The influence of predecessors and sowing methods on the productivity of spring wheat in the conditions of the Predkama zone of the Republic of Tatarstan

The aim of the study is to identify the best precursors and sowing methods in combination with other agricultural techniques to stabilize spring wheat productivity. Field experiments were carried out in 2023-2024 in Trud LLC in Baltasinskiy District of the Republic of Tatarstan. The soil of the experimental site are light gray forest. The humus content in the arable layer (0-20 cm) is 3.02-3.17% (according to Tyurin). The soil supply with mobile phosphorus can be estimated as low (66 mg/kg according to Kirsanov method), the content of mobile potassium (98 mg/kg according to Kirsanov), soil acidity pH of salt extract is 5.0. The research material is spring wheat (Triticum aestivum) of Ulyanovskaya 105 variety, originator is Ulyanovsk Research Institute of Agriculture, medium-ripened, high drought resistance. The experimental scheme provided for the following predecessors: fodder beet of Pioner variety, silage corn of Nur hybrid, winter wheat of Skipeter variety, repeated sowing of spring wheat of Ekada 109 variety. Two sowing methods were used against each background of the predecessor: an ordinary one with a row spacing of 15 cm and narrow-row with a row spacing of 7.5 cm. The maximum yield on average over 2 years (3.14 t/ha) was achieved with narrow-row sowing after silage corn. The yield increase was 0.65 t/ha compared to the control. At the same time, the use of corn for silage as a predecessor in combination with narrow-row sowing contributed to the formation of higher-quality grain: protein content - 12.4% (+ 1.8% to the control), the mass fraction of gluten is 3.7% higher than in the control.