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Aggregating available soil water holding capacity data for crop yield modelsThe total amount of water available to plants that is held against gravity in a soil is usually estimated as the amount present at -0.03 MPa average water potential minus the amount present at -1.5 MPa water potential. This value, designated available water-holding capacity (AWHC), is a very important soil characteristic that is strongly and positively correlated to the inherent productivity of soils. In various applications, including assessing soil moisture status over large areas, it is necessary to group soil types or series as to their productivity. Current methods to classify AWHC of soils consider only total capacity of soil profiles and thus may group together soils which differ greatly in AWHC as a function of depth in the profile. A general approach for evaluating quantitatively the multidimensional nature of AWHC in soils is described. Data for 902 soil profiles, representing 184 soil series, in Indiana were obtained from the Soil Characterization Laboratory at Purdue University. The AWHC for each of ten 150-mm layers in each soil was established, based on soil texture and parent material. A multivariate clustering procedure was used to classify each soil profile into one of 4, 8, or 12 classes based upon ten-dimensional AWHC values. The optimum number of classes depends on the range of AWHC in the population of oil profiles analyzed and on the sensitivity of a crop to differences in distribution of water within the soil profile.
Document ID
19840019185
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Seubert, C. E. (Purdue Univ. West Lafayette, IN, United States)
Daughtry, C. S. T. (Purdue Univ. West Lafayette, IN, United States)
Holt, D. A. (Purdue Univ. West Lafayette, IN, United States)
Baumgardner, M. F. (Purdue Univ. West Lafayette, IN, United States)
Date Acquired
September 4, 2013
Publication Date
January 1, 1984
Subject Category
Earth Resources And Remote Sensing
Report/Patent Number
E84-10161
LARS-TR-011584
NAS 1.26:171791
NASA-CR-171791
Accession Number
84N27253
Funding Number(s)
CONTRACT_GRANT: NAS9-16528
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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