TY - JOUR AU - Lugo López, M. A. PY - 1952/04/01 Y2 - 2024/03/29 TI - Available water capacity of the surface layer of various soils from the arid and semiarid region of Puerto Rico JF - The Journal of Agriculture of the University of Puerto Rico JA - JAUPR VL - 36 IS - 2 SE - Articles DO - 10.46429/jaupr.v36i2.12793 UR - https://revistas.upr.edu/index.php/jaupr/article/view/12793 SP - 134-140 AB - The available water of soils is considered to be in the moisture range from field capacity to permanent wilting percentage. The customary procedures for determining these two soil constants are quite inconvenient. Although data are presented that show good agreement between moisture equivalents and field-capacity values in selected soils, it was not possible to obtain a reliable regression with soils from the arid and semiarid regions of Puerto Rico. The regression of permanent wilting percentages by the plant method to 15-atmosphere percentages is expressed by the equation, <em>Y</em> = 2.37 + 0.76 <em>X</em>, in which <em>Y</em> is the permanent wilting percentage and <em>X</em> is the 15- atmosphere percentage. Data on the available water capacity of the surface layer of sons from the arid and semiarid regions of Puerto Rico are presented. The range of available water is adequate in most soils, fluctuating from about 18 to 25, except in sands where it is lower. It is about the same in heavy soils such as clays and clay loams as in lighter ones such as sandy loam and sandy clay loams. ER -