The Effect of Improved Management on the Yield and Nitrogen Content of Legume Hay/Barley Crop Rotations in West Asia

Abstract

In the light of growing governmental support in west Asia and north Africa for policies which either discourage cereal monoculture or encourage fallow replacement by farmers, two experiments were conducted in northern Syria. These were designed to evaluate and quantify the effect of agronomic interventions on the productivity and nitrogen content of legume hays, and the subsequent residual effects of these interventions on the yield and nitrogen content of a following barley crop. Quantitative estimates of the residual effects of legume hays, when grown under rainfed conditions, on the N uptake of barley are rarely available for the region at large.

The major management effects on the productivity of legume hays were the addition of phosphate fertilizer and a reduction in row spacing. Positive residual effects on the yields of following barley crops were shown to be small but not insignificant. They could be considered to be important influences in the sustained production of barley in legume hay-barley crop rotations.

It is suggested that the results give further positive evidence that farmers in west Asia will not resist the introduction of improved crop rotations including legumes in place of their current fallow-barley or continuous barley crop sequences.