四分之一(加拿大硬币)
种植
农业
土壤水分
环境科学
农业经济学
地理
作物
腐蚀
农林复合经营
农学
水文学(农业)
土壤科学
林业
地质学
经济
考古
生物
古生物学
岩土工程
作者
R. A. Brink,J. W. Densmore,G. A. Hill
出处
期刊:Science
[American Association for the Advancement of Science]
日期:1977-08-12
卷期号:197 (4304): 625-630
被引量:31
标识
DOI:10.1126/science.197.4304.625
摘要
A recent survey of five watersheds in south-central Wisconsin, where corn is now the dominant annual crop, illustrates the soil erosion damage that is occurring on sloping land under modern agricultural technology and prevailing market forces. In 70 percent of the 93 quarter-sections sampled, estimated soil losses, on the average, were more than twice the amounts considered compatible with permanent agriculture. Scattered studies by others indicate that the findings are meaningful for a large area in the United States when row cropping is prevalent on sloping soils.
科研通智能强力驱动
Strongly Powered by AbleSci AI