Correcting molybdenum deficiency of chickpea in the High Barind Tract of Bangladesh

A major limitation to chickpea grown on residual soil moisture after the harvest of rice in the High Barind Tract (HBT) of Bangladesh is acidic surface soil. A diagnostic trial conducted in the 2001/02 season showed that Mo was limiting growth and yield of chickpea. Multilocational on-farm trials in the 2002/03 season established that Mo applied to the soil at 500 g ha⁻¹ improved nodulation and plant growth and resulted in grain-yield responses of 58%-173%. In addition, we tested an application method suitable for resource-poor farmers where Mo and Rhizobium were added in the seed-priming process. Multilocational trials in farmers' fields in 2003/04 confirmed that this was as effective as soil application of Mo, giving yield responses of 37%-90%. In each of 2004/05 and 2005/06 seasons, 50 farmers implemented on-farm evaluations of adding Mo + Rhizobium in the priming solution in operational scale plots (666 m²) across the HBT. Mean responses of up to 50%, compared to priming in water only, were obtained. These results suggest that the severe N deficiency of chickpea commonly observed in the HBT can be effectively alleviated by applying Mo and Rhizobium inoculum through a simple low-cost technology within the scope of resource-poor farmers.