Double-Double Row Planting Mode at Deficit Irrigation Regime Increases Winter Wheat Yield and Water Use Efficiency in North China Plain

Low water availability coupled with poor planting method has posed a great challenge to winter wheat (Triticum aestivum L.) productivity. To improve productivity and water use efficiency (WUE) under deficit irrigation, an effective water-saving technology that is characterized by three planting modes has been developed (uniform with 30-cm row spacing (U), double-double row spacing of 5 cm (DD), and furrow-ridge row spacing of alternated 20 cm and 40 cm (F)) combined with three irrigation regimes (50 mm water each at growth stage 34 (GS34) and GS48 (W1), and 100 mm water at GS48 (W2), or 100 mm each water at GS34 and GS48 (W3)). Results showed that DD increased yield by 9.7% and WUE by 12.6% due to higher soil water status and less soil water depletion and evapotranspiration compared with U. Although the soil water status, soil water depletion, evapotranspiration, and yield increased with increasing irrigation amount, more soil water depletion and evapotranspiration resulted in low WUE. The deficit irrigation was beneficial for improving WUE as W1 had significantly increased yield by 5.4% and WUE by 7.1% compared with W2. Yield and evapotranspiration showed a quadratic dynamic equation indicating that yield increased with increasing evapotranspiration. Considering WUE and relatively higher yield under deficit water, W1 combined with DD is suggested to be a good management strategy to be applied in winter wheat of water-scarce regions.