Nitrogen fertilizer management under rainfed conditions is challenging since farmers may not be able to properly time the topdressing due to extended drought or flood (i.e., excess rainfall). This results in low nitrogen availability under rain-fed conditions. Deep placement of briquetted urea is considered a sustainable approach under irrigated rice conduction; however, its impacts on rain-fed drought conditions are not clear. 

Researchers from the Nepal Agricultural Research Council (NARC), the International Fertilizer Development Center (IFDC), and the Agriculture and Forestry University (AFU), with support from USAID’s Bureau for Resilience and Food Security (RFS), demonstrated that precision nitrogen management through deep placement of briquetted urea can achieve multiple benefits of increased crop yields and farm profits with reduced fertilizer application, compared to conventional broadcast application of granular urea.  

In Nepal, about 40% of the 1.5 million ha of arable land has no irrigation facilities, and rice is cultivated as a rain-fed crop. In addition, farmers do not apply fertilizers on time for several reasons, including shortage of fertilizers and lack of farmers’ awareness, resulting in poor crop productivity. The national average rice yield is the lowest among south Asian countries.  

This study compared deep placement of briquetted urea and granular urea against the conventional broadcast application of urea under rain-fed drought conditions of western Nepal. Results showed that deep placement of briquetted urea increased grain yields (by 21-23%) of a range of improved varieties, including hybrid, compared to broadcast and deep-placed granular urea. At the same time, deep placement of briquetted urea saves a significant amount of nitrogen fertilizer and decreases time spent on follow-on split applications. Additionally, it helps to reduce environmental loss of nitrogen and improve farmers’ net economic return. These results confirmed that deep placement of briquetted urea is equally effective under rain-fed conditions as under irrigated conditions. 

Research was conducted under the Feed the Future RFS Soil Fertility Technology Adoption, Policy Reform and Knowledge Management project.

Read the full article at Springer.