HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Arya, L. M. Articles by Farrell, D. A. Search for Related Content PubMed Articles by Arya, L. M. Articles by Farrell, D. A. Agricola Articles by Arya, L. M. Articles by Farrell, D. A.

A Field Study of Soil Water Depletion Patterns in Presence of Growing Soybean Roots: II. Effect of Plant Growth on Soil Water Pressure and Water Loss Patterns¹

ABSTRACT

Soil-water pressure and water-loss patterns in the root zone of soybean (Glycine max L.) genotype P.I. 79.648 were determined from daily observations during irrigation-drying cycles for four growth periods after planting. Tensiometric measurements of soil water pressure were made on a 10-cm square grid from one plant row to an adjacent one spaced 80 cm apart, and between 10- and 70-cm depths. Water contents were inferred from pressure-water content relationships.

During the first irrigation-drying cycle, soil-water pressures were marked by strong lateral and vertical gradients. As plants aged from one irrigation-drying cycle to the next, these gradients decreased; soil-water pressures at most depths decreased more slowly with the drying time. The proportional contribution of surface layers to the total water loss from the 10- to 70-cm depth interval decreased as the plants matured while contributions from the lower layers increased. These changing patterns of soil-water pressure and water loss are consistent with the expected shift in root activity.

¹ Contribution from the Minnesota Agricultural Experiment Station, Univ. of Minn., Scientific Journal Series Paper 8661, and the North Central Region, ARS, USDA, St. Paul, 55108. This investigation was supported by funds provided in part by the US Dept. of Interior, Office of Water Resour. Res. under act of 1964, P. L. 88-369.

² Research Assistant, Professor of Soil Science, and Soil Scientist (ARS, USDA), Univ. of Minn., St. Paul. The senior author is now in the Dept. of Soil Sci., Univ. of the West Indies, St. Augustine, Trinidad. Present address of the third author is Div. of Soils, CSIRO, Glen Osmond, South Australia 5064.

Received for publication April 11, 1974. Accepted for publication January 8, 1975.

This article has been cited by other articles:

				L. R. Ahuja, L. Ma, and D. J. Timlin Trans-Disciplinary Soil Physics Research Critical to Synthesis and Modeling of Agricultural Systems Soil Sci. Soc. Am. J., February 2, 2006; 70(2): 311 - 326. [Abstract] [Full Text] [PDF]