Soil loss tolerance

{{Dablink|T value redirects here. For the statistical test, see [[Student's t-test]].}}

'''Soil loss tolerance''' for a specific soil, also known as the '''T value''', which can be calculated with $T=\backslash upsilon\; Q\; \backslash rho\; C\; +R(1-C)${{Cite journal |last1=Li |first1=Yue |last2=Bai |first2=Xiao Yong |last3=Wang |first3=Shi Jie |last4=Qin |first4=Luo Yi |last5=Tian |first5=Yi Chao |last6=Luo |first6=Guang Jie |date=2017-05-29 |title=Evaluating of the spatial heterogeneity of soil loss tolerance and its effects on erosion risk in the carbonate areas of southern China |url=https://se.copernicus.org/articles/8/661/2017/ |journal=Solid Earth |language=English |volume=8 |issue=3 |pages=661–669 |doi=10.5194/se-8-661-2017 |issn=1869-9510|doi-access=free |bibcode=2017SolE....8..661L }} formula, is the maximum average annual [[soil loss]] expressed as tons per acre per year that will permit current production levels to be maintained economically and indefinitely. T values range from 1 to 5 tons per acre per year.{{cite web|url=http://www.iwr.msu.edu/rusle/tvalue.htm|title=T Value|publisher=NRCS-USDA State Office of Michigan|accessdate=9 December 2015}} According to the [[United States Department of Agriculture]]'s [[National Resource Conservation Service]], in 2007 in the US, 99 million acres (28% of all cropland) were eroding above soil loss tolerance (T) rates. This was compared to 169 million acres (40% of cropland) in 1982.{{cite web|url=https://www.nrcs.usda.gov/wps/portal/nrcs/detail/?ss=16&navtype=SUBNAVIGATION&cid=stelprdb1041887&navid=120110110000000&pnavid=120110000000000&position=Not%20Yet%20Determined.Html&ttype=detail&pname=Soil%20Erosion%20on%20Cropland%202007%20%7C%20NRCS |archive-url=https://web.archive.org/web/20120319153417/http://www.nrcs.usda.gov/wps/portal/nrcs/detail/?ss=16&navtype=SUBNAVIGATION&cid=stelprdb1041887&navid=120110110000000&pnavid=120110000000000&position=Not%20Yet%20Determined.Html&ttype=detail&pname=Soil%20Erosion%20on%20Cropland%202007%20%7C%20NRCS |url-status=dead |archive-date=March 19, 2012 |title=Soil Erosion on Cropland 2007 | NRCS |publisher=Nrcs.usda.gov |date= |accessdate=2011-09-11}} T-value's validity is questionable since T-values are [[Spatial heterogeneity|spatially heterogeneous]]. {{Cite journal |last1=Li |first1=Yue |last2=Bai |first2=Xiao Yong |last3=Wang |first3=Shi Jie |last4=Qin |first4=Luo Yi |last5=Tian |first5=Yi Chao |last6=Luo |first6=Guang Jie |date=2017-05-29 |title=Evaluating of the spatial heterogeneity of soil loss tolerance and its effects on erosion risk in the carbonate areas of southern China |url=https://se.copernicus.org/articles/8/661/2017/ |journal=Solid Earth |language=English |volume=8 |issue=3 |pages=661–669 |doi=10.5194/se-8-661-2017 |issn=1869-9510|doi-access=free |bibcode=2017SolE....8..661L }}

'''Soil loss tolerance''' for a specific soil, also known as the '''T value''', which can be calculated with $T=\backslash upsilon\; Q\; \backslash rho\; C\; +R(1-C)${{Cite journal |last1=Li |first1=Yue |last2=Bai |first2=Xiao Yong |last3=Wang |first3=Shi Jie |last4=Qin |first4=Luo Yi |last5=Tian |first5=Yi Chao |last6=Luo |first6=Guang Jie |date=2017-05-29 |title=Evaluating of the spatial heterogeneity of soil loss tolerance and its effects on erosion risk in the carbonate areas of southern China |url=https://se.copernicus.org/articles/8/661/2017/ |journal=Solid Earth |language=English |volume=8 |issue=3 |pages=661–669 |doi=10.5194/se-8-661-2017 |issn=1869-9510|doi-access=free |bibcode=2017SolE....8..661L }} formula, is the maximum average annual [[soil loss]] expressed as tons per acre per year that will permit current production levels to be maintained economically and indefinitely. T values range from 1 to 5 tons per acre per year.{{cite web|url=http://www.iwr.msu.edu/rusle/tvalue.htm|title=T Value|publisher=NRCS-USDA State Office of Michigan|accessdate=9 December 2015}} According to the [[United States Department of Agriculture]]'s [[National Resource Conservation Service]], in 2007 in the US, 99 million acres (28% of all cropland) were eroding above soil loss tolerance (T) rates. This was compared to 169 million acres (40% of cropland) in 1982.{{cite web|url=https://www.nrcs.usda.gov/wps/portal/nrcs/detail/?ss=16&navtype=SUBNAVIGATION&cid=stelprdb1041887&navid=120110110000000&pnavid=120110000000000&position=Not%20Yet%20Determined.Html&ttype=detail&pname=Soil%20Erosion%20on%20Cropland%202007%20%7C%20NRCS |archive-url=https://web.archive.org/web/20120319153417/http://www.nrcs.usda.gov/wps/portal/nrcs/detail/?ss=16&navtype=SUBNAVIGATION&cid=stelprdb1041887&navid=120110110000000&pnavid=120110000000000&position=Not%20Yet%20Determined.Html&ttype=detail&pname=Soil%20Erosion%20on%20Cropland%202007%20%7C%20NRCS |url-status=dead |archive-date=March 19, 2012 |title=Soil Erosion on Cropland 2007 | NRCS |publisher=Nrcs.usda.gov |date= |accessdate=2011-09-11}} T-value's validity is questionable since T-values are [[Spatial heterogeneity|spatially heterogeneous]]. {{Cite journal |last1=Li |first1=Yue |last2=Bai |first2=Xiao Yong |last3=Wang |first3=Shi Jie |last4=Qin |first4=Luo Yi |last5=Tian |first5=Yi Chao |last6=Luo |first6=Guang Jie |date=2017-05-29 |title=Evaluating of the spatial heterogeneity of soil loss tolerance and its effects on erosion risk in the carbonate areas of southern China |url=https://se.copernicus.org/articles/8/661/2017/ |journal=Solid Earth |language=English |volume=8 |issue=3 |pages=661–669 |doi=10.5194/se-8-661-2017 |issn=1869-9510|doi-access=free |bibcode=2017SolE....8..661L }}