How to achieve “more grain with less pollution”?

As the global population continues to grow and climate change intensifies, the challenges facing agriculture have become increasingly complex. There is a need to meet the rising demand for food while also reducing environmental costs associated with fertilizer overuse, soil degradation, and greenhouse gas emissions. Traditional agricultural research has often focused on single objectives, such as the early “Green Revolution”, which pursued high yields, or later shifts toward organic farming aimed at reducing external inputs. However, it has been difficult to simultaneously satisfy the dual demands of “more grain” and “less pollution”. Is there a method that can enhance agricultural productivity while also ensuring efficient resource use and ecological protection?

Recently, Professor Lin Ma et al. from Nanjing University, China Agricultural University, and Hebei Agricultural University proposed a new agricultural system research method that combines “top-down” and “bottom-up” approaches, providing a viable pathway to address this dilemma. The related paper has been published in Frontiers of Agricultural Science and Engineering (DOI: 10.15302/J-FASE-2025628).

The core of this new method is to construct an agricultural innovation system that balances food security, resource efficiency, and environmental sustainability through interdisciplinary integration and multi-scale collaboration. The “top-down” approach starts with national food security goals, setting a minimum grain production baseline that is then broken down by region. This involves considering local water resources, land carrying capacity, and greenhouse gas emission thresholds to develop specific technical pathways—such as identifying areas that require optimized fertilization or where water-saving technologies should be promoted. Ultimately, these plans are implemented through policy guidance and technical training.

Conversely, the “bottom-up” approach is more closely aligned with frontline production. Researchers embed themselves in rural areas, utilizing the “Technology Backyard” as an innovative platform to collect actual production data from smallholders. They diagnose key bottlenecks that limit yields and develop targeted technologies, such as drought-resistant varieties and precision fertilization techniques. These technologies are then integrated into replicable models for promotion in regions with similar natural conditions.

Notably, the “Technology Backyard” plays a critical role. It serves as both a problem collection station and a testing ground for technologies. Researchers live and work alongside farmers, directly obtaining real data from the planting process. Additionally, the backyard acts as a hub for technology dissemination, validating and improving laboratory results in the field before teaching them to more farmers. For example, in the corn-growing areas of the North China, the researchers identified issues in traditional farming practices, such as irrational nitrogen fertilizer application and sparse planting density. They developed technologies like “Dynamic Nitrogen Supply in Root Zones” and “High-Yield Dense Planting”. After applying these techniques in 66 farmers’ test fields, the average corn yield reached 13 tons per hectare—almost twice that of traditional practices—without increasing nitrogen fertilizer use. Similar cases abound: optimizing the layout of livestock and poultry farming could reduce nitrogen pollution exposure for 90% of the population; adjusting crop planting structures could meet future food demands while reducing active nitrogen loss by 18% and greenhouse gas emissions by 20%.

This method integrates “top-down” systematic planning with “bottom-up” frontline innovation, forming a complete chain from national goals to farmer practices. On one hand, the macro objectives ensure that technical directions do not deviate from the overarching priorities of food security and ecological protection; on the other hand, frontline data make technologies more grounded, addressing the disconnect between past research outcomes and production needs. Currently, relevant technologies have been applied in multiple major agricultural production areas in China, enhancing the planting efficiency of smallholders and providing a “Chinese solution” for global agricultural sustainability. For instance, similar “Technology Backyard” models have begun to be promoted in parts of Africa and Southeast Asia, helping local farmers increase production while reducing environmental burdens.