Gramíneas forrageiras em sistemas integrados com milho e soja no Cerrado

Abstract

Integrated production systems stand out as key agricultural technologies that enable more sustainable food production. However, the appropriate selection of forage grasses for intercropping with annual crops is a critical factor in this system. This study aimed to evaluate the productivity, nutritional value, and biomass decomposition dynamics of forage grasses intercropped with maize in integrated systems with soybeans in the Cerrado. The hypothesis is that these grasses establish adequately and differ in their agronomic characteristics, productivity, and nutritional value, with potential for use in animal feed and as cover crops. It is also expected that the genotypes will exhibit differences in biomass accumulation and nutrient decomposition dynamics during soybean cultivation in the Cerrado cropping season, without significantly affecting the agronomic traits and productivity of the crop. The experiment was conducted at Embrapa Cerrados, Planaltina, DF, using a randomized block design with a split-plot arrangement and four replications per treatment. The plots consisted of maize intercropped with seven forage species: Urochloa decumbens, genotypes “254-1”, “R86”, and cultivar “Basilisk”; U. ruziziensis, cultivars “Kennedy” and “BRS Integra”; hybrid of U. decumbens, U. ruziziensis, and U. brizantha, “1242-10”; and Andropogon gayanus cv. BRS Sarandi. The subplots corresponded to three evaluation periods: April, June, and September. The grasses “254-1”, “R86”, and “BRS Integra” showed high forage productivity, while the genotype “1242-10” stood out for its high nutritional value. The grasses “BRS Sarandi”, “254-1”, and “R86” produced 72.7% more biomass compared to the average of the genotypes “BRS Integra”, “Kennedy”, and “1242-10” (3184 vs. 1843 kg ha⁻¹). The genotype “254-1” released high amounts of essential nutrients to the soil, such as nitrogen, phosphorus, and potassium, promoting nutrient cycling. The results indicate that the grasses “R86”, “254-1”, and “BRS Sarandi” have high potential for intercropping with maize in the Cerrado, combining good productivity, nutritional value, and favorable decomposition patterns for soil fertility. These findings may contribute to the improvement of more sustainable agricultural systems in the Cerrado, helping to select more efficient forage grasses for agricultural intercropping.