Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In Brazil, most soils used in the livestock presents some fertility limitations. One of the alternatives to improve the soils quality is the introduction of perennial species, including grassy and associated legumes and correction of the soil that it will hold the cultures forage crop. There s a lack of Information and researches on soil quality improvement using perennial forages. Therefore, the objective of this work was to evaluate different systems of forage cultures constituted by Pennisetum americanum, Arachis pintoi and Stylosanthes guianensis associated with Cynodon dactylon and both isolated species, with and without mineral fertilizer, and evaluations of the attributes of a Ultisols. In both treatments, Cynodon dactylon received 100 kg of nitrogen during a year. The crops of forage samples were accomplished at every 28 days, making botanical separation and drying the same. After the weighting to calculate the dry matter per area (ha) the samples were crushed for analyses of fiber of neutral detergent (FDN), fiber of acid detergent (FDA), rude protein (PB), calcium (Ca), magnesium (Mg), phosphorus (P) and potassium (K). The samples collecting were taken during January, March, April and October of 2007. The best results of nutritional values were found in the legumes and in the consortium, being with inferior quality the grassy ones. The dry matter present a great variation among the cuts and the forage systems. After the winter the Stylosanthes portions were lost, due to the frosts that happened during this period. This confirms that it not has an adaptation on our conditions of winter. After a year of implantation of the experiment was collected soil to analysis: density of the soil (DS), microporosity (Mip) and macroporosity (Map) porosity and total porosity of the soil (PT) and size of aggregates. In the chemical part, were analyzed total nitrogen (NT), total organic carbon (COT) and phosphorus (P) and potassium (K). DS presented variation between the treatments and the appraised layers, since 1,40 to 1,62 Mg m-3. In Mip and PT didn't present significant differences between the treatments and layers, but Map presented significant differences. In the aggregate size there was significant differences, and the geometric medium diameter (DMG) it varied from 1,41 to 3,21 mm. In the soil chemical attributes both maintained similarities, in other words, larger concentration in the first layer (0 to 5 cm). But some treatments standing out in larger concentration in the first layer, however maintain similarities in the deep layers, unless the potassium (K), that has a distribution more constantly in the evaluated layers. / No Brasil, a maioria dos solos utilizados para pecuária apresenta algumas limitações de fertilidade. Uma das alternativas para melhorar as condições desses solos é a introdução de espécies perenes, incluindo gramíneas e leguminosas consorciadas e correção do solo que comportará as culturas forrageiras. Informações e pesquisas sobre melhorias de solos com uso de espécies forrageiras perenes são escassas. Nesse sentido, o objetivo deste trabalho foi avaliar diferentes sistemas de culturas forrageiras constituídas de milheto, amendoim forrageiro e estilosantes consorciados com tifton 85 e ambas as espécies isoladas, com e sem adubação mineral, e avaliações dos atributos de um Argissolo vermelho. Em ambas as parcelas adubadas e não adubadas, o tifton 85 recebeu 100 kg de nitrogênio ano-1. As colheitas de amostras de forragem eram realizadas a cada 28 dias, realizando-se separação botânica e secagem da mesma. Feita a pesagem para calcular matéria seca (MS) por área (ha) realizava-se a moagem das amostras para análises de fibra de detergente neutro (FDN), fibra de detergente ácido (FDA), proteína bruta (PB), cálcio (Ca), magnésio (Mg), fósforo (P) e potássio (K). Realizaram-se coletas nos meses de janeiro, março, abril e outubro de 2007. Os melhores resultados de valores de PB, FDA e FDN, foram encontrados nas leguminosas e no consórcio, ficando com qualidade inferior o tifton 85 + 100 kg ha-1 de N. Quanto à produção de MS, variou muito entre os cortes e os sistemas forrageiros. Após o inverno as parcelas de estilosantes foram perdidas, devido às geadas que ocorreram no período de inverno. Isso confirma que o mesmo não tolera frio e não se adapta a nossas condições de inverno. Após um ano de implantação do experimento realizou-se coletas para análise dos atributos do solo, sendo: densidade do solo (DS), micro (Mip) e macro (Map) porosidade e porosidade total do solo (PT) e tamanho de agregados. Na parte química, analisou-se nitrogênio total (NT), carbono orgânico total (COT) e teores de fósforo (P) e potássio (K). A DS apresentou variação entre os tratamentos e as camadas avaliadas, desde 1,40 a 1,62 Mg m-3. Na Mip e PT não apresentou diferenças significativas entre os tratamentos e camadas, mas o Map apresentou diferenças significativas. Nos tamanhos dos agregados houve diferenças significativas, sendo que o diâmetro médio geométrico (DMG) variou de 1,41 a 3,21 mm. Nos atributos químicos do solo, como NT, COT, P e K ambos mantiveram semelhanças, ou seja, maior concentração na primeira camada (0 a 5 cm). Mas alguns tratamentos se destacaram em maior concentração na primeira camada, mantendo semelhanças nas camadas mais profundas, exceto o K que teve uma distribuição mais uniforme nas camadas avaliadas.

