Fijación biológica de nitrógeno en chipilín (Crotalaria longirostrata Hook. & Arn.), una fuente sostenible de nitrógeno para la producción comercial

Abstract

The increasing demand for fresh produce traditionally consumed by members of the Latino community in their countries of origin provides an opportunity to produce these specialty crops in the Northeastern region of the United States. In Massachusetts, more commercial farmers are interested in growing vegetables common in Latin America. One example is chipilin (Crotalaria longirostrata Hook. & Arn.), a leguminous leafy green native to South and Central America. Preliminary studies indicate that this crop requires nitrogen (N) applications as high as 200 kg·ha-1 to achieve the quality standards required to market this vegetable. The objective of this study was to evaluate the capacity of specific Rhizobia strains to colonize chipilin roots and estimate the N supplied by the bacterial colonization and its impact on quality traits and economic yield. The effects of N supplied by biological fixation in plants inoculated with different Rhizobia species were evaluated. Rhizobium leguminosarum biovar colonized chipilin and enhanced the total fresh weight of the crop by 158 kg·ha-1. Supplementary applications of inorganic N had little effect on the efficiency of colonization by the bacterial strains. Furthermore, applying more than 80 kg·ha-1 of N increased only the green color of the leaves and was economically inefficient in increasing the total fresh weight of the crop. Thus, inoculations with Rhizobium leguminosarum biovar can be integrated into a sustainable production system for complementing or replacing chemical fertilizers and preventing deleterious effects on the environment.