Qualidade física e química do solo em função do sistema de produção e da aplicação superficial de silicato e calcário em experimento de longa duração

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Plantas de cobertura, adubação nitrogenada e produção de sementes de feijoeiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atributos do solo e modalidade de semeadura na consorciação de milho com forrageiras e desempenho agronômico do feijoeiro em sucessão

Pós-graduação em Agronomia - FEIS

Rehabilitation with forage grasses of an area degraded by urban solid waste deposits

Dry matter yield and chemical composition of forage grasses harvested from an area degraded by urban solid waste deposits were evaluated. A split-plot scheme in a randomized block design with four replicates was used, with five grasses in the plots and three harvests in the subplots. The mineral content and extraction and heavy metal concentration were evaluated in the second cut, using a randomized block design with five grasses and four replicates. The grasses were Brachiaria decumbens cv. Basilisk, Brachiaria ruziziensis, Brachiaria brizantha cv. Marandu and cv. Xaraés, and Panicum maximum cv. Tanzânia, cut at 42 days of regrowth. The dry matter yield per cut reached 1,480 kg ha-1; the minimum crude protein content was 9.5% and the average neutral detergent fiber content was 62.3%. The dry matter yield of grasses was satisfactory, and may be an alternative for rehabilitating areas degraded by solid waste deposits. The concentration of heavy metals in the plants was below toxicity levels; the chemical composition was appropriate, except for phosphorus. The rehabilitated areas may therefore be used for grazing.

How can an invasive grass affect fire behavior in a tropical savanna? A community and individual plant level approach

Some invasive grasses have been reported to change fire behavior in invaded plant communities. Urochloa brizantha is an aggressive invasive grass in the Brazilian Cerrado, an ecosystem where fire is a common disturbance. We investigated the effects of U. brizantha on fire behavior in an open Cerrado physiognomy in Central Brazil. Using experimental burnings we compared fire behavior at both the community and the individual plant level in invaded (UJ) and non-invaded (NJ) areas burned in July. We also assessed the effect of fire season in invaded areas by comparing July (UJ) and October (UO) burnings. We evaluated the following variables: fuel load, fuel moisture, combustion efficiency, maximum fire temperature, flame height, and fire intensity. Additionally, we evaluated the temperatures reached under invasive and native grass tussocks in both seasons. Fuel load, combustion efficiency, and fire intensity were higher in NJ than in UJ, whilst flame height showed the opposite trend. Fuel amount and fire intensity were higher in October than in July. At the individual plant level, U. brizantha moisture was higher than that of native species, however, temperatures reaching ≥600 °C at ground level were more frequent under U. brizantha tussocks than under native grasses. At the community level, the invasive grass modified fire behavior towards lower intensity, lower burning efficiency, and higher flame height. These results provide essential information for the planning of prescribed burnings in invaded Cerrado areas.

Supplementary feeding of horses with processed sorghum grains and oats

Two feeding experiments and in vitro hind gut fermentation tests were carried out to study the effect of processing sorghum grain on digestion of starch and on the gastrointestinal (GI) tract environment of the horse. In experiment 1, 12 yearling Australian stock horses were blocked on the basis of sex then randomly divided into four equal groups, each containing one castrated male and two females of approximately the same age and weight. Horses were offered at 0800 and 1500 h, 3 kg medium quality liverseed grass (Urochloa panicoides) hay and 2 kg of either oats (O), dry rolled sorghum (DRS), steam-flaked sorghum (SFS) or expanded sorghum (ES). Lanthanum was used as external solid marker for the measurements of apparent total tract digestibility. Fresh water was available ad libitum. Horses were allowed 18 days to adapt to the diets followed by a 3-day faecal collection period. Digestibility of dry matter (DM), and acid detergent fibre (ADF) were higher (P

Desenvolvimento do capim-marandu com altura fixa ou variável durante as estações do ano

Aimed to identify, for assessing the tillering dynamics and morphogenesis , strategy (s ) suitable ( s) defoliation management to optimize the appearance of tillers and biomass of Urochloa Brizantha syn. Brachiaria brizantha cv. Marandu ( marandugrass ) throughout the year. The experiment was conducted from January 2013 to May 2014 were studied three strategies defoliation: Marandugrass with 30 cm throughout the experimental period (constant height); Marandugrass 15 cm in winter, the spring 30 cm and 45 cm in summer (increasing height); and Marandugrass 45 cm in winter, the spring 30 cm and 15 cm in summer (descending height). The experimental design was completely randomized in a split plot in time, with four replications. In winter, in the spring and summer, the following variables were calculated: appearance rate (TApP), mortality (TMoP) and survival (TSoP) of tillers, balance (BAL) between TApP and TMoP, stability index (IE) numbers of tillers and leaf elongation rates and stem, length of leaf blade and stem, leaf senescence rate, phyllochron and duration of life of the sheet. The TAPP was higher in the early spring and summer. For TMoP, the highest values were in the late spring and summer. The balance between TApP and TMoP was negative in winter and late spring, regardless of defoliation strategy. There was no difference in IE between the heights of the canopy during winter and late spring .. The number of tillers was higher in early spring and summer and lower in winter and late spring. The defoliation strategies have not changed phyllochron, leaf elongation rate. In spring and summer, there were increases in the rates of appearance, elongation and leaf senescence and, furthermore, decreased life span and phyllochron sheet. The plant height with increasing showed a lower rate of senescence and lower culm length in the spring. To increase the number of tillers marandu, it is advantageous to handle the plant with increasing height, ie, 15 cm in autumn and winter, the spring 30 cm and 45 cm in summer.The maintaining of B. brizantha cv. Marandu with fixed height of 30 cm or with variations between 15 and 45cm from the fall/winter to summer, does not influence the appearance and the growth of leaves per tiller, which indicates great flexibility on management defoliation in this forage plant.

