S13 - Session O4 - Organic nutrients impact on the productivity of carrots (Daucus sativus Rohl.) and onions (Allium cepa L.)

Authors: Rasa Karkleliene *, Audrius Radzevicius, Danguole Kavaliauskaite, Danguole Juskeviciene

Researchers around the world are looking for ways to ensure crop productivity and soil sustainability and avoid negative impacts on the environment and human health. Biologically active substances that increase the germination and stimulate plant growing processes and enhance product quality are essential for organic horticulture. Investigation of organic soil supplements and their effect on growth and quality of organically grown carrot and onion was carried out at the Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry in 2020n2021 in a Calcic Endogleyic Luvisol ( LV-gl-n-cc) light loam with medium humus. Two types of biologically active substances were tested: substrate of organic origin that was applied into the soil before sowing, and liquid organic extract that was applied through irrigation system immediately after sowing and when the plants reached 3-5 leaf stage. The effect of bioactive nutrients was tested on two genetically different carrot cultivars 'Garduolės' and 'Rodelika', and onion cultivars 'Babtų didieji' and 'Rawska'. The total yield of carrots during the experimental years varied from 47.14 to 58.62 t ha -1 and marketable yield from 85.5% to 94.0%, respectively. The total yield of onions varied from 32.37 to 36.0 t ha -1 and marketable yield from 82.3% to 90.6%. Obtained results showed that bioactive organic nutrients significantly increased total sugar and soluble dry matter of tested vegetables. The study established that carrot cultivar 'Garduolės' and onion cultivar 'Babtų didieji' are more resistant to biotic and abiotic factors. Bioactive organic nutrients increased the amount of humus, and content of soil potassium and calcium.