Effect of chemical correctives and sources of phosphorus in soils degraded by salts cultivated with millet (Pennisetum glaucum L.).

Abstract

The correction of the soil salinity requires, besides the concentration reduction of soluble salts and sodium in the soil profile, the increase of the fertility in seeking satisfactory productions. The objective of this study was to evaluate the effect of chemicals correctives and phosphorus sources on pH and phosphorus availability in a soil degraded by salts. The experimental test was conducted in a greenhouse belonging to the CSTR/UFCG, in the city of Patos, PB. The soil used in the experiment came from the Irrigated Perimeter of Sao Goncalo, belonging to the municipality of Sousa, PB. The experiment was conducted in a completely randomized design in a factorial scheme 2 x 2 x 4, regarding to the correctives (gypsum and sulfuric acid), to sources of phosphorus (phosphoric acid and super simple) and to P doses (0, 70, 140 and 210 mg dm-3) with three replications. Soil was packed in pots, remaining incubated after the application of correctives for 20 days, then, was done the washing, and more 20 days after the addition of the phosphate sources. Soon after, millet was cultivated. The use of gypsum as corrective and application of phosphoric acid promoted greater availability of phosphorus in soil, resulting in a greater vegetal production of millet.