Leveraging sustainable agronomic practices in smallholder maize production for environmental and economic gains: Evidence from the Erhai Lake Basin, China

Abstract

Context

Global maize production faces multiple challenges of increasing food security, farmers’ profitability, and reducing environmental impacts, especially in smallholder-dominated, environmentally sensitive areas. Leveraging sustainable agronomic practices from high-performing smallholders holds the potential to reconcile crop production and environmental protection.

Objective

This study uses the Erhai Lake Basin, a typical lake basin in China surrounded by intensive crop production, as an example to illustrate how optimized agronomic practices can balance the environmental sustainability and economic benefits in maize production.

Methods

We conducted extensive farmer surveys across the Erhai Lake Basin, collecting 379 valid samples (comprising 226 grain maize and 153 sweet maize). From this dataset, we identified high yield and high N use efficiency (HH) maize farmers, and pinpointed key agronomic practices contributing to superior environmental and economic performance.

Results

Sweet maize had higher environmental impacts (N losses, global warming potential (GWP), eutrophication potential (EP), and acidification potential (AP)), but also higher economic benefits (net profit and net ecosystem economic benefits (NEEB)) than grain maize. Within the grain maize production system, the HH group reduced indicators of environmental impacts by 15.2 % - 18.2 %, and increased the net profit and NEEB by 35.1 % and 52.5 %, respectively, compared to the LL group (low yield and low N use efficiency). Similarly, in the sweet maize production system, the HH group reduced the indicators of environmental impacts by 22.7 % - 56.2 %, and increased the net profit, NEEB by 23.7 % and 36.5 %, respectively.

Key agronomic practices associated with improved performance in grain maize included adopting long-growth-period varieties (>153 days), reducing the N input (199 kg ha⁻¹), increasing the planting density (8.2 ×10⁴ plants ha⁻¹), and increasing the proportion of straw return, can reduce environmental impacts while enhancing sustainability. For sweet maize, less N input (243 kg ha⁻¹), higher planting density (7.9 ×10⁴ plants ha⁻¹), reducing K fertilizer input, and reducing the irrigation frequency can achieve similar effects.

Conclusion

Optimizing agronomic practices based on HH group can simultaneously reduce environmental impacts and improve economic benefits in maize systems. This approach demonstrates the potential for integrating productivity and sustainability goals in smallholder-dominated agriculture, particularly within intensification and water-sensitive production contexts.

Significance

This study offers practical guidance for improving the sustainability of smallholder maize systems under both environmental and economic pressures. It also provides a transferable framework for other ecologically and hydrologically sensitive agricultural regions worldwide.