Improving water use efficiency is beneficial for the sustainable production of wheat. Both ridge and furrow planting and soil moisture-based supplemental irrigation techniques can significantly enhance crop water use efficiency. However, whether the combination of these two approaches can achieve effective water-saving outcomes and further improve the water use efficiency of wheat remains unclear.

This study aimed to explore the effects of ridge-furrow planting combined with soil moisture measurement and supplementary irrigation on the population, yield and water use efficiency of wheat.

In this study, a two-year field experiment was conducted. The winter wheat variety Xinong 20 was selected, and three planting methods of furrow sowing (P1), ridge sowing (P2) and flat planting (P3) were used. Three irrigation treatments were set up, including supplementary irrigation of soil moisture content in the 0-40 cm soil layer to field water holding capacity (S40), supplementary irrigation of soil moisture content in the 0-60 cm soil layer to field water holding capacity (S60), and traditional flood irrigation as the control irrigation (SCK). By measuring the soil moisture content, the dynamics of tillers of winter wheat, dry matter accumulation, yield and its constituent factors, and calculating the total water consumption of farmland, precipitation use efficiency, irrigation water use efficiency, total water consumption use efficiency, border row index and economic benefits, the effects of ridge-furrow planting and soil moisture measurement-based supplementary irrigation techniques on the growth and development, yield, water use efficiency and economic benefits of winter wheat were explored.

The furrow sowing combined with soil moisture measurement and supplementary irrigation at 60 cm depth (P1S60) maintained similar soil water content, tillers number, and dry matter accumulation as the flat planting with traditional flood irrigation (P3SCK). By leveraging the marginal effect, furrow sowing increased spike number and grains per spike of border-row winter wheat. For ensuring stable wheat yield, P1S60 saved 34.5% of irrigation water and reduced total farmland water consumption by 10.8%. It also boosted irrigation water use efficiency (IWUE) by 79.5% and water use efficiency (WUE) by 14.7% (two-year average). Compared with P3SCK, P1S60 raised total income by 3.2%, indicating high economic viability.

Considering the utilization efficiency of water resources, yield and income potential, P1S60 was a planting method with high potential in Guanzhong irrigation area.