The research mainly aimed at the economics of production and costs of the barley crop in South Sinai Governorate with determining the optimal volume of production, and the research was conducted in the Al-Tur Center in South Sinai Governorate, which ranked first in barley cultivation for the year 2019-2020, and the selection was for the villages of Jubail and Wadi Al-Tour in the Tor Sinai Center. Where it was found from the total product function (Q) that the most important productive elements that have a significant effect on the total output per feddan of the barley crop are human labor, mechanical work, nitrogen fertilizer and phosphate fertilizer, and by estimating the different partial production elasticities of these elements, it was found that the productive flexibility of human labor and machine work It amounted to about 0.153 and 0.261, respectively, which indicates that an increase in the quantity used of the two elements by 10% leads to an increase in the feddan production of barley by 1.53% and 2.61%, respectively, and the productivity elasticity of nitrogen fertilizer and phosphate fertilizer was estimated at about 0.498 and 0.124 respectively. Which indicates that increasing the nitrogen fertilizer and phosphate fertilizer by 10% leads to an increase in barley feddan production by 4.98% and 1.24%, respectively. The significance of these results was statistically proven at a significant level (0.01).
It was also found that the optimal production volume, that lowers costs, of producing barley in the study sample amounted was about 11.09 ardeb/feddan, and that the actual total output amounted to about 10.48 ardeb/feddan. As for the volume of economic production that maximizes profit, it reached about 12.81 ardeb/feddan.
The study also recommended increasing attention to the human element, using modern agricultural mechanization in agricultural operations and adding appropriate amounts of organic fertilizer and phosphates. To increase farms less than 5 acres.