Yield and biochemical properties of grain sorghum (Sorghum bicolor L. Moench) affected by nano-fertilizer under field drought stress

The use of new and efficient methods for fertilizing plants is of economic and environmental significance. A 2-year field experiment was conducted to investigate the effect of nano (micro and macro) and chemical fertilizers (N, P, K) on grain sorghum yield and biochemical properties including phosphorus (P), calcium (Ca), protein, crude fat and tannin contents under drought stress. The experiment was setup in a split plot randomized complete block design with four replications. The drought stress treatment (main plots) consisted of stoppage of irrigation before (D1) and after flowering (D2), and control (normal) irrigation (D3). The single and the combined use of nano- and chemical fertilizers including control (without fertilization) were used as the sub plots. In control (non-stress) conditions, there were not any differences between nano-fertilizer with chemical fertilizer on nutrient uptake (P and Ca), crop yield, and seed protein content. However, nano-fertilizer enhanced sorghum yield and biochemical properties in drought stress conditions. In D1, grain yield (6240 kg ha−1), and crude fat (5.29%), and in D2, P uptake (3498.87 mg kg−1), protein (21.5%) and tannin (0.373%) were most affected by nano- and chemical fertilizers. Control irrigation and chemical fertilization resulted in the highest grain yield, which was not significantly different from control irrigation with macro- and micro-fertilizer (6213.3 kg ha−1). The tested nano-fertilizers can be used as a suitable source of nutrients for planting sorghum plants in the arid- and semi-arid areas of the world, with economic and environmental benefits.