ABSTRACT Phytogenic additives are organic molecules that also improve ruminal fermentation, turning the supplemented individuals into more productive animals, without damage the population welfare. The objective of this study was to evaluate the effects of mesquite (Prosopis juliflora [Sw.] DC.) extract as phytogenic additive for sheep finished on pasture in the Brazilian Northeast semiarid region. Twenty-four intact lambs (Santa Ines × Dorper F1 crossbred) were used, with an initial body weight of 23.00 ± 1.83 kg. The experiment was carried out in a complete randomized design with four treatments and six replicates. Treatments consisted of four diets: Pasture and no supplementation; grazing pasture and phytogenic additive; pasture, supplementation with Tifton 85 hay, and concentrate; and pasture, phytogenic additive, and supplementation with Tifton 85 hay and concentrate. Prior to supplementation, animals received the phytogenic additive according to treatment. There were nonsignificant differences for nutrient intake and behavior patterns (P > 0.05). However, additive intake derived from mesquite provided an increase (P < 0.05) in digestibility (14.40% total digestible nutrients), N balance (27.12% retained N:ingested N) and performance (8.82% final body weight, 21.81% total weight gain, and 30.81% average daily gain) compared to animals consuming only pasture in rainy period. Thus, the use of mesquite extract as phytogenic additive is recommended for sheep finished on pasture in the Brazilian semiarid region.

Com este trabalho objetivou-se caracterizar os efeitos da erosão e da conservação do solo nas propriedades de um Luvissolo e avaliar o comportamento da rotação algodão/adubo verde com e sem inoculação de rizóbio na melhoria da produtividade do solo e do rendimento do algodoeiro. O experimento foi desenvolvido em casa de vegetação da UFC/CCA, utilizando-se cilindros de PVC com 11 kg de solo. Os tratamentos foram definidos como: camada ligeiramente erodida (CI e C) e camada severamente erodida (DI e D) cultivada com adubo verde com e sem inoculação de rizóbio. O delineamento experimental utilizado foi o inteiramente casualizado, com 6 repetições. Avaliaram-se: altura de plantas, número de maçãs por planta, matéria seca da parte aérea, massa de capulho por planta, número de sementes por planta, massa de sementes e nutrientes no solo, antes e após a aplicação do adubo verde. As melhores condições edáficas encontradas no solo conservado potencializaram os efeitos positivos do tratamento CI com aumento significativo do rendimento do algodão; as condições no solo degradado foram melhoradas pela rotação feijão-de-porco/algodão e os rendimentos, do adubo verde ou do algodão em DI, não atingiram aqueles obtidos em C.

The objective of this work was to characterize erosion and soil conservation effect on properties of Luvissolo and to evaluate the behavior of cotton/green manure rotation with or without rhizobium inoculation in the improvement of soil productivity and cotton yield. The experiment was conducted in a greenhouse of UFC/CCA, using cylinders of PVC with 11 kg of soil. The treatments had been defined as: slightly eroded layer (CI and C) and severely eroded layer (DI and D) cultivated with green manure with and without rhizobium innoculation. The experimental design was completely randomized, with 6 replications. The height of plants, number of fruit per plant, dry matter of the aerial part, boll weight per plant, number of seeds per plant, weight of seeds and nutrient contents in the soil before and after the application of the green manure were evaluated. The best edaphic conditions found in the conserved soil potentialised the positive effect of treatment CI with significant increase in cotton yield; the conditions in the degraded soil had been improved by the rotation beans cotton; the yields in both green manure and cotton in DI were lower than obtained in C.