Pintoi peanut (Arachis pintoi Krapovickas & Gregory) is a warm‐season perennial legume that has been used in grass–legume mixtures; however, management practices to successfully establish pintoi into warm‐season grass swards have not been fully examined. Two experiments were conducted to evaluate different sward compositions and methods of establishment of pintoi peanut or pintoi peanut–palisadegrass [Urochloa brizantha (A. Rich.) R.D. Webster] mixed swards. The first experiment evaluated pintoi peanut and palisadegrass established as monocultures or in a pintoi peanut–palisadegrass mixture. Pintoi peanut ground cover and density was greater for pintoi peanut than pintoi peanut–palisadegrass mixed swards (29 vs. 8%, and 42 vs. 19 plants m−2 for ground cover and density, respectively). Concomitant seeding of pintoi peanut and palisadegrass showed no negative effect on palisadegrass herbage mass (HM). In the overseeding experiment, treatments were: (i) peanut interseeded into glyphosate‐treated rows subsequently strip tilled into prepared seedbed strips (0.4 m) with intervening untilled areas (2 m); (ii) peanut no‐till seeded into glyphosate‐treated rows (0.4 m) with intervening untilled areas (2 m); and (iii) an undisturbed sward of palisadegrass with no pintoi peanut. Prepared seedbed and no‐till treatments had similar pintoi ground cover (2.9%), density (8.7 plants m−2), spread (11.7 cm), and HM (170 kg ha−1 yr−1). Glyphosate treatment of rows followed by no‐till seeding was an effective strategy to establish pintoi peanut into palisadegrass swards. Pintoi peanut contribution during the early stages after establishment is insufficient to generate sufficient biological N fixation and produce forage for livestock.

Rhizoma peanut (Arachis glabrata Benth.) is a warm‐season legume adapted to the southern United States. ‘Florigraze’ is the most cultivated rhizoma peanut; however, recent studies have demonstrated that the genotype Ecoturt has attractive forage characteristics. The objectives of this study were to evaluate the effect of leaf and stem proportions on dry matter (DM) and crude protein (CP) disappearance of Ecoturf and Florigraze rhizoma peanut. Treatments were two genotypes of rhizoma peanut (Florigraze or Ecoturf) and three leaf and stem proportions (100, 50, and 0%) distributed in a randomized complete design with four replicates. Crude protein and DM disappearances were estimated using a nonlinear model. Dry matter and CP fractions were described as rapidly degradable (Fraction A), potentially degradable (Fraction B), and undegradable (Fraction C). Florigraze had greater DM Fraction A than Ecoturf (349 vs. 339 g kg−1), but there was no difference in Fractions B and C (means = 427 and 230 g kg−1, respectively). The leaf and stem proportions have significant impact on DM and CP fractions and effective degradability. There was a linear decrease in DM Fractions A and B and a decrease in Fraction C with increasing leaf proportion. Conversely, CP Fractions A and C increased with increasing leaf proportion, whereas Fraction B decreased. The leaf and stem proportions are important indicators of nutritive value of rhizoma peanut, and the models generated by this study may allow managers to have a more accurate prediction of forage nutritive value for ruminants.

A existência de variabilidade espacial nas propriedades do solo influencia na produção da forrageira. O trabalho teve como objetivo determinar a distribuição espacial das propriedades químicas do solo relacionando-a com a produção e a preferência de forragem por animais em pastejo de Urochloa brizantha cv. Marandu (Syn. Brachiaria brizantha) sob lotação contínua. Para caracterização da área de pastagem, foram realizadas medições de 108 pontos com distribuição em malha irregular, com coletas de solo para determinação dos atributos químicos (pH, matéria orgânica, P, K, Ca, Mg, Al, H+Al) e densidade do solo, produção de forragem, altura do dossel forrageiro, índice SPAD e intensidade de pastejo, no período das águas de 2012. Realizou-se o teste de normalidade, seguido de análise descritiva dos dados e análise geoestatística. As características químicas e densidade do solo, bem como a produção e altura do pasto, apresentaram dependência espacial, com mesmo padrão de resposta, inferindo que tais respostas são interrelacionadas. Os fatores que causam a variabilidade nas características do solo também interferem nas relacionadas ao pasto influenciando em parte no pastejo animal. Os atributos químicos do solo, densidade, massa seca, altura e intensidade de pastejo, ajustaram-se ao modelo exponencial. A estimativa da variabilidade espacial dos atributos do solo juntamente com avaliação da disponibilidade do pasto e os pontos de preferência do pastejo animal são ferramentas importantes para estabelecer critérios de uso e manejo diferenciado dentro de uma mesma área de pastagem, na perspectiva de evitar degradação do solo e do pasto.

No abstract