Оценка взаимодействия видов многолетних мятликовых трав (Poaceae) с клевером ползучим (Trifolium repens L.) в смешанных агрофитоценозах в контексте биологизации семеноводства

Abstract

Nitrogen consumption is one of the most important factors and necessary conditions for plant growth and development. The contribution from the biological fixation of N2 by legumes in grass mixtures can reduce or completely replace the need for industrial nitrogen fertilizers for perennial bluegrass grasses. When white clover is cultivated in grass mixtures, the net nitrogen gain to the ecosystem from the atmosphere during the growing season as a result of biological fixation can vary from 100 to 300 kg/ha or more. This is equivalent in effect to the application of mineral nitrogen fertilizers on grass in doses from 150 to 350 kg/ha. Types and varieties of perennial grasses have different competitiveness and complementarity when they are jointly cultivated in mixed crops. The use of grasses to create less lying grass stands allows you to increase the collection of white clover seeds. When cultivating white clover in grass mixtures, there was a decrease in the biological yield of seeds compared to mono-crop by 15–38% due to a decrease in the number of generative shoots. However, seed losses during harvesting decreased by up to 9–23% depending on the type of accompanying cereal crop and the method of harvesting. They were minimal in mixed crops of clover with pasture ryegrass or reed fescue and accounted for 9–11% and 12–13% of the biological yield of seeds, respectively. The highest seed collections were obtained from grass stands of the second year of use without the use of nitrogen fertilizers from crops of pasture ryegrass, reed fescue and meadow fescue: 761, 402 and 373 kg/ha, respectively. Along with the types of cereal components, the nature of plant interaction in grass mixtures and their response to anthropogenic stresses also depend on the genotypes of white clover varieties. A comparative assessment of the effectiveness of cultivating clover varieties mixed with reed fescue showed that the highest collection of legume seeds 188 kg/ha from grass stands of the first year of use was provided by the 'Lugovik' variety – 36–68% more than with grass mixtures of the cv. 'Volat' variety f. giganteum and cv. 'VIK 70' of the f. hollandicum variety.