A Whole-Farm Model Based on Experimental Flocks and Crop Rotations in Northwest Syria

This document describes a whole-farm model based on data from farm scale crop, sheep and native pasture experiments managed by scientists. The data are integrated using linear programming (LP), and tests of the economic viability of intensified production systems are presented. A six year experiment at Tel Hadya, 30 km SW of Aleppo, Syria, provided data on four rainfed crop rotations: (1) barley-fallow, (2) barley-vetch, (3) wheat-lentil-water melon and (4) wheat-vetch-water melon. “Traditional” rotations (1 and 3 above) were managed as by farmers in the area; “high-input” rotations (2 and 4) incorporated vetch crops for pasture or hay and used “improved” cultural practices and cereal varieties. Experimental flocks of Awassi ewes provided three levels of nutrition-performance data. Preliminary estimates were used for native pasture offtakes, with and without phosphate fertilizer. A farm survey in 1985 provided price data. The LP model was used to compute optimal solutions for 36 resource and management scenarios. Farm profits with the “high input” rotations were greater than those of the “traditional” rotations under all comparable resource conditions, the former being associated with greater crop yields and sheep numbers. Profits and ewe numbers increased when native pasture was added to the farm, and increased further with fertilized pasture. Optimal ewe numbers declined with a change from low to high nutritional regimes, but farm profits were little affected. The present analysis suggests the replacement of fallow and lentils by vetch, with judicious management, may lead to more productive and profitable crop-livestock husbandry in environments similar to Tel Hadya