Tillage practices for soil and water conservation in the semi-arid zone II. Development of the basin-tillage system in wheat fields

In the northern Negev of Israel, a typical semi-arid region with a Mediterranean rainfall pattern, wheat production is limited mainly by the amount of available water. Despite the common occurrence of drought years, storm runoff coefficients for unit areas may reach 30-50% of rainfall. Runoff is the main cause of serious erosion damage consisting of soil loss, gully development and loss of productivity. The system of tied ridges or basin tillage, which effectively eliminated over 90% of runoff and erosion in fallow fields before cotton, appears to be a promising solution to the problem of both soil and water conservation in drilled crops as well. Analysis of the long-term rainfall record of the region and the predicted runoff indicates that the basin-tillage system can decrease runoff by at least 50% as compared with the conventional planting system. Experiments carried out during the 1980-1981 rainy season proved that even in a relatively dry year the basin tillage system was effective in increasing wheat yield by about 50% and eliminating erosion.