水田転換樹園地におけるインテークレイトの測定 Measurement of Intake Rates in a Paddy-converted Orchard
Measurement of cylinder intake rates in the soil right over the under-drainage pipes and between them has produced the following findings. Let Integrated Infiltration (D) and Intake Rate (I) be defined respectively by the following formulae : D=CT^n, I=60CnT^<n-1>, where T stands for the elapse of time and constant n for the gradient of the line which is formed by the Cartesian product of logarithmically adjusted D and T. (1) The values of this gradient obtained in the same test field were found to be nearly the same both over the under-drainage pipes and in the spaces between them. This suggests that constant n has something to do with the characteristics of the soil. (2) The values of constant C obtained right over the under-drainage pipes were found to be greater than those obtained between them. C is generally considered to be affected by soil moisture and soil structure. That is to say, the value of constant C is expected to increase in proportion to the efficiency of a drainage system. Conversely, the fact that the use of the under-drainage pipes increased the value of C shows that they have some degree of efficiency as a drainage system.
富山県立大学紀要 3, 219-223, 1993-03