Narrowing row space improves productivity and profit of enlarged lateral space drip irrigated spring wheat system in Xinjiang, China

A moderate reduction in irrigation and nitrogen improves water-nitrogen use efficiency, productivity, and profit under new type of drip irrigated spring wheat system

“…Shortage of fresh water resources has become a severe problem in agricultural regions worldwide ( Savary et al., 2005 ; Si et al., 2020 ). Xinjiang Uygur Autonomous Region is a typical arid and semi-arid region of China with minimal freshwater resources; here, the annual rainfall is only one-tenth of evapotranspiration ( Deng et al., 2006 ; Wan et al., 2018 ; Lv et al., 2019 ; Wan et al., 2022 ). Water scarcity has adversely affected the growth and production of wheat, the most important food crop in this region ( Lv et al., 2019 ).…”

“…However, most studies are based on the traditional drip irrigated wheat planting system in Xinjiang with high cost of drip tubes (TR4; one drip tube service four rows of wheat, row spacing of 15 cm) ( Liu et al., 2013 ; Jin et al., 2014 ; Lv et al., 2019 ). Recently, to reduce the cost of drip tubes and achieve higher economic profit, we have developed a new type of drip irrigated spring wheat system called TR6S, which serves more wheat rows with a single drip tube and uses narrow row spacing ( Wan et al., 2022 ). This system uses one drip tube service for six rows of wheat, with a row spacing of 10 cm and an inter-block space of 25 cm ( Supplementary Figure 1 ) ( Wan et al., 2022 ).…”

“…Recently, to reduce the cost of drip tubes and achieve higher economic profit, we have developed a new type of drip irrigated spring wheat system called TR6S, which serves more wheat rows with a single drip tube and uses narrow row spacing ( Wan et al., 2022 ). This system uses one drip tube service for six rows of wheat, with a row spacing of 10 cm and an inter-block space of 25 cm ( Supplementary Figure 1 ) ( Wan et al., 2022 ). TR6S with the traditional irrigation (4500 m 3 ha −1 ) and nitrogen (300 kg N ha −1 ) levels increased the economic profits by 3.44%–5.35% and reduced costs by 12.32% compared with TR4 (the grain yield was not significantly different with TR4) ( Wan et al., 2022 ).…”

“…This system uses one drip tube service for six rows of wheat, with a row spacing of 10 cm and an inter-block space of 25 cm ( Supplementary Figure 1 ) ( Wan et al., 2022 ). TR6S with the traditional irrigation (4500 m 3 ha −1 ) and nitrogen (300 kg N ha −1 ) levels increased the economic profits by 3.44%–5.35% and reduced costs by 12.32% compared with TR4 (the grain yield was not significantly different with TR4) ( Wan et al., 2022 ).…”

“…However, the horizontal transport of irrigation water mainly depends on the distance between the drip tube and the wheat row ( Wang et al., 2006 ; Payero et al., 2008 ; Wang et al., 2013 ). Compared with TR4, TR6S not only reduced the distance between drip irrigation tube and wheat row by reduce row spacing ( Wan et al., 2022 ), but also have higher water use efficiency (WUE) due to the significant increase of WUE at the distant rows from the drip tube [unpublished data, the WUE calculated by the differentiation of stable carbon isotopes (δ 13 C)]. From the perspective of crop physiology, crops tend to show higher WUE in response to drought [the distance between drip tube and the farthest rows of TR6S (27.5 cm) was longer than TR4 (22.5 cm)] ( Abbate et al., 2004 ; Zhang et al., 2020 ).…”