Phytosociological characterization of weed species as affected by soil management

Resumo

Under tropical environments, the soil seed bank ensures floristic diversity and raises the ability of weeds to infest the area repeatedly whn weed/soil management practices are applied. The objective of this study is to identify weed species emerged phytosociologically from different depths in soils with distinct uses. The trial was carried out with soil samples collected from four agricultural areas with contrasting activities (1) Silvopastoral system composed by coconut trees with Brachiaria decumbens subjected to grazing;(2) same as 1, but without grazing;(3) sugarcane field; and (4) area with conventional tillage used for annual crops. The experiment was set up at the Campus II of the Vale do Rio Doce University, Minas Gerais, Brazil. Phytosociological characterization of weed species emerged from soil seed bank was carried out at soil depths of 0-5, 5-10 and 10-15 cm in each area. The results showed that a total of 32 species were emerged in the samples. The higher similarity of plant species was observed in the upper layer of soil by decreasing in the total number of species where depth increased. For areas with lower machine traffic and/or trampling by animals, ie, with less compaction, the greatest similarity of plant species was observed in the upper layer, indicating either a decrease in number of seeds or increase in seed dormancy as depth increased/or both of them. Results showed that the management applied in each area promotes changes in the seed bank also as a function of soil depth.

Publicação
Australian Journal of Crop Science