Taking west Jilin Province as an example, this paper put forward the assessment index of salinization, and based on it, the authors present the distribution characteristics of saline-alkali soil in the 1980s and the 1...Taking west Jilin Province as an example, this paper put forward the assessment index of salinization, and based on it, the authors present the distribution characteristics of saline-alkali soil in the 1980s and the 1990s in west Jilin and analyze its physical and chemical properties in detail. The developing tendency of salinization was also inferred by comparing the saline-alkali soil of the 1980s with that of the 1990s. Finally, the natural and human factors leading to salinization are analyzed.展开更多
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 Distr...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:P_2O_5), recommended dose(RD, 120:90:60 kg ha^(-1) N:P_2O_5:K_2O), 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.展开更多
Construction in urban zones compacts the soil, which hinders root growth and infiltration and may increase erosion and degrade water quality. The purpose of our study was to determine whether planting prairie grasses ...Construction in urban zones compacts the soil, which hinders root growth and infiltration and may increase erosion and degrade water quality. The purpose of our study was to determine whether planting prairie grasses and adding compost to urban soils should partially mitigate these concerns. We simulated construction activities by removing the topsoil, and compacting the soil by repeatedly driving over it with a tractor. Additionally, treatments included three compost application methods (compost and aeration, rototill and compost, surface compost). Plots were subjected to simulated rainfall applied using overhead sprinklers at a rate of 65 or 72 mm·h-1. Bulk density was significantly reduced in surface soil where compost had been added. Compost plus prairie grasses resulted in significantly faster infiltration (63 vs. 52 mm·h-1), slower runoff (4 vs. 25 mm·h-2), less soil loss (25 vs. 119 kg·Ha-1·h-1), and reduced loss of ortho P (57 vs. 410 g·Ha-1) compared to plots planted with bluegrass (Poa pratensis L.). A 5 to 7.5 cm thick compost blanket reduced time to runoff (60 min) compared to no compost addition (9 min). Topsoil addition without compost did not develop dark surface soil. Compost additions are recommended to reduce negative effects of urban compaction. Over time, the depth of compost additions decreased, necessitating further additions.展开更多
基金National Natural Science Foundation of China, No.49671077 Project of Jilin Provincial Committee for Science and Technology, No.
文摘Taking west Jilin Province as an example, this paper put forward the assessment index of salinization, and based on it, the authors present the distribution characteristics of saline-alkali soil in the 1980s and the 1990s in west Jilin and analyze its physical and chemical properties in detail. The developing tendency of salinization was also inferred by comparing the saline-alkali soil of the 1980s with that of the 1990s. Finally, the natural and human factors leading to salinization are analyzed.
文摘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:P_2O_5), recommended dose(RD, 120:90:60 kg ha^(-1) N:P_2O_5:K_2O), 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.
文摘Construction in urban zones compacts the soil, which hinders root growth and infiltration and may increase erosion and degrade water quality. The purpose of our study was to determine whether planting prairie grasses and adding compost to urban soils should partially mitigate these concerns. We simulated construction activities by removing the topsoil, and compacting the soil by repeatedly driving over it with a tractor. Additionally, treatments included three compost application methods (compost and aeration, rototill and compost, surface compost). Plots were subjected to simulated rainfall applied using overhead sprinklers at a rate of 65 or 72 mm·h-1. Bulk density was significantly reduced in surface soil where compost had been added. Compost plus prairie grasses resulted in significantly faster infiltration (63 vs. 52 mm·h-1), slower runoff (4 vs. 25 mm·h-2), less soil loss (25 vs. 119 kg·Ha-1·h-1), and reduced loss of ortho P (57 vs. 410 g·Ha-1) compared to plots planted with bluegrass (Poa pratensis L.). A 5 to 7.5 cm thick compost blanket reduced time to runoff (60 min) compared to no compost addition (9 min). Topsoil addition without compost did not develop dark surface soil. Compost additions are recommended to reduce negative effects of urban compaction. Over time, the depth of compost additions decreased, necessitating further additions.
