Desenvolvimento do feijoeiro caupi inoculado com rizóbio cultivado em solos salino-sódicos corrigidos com gesso

Abstract

In arid and semiarid regions mainly due to incorrect use of irrigation, the problems of salinity and / or sodicity has been aggravated. Two experiments were conducted: the first in laboratory using soil columns to identify the best level of gypsum to be applied in saline-sodic soils of semiarid Pernambucano, so that the correction was achieved. This research aims to assess the development and availability of calcium, magnesium , potassium, phosphorus and sodium to the cowpea bean crop grown in saline-sodic soils corrected with application of gypsum. Treatments were arranged in a randomized block design with a factorial arrangement (2 X 5): two soils and five levels of gypsum requirement (NG), equivalent to 50%, 100%, 150%, 200% and 250% of NG soil, determined by the method Schoonover M-1, with five repetitions. The second experiment was conducted in a greenhouse after correcting the soil, as test crop was used the cowpea bean [Vigna unguiculata L. (Walp.)], cultivar pele de moça, inoculated with Rhizobium, to determine the effect of gypsum in recovery of the soil and nutrient and sodium absorption by bean plants at 40 days after planting. It was evaluated: number and dry weight of nodules, dry matter of shoots, plant height, the levels of nitrogen, calcium, magnesium, potassium, phosphorus and sodium of plant material of shoot. The application of levels of gypsum requirement, followed by leaching depths were effective for the correction of sodicity and salinity of soil samples. Regardless of gypsum levels applied to the soil did not occur cationic unbalance between Mg2 + + Ca2+ and K+. Levels of gypsum applied promoted a small reduction of levels of phosphorus in the plant, not affecting the production of dry mass of shoots.