Productivity of Leeks Depending on the Application of Mineral Fertilizers and Soil Biopreparation in the Right-Bank Forest-Steppe of Ukraine

Abstract

Providing consumers with high-quality vegetables and preserving soil fertility requires the rational use of fertilizers. Growing vegetable plants on drip irrigation significantly increases their yield, but requires additional research to determine the most effective fertilization. Combined mineral fertilization of leeks with soil biological preparation improves plant assimilation and the composition of the rhizosphere microbiota. The aim of this study is to identify effective combinations of leek fertilization for drip irrigation. The variants of the two-factor experiment were: factor A – soil biological preparation Groundfix and factor B – mineral fertilizers DripFert – N20Р20К20, N40Р10К10, N20Р20К20 +N10Р10К40, N40Р10К10 +N10Р10К40, control variant – without fertilization. Field, laboratory, and mathematical and statistical research methods were used to record data and analyze the results. After fertilizing with mineral fertilizers alone, the share of nitrogen-fixing bacteria was 11–19%, and combined with Groundfix it increased to 37–39%. According to the dynamics of leek leaf mass formation, the advantage of combined fertilization with mineral fertilizer and Groundfix was noted. Within factor B, the largest leaf area was after fertilizing with N20Р20К20 + N10Р10К40 – 19.12 ths. m2 per hectare. Factor A (Grandfix) accounts for 32% of leeks' marketable yield, and factor B (mineral fertilizer) for 60%, but the effect of their interaction is unreliable. Depending on mineral fertilizers, the yield was lower when using N20P20K20. and N40Р10К10. The maximum level of marketable yield was with the combined fertilization of Grandfix + N20Р20К20 + N10Р10К40 – 35.3 t/ha. The application of mineral fertilizer N10P10K40 has a positive effect on the content of sugars and ascorbic acid. Thus, to optimize the nutritional regime of leeks under drip irrigation, it is advisable to apply the soil biological preparation Groundfix and the mineral fertilizers N20Р20К20+N10Р10К40 combined. Intensive fertilization is a classic measure to increase the productivity of vegetable plants under irrigation.