Certain irrigation practices degrade soil quality and reduce agricultural productivity.
某些灌溉措施会降低土壤质量，降低农业生产力。
Under the irrigation conditions at present, the main limited factor of productivity is soil quality.
在现有灌溉条件下，土壤质量是制约生产力的主导因子。
The results revealed soil erosion types diversified, erosion module was higher, the effects of soil erosion on land productivity mainly involved intodestroying land quality and reducing crop yield.
分析结果表明：该区土壤侵蚀类型多样，侵蚀模数高； 土壤侵蚀对土地生产力的影响主要表现为破坏土地质量，降低农作物产量。
The quality and productivity of sedge pasture in the alpine meadow area are determined by the moisture ana nutrient of the soil.
高寒草甸莎草科草地的土壤水分和营养决定着草地质量及其生产能力。
As the main reason for the worse water quality, agricultural non-point pollution, which also causes soil productivity to degenerate directly, is tightly related with the hydrological process.
农业非点源污染是水系或水体水质恶化的最主要原因，同时也是土地生产力退化的直接动因，农业非点源污染又往往与流域水文过程具有不可分割的关系。
As the main reason for the worse water quality, agricultural non-point pollution, which also causes soil productivity to degenerate directly, is tightly related with the hydrological process.
农业非点源污染是水系或水体水质恶化的最主要原因，同时也是土地生产力退化的直接动因，农业非点源污染又往往与流域水文过程具有不可分割的关系。
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