Soil water and nitrogen dynamics from interaction of irrigation and fertilization management practices in a greenhouse vegetable rotation

Abstract

Quantifying the interactive effects of different irrigation and fertilization strategies on soil water and mineral N dynamics provides an important insight for developing more effective water and N use management practices. This experiment was carried out in a tomato (Solanum lycopersicum L.) (2016)–cucumber (Cucumis sativus L.) (2016)–tomato (2017) rotation, with 12 treatments in total combining two irrigation methods (drip and furrow), two irrigation levels (high and low), and three fertilizer types (control [N0], organic N [N1], and inorganic N [N2]). Soil water content (SWC) and soil mineral N concentration were measured for soil depth of 0–80 cm. Relative to furrow irrigation, drip irrigation led to lower temporal variation and smaller differences between soil depths and treatments in SWC and soil NO3−–N concentration. A high irrigation level led to higher SWC and soil NO3−–N concentration for N1 and N2 treatments under drip irrigation, whereas furrow irrigation had the opposite results. About 42.8% mineral N (over soil depth of −20 to 80 cm) was stored at the ridge under furrow irrigation. Relative to the start of the experiment, N2 fertilizer application increased the soil mineral N content by about 450 kg ha−1, whereas N0 and N1 application decreased soil mineral N content by about 200 kg ha−1 by the end of the rotation. Yield for N1 was similar or higher than that of inorganic N treatments, with drip irrigation–high irrigation–organic N having the highest soil mineral N and the greatest yield, indicating that a combination of organic N fertilizer with appropriate irrigation practices can achieve the balance of high yield and low environmental risks.