Over the past thirty years, price relativities and technological development have motivated an increase in the area of land allocated to cropping, as opposed to pasture production, throughout the central wheat belt of Western Australia. Nevertheless, reducing the proportion of pasture in these rotations has challenged the future productivity of farming systems in this area. First, the frequent application of selective herbicides for weed control in extended cropping rotations has promoted the development of herbicide resistance in a number of major agricultural weeds. Second, the primary use of annual plants has promoted the development of soil salinisation by allowing a significant proportion of rainfall to recharge saline water tables. The inclusion of perennial pasture phases between extended periods of cropping may mitigate or delay these constraints to production through (a) allowing the use of costeffective forms of non-selective weed control, and (b) through creating a buffer of dry soil that absorbs leakage occurring beneath subsequent crops. This study consequently explores the value of including perennial pasture phases in dryland agricultural systems in the eastern-central wheat belt of Western Australia, accounting for benefits related to herbicide resistance and water table management. A novel computational algorithm for the solution of multiple-phase optimal control problems is developed and used to conduct a conceptual analysis of the value of lucerne (Medicago sativa L.) pasture for managing annual ryegrass (Lolium rigidum Gaudin), the primary weed in wheat belt cropping systems. The competitiveness and fecundity of annual ryegrass provide strong economic incentives to maintain a low weed population, irrespective of herbicide-resistance status. Consequently, the ineffectiveness of selective herbicides primarily reduces the profitability of cropping by motivating the adoption of more costly non-selective forms of weed control. The inclusion of lucerne in land-use rotations is only optimal in the presence of severe herbicide resistance given (a) the low efficiency of alternative weed-management practices available during the pasture phase, relative to selective-herbicide application; (b) the significant cost of establishing this perennial pasture; and (c) the high relative profitability of cereal production in the absence of resistance. The value of lucerne, relative to annual pastures, for weed management is explored in greater detail through the use of compressed annealing to optimise a sophisticated simulation model. The profitability of candidate rotations is also manipulated to account for the long-term production losses accruing to the recharge of saline groundwaters that occurs beneath them. Sequences incorporating lucerne are only more profitable than those that include annual pasture at the standard set of parameter values if (a) annual ryegrass is resistant to all selective herbicides, (b) the water table is so shallow (approximately less than 3.5 m deep) that frequent rotation with perennials is required to avert soil salinisation, or (c) sheep production is highly profitable. The value of perennial pasture is sufficient under these circumstances to overcome its high establishment cost. Consistent with intuition, these benefits are reinforced by lower discount rates and higher rates of leakage occurring beneath annual-based systems. Formulation of an effective communication strategy to report these results to producers is justified given the complexity involved in determining the true magnitude of these intertemporal benefits through alternative means, such as field trials.