Protected urea as a nitrogen source for Mulato II grass: impacts on forage production, feed value and composition

Abstract

The growing demand for high-yielding forage cultivars with drought tolerance, broad environmental adaptation and sustained feed quality has stimulated the development of new Urochloa (syn. Brachiaria) genotypes, such as Mulato II. Efficient nitrogen (N) fertilization strategies are essential to optimize their productivity and nutritional value. This study aimed to evaluate the effects of N fertilization, using conventional and protected urea at 0, 50, 100 and 150 kg N/ha on green mass production (GMP), dry matter production (DMP), leaf:stem ratio (LSR), nutritional value, apparent nitrogen recovery (ANR), apparent nitrogen conversion efficiency (ANCE), and crude protein yield per hectare (CP/ha) of Mulato II. The experiment followed a completely randomized 4 × 2 factorial design. The results showed that the N source significantly affected GMP, DMP, neutral detergent fiber (NDF) during the second growth period, and ANCE. Increasing N rates led to higher GMP, DMP and CP concentration, while decreasing ANCE. Fertilization with protected urea improved ANCE and reduced NDF concentration, indicating greater efficiency in nitrogen utilization. These findings support the strategic use of protected urea at moderate N rates to enhance forage productivity and nitrogen use efficiency in Mulato II.