Nitrogen (N) management needs to be significantly improved to address the triple challenge of global food security, environmental pollution and climate change. In addition to being site-specific, dynamic in-season management is needed to respond to temporal variability in soil N supply and crop N demand. Active canopy sensor-based precision N management (CS-PNM) aims to match N supply with crop N demand in both space and time. Studies that systematically compare this strategy with other N management strategies are limited, especially in intensively farmed regions of developing countries. The objective of this study was to compare CS-PNM strategy in terms of agronomic and environmental impacts in comparison with farmer's N practice, regional optimum N management, modified Green Window-based N Management and soil test-based in-season root zone N management for an intensive winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) rotation system in North China Plain. A field experiment was conducted from 2008 to 2012 in Quzhou, Hebei Province of China to evaluate these systems. The CS-PNM strategy was consistently better for both crops than the other tested strategies. In comparison with farmer's practice and regional optimum N management, the CS-PNM strategy reduced N fertilizer applications by 62% and 36%, increased N use efficiencies by 68–123% and 20–61%, decreased apparent total N losses by 81% and 57%, and lowered intensities of total N2O emission, greenhouse gas emission and reactive N losses by 54–68% and 20–42%, respectively. Here we demonstrate that relative to current N management strategies, the CS-PNM strategy has significant potential to improve N use efficiencies and mitigate environmental degradation for sustainable intensification of agriculture in developing countries.
Bibliographical noteFunding Information:
This study was financially supported by National Basic Research Program ( 973-2015CB150405 ), The Innovative Group Grant of National Natural Science Foundation of China ( 31421092 ) and the National Natural Science Foundation of China ( 31601222 ). We would like to thank Shanshan Cheng, Jianning Shen, ShanchaoYue, Zhenling Cui and Xinping Chen for their assistance in this study. We also would like to thank Dr. Syed Tahir Ata-Ul-Karim for his constructive comments for improving this manuscript.
© 2017 Elsevier B.V.
- Greenhouse gas emission
- In-season nitrogen management
- Intensive agriculture
- Nitrate leaching
- Precision agriculture
- Sustainable development