Study on the organic carbon and total nitrogen reserves in brown soils in the Chirchik river basin: A case study of Tashkent region, UzbekistanAbdunabi Bairov, Khurshida Nuriddinova and Shukhrat JuraevE3S Web Conf., 304 (2021) 03006DOI: https://doi.org/10.1051/e3sconf/202130403006