Water use efficiency and productivity of wheat as a function of clay amendment

Growth performance and water use efficiency (WUE) of wheat in loamy sand treated with various proportions of silt loam were investigated by executing field experiments consisting of five soil treatments. The treatments were: (i) T₁: loamy sand (6.04% clay) (control), (ii) T₂: sandy loam (8.50% clay), (iii) T₃: loam 1 (9.04% clay), (iv) T₄: loam 2 (10.00% clay), and (v) T₅: silt loam (13.00% clay) (amendment as a source of clay). Wheat was cultivated in two consecutive growing seasons with four irrigations and an identical recommended fertilizer dose. The leaf area index, plant height, number of tillers per plant, spike length, number of spikelets per spike, number of grains per spike, and yields (grain and biomass) significantly (P = 0.05) improved in the amended treatments compared to the control. The amended treatments (T₂-T₅) produced 1.2-2.9 and 1.2-2.8 times more grain and biomass yields, respectively compared to T ₁. The WUE increased progressively with increasing quantity of clay in the treatments; the amendment saved 30 to 60% irrigation water compared to T₁. The treatment T₄ producing significantly improved leaf area index, grain and biomass yields, and WUE appeared to be the best soil texture for wheat cultivation. Soil amendment thus improved agricultural productivity of loamy sand by improving its water regimes.