Nitrogen regime of haplic Luvisol in orchards at fertilization

Russian Research Institute of Fruit Crop Breeding (VNIISPK), Zhilina, Orel district, Orel region, Russian Federation

^* Corresponding author: agro@vniispk.ru

Abstract

The aim of the investigation was to research the mineral nitrogen (N_min) behavior in loamy haplic Luvisols of orchards located in the forest-steppe zone of the Central Russian Upland. The seasonal dynamics of N min (ammonium + nitrates) was studied during the growing seasons of 2018 and 2019 in field experiments with apple and sour cherry. Fertilizers were applied annually in spring at doses increasing from N30K40 to N120K160. The most important factors influencing the nitrogen dynamics were meteorological conditions, productivity of trees, peculiarities of nitrogen uptake by the studied crops. Fertilization of orchards with nitrogen contributed to an increase in N_min content by 1.5 … 5 times, depending on the dose. The dynamics of N_min in the soil of fertilized and unfertilized plots was similar and depended on the biological features of the crops: the lowest indicator’s level in the soil under sour cherry was in July during fruit ripening, while in the apple orchard a low nitrogen content was noted in August. Studies have shown that in the climatic conditions of the Central Russian Uplands, loamy haplic Luvisols without additional application of nitrogen fertilizers can provide a favorable level of nitrogen nutrition for apple and sour cherry trees in the first years of fruiting.