The article presents the results of studies on the impact of bioorganic fertilizers on the cultivation of winter wheat, sugar beet, and soybeans in irrigated light sierozems of southeastern Kazakhstan. The study focuses on the effects of these fertilizers on the mineral forms of nitrogen content and the size of N2O emissions from the soil. When applying leaf treatments of mineral and bioorganic fertilizers to cultivated crops, the nitrogen content in light sierozems is enhanced. The main sources of nutrition are easily hydrolyzable and nitrate nitrogen, which accounts for more than 80 %. The contribution of ammonium forms to plant nutrition is insignificant. The size of nitrous oxide emissions was recorded at the beginning of the experiment and after the initial leaf treatment. Under winter wheat crops, the initial concentration of nitrous oxide was 440.3 µg/m³. In the field prepared for sowing sugar beet and soybean in 2023, the concentrations were 373.7 µg/m³ and 557.7 µg/m³, respectively. After the initial treatment, the vegetation on the leaves showed that, on average, the indicator in the different experimental variants for winter wheat crops was 679 µg/m³, for sugar beet crops was 576.8 µg/m³, and for soybean crops was 637.2 µg/ m³. In agroecosystems, N2O emissions are higher under winter wheat compared to row crops such as sugar beet and soybean.