Energy efficiency of protection of black poplar plantings from weeds

Abstract

Purpose. Determine the energy efficiency of growing black poplar plantings.Methods. Field, laboratory.Results. It is established that from the energy point of view, the use of mulching allowed to obtain more energy with the harvest than spent on the technology of planting and caring for black poplar plants. The best mulching options were the use of straw layer 5 cm with Kee of 4.78. In addition, with the use of wood sawdust Kee values were at the level of the control weed version of the experiment. Application of the herbicide Stomp 330 EC, 5 l/ha contributed to obtaining Kee at the level of 4.21, and for the application of herbicide Zenkor 70, WG, 1.5 kg/ha, Kee was 4.77, and for the application of herbicide Starga EC, 2.0 respectively 4.24 and with the application of Stefam New, EC, 1.0 l/ha,4.89. The highest energy efficiency ratio was obtained with the combined application of Starga (1.5 l/ha) + Stefam New (0.5 l/ha), 5.27. In black poplar plantations, where in the first year of vegetation three consecutive inter-row cultivations were carried out, a total of 97.9 GJ/ha of energy was formed in three years at an energy efficiency coefficient of 4.77. The use of three hand weeding required additional human labor costs, but in total this had a negligible effect on the energy efficiency ratio of 4.94. However, the use of manual labor on an industrial scale is impossible due to the actual lack of sufficient labor reserves and the need for decent pay for employees, which cannot be justified even by high values of energy efficiency.Conclusions. It was established that in black poplar plantations without the presence of weeds the total energy yield for three years was 107.6 GJ/ha, whereas plantings without weed control provided the formation of only 46.1 GJ/ha, and the energy efficiency of the herbicide protection of black poplar provided the formation of 87.1 to 106.4 GJ/ha.