Biological nitrification inhibition and forage productivity of Megathyrsus maximus in Colombian dry tropics

Abstract

Agronomic, nutritional, and environmental aspects are integrated to promote sustainable tropical grassland production. Biological nitrification inhibition (BNI) is a plant-based strategy to improve nitrogen use efficiency by grasses in which they suppress the pace of soil nitrification via exudation of inhibitory compounds. To evaluate the effect of BNI on the productive performance of Megathyrsus maximus under field conditions, we evaluated a collection of 27 germplasm accessions and commercial cultivars of the forage grass in the dry tropics of Colombia. We measured plant yield dry matter, nutrition quality parameters, and nitrification rates of soil at 22 months after pasture establishment. Our results highlighted germplasm accessions of superior agronomic performance (for dry matter production and nutrition quality) and high capacity to decrease nitrification. Although no relation was observed between agronomic aspects, nutritional aspects, and nitrification rates, we conclude that there is no agronomic or nutritional penalty on environmentally friendly grasses, and BNI could be adopted as a target trait in plant breeding programs toward the development of eco-efficient forages and contribute to the sustainable intensification of livestock systems.

Keywords

• guinea grass
• tropical agroecosystem
• tropical forages
• n uptake
• environmental pollution