Variegated alfalfa seed yield depending on sowing methods in the Cis-middle Urals

Abstract

The aim of the research was to study the influence of sowing methods (cover crop, sowing method) of variegated alfalfa Victoria on its seed productivity in the Cis-Middle Urals. The research was conducted in 2019–2023 on sod-podzolic medium loamy soil of the Udmurt Republic. Meteorological conditions of the growing seasons during the research years were contrasting. The regrowth of alfalfa was noted on average in the 2nd-3rd decade of April, harvesting for seeds was carried out in the 1st-2nd decade of September, the vegetation period lasted 124–142 days. Over four years of using the grass stand, it was found that variable alfalfa forms seed productivity at a fairly high level: in the first year of use – 570-759 kg/ha, in subsequent years – 234–309 kg/ha. On average, the highest seed yield was obtained when sowing in wide rows (60 cm) in variants with cover crops of spring wheat (360 kg/ha) and vetch-oat mixture for green mass (359 kg/ha), with the formation of the following structural elements: the number of generative shoots - 238 and 279 pcs/m², the number of brushes on a shoot – 16.0 and 15.5 pcs, pods on a brush – 6.9 and 7.9 pcs, seeds in a pod – 3.3 and 2.8 pcs, the weight of 1000 seeds is 1.94 and 1.96 g, respectively. The number of brushes on a shoot and the number of pods on a brush had an average positive effect on the yield level, correlation coefficients r=0.47 and r=0.53, respectively. Laboratory seed germination in the harvest was at the level of 77–90 %. Relatively the highest germination (90 %) was in wide-row sowings with row spacing of 60 and 30 cm in the variant with a vetch-oat mixture. When cultivating alfalfa for seed purposes, the most energy-efficient method is to use a vetch-oat mixture as a cover crop (energy efficiency coefficient – 5.65); coverless sowing is economically advantageous (profitability level – 556 %).