Produção de fitomassa fresca e seca e de grãos de sorgo (Sorghum bicolor L. Moench) sob adubação orgânica e mineral

Abstract

The sorghum crop by resisting the irregularities of rainfall, in quantity and distribution in time, presents with strong potential for exploitation in rainfed agriculture.The rigorous climate of ortheastern Brazil, has provided both unstable production of agricultural products such as livestock force, which in most cases has proven inadequate to meet local needs.The research aimed to evaluate the effect of organic and mineral fertilization on yield of grain sorghum and forage explored in rainfed agriculture in the micro-Guarabira of PB. The test was conducted in the rainy season of 2009 at the Experimental Station of the State Enterprise for Agricultural Research of Paraiba (PBEMEPA), in the municipality of Alagoinha - PB in Alfisol, with 9% slope. The experimental design was a randomized block design, using three cultivars of sorghum (Sorghum IPA 1011, IPA 2502 and Sorghum Sorghum SF120) under ten (10) treatments (1 - Without fertilization, 2 - With 10 tons, 3 - With 20 tons, 4 - With 30 tons, 5 - With 40 tons of manure per hectare, 6 - 0 with mineral fertilizer - 70 - 45 kg / ha, 7 - with mineral fertilizer 30 - 70 - 45 kg / ha, 8 - mineral fertilizer with 60 - 70 - 45 kg / ha, 9 - 90 with mineral fertilizer - 70 - 45 kg / ha and 10 - with mineral fertilizer 120 - 70 - 45 kg / ha with three replicates, totaling 90 experimental units, represented by plots of 5.0 m by 5.0 m. On trial were evaluated for plant height and diameter stem sorghum and production of fresh biomass and dry biomass and grain yield of three cultivars in the first cut. Among the results was found that the greatest differences between plant height and stalk diameter for sorghum cultivars were provided by the genetic load, the maximum yield of fresh biomass and dry biomass sorghum cultivar was provided by SF 120. The increasing amounts of nitrogen and manure applied to the soil does not yield increases in the production of fresh biomass and dry biomass sorghum and the organic and mineral fertilizer increased the production of fresh biomass and dry matter Three varieties of sorghum, as well as the production of seeds.