EFFECTIVENESS OF LOCAL DOLOMITE FLOUR VARIOUS GRAIN SIZES UNDER RESOURCE TECHNOLOGIES
Laboratory and field researches are conducted to establish the optimum size of particles of a local dolomitic flour to improve efficiency of use of lime and economic expenses of limy fertilizers. Results of researches say that a dolomitic flour of smaller grinding, 0,25 mm, the most active size to reduce acidity of the soil in laboratory trials on 1,1 units рНсол. and at the size of particles (≤1 mm) - on 0,6 units рНсол. to a background respectively. Extent of reduction in hydrolytic acidity was directly connected with small grind of dolomite. The smallest size of fractions of a dolomitic flour (0,25мм) in laboratory researches reduced hydrolytic acidity by 2,89 mg-ekv/100 of the soil, and in field experiments (≤1 mm) - by 2,0 mg-ekv/100 of the soil to a background respectively. Increase in mobile phosphorus (on 19,0 mg/kg) and exchange potassium (on 10,0 mg/kg) is noted under the influence of small fractions in options of laboratory researches. It is established that the smallest fractions of a dolomitic flour of 0,25 mm and smaller and 0,25-1,0 mm in the first months after introduction reduce acidity of the soil. The dolomitic flour with particles of 1,0-3,0 mm also improved physical and chemical properties of the soil, but longer contact of lime with the soil for this purpose was required. More rough particles of limy fertilizer worked more slowly, but eventually their neutralized action increased. Within the fourth year of field researches the greatest influence on the reduction soil (on 0,7 and 0,6 units рНсол. ) and hydrolytic (on 2,5 and 2,4 mg-ekv/100) acidity, increases in the content of mobile phosphorus (on 36,0 and 33,0 mg/kg) and exchange potassium (on 20,0 and 24,0 mg/kg) in the soil of fraction of a dolomitic flour with sizes of particles ≤3 and ≤5 from mm to a background respectively. Efficiency of use of local limy fertilizer is confirmed, biological activity of the soil amplified. It is shown that fractions of a dolomitic flour the size smaller 0,25 to 5,0 mm with service of small particles (less than 0,25 mm) to 48,0-50,0% created the best conditions for activity of microorganisms of the soil. Thus by laboratory and field researches it is established that in an acute shortage of limy fertilizers it is recommended to apply local friable breeds of a carbonate of more rough grind of 5,0 mm. In a five-year cycle of use of lime the preference has to be given to limy fertilizers with prevalence of particles less than 3,0 mm as they have positive impact on agrochemical properties of the soil more strongly.