Environmental impact and mitigation potentials in Greenhouse tomatoes production system in Yangtze River Delta

Greenhouse tomatoes production with high productivity but also with high fertilizer inputs has rapidly developed in the Yangtze River Delta. It is a great significance to explore methods for reducing environmental cost for the sustainable development of facility agriculture in the region.

Based on farmer survey data grouped according to yield and efficiency, this study analyzed the resource input, environmental cost, and mitigation potential of plastic-greenhouse tomato production and identified reasonable mitigation measures for tomato production in the Yangtze River Delta.

The average loss of reactive nitrogen (Nr) in the farmers’ tomato production systems was 96.7 kg N ha⁻¹; the N footprint was 1.14 kg N t⁻¹; and the Nr emission per unit net profits (Nr_NP) was 7.75 kg N $1000^–1. There was a large difference in the active nitrogen (Nr) loss and greenhouse gas (GHG) emissions for tomato production among farmers. Compared with the high-yield and high-efficiency (HH) group, Nr loss of the low-yield and low-efficiency (LL) and high-yield and low-efficiency (HL) groups were 60.6% and 80.9% higher, and the GHG emissions of the LL and HL groups were 29.2% and 41.6% higher, respectively. Meanwhile, Nr loss and GHG emissions of the low-yield and high-efficiency (LH) group were 17.5% and 13.4% lower than those of the HH group.

Based on these findings, reducing the amount of nitrogen applied, using organic alternative methods, returning straw to the field, and reducing irrigation water are the recommended mitigations to reduce the environmental costs of greenhouse vegetable production.