The Conservation Reserve Program (CRP) is a USDA program introduced in 1985 to reduce soil erosion by increasing vegetative cover of highly erodible land. Participation in the CRP is done via contracts (10 - 15 years ...The Conservation Reserve Program (CRP) is a USDA program introduced in 1985 to reduce soil erosion by increasing vegetative cover of highly erodible land. Participation in the CRP is done via contracts (10 - 15 years in length) and currently the total area of land under contract is set to decline as per the 2014 Farm Bill. The Texas High Plains (THP) leads the US with >900,000 ha enrolled in CRP. A potential long- term benefit of CRP is to increase soil organic matter and to improve soil structure leading to increased water infiltration. Our objective was to evaluate the feasibility of using stable isotopes of water to measure and compare infiltration of rain in land under CRP management to land under continuous dryland cotton in the THP. For this purpose we selected two sites, with soils in the Amarillo series, enrolled in CRP, one for 25 years and the second site for 22 years. Results from several rain events showed that stable isotopes of water are a method that can be used to evaluate the depth of rainwater infiltration for soils under CRP and dryland management.展开更多
Regions of land that are brought into crop production from native vegetation typically undergo a period of soil erosion instability,and long term erosion rates are greater than for natural lands as long as the land co...Regions of land that are brought into crop production from native vegetation typically undergo a period of soil erosion instability,and long term erosion rates are greater than for natural lands as long as the land continues being used for crop production.Average rates of soil erosion under natural,non-cropped conditions have been documented to be less than 2 Mg ha^(-1) yr^(-1).On-site rates of erosion of lands under cultivation over large cropland areas,such as in the United States,have been documented to be on the order of6 Mg ha^(-1) yr^(-1)or more.In northeastern China,lands that were brought into production during the last century are thought to have average rates of erosion over this large area of as much as 15 Mg ha^(-1) yr^(-1) or more.Broadly applied soil conservation practices,and in particular conservation tillage and no-till cropping,have been found to be effective in reducing rates of erosion,as was seen in the United States when the average rates of erosion on cropped lands decreased from on the order of 9Mg ha^(-1) yr^(-1) to 6 or 7Mg ha^(-1) yr^(-1) between 1982 and 2002,coincident with the widespread adoption of new conservation tillage and residue management practices.Taking cropped lands out of production and restoring them to perennial plant cover,as was done in areas of the United States under the Conservation Reserve Program,is thought to reduce average erosion rates to approximately 1 Mg ha^(-1) yr^(-1) or less on those lands.展开更多
文摘The Conservation Reserve Program (CRP) is a USDA program introduced in 1985 to reduce soil erosion by increasing vegetative cover of highly erodible land. Participation in the CRP is done via contracts (10 - 15 years in length) and currently the total area of land under contract is set to decline as per the 2014 Farm Bill. The Texas High Plains (THP) leads the US with >900,000 ha enrolled in CRP. A potential long- term benefit of CRP is to increase soil organic matter and to improve soil structure leading to increased water infiltration. Our objective was to evaluate the feasibility of using stable isotopes of water to measure and compare infiltration of rain in land under CRP management to land under continuous dryland cotton in the THP. For this purpose we selected two sites, with soils in the Amarillo series, enrolled in CRP, one for 25 years and the second site for 22 years. Results from several rain events showed that stable isotopes of water are a method that can be used to evaluate the depth of rainwater infiltration for soils under CRP and dryland management.
文摘Regions of land that are brought into crop production from native vegetation typically undergo a period of soil erosion instability,and long term erosion rates are greater than for natural lands as long as the land continues being used for crop production.Average rates of soil erosion under natural,non-cropped conditions have been documented to be less than 2 Mg ha^(-1) yr^(-1).On-site rates of erosion of lands under cultivation over large cropland areas,such as in the United States,have been documented to be on the order of6 Mg ha^(-1) yr^(-1)or more.In northeastern China,lands that were brought into production during the last century are thought to have average rates of erosion over this large area of as much as 15 Mg ha^(-1) yr^(-1) or more.Broadly applied soil conservation practices,and in particular conservation tillage and no-till cropping,have been found to be effective in reducing rates of erosion,as was seen in the United States when the average rates of erosion on cropped lands decreased from on the order of 9Mg ha^(-1) yr^(-1) to 6 or 7Mg ha^(-1) yr^(-1) between 1982 and 2002,coincident with the widespread adoption of new conservation tillage and residue management practices.Taking cropped lands out of production and restoring them to perennial plant cover,as was done in areas of the United States under the Conservation Reserve Program,is thought to reduce average erosion rates to approximately 1 Mg ha^(-1) yr^(-1) or less on those lands.
