Abstract

The main residue of iron and nickel mining is slag, a solid residue of low solubility and rich in magnesium silicate. A residue with potential use as a soil conditioner, however, it is still necessary to investigate whether its use brings impacts to the environment. Microorganisms are extremely sensitive to environmental changes, changes that can be used as environmental quality indicators. Among the organisms that act as microbiological indicators of soil quality, the activity of arbuscular mycorrhizal fungi stands out. With this, this study aimed to verify the mycorrhizal activity as a quality indicator under application of nickel iron mining slag as soil conditioner. The experiment was carried out in the greenhouses of the agronomy course and in the laboratory of agricultural microbiology of the Evangelical College of Goianésia. Magnesium silicate was supplied by Anglo American Mining Company, located in Barro Alto, Goiás. Agronomic and microbiological analyses were performed at the Evangelical College of Goianésia, Goiás. The experimental design used was completely randomized, arranged with five treatments and with five replications, where the treatments were composed of four doses of magnesium silicate: 9, 12, 15, and 18 g dm^-3 of soil in addition to the control without application. Ten golden saw rice seeds were planted in 10-L pots. Soil analysis used in the experiment was performed to determine soil nutritional parameters. The application of iron and nickel mining slag does not influence the development of rice in the first application. The application of 9 dm³g^-1 of iron and nickel mining slag soil positively influences mycorrhizal activity on roots and soil.

Key words: Mycorrhiza, magnesium silicate, stress, cerrado.