Cucumber production and the economic revenues under various nitrogen applications in an unheated solar greenhouse on the North China Plain

The over-application of cucumber (Cucumis sativus L.) with nitrogen (N) fertilizers grown in greenhouses can produce adverse environmental consequences. In this study, a five-season experiment was conducted from 2014 to 2018 to determine the influence of N rate on N use and economic returns. The experiment contained traditional N application under furrow irrigation (CK) and three N rates with drip irrigation, they are 100, 75, and 50% N applied in the check, referring to T100, T75, and T50, respectively. However, the irrigation rates in drip irrigation were approximately 40% lower than the check. The N losses from gas emission and leaching nitrate accounted for approximately 70% of the applied N when the traditional N rate was applied (CK and T100); however, the loss reduced to 12% in the T50 treatment. The highest cucumber production was found in the T100 treatment, which was 6.1 and 9.4% higher than the T75 and T50 treatments, respectively. The highest net revenue was found in the T100 treatment, followed by the CK (-5.8%), T75 (-7.6%), and T50 (-9.4%) treatments. The highest N productivity and economically applied N productivity were found in the T50 treatment, which were approximately 60% higher than those in the T100 and CK treatments. Fully considering the economic benefit, N productivity and environmental protection, the local N application for cucumber cultivation in greenhouses on the North China Plain (NCP) can be reduced by 50% with drip irrigation system.

Automated summary

The study suggests that in greenhouse cucumber cultivation on the North China Plain, reducing nitrogen fertilizer application can help mitigate adverse environmental impacts, while also increasing economic returns and nitrogen use efficiency.