Efficiency of partial replacement of macro fertilisers with nano chelates for spring wheat

Purpose. To determine the effect of partial replacement of basic macro fertilisers with nano chelate micro fertilisers (NCMF) on the spring wheat productivity. Methods. The study was conducted in 2019–2020 at the Plant Breeding Department of the National University of Bioresources and Nature Management of Ukraine (Kyiv). Field experiments were carried out at the educational and scientific laboratory Demonstration and Collection Crop Field. Laboratory analyses were performed at the laboratories Quality of Seeds and Planting Material and Analytical Studies in Crop Production. Nano chelate micro fertilisers were used according to the replacement scheme developed by the manufacturer (Innoparmis Agroscience SRL) in two stages: at the beginning of the stem emergence (BBCH 30–32) and at the beginning of grain filling (BBCH 71–75). A single plot area was 2 m2 in six replications. Results. Partial replacement of the application rate with nano chelate micro fertilisers can have a positive effect on wheat yield and compensate for up to 30% of the application rate of each of the macronutrients. In the block of replacing mineral nitrogen with nano chelate micro fertilisers, the highest reliable yield reached 3.97 t/ha in the N40 + NCMF treatment with a 16.7% decrease in yield relative to control 2. In the block of phosphorus substitution, the average yield was lower and reached the maximum value of 3.52 t/ha in the treatments P40 + NCMF and P30 + NCMF. In the block of potassium replacement, yield reduction was even more significant: it did not exceed 3.2 t/ha. A significant decrease of the 1000-kernel weight by 3.7–13.1% was recorded in each of the blocks of macronutrient replacement: 40–41 g for application of only N; 37–40 g for applying only phosphorus or potassium. Conclusions. In the fertilization system for grain crops (for example, wheat), it is possible to replace nitrogen fertilisers with nano chelate micro fertilisers by 25–30%, phosphorus and potassium by up to 40% of the recommended rate of mineral fertilisers. The yield values in these cases were 3.97 t/ha (N40 + NCMF), 3.52 t/ha (P40 + NCMF), and 3.24 t/ha (K40 + NCMF).