Comparison of emitters of ceramic tube and polyvinyl formal under negative pressure irrigation on soil water use efficiency and nutrient uptake of crown daisy

Negative pressure irrigation increases vegetable water productivity and nitrogen use efficiency by improving soil water and NO3–-N distributions

“…Li et al (2017a) studied the changes in soil water content during cucumber growth period in a pot experiment using the NPI system and found that the system significantly reduced the fluctuation of volumetric soil water content during the cucumber growth period compared to artificial irrigation with a measuring cylinder. Yang et al (2020) also found that the soil water content range under water supply pressure of -4 kPa, -8 kPa, and -12 kPa were 26. 3-27.2%, 23.5-24.6%, and 18.1-19.9% during the crown daisy growth period in a pot experiment, respectively.…”

“…Negative pressure irrigation (NPI) integrates the advantages of the aforementioned methods and improves vegetable yield and water use efficiency (Li et al, 2017b;Yang et al, 2020). The pressure of the water supply in the NPI system is set as an appropriate negative value according to the soil matric potential and attempts to meet the water requirements for vegetable growth.…”

“…The optimum soil matric potential for each crop species is different (Contreras et al, 2017). Some studies have shown that the optimum NPI water supply pressure for rapeseed (Zhao et al, 2019), crown daisy (Yang et al, 2020), cucumber (Zhao et al, 2017), and tomato (Gao et al, 2019; were -5 kPa, -8 kPa, -3 to -5 kPa, and -5 kPa, respectively. Both cucumber and tomato are sensitive to soil water content and N supply (Badr et al, 2016;Wang et al, 2019aWang et al, , 2019b.…”

“…Therefore, cucumber and tomato were used in our study to reveal the effect of NPI on vegetable water productivity and nitrogen use efficiency. Although the effect of NPI on vegetable crop growth has been extensively studied (Li et al, 2017b;Yang et al, 2020;Zhao et al, 2017), it is still not clear how NPI improves water productivity and nitrogen use efficiency through its water supply characteristics.…”

“…Although the result is inconsistent, the distribution uniformities of soil water and nitrate remain one of the most important considerations when designing irrigation systems, such as drip irrigation and sprinkler irrigation (Kang et al, 2000;Li and Liu, 2011). However, previous studies of the NPI system have focused on the effect of soil water content (Yang et al, 2020) and NO 3 --N concentration on vegetable yield rather than the soil water and NO 3 --N distribution uniformities.…”