Conservation agriculture optimizes nitrogen use and weed management

In this study, researchers from the ICAR-Indian Agricultural Research Institute in India focused on efficient nitrogen (N) management and weed management in the Indo-Gangetic Plains using different means. The results of their study were published in the journal Archives of Agronomy and Soil Science.

• Conservation agriculture (CA) practice increases agronomic productivity and soil fertility. However, CA stimulates N immobilization and weed interference during the early periods of implementation.
• To address this, the researchers used soil testing and an optical sensor (GreenSeeker^TM) for nitrogen management. They also used brown manuring (Sesbania aculeata co-culture) and herbicide mixtures under CA-based maize (Zea mays) – wheat (Triticum aestivum L. emend Fiori & Paol) system for weed management.
• The researchers reported that compared with whole N application at sowing, optical sensor-guided fertilizer N application increased maize and wheat yields up to 20 and 14 percent, respectively.
• Compared with weedy check, brown manuring in maize and herbicide mixtures in wheat also increased the grain yields up to 10 and 21 percent, respectively.
• Meanwhile, the optical sensor-based N management method saved up to 45 and 30 kg N ha^–1 of the optimized N fertilizer rate in maize and wheat, respectively.
• The combination of fertilizer N management and brown manuring resulted in 5 and 4 percent higher soil organic carbon accumulation.

Based on these results, the researchers concluded that the implementation of efficient N fertilizer and weed management in the early years of CA can improve agronomic yield, fertilizer savings, and soil organic carbon content.

Journal Reference:

Oyeogbe AI, Das TK, Bandyopadhyay KK. AGRONOMIC PRODUCTIVITY, NITROGEN FERTILIZER SAVINGS AND SOIL ORGANIC CARBON IN CONSERVATION AGRICULTURE: EFFICIENT NITROGEN AND WEED MANAGEMENT IN MAIZE-WHEAT SYSTEM. Archives of Agronomy and Soil Science. 22 March 2018;64(12):1635–1645. DOI: 10.1080/03650340.2018.1446524