Seed productivity of perennial leguminous herbs depending on the sowing method
The method of sowing perennial leguminous herbs for seed purposes remains relevant today. The choice of the method should involve considering biological characteristics of the cultivated crop, technical capacity of the farm, and weather conditions. Udmurt Research Institute of Agriculture was engaged in studies on the impact of the sowing method on the seed productivity of the eastern galega «Gale» (1995-2001) and the birds-foot trefoil «Sol-nyshko» (2010-2017). The research objectives included the issues of seed yields, structure, sowing qualities of the obtained seeds, energy assessment of the cultivation methods under study. The study revealed the potential of the eastern galega to achieve relatively high seed productivity both in wet (490 kg/ha) and in arid (158 kg/ha) years. On average for six years of grass use, the wide-row method of cultivating galega with a row space of 30-45 cm produced a seed yield of 357-370 kg/ha. The galega seeds had laboratory germination of 93-94 %; the weight of 1000 seeds was 7,46-7,48 g. The grass had the following parameters: stalk stand density was 40-52 pieces/m2, the number of seeds in a bean was 2 pieces. The birds-foot trefoil did not give seeds every year. The wet conditions of the second half of the growing season in 2012 resulted in vegetative growth, continuous flowering of plants and no mature beans. On average, over a three year period of grass use, the highest yield of birds-foot trefoil seeds (255 kg/ha) was obtained through ordinary row sowing. The grass had the following indices: stalk stand density was 580 pieces/m2, the number of beans on one stem was 11 pieces, the number of seeds in a bean was 13 pcs, laboratory germination of seeds was 69 % and the mass of 1000 seeds was 1,12 g. The eastern galega had the energy efficiency coefficient of 4,9 under wide-row sowing, and the birds-foot trefoil had the energy efficiency coefficient of 5,5 under ordinary sowing.