Reducing the environmental risks related to phosphorus surplus resulting from greenhouse cucumber production in China

Abstract

Excessive phosphorus (P) inputs from manure and synthetic fertilizers leads to high environmental risk in greenhouse vegetable production systems. In the current study, we determined whether a system of P fertilization that attempts to achieve a zero-P surplus balances agronomic, economic, and environmental concerns. A field experiment was conducted to evaluate the potential of integrated inorganic and organic nutrient management to provide both high yield and minimal environmental risk in a typical region of greenhouse vegetable production in China. Three treatments were compared: farmers’ practice (FP), current recommended nutrient management (CRNM), and designed balanced nutrient management (DBNM, with P input optimized based on crop demand). The results indicated that in the greenhouse cucumber production system, the seasonal P surplus of FP was as high as 410 kg P ha−1; this increased the movement of P to the subsoil, causing a high risk of P loss, i.e., a P index >9, and a high eutrophication potential (87.4 kg PO4-eq ha−1). Compared with FP, CRNM (which had a 76% lower P fertilizer input) significantly reduced the P surplus, the risk of P loss, and the eutrophication potential, and increased yield incomes and net ecosystem economic benefits by 18.0% and 31.8%, respectively. Compared with CRNM, DBNM significantly reduced the P surplus by 84.5% and the environmental damage cost by 19.0%, while increased the input cost by 23.0%. Therefore, the DBNM strategy is recommended in greenhouse vegetable production to reduce the P surplus and environmental costs, and to obtain high yield and economic benefits.