Some Empirical Relations of Soil‐Moisture Tensions

Abstract

An analysis was made to compare methods of designating soil mositure tension for an entire irrigation season. Using the field data from a sugar‐beet irrigation experiment, seasonal values for soil‐moisture tension at a given depth were calculated as a simple mean of all readings, and as a mean of the tensions just prior to each irrigation. These values were found to correlate closely with mean tensions calculated similarly to Taylor's mean integrated tension for a single depth. Yields were found to correlate equally well with either mean integrated tension or the mean of tensions prior to irrigation. Under soil and growth conditions encountered, no advantage was found in using mean integrated soil‐moisture tension or the arithmetic mean of all readings, in preference to the simpler mean of pre‐irrigation tensions.

The Effect of Farmyard Manure on Matric Suctions Prevailing in a Sandy Loam Soil

“…Various methods have been proposed for combining soilmoisture suctions into single values to relate to plant response. These include the use of arithmetic means of suctions (Miller, 1954), integration over depth and time (Taylor,195z), and various weightings of mean suction based on root distribution (Taylor, 1965), while Webster (1966) has argued for the use of geometric means of suctions. For this work geometric mean suctions at each depth were weighted on the basis of the estimated distribution of roots in the profile.…”