Emissão de gases do efeito estufa em solo sob plantio direto com plantas de cobertura

Abstract

The main gases of the greenhouse effect are carbon dioxide (CO2), methane and nitrous oxide have increased considerably since the industrial revolution causing an imbalance in the atmosphere intensify the greenhouse effect, influencing the planet's climate and causing heating global. The study aims to evaluate the effect of summer legumes as ground cover plants on carbon dioxide emissions. It was established seven ground cover systems[Feijão de Porco(Canavaliaensiformes) MucunaAnã (Mucunadeeringiana), MucunaPreta (Mucunaaterrima), GuanduAnão (Cajanuscajan), CrotaláriaJuncea (Crotalaria juncea), CrotaláriaSpectabilis (Crotalaria spectabilis) e Lablab (Dolichos lablab)] plus a system fallow. It was determined dry matter production, atmospheric nitrogen fixation and decomposition rate of the biomass of cover crops. After the management of cover crops culture of canola was planted and then started the evaluation of gas. The CO2 was collected over a period of 90 days, with initial three-day intervals until 21 days the management of cover crops and then only once a week. They evaluated the availability of mineral N in the soil. Crops with higher dry matter production were those that most contributed to higher CO2 emissions. The Crotalaria juncea was the culture with the highest production of dry matter. Nitrogen (N) in the ammonium form in the soil do not differ between treatments. Levels of total mineral N and N as nitrate present difference between the systems until 30 days after the management of legumes.