USING SAND SAINFOIN (ONOBRYCHIS ARENARIA KIT.) TO RESTORE DEGRADED SOILS

Abstract

Further soil degradation in Ukraine, caused by the intensification of agriculture, is being exacerbated by military aggression. More than 16 million hectares of Ukrainian soils have been degraded. Under such conditions, Ukrainian soils are characterized by low ecological stability, high vulnerability to anthropogenic and climatic influences, which leads to a reduction in the volume of agricultural production, a decrease in its ecological safety, which directly threatens the health and life of the population. Perennial leguminous grasses play an important phytomeliorative role on arable lands. Among the phytomeliorative properties of perennial leguminous grasses, sand sainfoin (Onobrychis arenaria Kit.) plays an important role, especially in conditions of climate change. The aim of the study was to establish the complex agroecological impact on the soil condition of twoand four-year cultivation of sand sainfoin (Onobrychis arenaria Kit.). The assessment of the ecological and agrochemical condition of the soil was carried out according to the following indicators: the content of humus, hydrolyzed nitrogen, mobile forms of phosphorus and potassium, the pH level of the soil solution and hydrolytic acidity. Two-year cultivation of sand sainfoin (Onobrychis arenaria Kit.) contributes to the improvement of the agroecological condition of the soil due to the formation of a developed root mass of grasses, which is equivalent to the application of 35–40 t/ha of manure. This provides an increase in the content of mobile forms of phosphorus by 5.1%, potassium by 23.8%, a decrease in hydrolytic acidity to 26.4% and an increase in the pH level of the soil solution by 0.3–0.7 units. With four-year cultivation of this crop, an increase in the content of humus by 0.3%, hydrolyzed nitrogen by 6.3%, mobile forms of phosphorus by 12.2%, potassium by 30.4% and an increase in the pH reaction of the soil solution by 2.8%. Two-year cultivation of sand sainfoin (Onobrychis arenaria Kit.) contributes to a significant reduction in the content of mobile forms of heavy metals in the soil: lead – by 74.6%, cadmium – by 96.7%, copper – by 11.8% and zinc – by 69.2%. With four-year cultivation of sand sainfoin, an even more significant reduction of these indicators was found: lead – by 74.6%, cadmium – by 98.3%, copper – by 94.1% and zinc – by 73.6%.