THE BALANCE OF THE MAIN NUTRIENTS IN THE SOIL UNDER HULLESS SPRING BARLEY CROPS DEPENDING ON FERTILIZER

Abstract

Barley is the main grain crop in Ukraine. Mineral nutrition is one of the main factors to regulate plant growth and development. To form highly productive agrocenoses, it is important to provide spring barley with available elements of mineral nutrition, nitrogen, phosphorus and potassium, in particular. They are needed by the plants within a shorter period compared to the winter forms. The optimal balance of nutrients is ensured by applying mineral fertilizers into the soil. Timely and correct application of fertilizers creates favourable conditions for winter barley plants and needs to be clarified in specific soil and climatic conditions. The article presents the research results of fertilizer effect on the content of the main elements in the grain and straw of hulless spring barley, their economic application and balance in the soil. As a result of the conducted research, it was established that the total nitrogen content in hulless spring barley grains is 2.72–2.98%, the phosphorus content is 0.91–1.01%, the potassium content is 0.62–0.71% depending on fertilizer system. Straw has the highest potassium content and the lowest phosphorus and nitrogen one. It should be noted that on fertilizer omitted plots, regardless of combinations with straw, the balance of the main nutrients in the soil was negative -14.8...-79.4 kg/ha. Under the condition of removing straw from the field, the balance of nitrogen and potassium was negative regardless of the fertilization system of the hulless spring barley. Phosphorus balance after application of P60K70, N70P60, N70P60K70, N70P60K35 was positive – 5.5–20.5 kg/ha. To leave straw on the field as fertilizer did not provide a positive nitrogen balance – -30.2...-64.7 kg/ha depending on the experiment variant. At the same time, phosphorus balance was positive under the condition of using 60 kg/ha of phosphorus fertilizers as part of the fertilization system. Potassium balance was positive when using fertilizer systems that contained potassium. Phosphorus and potassium balance on nitrogen systems was negative.