Physical and chemical attributes of a typic ultisol in organic citrus orchard with weed control between the lines/Atributos fisicos e quimicos de um argissolo vermelho, em pomar organico de citros com manejo da vegetacao nas entrelinhas

The management in organic citrus orchards is differentiated with respect to conventional orchards. Thus, it was aimed to evaluate some physical and chemical attributes of a typic ultisol and productivity of a mandarin orchard, cv. Montenegrin under organic production system, with different vegetation management between the lines. The treatments were: harrowing, mowing, lodging with coulter and log dragging. The evaluation of the physical attributes occurred under the canopy and in the machinery traffic area, in the depths of 0.0-0.1 and 0.1-0.2 m. The chemical fertility of the soil was determined in the layer of 0.0-0.1, 0.1-0.2 and 0.2-0.4 m, while the fruit yield was estimated from central plants of each portion. Machine traffic negatively affected the physical attributes of soil below the interface patch, although it was not restrictive to fruit yield. In all treatments there was an increase of organic matter in the topsoil, and the levels of P, [K.sup.+], [Ca.sup.2+] and [Mg.sup.2+] in the three soil layers in relation to the adjacent area with native vegetation. The handling with harrowing showed significantly higher productivity in relation to the management with mowing.