Weed communities in the organic cultivation of fresh maize intercropped with legumes and coffee husk

Abstract

The objective of this study was to evaluate the phytosociology of the weed communities in maize intercropped with legumes and coffee husk in an organic production system, emphasizing on the relative importance of the weeds and their biomass. The experiment was implemented with the following treatments: T1 - Maize intercropped with Phaseolus vulgaris and weed mowing, T2 – maize intercropped with Crotalaria juncea and weed mowing, T3 - Maize intercropped with Canavalia ensiformis and weed mowing, T4 - Maize intercropped with Cajanus cajan and weed mowing, T5 - Maize grown on soil covered with coffee husk (100 m3 ha-1) and manual weeding and T6 - Maize grown under conventional tillage system and manual weeding (control). The treatments were performed under a random block design with five replications each. A phytosociological analysis of the weeds was performed at stages V4, V8, and R1 to determine the relative importance (RI%) and biomass. The lowest biomass (11.6 g m-2) of weeds occurred when maize was grown on soil covered with coffee husk. In total, 13 species of weeds were identified, being Cyperus rotundus L. the most prevailing species (%). From this study, it was determined that growing maize on soil covered with coffee husk is an alternative to suppress weeds in the organic fresh maize system when coffee husk is available.

Influence of burning and weed control on the soil fertility and vegetation cover of Brazilian Amazon pastures

“…Group III had the highest average weed cover (53.4%), followed by Group I (9.3%) and II (3.6%). Group III (only contained pasture plot 3) had the highest average weed cover because it received no weed control, as opposed to Santos et al (2019), who considered mowing as an inefficient activity for weed control. In this study, this method proved to be effective, since Group I and Group II showed less weeds compared to Group III.…”

Survey of the floristic composition and the structure of spontaneous vegetation present at green corn cultivated in organic no-tillage system

“…[9] In regards to the management of spontaneous plants, the use of mulch in NTS has been considered as an excellent alternative since if it is well formed and evenly distributed over the soil surface acts physically and mechanically over the bank of seeds of spontaneous plants decreasing its germination rate. [10,11,12,13,14] This physical and mechanical control occur by reducing the incidence of light and variation in soil temperature and by inhibiting the germinative process of seeds that have a small amount of reserves in their diaspores. [12,15,16] The presence of straw also favors the biological and chemical control of the spontaneous community: a) the first occurs through the population of microorganisms increasing which can destroy the seeds of spontaneous plants [17] and b) the second through the release of allelopathic compounds that can inhibit the growth of the community.…”