Preliminary Studies on the Effect of Soil Conditioner (AMP) Application on the Chemical and Microbiological Properties of Soil under Winter Oilseed Rape Cultivation

This study analyzed the effect of the application of a soil conditioner under the trade name of the Agro Mineral Product (AMP) in the winter rapeseed cultivation on the bacterial and fungal abundance, ion concentrations, and electrolytic conductivity of the soil solution. It was demonstrated that the AMP influenced changes in the total abundance of the culturable fractions of the soil bacteria and fungi at each of the tested time points. A stimulatory effect of the preparation on the growth of the soil bacteria and an inhibitory effect on the development of the fungi was observed, particularly at doses of 4 and 8 t·ha−1. A dose of 12 t·ha−1 proved to be the least effective in relation to the development of the soil microbiome. Increasing the AMP fertilization dose above 4 t·ha−1 caused changes in the chemistry of the soil solution (pH, EC, HCO3−, K+, and PO4-P). It is worth noting that this primarily resulted in decreases in the amounts of mobile forms of potassium (from 40.4 mg·dm−3 in the control to 26.7 mg·dm−3 at the 8 t·ha−1 dose) and orthophosphate as phosphorus (from −6.00 mg·dm−3 in the control to 3.75 mg·dm−3 at the 8 t·ha−1 dose) in the soil solution, which resulted in a reduction in the yield of the winter rapeseed (from 4.76 t·ha−1 in the control to 4.61 t·ha−1 at the 8 t·ha−1 and 4.43 t·ha−1 at the 12 t·ha−1 AMP dose).