Density of arbuscular micorrystal fungi in soils of different sugar cane cultivation systems in the cerrado
The so-called mycorrhizal fungi (FMA) are the most important, because they are associated with most plants and when in association, favor growth due to the higher absorption of water and nutrients, mainly phosphorus (P). This gives the plant greater tolerance to biotic and abiotic stresses. The evaluations were conducted in the area of the Jalles Machado plant in the municipality of Goianésia, Goiás. The local climate is Tropical Seasonal (Aw) according to Köppen. The experimental design chosen was a randomized block factorial with four replicates, where the factors are three sugarcane varieties: IACSP94-2101, IACSP95-5000 and CTC4; and two cultivation systems: Conventional and Organic. FMA spores were extracted from the soil using 50 cm³ of each compound sample from a plant chosen at random by the wet sieving technique followed by centrifugation in water and then in 50% sucrose solution. Subsequently, the spores were quantified and separated by morphological characteristics, using stereoscopic bilocular loupes. Symbiotic association of mycorrhizae is essential for the survival of the plant, and this association may be impaired in soils with plowing and fertilization, and in extensive crops using agrochemicals. The occurrence of associations occurs more frequently in plants under stress and in soils with low fertility. These associations only benefit plants and plants that are under stress or lacking in nutrients. There are some varieties that have greater resistance to stress in these occur a smaller number of associations.