirmed significant improvement only in LAI（25%） over CC. Response to nutrient inputs from all sources was in the order of INM > RD > FP > control, and the maximum net economic return by INM（23% and 2.5 times higher than RD and FP, respectively） indicated severe deficiency of both macro-and micro-nutrients in the soil as well as degraded physical properties. Increases in soil organic matter, total N, total mineral N, available P and K, total porosity, and available water-holding capacity by 6%, 34%, 24%, 50%, 13%, 5%, and 7%, respectively, and decrease in soil bulk density by 4% after four crop seasons indicated optimistic changes in soil quality as a result of the combined effects of fertilization from organic and inorganic sources and legumes within crop rotation. This study suggests that keeping the soil covered under cereal-legume rotation crops all year round and treatment with INM（50% N from organic source and 50% from inorganic source） are the best management practice for sustained production on degraded Alfisols.更多还原