Integrated management strategies for sustainable intensification of a sweet maize–vegetable triple-cropping system in a water-sensitive region

Abstract

Context and objective Intensive sweet maize–vegetable cropping systems are critical for food production but typically rely on excessive nutrient inputs, leading to substantial nitrogen (N) and phosphorus (P) losses, particularly in water-sensitive regions. However, most field studies have evaluated crop productivity, nutrient uptake, or individual loss pathways separately, resulting in limited evidence of whether management redesign can simultaneously enhance productivity, improve nutrient recovery, and reduce multi-pathway N and P losses at the annual cropping-system scale. We hypothesized that optimized fertilizer management combined with increased planting density would improve nutrient recovery and reduce environmental losses without compromising productivity. This study tested this hypothesis in a sweet maize–stem lettuce–sweet maize triple-cropping system. Methods A two-year field experiment covering two consecutive annual cycles was conducted from 2023 to 2025 in the environmentally sensitive Erhai Lake Basin, China. Treatments included an unfertilized control (CK), farmers’ practice (FP), and two integrated management strategies combining optimized fertilizer management with increased planting density. Fresh yield, plant N and P uptake, NH 3 volatilization, N 2 O emissions, N and P runoff and leaching losses, nutrient budgets, and environmental footprints were quantified through in situ field monitoring. Results and conclusions Under FP, excessive nutrient inputs and low planting density resulted in low nutrient use efficiency, substantial N and P losses, and large nutrient surpluses. In contrast, the integrated management strategies increased annual fresh yield by 8.8–23.2%, N uptake by 8.4–24.3%, and P uptake by 11.3–19.2%, while reducing multiple N and P loss pathways, including N and P leaching, N and P runoff, NH 3 volatilization, and N 2 O emissions. These improvements also enhanced fertilizer nutrient recovery, shifted nutrient budgets toward more balanced conditions, and substantially reduced N and P footprints. Pathway analysis indicated that optimized fertilizer management and planting density jointly regulated nutrient losses and environmental footprints through pathways associated with nutrient uptake and hydrological losses. These results demonstrate that integrated management strategies can enhance productivity while reducing multi-pathway nutrient losses in this sweet maize–stem lettuce–sweet maize triple-cropping system. Significance Overall, our findings demonstrate that demand-driven input management can effectively decouple crop productivity from nutrient losses. This provides a practical pathway for sustainable nutrient management and sustainable intensification in high-fertility, water-sensitive agricultural systems.

The authors' abstract, as published at the source. Field Crops Research, 2026 · DOI ↗