Weed infestation of maize grown in the sustainable system of cultivation

Abstract

The crop cultivation with the herbicide application as lower as possible and favouring other measures (cultural, biological, ecological) is one the postulates of sustainable agriculture. Therefore, cover crops and tillage systems may contribute to a significant reduction in maize weed infestation, maintenance and improvement of soil fertility. The trial, set up at the Maize Research Institute, Zemun Polje in 2020, was aimed at determining differences between a sustainable growing system (with cover crops) and a conventional/extensive and intensive growing system in soil fertility, weed control and maize productivity. The trial encompassed three maize growing systems: - extensive system: after winter wheat harvest, the field was left uncultivated; during summer, a total herbicide was applied to suppress weeds; in spring, maize was directly sown; - intensive system: after winter wheat harvest, stubble field was shallowly ploughed; then a total herbicide was applied to suppress emerged weeds; in autumn, soil was deeply ploughed; in spring, pre-sowing cultivation was done by a cultivator and then sowing was performed; -sustainable system: after winter wheat harvest, stubble field is shallowly ploughed and then winter cover crops were sown: winter oats, winter fodder kale and winter field pea; cover crops were mown in spring and when biomass was partially decomposed, maize was sown by direct sowing. The high-yielding maize hybrid of the latest generation, ZP5601, was sown on May 6, 2021, at the density of 60,606 plants ha-1. In the stated maize growing systems, the presence of weeds was analysed at the 5-6-leaf stage of maize. A significantly lower number of species and biomass of weeds were determined in all variants of cover crops (sustainable cultivation) already in the first year of investigation, while the highest presence of weeds was recorded in the conventional/intensive maize growing system. The number of weed species and biomass were the lowest on the area with the extensive maize growing system, but maize was in the lower BBCH 15 stage in comparison to remaining two growing systems (BBCH 17). A sustainable maize growing system was more efficient with respect to the maintenance of soil fertility and weed control.