Chemical alteration of soil irrigated by sprinkler, subsurface and surface drip irrigation with wastewater

摘要

The purpose of this study was to compare the variation of soil chemical constituents due to wastewater and surface water reservoir applications, during two cycles of the lettuce (Lactuca sativa L.), cv Elisa, using sprinkler, surface and subsurface drip irrigation. The soil layers of 0 - 0.1 m and 0.1 - 0.2 m were analyzed, after 6, 26 and 46 days of transplanting in the 1st cycle and after 7, 27 and 49 days in the 2nd cycle. The results showed an elevation of sodium concentration in the 1st cycle for the treatments irrigated with wastewater in both soil layers. The manganese and copper concentrations increased in the 1st cycle in the soil layer of 0 - 0.1 m for the sprinkler and surface drip irrigated with wastewater. In the 2nd cycle the treatments with waste water presented an elevation of total nitrogen in both analyzed layers and for organic matter in the layer of 0 - 0.1 m. Also in this cycle, a reduction in the manganese and copper concentrations was found, attributed to the rainfall that occurred in the period.