The influence of mineral nitrogen fertilisers on the formation of winter pea productivity

Purpose. To determine the effect of the method (split application of fertilisers in autumn and spring) of applying the maximum recommended rate of nitrogen fertilisers of 60 kg/ha on the formation of the productivity of winter pea variety ‘NS Moroz’. Methods. The research was conducted in the fields of Agrofirma Sylchenkove (Talalaiv district, Chernihiv region) in 2022–2023 on podzolized chernozems. The following fertilisation treatments were studied: 1. P45K45 (background); 2. N15P45K45; 3. N15P45K45 + N15; 4. N15P45K45 + N30; 5. N15P45K45 + N45; 6. N30P45K45; 7. N30P45K45 + N15; 8. N30P45K45 + N30; 9. N45P45K45; 10. N45P45K45 + N15; 11. N60P45K45. The sowing area was 25 m2, the recorded area was 20 m2. Results. The highest yield of winter peas variety ‘NS Moroz’ (3.92 t/ha) on podzole chernozems of the Chernihiv region was formed by applying the start dose (15 kg/ha) of nitrogen mineral fertilisers in the main fertilisation in autumn and 45 kg/ha in the early spring after recovery of vegetation. Nitrogen fertilisers applied in early spring at the rates from 15 to 45 kg/ha against the background of N15P45K45 had a positive effect on the formation of taller winter pea plants with more beans and a higher 1000-kernel weight. The application of nitrogen mineral fertilisers in spring helped to increase the average height of plants by 9.5 cm, the number of beans per plant by 1.6, and the 1000-kernel weight by 19.7 g. The highest protein content in pea grains (23.4%) was provided by the complex application of N15P45K45 in autumn application and N45 in early spring. Conclusions. To obtain a yield of winter pea on podzolic chernozems of the Chernihiv region at the level of 3.5–4.0 t/ha, it is recommended to apply fertilisers N15P45K45 in autumn during the main tillage and N15–45 in spring.