Ecological intensification management of maize in northeast China: Agronomic and environmental response

Abstract

Optimum field management practices need to be developed and improved to solve the challenge of increasing food production while retaining the ecological integrity of farming system underlying the goal of sustainable agriculture. In our study, the concept of ecological intensification (EI) was applied to a spring maize cropping system in Jilin province, China during 2009–2013. Results indicated that the average grain yield was 11.8tha−1 in the EI treatment; while the farmers’ practice (FP) treatment had an average of 11.4tha−1 grain yield across five seasons. The Hybrid Maize Model was used to simulate the potential yield under water-limited condition, and the results showed that grain yield with 92.6% of the average potential yield (14.3tha−1) in EI treatment was closer to the yield potential than FP treatment. Adjusted nitrogen (N) fertilizer rate, split-application of N at the right time and suitable recommended hybrid maize plant density were used for improving N use efficiency and decreasing the negative effects to the environment. Consequently, a total of 180kgNha−1 was enough for maize growth and resulted in equal plant N uptake as the 251kgNha−1 applied in FP. Higher agronomic efficiency of N (AEN), recovery efficiency of N (REN) and partial factor productivity of N (PFPN) in EI treatment (39.7kgkg−1, 66.1% and 66.2kgkg−1, respectively) were observed relative to those in FP treatments (26.9kgkg−1, 42.5% and 50.4kgkg−1, respectively). Improved N use efficiency contributed significantly less N loss to the environment. Our results showed that calculated residual Nmin, the apparent N loss and total GHG emission was 37.5%, 34.3% and 29.8% lower in EI treatment when compared to FP treatment. This study helps quantify and understand the concept and practices of EI. Adoption of 4R Nutrient Stewardship (fertilizer right source, right rate, time and placement) and supporting agronomic practices (optimizing plant density and plant hybrid selection) in our study optimized crop production and minimized potential environmental impact.