Livestock-Crop Interactions: The Decision to Harvest or to Graze Mature Grain Crops
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Citation
Thomas L Nordblom. (1/5/1983). Livestock-Crop Interactions: The Decision to Harvest or to Graze Mature Grain Crops. Aleppo, Syrian Arab Republic: International Center for Agricultural Research in the Dry Areas (ICARDA).
Abstract
Farmers in the driest areas of the ICARDA region frequently face the question of whether to harvest or graze mature grain crops, particularly barley. Farmers persist in cultivating barley under poor and highly variable growing conditions and often graze rather than harvesting their plots. It can be shown that a grazed crop is not a failure.
The process by which farmers decide to harvest rather than graze barley plots is described with the use of harvest-time budgets. Anticipated harvest costs, harvested straw, and grain values, and directing grazing values, are all expressed as functions of grain yield in an analytical framework to introduce the idea of “grazing thresholds”: grain yield levels below which direct grazing of the crop is most profitable and above which harvesting is most profitable.
At yield levels below a grazing threshold, the direct grazing value forms the upper revenue boundary for that crop. At the yields above the threshold, the net harvest benefits (straw plus grain values minus harvest costs) form the upper revenue boundary. Straw and grazing values differ among cultivars, as do the frequency distributions of grain yield over time. Therefore, cultivars should be compared on the basis of their upper revenue boundaries and their yield distributions.
In the drier areas, where crop residue and direct grazing values account for a large proportion of the crop values, farmers will continue to evaluate cultivars with respect to both mature forage and grain production characteristics. It is unlikely that breeders will meet the goal of developing cultivars that are superior according to farmers’ criteria.