Fallowing farmland is one of the ways of keeping soil excluded from agricultural production. A fallow field is not cultivated or cropped for many years. Proper management of fallow land can bring meaurable profits for both the producer and the soil environment. The purpose of this study has been to evaluate the abundance of soil in avialable forms of phosphorus, potassium and magnesium on farmland excluded from production. In 1996, an experiment was run, comprising five treatments: a bare fallow field, a field turfed with fodder galega (Galega orientalis Lam.), a classical fallow field, a fallow field covered with fodder galega (Galega orientalis Lam.) with awnless bromegrass (Bromus intermis) and a fallow field sown with awnless bromegrass (Bromus intermis). The only agritechnical treatment performed periodically was mechanical weeding of the bare fallow. The plant biomass grown on plant-covered treatments remained on field every year. Plant material was sampled only for tests. Once the growing season finished, soil samples were taken from each treatment in four replicates from the 0-25 cm and 25-50 cm deep layers. The soil samples were assayed in order to determine concentrations of available forms of phsophorus, potassium and magnesium using generally applicable analytical methods. In both layers of soil (0-25 and 25-50 cm deep), significantly more P, K and Mg available to plants were found in soil turfed with fodder galega. It was also observed that the concentration of phosphorus in the subsoil from this treatment was significantly higher in 2007 than in 2000. Strong correlation was determined between the uptake of phosphorus by plants and the concentration of its bioavailable form in soil in the following year. Keeping soil as a bare field as well as leaving natural plants for several years resulted in the biggest depletion of bioavailable forms of macronutrients in soil.