Eficiência do fertilizante biológico com quitosana fúngica no controle de nematoides, indução de resistência e nutrição na cana-de-açúcar

Abstract

Sugarcane is a very important economic crop and since Brazil is the world’s largest producer, in order to improve crop yields, it is recommend adding chemical fertilizers and pesticides in agriculture and these actions may promote serious risks to the environment. An alternative is the use of microbiological processes in the control of plant diseases and on availability of nutrients, such as the production of biofertilizers of phosphate and potassium rocks, mixed with organic matter inoculated with Beijerinckia indica and with fungi Cunninghamella elegans. This work aims to evaluate the nematicidal and nutritional effect of biological fertilizer on sugarcane, as well as on the microbial community and soil chemical attributes. The experiment was realized in a factorial arrangement (8x2), with 8 treatments, four with conventional fertilizer in recommended dose, applied in isolate and combined with nematicides (Azadirachtin, Bacillus spp. and Benfuracarbe), with biological fertilizer applied in three doses (2.5 t ha-1, 5.0 t ha-1 and 7.5 t ha-1), and a control treatment with sugarcane mud cake (20 t ha-1), with and without inoculation with nematodes, in four replicates. The biofertilizer in higher doses (100% and 150%) had positive effects with better chemical and biochemical properties of the soil, besides promoting structural changes in the microbial community, depending on the fertilization treatment. The soluble fertilizer in combination with nematicides and the different doses of the biological fertilizer provided the decrease of the reproduction factor, reducing the population density of M. incognita in sugarcane. Biological fertilizer positively affected the chemical properties of the soil (P and K available), yield and industrial characteristics in the two crop cycles, especially applying at the highest dose. The results confirmed the efficacy of the biological fertilizer in the sustainable management of cultures with double action bioagents and can be a viable alternative to promote soil fertility.