Effects of row spacing on soil water and water consumption of winter wheat under irrigated and rainfed conditions

Abstract

The results of two seasons' work on soil water content (SWC), evapotranspiration (ET), total dry matter (TDM), and harvest index (HI) of crops under different row spacing (RS), as well as possible ways to improve water utilization, have been reported. Field experiments were carried out at the Experimental Farm of Shandong Agricultural University (36°09'N, 117°09'E) in 2006-2007 and 2007-2008. Four types of RS were treated under two different water conditions (rainfed and irrigated) and set up in a randomized plot design. RS did not exhibit any obvious effects on SWC during the study period. SWC was enhanced evidently by irrigation, especially in the 10-60 cm soil layer. Irrigation increased the ET of crop. At the seeding-jointing stage, the ET of RS14 was significantly higher than those during other treatments (P < 0.05). Irrigation increased yields, ET, and TDM, while it decreased water use efficiency and HI. There were significantly negative correlations between TDM and RS (P < 0.05). The HI of the rainfed crop was higher than that of the irrigated crop. Results showed that high yields of wheat could be achieved in northern China by reducing RS under uniform planting density conditions.