Effectivenes of fertilization at onion depending on nitrogen rate and irrigation scheduling

Ivanka Mitova, Vesela Petrova

Abstract: The experimental studies are made on leached cinnamon forest soil, in the experimental field of ISSAPP “N. Pushkarov” in Chelopechene district. The purpose of the study is to determine the impact of the irrigation regime and the nitrogen fertilizer rate on the absorption of the main nutrients, their export and consumption for the onion production, as well as the influence of these factors on the efficiency indicators of the nitrogen fertilization. The study includes 10 variants with surface, subsurface irrigation and micro-jet devices, as well as two nitrogen fertilization standards and a control variant (without irrigation and fertilization). The obtained yields in the experiments are inrange from 1732 (reduced irrigation and fertilization norms – subsurface drip irrigation DI – 50% irrigation rate and fertilization with N5) to 3200kg/da (subsurface drip irrigation SDI – 100% irrigation rate and N10 fertilization). The highest values of the partial productivity, of partial nutritional balance, of the efficiency of return – 0.47 kg.kg-1 and of agro-economic performance (162 kg. kg-1) have plants with SDI with 100% irrigation rate and fertilization N5. Variants with reduced watering and fertilizer rates, which yields are lower than those in the control variant, have proven their agricultural ineffectiveness.

Keywords: efficiency of return; nitrogen fertilization with N5 and N10; onion; partial nutritional balance; partial productivity

Date published: 2017-10-16