Resumo

BAIGORRIA, Tomás et al. Environmental impact and cover crop roller crimper in no-till soybean production. Cienc. suelo [online]. 2019, vol.37, n.2, pp.355-366. ISSN 1850-2067.

The massive adoption of no tillage sowing system and the use of soybean cultivars tolerant to glyphosate caused dependence on herbicides with total weed control spectrum (e.g.: glyphosate). The increase in costs of herbicides and a greater awareness on environmental issues, lead to search for alternatives to reduce the use of weed chemical control. Cover crops (CC) constitute a practice to reduce the use of post-emergence herbicides in soybean, minimizing environmental impact. The objective of this work was to evaluate the effect of CC termination methods and chemical weed control programs on water dynamics, environmental impact and soybean crop yield. Three species, two different termination methods (chemical vs. mechanical) and two weed control programs were studied on a typical Argiudoll. Soil available water (AW), environmental impact quotient (EIQ) and soybean productivity were measured. At termination CC moment, AW was 35% lower in CC than in fallow, while at sowing soybean AU was 16 % upper in CC treatments. CC and roller crimper decreased EIQ values more than 70 % without affected soybean yield. CC could allow a more sustainable use of natural resources and could also be a promising option in areas with restrictions to herbicide application, such us organic agriculture and peri-urban areas.

Palavras-chave : Fallow; available water; weeds; termination method.