Emprego de corretivos químicos, fontes e doses de fósforo em solo degradado por sais cultivado com milheto (Pennisetum glaucum L.).

Abstract

Correcting the problem with soil salinity requires in addition to reducing the concentration of soluble salts and sodium in the soil profile, increased fertility in order to satisfactory yields. The objective was to evaluate the effect of lime, phosphorus sources and rates of improvement in the physics and chemistry of a saline-sodic soil and yield of millet. The research was conducted in a greenhouse belonging to the CSTR / UFCG, Patos-PB. The soil used in the experiment comes from the Irrigated Perimeter of São Gonçalo, in the municipality of Sousa-PB. The experiment was conducted in a completely randomized design in factorial 2 x 2 x 4 concerning the corrective (gypsum and sulfuric acid), sources of phosphorus (phosphoric acid and superphosphate) and P rates (0, 70, 140 and 210 mg dm-3) with three replications. The soil was packed in jars incubated remaining after application of lime for 20 days, then done washing, and 20 days after the addition of phosphate sources. Soon after, he grew up millet. Both corrective further reduction in salinity and sodicity. Interactions were observed between the lime and phosphorus sources. Phosphoric acid was more effective than superphosphate in soil P availability. Plants grown with phosphoric acid showed higher vegetative growth and nutrient accumulation.