[Effect of mixing seed with fulvic acid on spring wheat yield and its water use efficiency]

Four treatments were installed to study the effect of seed mixed with fulvic acid on sring wheat yield and water use efficiency: CK(without any treatment of fulvic acid); FA(seeds were mixed with fulvic acid before sowing), WM(pre-sowing irrigation of 30 mm plus clear plastic film mulch), and WMFA(pre-sowing irrigation of 30 mm plus plastic film mulch, and seeds were mixed with fulvic acid before sowing). The plastic film mulches in WM and WMFA treatments were removed after sowing for 62 days. Compared to treatment CK, the spring wheat in FA treatment grew more roots and absorbed more water from soil, and increased the spike weight and grain weight per spike and harvest index, which resulted in a higher yield and higher water use efficiency. There was no differenece in water consumption between treatments WM and WMFA, but in treatment WMFA, more dry matter was distributed in shoots, and hence yield and water use efficiency were improved significantly. The yields for the four treatments CK, FA, WM, WMFA were 917.7, 1275.1, 1269.4, 1737.1 kg.hm-2, respectively; and the water use efficiencies were 6.58, 7.85, 6.20, 9.05 kg.hm-2.mm-1, respectively.