Luís Armando Zago Machado

Produção de palha e forragem por espécies anuais e perenes em sucessão à soja

The objective of this work was to evaluate forage and straw production, of annual and perennial forage implanted in succession to soybean, and their effects on crop grain yield in the following season. The experimental design was in randomized blocks with four replicates, in a split-plot arrangement (free growth and successive cuts). Eight forages were evaluated in two municipalities of the state of Mato Grosso do Sul, Brazil. Straw and forage production was evaluated in 2005 and 2006, in the following species: Urochloa ruziziensis, U. decumbens; U. brizantha cv. Marandu and Xaraes; Panicum maximum cv. Tanzânia and Mombaca, P. maximum x P. infestans cv. Massai, Pennisetum americanum cv. BRS 1501, and Sorghum bicolor cv. Santa Elisa. Forages were planted mechanically, after the soybean crop harvest on 4/1/2005 and 3/24/2006, in Sao Gabriel do Oeste, and 3/20/2005 and 3/13/2006, in Dourados. Sorghum, U. brizantha cv. Xaraes and P. maximum cv. Tanzânia characteristics, such as high productivity, high forage quality and easiness in control, were favorable for production of both forage and straw. Urochloa ruziziensis and U. decumbens showed better performance for straw production. Forage cultivation in soybean succession does not affect crop yield.

LEGUMES AND FORAGE SPECIES SOLE OR INTERCROPPED WITH CORN IN SOYBEAN-CORN SUCCESSION IN MIDWESTERN BRAZIL

The feasibility of no-tillage in the Cerrado (Savanna-like vegetation of Brazil) depends on the production of sufficient above-ground crop residue, which can be increased by corn-forage intercropping. This study evaluated how above-ground crop residue production and yields of soybean and late-season corn in a soybean-corn rotation were influenced by the following crops in the year before soybean: corn (Zea mays L.) intercropped with Brachiaria (Urochloa) brizantha cv. Marandu, B. decumbens cv. Basilisk, B. ruziziensis, cv. comum., Panicummaximum cv. Tanzânia, sunn hemp (Crotalaria juncea L.), pigeon pea [Cajanus cajan (L.) Millsp]; sole corn, forage sorghum [Sorghum bicolor (L.) Moench (cv. Santa Elisa)], and ruzi grass. In March 2005, corn and forage species were planted in alternate rows spaced 0.90 m apart, and sole forage species were planted in rows spaced 0.45 m apart. In October 2005, the forages were killed with glyphosate and soybean was planted. After the soybean harvest in March 2006, sole late-season corn was planted in the entire experimental area. Corn grain and stover yields were unaffected by intercropping. Above-ground crop residue was greater when corn was intercropped with Tanzania grass (10.7 Mg ha-1), Marandu (10.1 Mg ha-1), and Ruzi Grass (9.8 Mg ha-1) than when corn was not intercropped (4.0 Mg ha-1). The intercropped treatments increased the percentage of soil surface covered with crop residue. Soybean and corn grain yields were higher after sole ruzi grass and intercropped ruzi grass than after other crops. The intercropping corn with Brachiaria spp. and corn with Panicum spp. increases above-ground crop residue production and maintains nutrients in the soil without reducing late-season corn yield and the viability of no-till in the midwestern region of Brazil.

Estrutura do dossel em pastagens de capim-marandu submetidas a quatro ofertas de lâminas foliares

The objective of this work was to evaluate the sward structure of Brachiaria brizantha cultivar Marandu pastures in response to leaf blade allowance. The forage grass was sown in January 2001, at Embrapa Agropecuaria Oeste, Dourados, MS, Brazil and the allowances were 4, 8, 12 and 16% (kilograms of leaf blade per 100 kg of live weight per day). The experimental design was complete randomized blocks, with two replicates. The pasture was monthly evaluated during from October 2002 to May 2003, October 2003 to June 2004 and November of 2004 to June of 2005. The allowances were kept constant with put-and-take animals and continuous stocking grazing. The leaf blade mass and sward height increased linearly as a function of leaf blade allowance. The leaf blade accumulation rate and the root dry matter did not respond to the increase of allowance. The leaf blade mass and sward height vary with leaf blade allowance.

Desempenho agronômico de genótipos de capim-braquiária em sucessão à soja

The objective of this work was to evaluate the agronomic performance of palisade grass genotypes [Urochloa brizantha (Syn. Brachiaria brizantha)] in succession to soybean, for use on crop-livestock integration systems. The Marandu, MG 4, Xaraes, Piata, Arapoty e B 6 genotypes were evaluated as a second crop, during the dry season, and soybean, in the summer crop, in a succession scheme, from 2007 to 2010. In each year, forages were sown in March and evaluated at successive cuts until late September, then desiccated in October to allow for no-tillage soybean seeding in november. A randomized complete block design with four replicates was used. Xaraes and B 6 genotypes were among those with higher forage production. The Xaraes cultivar showed lower contents of crude protein, in vitro digestibility of organic matter, calcium, and phosphorus, which, however, can be considered good for this genus, since it was grown in fertile soil. There is variation among U. brizantha genotypes as to their performance in the second crop. The Xaraes and B 6 genotypes show better performance in succession to soybean, in integrated production systems. The MG 4 and B 6 genotypes are easily desiccated with glyphosate herbicide. Soybean yield is not significantly affected by the cultivation in succession to the U. brizantha genotypes.