Moisture and thermal regimes of the desert soils of Rajasthan, India, and their management for higher plant production

Studies were conducted during the years 1977–1982 to determine the moisture and thermal regimes of the desert soils of western Rajasthan (India) and their management for better plant production. The results showed that during the high rainfall year of 1977 (628 mm) about 50% of the rainfall percolated down a 900 mm soil profile at Palsana, leading thereby to low moisture regimes and a moisture utilization by the the grass vegetation of only 276–294 mm. Wide variations in diurnal soil temperatures ranging from 28°C to 56°C at the surface and from 33°C to 37°C at 300 mm depth were observed at Jodhpur leading thereby to downward movement of moisture during the day-time (1400 h) and upward during the nighttime (0400 h). The moisture movement was predominantly in the vapour phase as observed by higher values of thermal vapour diffusivity. The monthly variations in soil temperature controlled the movement of moisture which was observed by the increase in the profile moisture storage during the winter month of December at Beechwal and Palsana. An integration of management techniques such as a subsurface moisture barrier of pond sediments, water harvesting, and the use of pond sediments and farmyard manure, increased the initial moisture storage of the 600 mm soil profile from 73 to 91 mm. It also significantly increased the height, canopy diameter and dry matter production of pruned material of Acacia tortilis tree seedlings from 980 to 1750 mm, from 594 to 1100 mm, and from 40.6 to 123.5 g respectively.