Response of yield and nitrogen use efficiency to aerated irrigation and N application rate in greenhouse cucumber

Abstract

Excessive irrigation and fertilization in greenhouse cultivation have a major negative impact, causing economic and environmental problems. Efficient water and fertilizer management methods to increase water use efficiency (WUE) and nitrogen use efficiency (NUE) have been studied often in greenhouses where vegetables are cultivated. However, optimizing the application of nitrogen under certain water conditions does not continue to increase yield. This may be due to oxygen deficiency caused by water saturation in the root zone after irrigation. Aerated irrigation (AI) may be an effective management measure to further reduce the application of nitrogen fertilizer and increase the yield. In order to determine the interaction among irrigation water aeration and N application, a greenhouse study was conducted in Yangling, China, setting up two irrigation methods(AI and drip irrigation)and three N application rates (0, 240, 360 kg ha−1). In this study, AI significantly improved the nitrogen use efficiency (NUE) and yield of cucumber (Qiande 777, p < 0.05). As compared to drip irrigation, the partial factor productivity of applied N (PFP) under AI increased 28.95 % and 18.53 % at 240 and 360 kg N ha-1 nitrogen levels, respectively; cucumber yield under AI was 17.50 % higher than that with drip irrigation condition. AI and N application significantly improved crop yield: the highest yield obtained at AI and nitrogen reduction treatment (I1N2) was 72.3 t ha−1, which was 1.19 and 1.29 times higher than that of non-aerated nitrogen reduction (I0N2) and conventional nitrogen application (I0N3) (p < 0.05). Therefore, AI along with nitrogen application of 240 kg ha−1 is recommended for greenhouse cultivation of cucumber.