Nutrient requirement of switchgrass (Panicum virgatum L.) cultivated on marginal land of the Right Bank Forest Steppe of Ukraine

Abstract

The study aimed to investigate the peculiarities of the nutrient requirement of switchgrass cultivated on marginal land under the application of lime, adsorbent and foliar application of fertilizers in the Right Bank Forest Steppe of Ukraine. The experiment was conducted in the Uladivka-Liulyntsi Experimental Breeding Station of the Institute of Bioenergy Crops and Sugar Beet National Academy of Agrarian Sciences in 2019−2022. The soil of the experimental field was deep, leached, sandy, medium-loamy chernozem with low humus content in the 0−30 cm layer (3.9 %). Mineral nitrogen content was as following: 16.4 mg/kg (nitrate) and 38.7 mg/kg (ammonium). Mbile phosphorusav ailability was low (8.3 mg/kg), while the content of exchange potassium was high −10.3 mg/kg. Soil pH was 5.1, and hydrolytic acidity was high − 4.2 mg eq/100 g. Application of lime (25 % of the required rate), MaxiMarin granulated adsorbent and foliar fertilizer aimed at the alleviation of plant stress related to soil acidity and formation of high productivity of plantations taking into account nutrient removal with harvested biomass. In the experiment, the nitrogen removal was 57.5 kg/ha, phosphorus 39.3 kg/ha and potassium 118.7 kg/ha, while 25.0 kg/ha of nitrogen, 17.6 kg/ha of phosphorus and 55.8 kg/ha of potassium was returned to the soil with harvest residues. The application of the studied agronomic practices led to an increase in both the removal and recycling of nutrients. In the 4th vegetation season, nutrient recycling of switchgrass (% to the nutrient removal) made up 43.6 % of nitrogen, 44.7 % of phosphorus and 47.0 % of potassium from the total removal of the crop were returned to the soil. Key words: liming, adsorbent, foliar application of fertilizers.