CHANGE IN THE TYPICAL BLACK FERTILITY INDICATORS FOR THE CONVERSIONAL GROWING OF MAIZE

Abstract

The change of the agrochemical parameters of the typical black soil is investigated and the balance and the efficiency of using NPK for the cultivation of corn in the technology of constant sowing using different systems of chemical protection of plants in the conditions of the Left Bank Forest Steppe were calculated. It was found that in three years humus content in soil decreased by 0.2%, nitrogen content of easily hydrolyzed compounds — by 2.9–18.6%, mobile phosphorus — by 2–8.1%, exchangeable potassium — by 10.2–19.5% and increased soil acidity by 0.5 units compared to baseline. A significant decrease in the content of basic macronutrients in soil, depending on the system of chemical protection of plants, is shown. In maize cultivation technology with application of only soil herbicides (Harnes, KE, Stomp 330, KE), Nleg losses in soil were 5–9 mg/kg, P2O5 — 8–10 mg/kg and K2O — 15– 16 mg/kg soil; for application only of insurance herbicides (Callisto 480 SC, KS; Milagro 040 SC hp; Dianate, VRK; Estero 60 ke) losses were: Nleg — 3–8 mg/kg, P2O5 — 3–7 mg/kg, K2O — 12–18 mg/kg soil; for combination in the system of chemical protection of maize plants soil and insurance herbicides: Nleg — 5–19 mg/kg, P2O5 — 5– 12 mg/kg, K2O — 17–23 mg/kg of soil. The lowest nutrient content in soil was recorded by application of pre-harvest herbicides Milagro 040 SC hp and Callisto 480 SC, COP on the background of the soil herbicide Harnes, ke, as well as the preparation Callisto 480 SC, COP on the background of the herbicide Stump 330, ke. — Nleg 83–90 mg/kg, P2O5 147–149 mg/kg and K2O 95–98 mg/kg soil. The calculations confirmed a negative balance of N to –176.1 kg/ha/year and P2O5 to –50.3 kg/ha/year. It was determined that weed vegetation in maize agrocenosis on average per year is able to carry 15,06–53,53 kg/ha of nitrogen, 5,21–18,51 kg/ha of phosphorus, 23,02–81,79 kg/ha of potassium and 78.1–277.6 mm/ha of moisture, creating significant competition for nutrients for maize plants.