Chemical composition of chicory root ash (Cichorium intybus L.)depending on the yield level

Abstract

The world practice of growing chicory root is ineffective for Ukrainian phenotypic forms of varieties, since the weight and shape of the root crop, and the accumulation of ash elements in the plant, differ from modern forms. The purpose of the study was to establish the features of accumulation of the main ash macro- and microelements in the root crop and leaf mass of chicory of the Umanskyi-99 variety, considering the different background of mineral nutrition, the size of root crops, and yield levels. The study was conducted on the premises of the Khmelnytskyi state agricultural experimental station of the Podillia Institute of Feed Research and Agriculture of the National Academy of Sciences of Ukraine. The leaf mass (petioles and leaf blade) and root crops were combusted, and then the content of potassium, phosphorus, calcium, magnesium, sodium, and a complex of meso- and microelements (Ba, Si, Fe, Mn, Al, Cu, B, Cr, Zn, Co) was determined in the ash using a spectrograph, or using standardised methods. The content of the studied trace elements in leaves, roots, and petioles ranged from 1×10-4 up to 1×10-2%. The specific removal of nutrients to form 8.1 t/ha of root dry matter and the corresponding amount of by-products was 216.6 kg/ha of nitrogen, 79.6 kg/ ha of phosphorus, 277.9 kg/ha of potassium, 92.7 kg/ha of calcium, 88 kg/ha of magnesium, and 109.3 kg/ha of sodium. A significant part of macronutrients accumulated in the leaf mass, so about 60-84% of the removed elements were returned to the soil. It is established that the chemical composition of ash of different-sized and different-yielding root crops differs. The content of phosphorus and potassium in root crops at an average yield level is the lowest among the samples under study, and at a high yield, it significantly exceeds low-yielding ones. Therefore, for optimal removal of nutrients when growing chicory root crops, a fertiliser system should be developed to obtain commercial roots at the level of average yield, which would reduce the specific removal of phosphorus and potassium. The practical significance of the results obtained is to highlight the features of the removal of the main macronutrients by chicory root plants, which is the basis for developing an effective fertiliser system for a high planned yield and choosing a strategy for using by-products (leaf mass) as a source of immobilised nitrogen, phosphorus, and potassium