Nitrogen fertilization in grasses of the genus Cynodon

Abstract

Nitrogen fertilization of pastures is an agronomic practice used to increase forage´s yield. In this research, literature was reviewed in different countries of America with the objective of identifying the effect of inorganic and organic nitrogen (N) fertilization in different dosages on the production and quality of Cynodon´s grasses.  The information was analyzed by grouping the type of fertilizer and the doses of N. For inorganic fertilizers, dosage ranges from 25 to 400 kg N/ha per year were found. The information was related to the productive response of Cynodon´s grasses in terms of fresh and dry biomass production; dry matter (%DM); crude protein (%CP); neutral detergent fiber (%FDN); acid detergent fiber (%FDA) and in vitro digestibility of dry matter (%DIVMS). DM production was higher for organic fertilizers. CP was higher for nitrogen applications at doses greater than 201 kg N/ha and organic treatments. DM percentage was higher in N doses of 101-200 kg N/ha (27.4%). The FDA and NDF obtained lower values for N doses >201 kg N/ha (63.3% and 31.7%). The in vitro dry matter digestibility was higher in N doses of 25-100 kg N/ha. Fresh biomass production was higher in organic fertilizers (13 723 kg N/ha). Plant height had similar values in organic fertilizers and in N treatments of 25-100 kg N/ha (40,90 and 40,78 cm). Due to the diverse behavior of the productive, nutritional, and physiological variables presented in this review, producers should establish parameters based on system objectives, in order to choose doses and type of fertilizer that covers the needs of their pastures.