• Using Precipitation to Predict Range Herbage Production in Southwestern Idaho

      Hanson, C. L.; Morris, R. P.; Wight, J. R. (Society for Range Management, 1983-11-01)
      Analyses of 9 years of herbage yield and precipitation data from the Reynolds Creek Experimental Watershed in southwest Idaho show that annual herbage yield can be estimated by the Sneva and Hyder procedure (Sneva and Hyder 1962a, 1962b) at locations other than where their procedure was developed. These analyses did indicate that for sites below 1,680 m, their procedure was more useful when the crop-year precipitation index was based on a variable number of winter and spring months, rather than September through June. For sites above 1680 m, using winter and spring separately in a modified form of their basic equation may improve yield predictions.
    • Water Properties of Caliche

      Hennessy, J. T.; Gibbens, R. P.; Tromble, J. M.; Cardenas, M. (Society for Range Management, 1983-11-01)
      Water absorption and retention by hard caliche nodules (rocks) collected from soils in southern New Mexico were determined. The rate of water uptake by the caliche rocks was rapid and water content at saturation was 13.0% by weight (24.7% by volume). At a matrix potential of -0.7 MPa, the rocks retained 10.6% water by weight, an 18% loss from saturation. Water loss from saturated rocks to a dry atmosphere was slow, but most of the absorbed water was released. The rocks contained only 0.6% water by weight (1.1% by volume) after 34 days in a desiccator. Both laboratory and field trials indicated that, although indurated caliche layers will absorb large amounts of water, the water does not pass through the layers to the soil below.