Constraints to improving nitrogen fixation in chickpea in the Central Dry Zone of Myanmar

Abstract

Myanmar is one of the largest pulse-producing nations, with chickpea being an important export crop. Despite this, there is very little knowledge of the extent to which soil rhizobial populations contribute to N2 fixation by crop legumes. Chickpea rhizobial populations were estimated in 20 soils in the Central Dry Zone of Myanmar and seven field experiments were established to determine whether the combined inputs of phosphorus (P) fertiliser and rhizobial inoculation improved chickpea yields. Chickpea rhizobial populations in the sampled soils were generally small, indicating potential for increasing N2 fixation through inoculation. Although the combined inputs of P fertiliser and inoculation increased nodulation and grain yield at some sites, the impacts were moderate and likely to have been constrained by effective agronomic management, multiple nutrient deficiencies and crop weeds and diseases.