Fungo micorrízico arbuscular e biofertilizantes no crescimento e nutrição da sabiá (Mimosa caesalpiniaefolia Benth.).

Abstract

The arbuscular mycorrhizal fungi – AMF, Gigaspora margarita Becker & Hall has the ability to colonize roots and stimulate plant growth. The P biofertilizers (BP) and K biofertilizers (BK) aim to increase the nutrient content of minerals contained in rock and promote nutrients availability for plant growth. The research aimed to determine the effect of interaction by BP, BK and AMF on initial growth of seedlings of Mimosa caesalpiniaefolia Benth (Sabiá), compared to mineral fertilizers (SSP and KCl). The experiment was conducted in the greenhouse of the Department of Agronomy, Campus of UFRPE. The P fertilization was performed with addition of two levels of BP (215 mg.kg-1 soil - BP1 and 430 mg.kg-1 soil - BP2), and mineral fertilizer in recommended doses of 215 mg.kg-1 soil (SFS). Fertilization with K was carried out with addition of two levels of BK (136 mg.kg-1 soil - BK1 and 272 mg.kg-1 soil - BK2, and mineral fertilizer in recommended doses of 68 mg.kg-1 soil (KCl). At the control treatment, was not applied fertilizer (biofertilizer and mineral fertilizers) or inoculant. The isolated fungus (Gigaspora margarita) was from the CNPAB (Centro Nacional de Pesquisa EMBRAPA - Agrobiologia). The experimental design was completely randomized in factorial scheme 4 x 4 x 2, four doses of P fertilizers, four doses of K fertilizer and two levels of mycorrhiza (presence or absence), with four replications. The height (cm) and diameter (mm) of the stem of the plant were observed at 30, 60, 90 and 120 days after transplanting and inoculation. At 30 days after inoculation, no significant effect was found for any of the treatments. At 60 and 90 days, treatment with mycorrhiza and different sources of phosphate, had similar means for height, while in the absence of AMF was the best performance when using the addition of SSP. At 120 days, it was found that plants inoculated with AMF grew faster than plants without AMF. Different sources and levels of phosphorus promoted significant effect on the variables dry matter and biomass allocation (leaf, stem and root). The accumulation of nutrients (Ca, Mg, K and P) in promoted significant effect on the initial growth, until 120 days, dependent on the inoculation. Inoculation with AMF Gigaspora margarita was as effective for growth of leguminous Sabiá, and chemical fertilizers (SSP and KCl)