Growth, Water Use, and Nitrate-15N Uptake of Greenhouse Tomato as Influenced by Different Irrigation Patterns, 15N Labeled Depths, and Transplant Times

Abstract

Increasing water use efficiency and reducing nitrogen pollutant discharge are important tasks for modern agriculture. To evaluate the effect of alternate partial root-zone irrigation (APRI) on tomato plant growth, water use efficiency and nitrate-15N uptake, an experiment was conducted from June to December in 2014 under greenhouse condition in northern China. The experiment contained two irrigation patterns [APRI and conventional irrigation (CI)], two 15N labeled depths in soil (10 and 50 cm) and two transplant time (early and late summer). Results showed that, compared to CI, APRI did not significantly (p > 0.05) impact the growth and biomass accumulation in aboveground part of tomato, while it enhanced the root, reflecting by greater length density, and more dry mass. APRI produced marginally lower yields, but saved 34.9% of irrigation water, and gave a 37.6–49.9% higher water use efficiency relative to CI. In addition, APRI improved fruit quality, mainly through increasing the contents of soluble solid (by 12.8–21.6%), and vitamin C (2.8–12.7%), and the sugar/acid ratio (3.5–8.5%). The 15N utilization efficiency (15NUE) in APRI was higher than that in CI, which was more evident when 15N was labeled at 50 cm depth. Significant (p < 0.05) 15N recovery increase of 10.2–13.2% and 15N loss decrease of 35.4–54.6% were found for APRI compared to CI. The overall results suggest that APRI under greenhouse could benefit the nitrate-N recovery and increase the water use efficiency in tomato.

Interactive Effects of Elevated CO2 and N Fertilization on Yield and Quality of Tomato Grown Under Reduced Irrigation Regimes

“…It is widely accepted that reduced irrigation could maintain or enhance various aspects of tomato fruit quality ( Zegbe et al, 2003 ; Campos et al, 2009 ; Xu et al, 2009 ; Patanè and Cosentino, 2010 ; Sun et al, 2014 ). The higher TS and lower OA together with higher SAR in fruit juice under reduced irrigation regimes indicate an improvement of fruit sweetness ( Wang and Frei, 2011 ; Hou et al, 2017 ). As for the increased TSS and TS concentrations in tomato fruit, it is probably ascribed to the modulation of underlying physiological mechanisms.…”

“…PRI is a further refinement of DI and the principle behind PRI is to alternately allow one part of the root system to be irrigated to keep the leaves hydrated while the other part is exposed to soil drying, triggering stronger root-to-shoot abscisic acid (ABA) hormonal signaling, inducing partial stomatal closure ( Kang and Zhang, 2004 ; Liu et al, 2006 ), better water status in plant ( Xu et al, 2009 ; Sun et al, 2014 ), greater water, and N use efficiency ( Wang et al, 2010 ). Moreover, accumulated evidence has demonstrated that, compared with the full irrigation (FI), both DI and PRI could save up to 25–50% irrigation water without reduction in yield ( Wang et al, 2010 ; Barrios-Masias and Jackson, 2016 ; Wei et al, 2016 ), accompanied with several significantly improved fruit quality attributes, such as firmness, TSS, and sugar to acid ratio (SAR) ( Davies et al, 2000 ; Zegbe et al, 2003 , 2004 , 2006 ; Campos et al, 2009 ; Patanè and Cosentino, 2010 ; Wang and Frei, 2011 ; Hou et al, 2017 ), as well as ionic concentrations in fruit juice of tomatoes ( Sun et al, 2014 ).…”

Alternate Partial Root-Zone Drip Nitrogen Fertigation Reduces Residual Nitrate Loss While Improving the Water Use but Not Nitrogen Use Efficiency

“…Alternate partial root-zone irrigation can facilitate the accumulation of nitrate in the topsoil, promote the absorption of N by plants, and reduce the potential risk of nitrate leaching (Tafteh and Sepaskhah, 2012;Wang et al, 2014Wang et al, , 2020Hou et al, 2017). However, whether the NUE in plants has improved under APRI is unclear.…”

Fate of urea-15N as influenced by different irrigation modes

“…Water is the carrier of N transport in SPAC system. 7 Many studies have shown that there is a coupling effect between water and N. 13,14 The mechanism of water and N coupling in the research by Kim 8 shows: (1) the response of plants to water and N occurs simultaneously; (2) N application can increase water use efficiency; (3) water improves the ability of crops to absorb soil N and fertilizer N. Under sufficient water supply, the crop N use efficiency is higher due to the increased crop growth and evapotranspiration and the enhanced movement of N towards to root system along with water. The mode of water supply affects the crop utilization of N through changing the soil water condition.…”