Study links green farming to higher yields, lower fertilizer use in China

China has significantly boosted staple crop yields while reducing fertilizer use, according to a study reviewing two decades of green farming practices. The findings outline a model for improving food security while lowering environmental impacts in one of the world’s largest agricultural producers.

Researchers from Southwest University, China Agricultural University, and the Chinese Academy of Agricultural Sciences conducted the study. It examined the performance of rice, wheat, and corn production from 2000 to 2022, focusing on yield gains and resource efficiency.

During the study period, the total output of these three crops rose by 58%, while the planted area expanded by only 8.6%. Corn saw the largest jump in output at 162%, largely due to yield improvements. 

Wheat and corn yields increased by 56.7% and 40%, respectively, while rice yield rose 12.9%. Meanwhile, nitrogen fertilizer use declined by 9.4%, and overall fertilizer use dropped by 0.83 million tons. Nitrogen use efficiency rose from 27.5% to 41.3%.

The findings are published in Frontiers of Agricultural Science and Engineering.

Green agriculture techniques

The researchers attribute these gains to innovations in green agricultural technology. For instance, Integrated Soil-Crop System Management (ISSM) improved light and nutrient use efficiency, leading to a 91.2% increase in corn yields in North China, along with reductions in nitrogen loss and GHG emissions. 

Other technologies, such as the Root Zone Nutrient Regulation Technology, which precisely matches the nitrogen needs of crops at different growth stages, led to an 8% increase in corn yield while reducing nitrogen fertilizer use by 25%. 

Meanwhile, the Rhizosphere Nutrient Regulation Technology, focusing on the smaller-scale root zone environment, optimized fertilizer application locations and microbial interactions. It led to a 20.2% increase in rice yield and cut nitrogen fertilizer use by 20% to 30%.

Tackling long-term challenges

Despite these achievements, challenges remain. Corn demand in China is projected to rise by 30% by 2050, and nutrient surpluses in farmland continue to pose environmental risks, notes the study. Utilization of organic resources also remains low.

To address these issues, the researchers propose four strategies: precision management of organic materials, wider use of enhanced-efficiency fertilizers, adoption of rhizosphere nutrient regulation, and implementation of intelligent nutrient management systems. 

Their projections suggest that, if fully implemented, the proposed ISSM approach could raise rice, wheat, and corn output by 45.8 million, 115 million, and 360 million tons, respectively, by 2050.