Downslope Areas Research Articles

Rainfall Use Efficiency for Dryland Barley with Three Crop and Water Management Systems

AbstractThree crop and water management systems for barley (Hordeum vulgare L.) were compared in a winter rainfall climate on Hanford sandy loam. These systems were (i) annual corpping with runoff retention, (ii) a fallow‐crop sequence with runoff retention, and (iii) induced runoff on one‐half the area for concentration and annual cropping on the remaining half. Land slope was 2–3% and runoff was retained with dikes at 7.6‐m intervals in the first two systems. Over a 3‐year period average grain yields were 1.58, 2.04, and 2.29 ton/ha with rainfall use efficiencies of 41, 29, and 31 kg/ha‐cm for annual cropping, fallow‐crop, and induced runoff concentration systems, respectively. The additional soil water in downslope areas of the annual and fallow‐crop systems and in areas receiving induced runoff was reflected in increased barley kernels per head and greater kernel weight. Holding runoff on the land and cropping annually increased rainfall use efficiency 42% over both that obtained where runoff occurred in the annual cropping system and that obtained for the entire plot area in the fallow‐crop system. The efficiency of fallow for storing water in the soil was 16.7%.

A METHOD FOR THE RAPID COMPUTATION OF INDICATOR-DILUTION DOWNSLOPE AREAS.

A METHOD FOR THE RAPID COMPUTATION OF INDICATOR-DILUTION DOWNSLOPE AREAS.