Banca de DEFESA: DAYANNE CAMELO

Microbial biomass, carbon stock, biological nitrogen fixation, productivity, soil organic matter, integrated systems.

Microbial biomass, carbon stock, biological nitrogen fixation, productivity, soil organic matter, integrated systems.

Integrated forage production systems can promote several ecosystem services. The effect of cultivation systems (monoculture or intercrops) of elephant grass (Cenchrus purpureus) of different sizes (Elefante B and Mott), intercropped or not with butterfly pea (Clitoria ternatea) on agronomic characteristics, microbial activity, quality of organic matter, glomalin, C and N stores in a dry tropical climate. The elephant grass monoculture was fertilized with N (300 kg N ha-1 year-1). The experimental design used was randomized blocks with four replications. Butterfly pea in monoculture presents greater accumulation of forage than when intercropped with elephant grass genotypes. High and low genotypes do not differ in forage accumulation. The leaf/stem ratio of butterfly pea and elephant grass was similar for the different cultivation systems. Forage accumulation and N content and stock in the soil did not differ between elephant grass monocultures and intercrops with butterfly pea. The butterfly pea monoculture stores more N in the soil compared to other cropping systems. The quality of organic matter, C and N of microbial biomass, metabolic and microbial quotient of the soil did not differ between elephant grass monocultures and intercrops with butterfly pea. During the rainy season, there is a higher quality of organic matter, glomalin content, microbial activity and biomass, and a higher microbial and mineralization quotient compared to the dry season. In the dry season there is a higher C content and stock, in addition to the greater participation of elephant grass in the botanical composition in relation to butterfly pea. In the most superficial layer of the soil (0-0.10 m) greater microbial activity, higher N-mic and lower C/N ratio in the microbiota were observed. The stock of C and N is greatest in the 0.20-0.40 m layer of soil. Compared to monoculture, the inclusion of butterfly pea in elephant grass weeds, regardless of the size of the grass, maintains the accumulation of forage, the quality of organic matter and microbial activity, and the storage of C and N in the soil, without the need for fertilization. nitrogenated.