The effect of nutritional backgrounds on the formation of leaf surface and yield and green mass of corn

The leading branch of agriculture in Tatarstan is animal husbandry. In animal husbandry, the main direction is the production of milk and cattle meat. In the diet of dairy cows, corn is an integral component. The share of fodder corn in the total cultivated areas is on average 30–35 %. A limiting factor in the cultivation of corn is the lack of macronutrients in the soil. To obtain stable high yields of green mass of corn, it is necessary to choose the right combination of NPK, based on soil indicators. In this regard, it is necessary to improve the mineral nutrition systems of highly productive adaptive maize hybrids. The effect of fertilizers on leaf surface growth and photosynthetic potential in maize crops was studied in the field on gray forest soils of the Volga region of the Republic of Tatarstan. A significant increase in the yield of green mass was found due to the increased level of mineral nutrition of plants. The fertilizer provided an increase in leaf area by 2.6–9.82 thousand m2/ha on the option N60P54K168 and 4.85–14.56 thousand m2/ha in N180P154K294. The maximum value of this indicator was obtained from the Newton hybrid for the interphase period of flowering-milk ripeness on fertilized variants was between 9.79 and 10.23 thousand m2/ha, against 7.07 thousand m2/ha on the control variant. The photosynthetic potential was the highest hybrids (1924.91 and 1956.91 thousand m2 x day/ha for the option of N60P54K168 and 2039.84 and 2066.31 thousand m2 x day/ha for the N180P154K294). Consequently, the planned yields of green mass were obtained on crops of hybrids Flint-200 and Newton 42, 9 and 43.9 t/ha with the introduction of calculated doses of mineral fertilizers at 50 t/ha and 62.6 and 65.3 t/ha against the background of mineral fertilizers at 70 t/ha. Based on the calculations of economic efficiency, it follows that the cultivation of the Newton hybrid against the background of making NPK at the highest cost (28151.5 RUB/ha) and the lowest cost of 1 ton of green mass of corn (431.1 RUB) provides a greater net income (11028.5 RUB/ha) with the best level of profitability (39.2 %).