Efficiency of cultivation of variegated alfalfa and awnless brome in pure form and in mixed sowings

Abstract

The development of technology elements for the cultivation of perennial alfalfa-brome mixtures contributes to the formation of highly productive agrocenoses and reduce the cost of fodder mass. In 2017-2022, in the conditions of the Penza region, there has been studied the effect of seeding rates of alfalfa variegated of Daria variety and awnless brome Udalets in pure and mixed sowings, the level of mineral nutrition and the time of harvesting green mass on the economic and energy efficiency of cultivation. Growing seasons of 2017-2021 were characterized by dry conditions (HTC = 0.4-0.8), of 2022 – by normal moisture (HTC = 1.0). The calculation of the cost of production showed the advantage of the seeding rate of alfalfa and brome 70+40 %, the introduction of N45P60K90 and harvesting in the early phase the cost of 1 ton of feed units amounted to 2.36 thousand rubles, in the variant without fertilizers at this seeding rate, the cost was 6.8 % higher – 2.52 thousand rubles. The level of profitability of alfalfa-brome mixtures when cultivated for green mass was at a high level and amounted to 161-238 % according to the variants. Higher rates were obtained in variants with a seeding rate of 70+40 %, the introduction of N45P60K90 during harvesting both in the budding phase and variable mowing – 235-238 %. Cost of 1 ton feed units at a seeding rate of 70+40 % was 1.51-1.96 GJ (depending on the mowing period), a decrease in the seeding rate of alfalfa to 40 % increased the cost of 1 ton of feed units up to 1.74-2.20 GJ. The use of mineral fertilizers increased the cost of 1 ton of feed units when applying P60K90 by 0.02-0.06 GJ, and when introducing N45P60K90 by 0.29-0.36 GJ. The early phase of harvesting was energetically favorable – the cost of 1 ton of feed units was lower than when harvesting in the flowering phase by 0.08-0.15 GJ. With a high seeding rate of alfalfa and a low seeding rate of brome (70+40 %), the maximum energy efficiency coefficient (EEC) was obtained – 5.2-7.1 (depending on the background of nutrition and the mowing period). With a decrease in the seeding rate of alfalfa from 70 to 40 %, a decrease in the EEC to 4.5-6.1 was noted. The application of mineral fertilizers significantly reduced the EEE indicators – from 5.8-7.1 to 5.5-6.7 with the application of P60K90 and to 4.3-5.3 with the application of N45P60K90. At an early harvesting time (budding phase), the EEC was slightly higher – 4.7-7.1, than at a late harvesting time (flowering phase) – 4.5-6.8.