Abstract
Taking the importance of agricultural production sustainability with limited resources to use efficiency in an arid area, afield experiment was designed to investigate the effect of three, Acacia trees (Acacia nilotica, A. seyal, and A. tortilis) planting combination on soil fertility and Sorghum bicolor L. growth and physiological performance. The sorghum planted in 7 strips between 14 rows of Acacia trees planting combinations and one treeless strip as control. Acacia species plantations significantly increase soil fertility in terms of available nitrogen (N), phosphorus (P), potassium (K) and organic carbon (OC) contents as compared to control, highest level of N and P content (59.01 +/- 1.45 and 58.77 +/- 1.10 mg/kg) was reported in strip between rows of A. tortilis. Although the highest net photosynthesis rate (P.) and stomatal conductance (g(s)) recorded in plants grown between rows of pure A. torilis, and rows of A. torilis-A. seyal, but different Acacia significantly enhanced sorghum growth and physiology with reference to net photosynthesis rate, stomatal conductance and chlorophyll fluorescence (chlF). The results stated linear relation between soil nutrients (N, P, K), P-n, and chlF increasing soil fertility improve physiological performance of sorghum. In conclusion, the three Acacia improve soil fertility and sorghum growth. Generally, this plantation trial can be environment-friendly alternative agricultural practices in Saudi Arabia or any area with a similar ecological condition to amend the soil and improve crop performance.