Biological activity in saline sodic soil saturated by water under cultivation of Atriplex nummularia

Abstract

The salinity constitutes a serious limiting factor for agriculture, because most crops are sensitive to salinity, being much affected by the harmful effects of salts. Halophyte species of the genus Atriplex are characterized by high tolerance to drought and soil salinity, a viable alternative to reduce negative impacts of salinity, associated with the microbial biomass. Therefore, the aim of this study was to assess the microbial activity in saline sodic soil of the Agreste of Pernambuco, in the presence and absence of plants of Atriplex nummularia. For that, there were samples of soil to 20 cm depth in different situations: 1 and 2) in the proximity of roots (20 cm from the stem of each plant) in treatments with and without pruning, 3 and 4) at the midpoint of plant spacing (125 cm) in treatments with and without pruning, 5) bare soil (control treatment), in the rainy season. These samples were analyzed for C and N microbial biomass, basal respiration and C and N content of soils. It was observed that the control treatment had different results compared with other treatments, indicating that without plants of atriplex the soil microbiota is highly affected by the high salt concentrations. There was also a tendency for increased microbial activity with proximity of pruned plant roots of atriplex, showing that, besides being a viable plant for phytoremediation of salinized soils, still promotes an improvement of soil microbes.