CRESCIMENTO INICIAL E CONCENTRAÇÃO DE NUTRIENTES EM CLONES DE Eucalyptus urophylla x Eucalyptus grandis SOB INTERFERÊNCIA DE PLANTAS DANINHAS

A presença de plantas daninhas em plantios de eucalipto, especialmente nos dois primeiros anos, pode acarretar grandes prejuízos à produtividade, pois reduz a eficiência de aproveitamento dos recursos de crescimento pela cultura. Assim, objetivou-se com este trabalho avaliar os efeitos da interferência de plantas daninhas sobre o crescimento inicial de dois clones de Eucalyptus urophylla x Eucalyptus grandis e a concentração foliar de nutrientes na cultura e nas plantas daninhas. O experimento foi instalado em esquema fatorial 2 x 5 + 7, sendo dois clones de híbridos de Eucalyptus urophylla x Eucalyptus grandis, identificados como CNB001 e CNB016, em competição com cinco plantas daninhas Urochloa decumbens (capim-braquiária), Ipomoea nil (corda-de-viola), Commelina diffusa (trapoeraba), Spermacoce latifolia (erva-quente) e Panicum maximum (capim-colonião). Adicionalmente, foram cultivados os dois clones de eucalipto e as cinco plantas daninhas em monocultivo como padrão de comparação, no delineamento inteiramente casualizado, com quatro repetições. Foram avaliados eucalipto através da altura de plantas, o diâmetro do coleto, o número de ramos, a área foliar, a matéria seca e, o teor foliar de nutrientes do eucalipto, bem como o teor de nutrientes nas folhas das plantas daninhas. O clone CNB001 apresentou crescimento inicial superior ao clone CNB016, no entanto, livre da interferência de plantas daninhas, verificaram-se teores foliares semelhantes para a maioria dos nutrientes em ambos os genótipos. O clone CNB016 mostrou maior sensibilidade à interferência negativa das plantas daninhas que o clone CNB001, sendo seu crescimento inicial mais afetado por Ipomoea nil e a concentração de nutrientes reduzida pelas espécies Panicum maximum, Urochloa decumbens e Commelina diffusa. Panicum maximum apresentou maior interferência com o clone CNB001, enquanto Ipomoea nil pouco influenciou o crescimento e o teor de nutrientes deste híbrido. As plantas daninhas apresentaram elevada capacidade de extrair nutrientes do solo, mesmo em convivência com os clones de Eucalyptus urophylla x Eucalyptus grandis. A interferência imposta à cultura é dependente da espécie infestante e do genótipo de eucalipto.

Integração lavoura-pecuária-floresta como estratégia para aumentar a produtividade e prover serviços ambientais no noroeste do Paraná.

RESUMO: Os solos da região Noroeste do Paraná apresentam cerca de 85 a 90% de areia e níveis críticos de nutrientes, conferindo alta suscetibilidade à erosão e baixa capacidade de armazenamento de água. Além disso, a região apresenta clima quente, tornando-a bastante vulnerável a estresses abióticos. Uma das estratégias para aumentar a produtividade e, ao mesmo tempo, incrementar serviços ambientais é aumentar a diversidade de atividades, por meio do sistema de integração lavoura-pecuária-floresta (iLPF). O sistema iLPF pode conferir maior taxa de sequestro de carbono, conservação da biodiversidade e melhoria da qualidade do solo, água e ar, em comparação a sistemas não integrados. No município de Santo Inácio, PR, foram conduzidas por cinco anos duas áreas com sistema iLPF. Nos três primeiros anos de condução, foi possível conciliar a produção de grãos (soja), forragem (Brachiaria ruziziensis e B brizantha ) e madeira (eucalipto), sem que um componente prejudicasse o outro. A partir do terceiro ano, as árvores interferiram expressivamente na produtividade de grãos e forragem, indicando a necessidade de redução do número de árvores por área. O iLPF é um sistema de produção relevante para aumentar a provisão de bens e serviços ecossistêmicos na região Noroeste do Paraná, mas que ainda precisa de ajustes tecnológicos para incrementar os ganhos econômicos e ambientais. ABSTRACT: Most soils in Northwest of Paraná state, Brazil, are sandy (85 to 90% sand), with critical nutrient levels, high susceptibility to erosion and low water storage capacity Moreover, the region?s warm weather confers to these soils high vulnerability to abiotic stresses The diversification of production via adoption of integrated cropping-livestock-forestry (ICLF) systems is an important strategy to increase productivity and, simultaneously enhance ecosystem services. ICLF systems can increase carbon sequestration, conserve biodiversity and improve soil, water and air quality, compared with specialized production systems. Two trials were carried out for five years using ICLF in Santo Inácio county in Paraná state, Brazil. In the first three years, it was possible to harmonize production of grains (soybean), fodder (Brachiaria ruziziensis and brizantha) and wood (Eucalyptus) without negative effects of three components on each other. After the third year, the trees significantly reduced grain yield and fodder production, indicating the need for thinning to reduce tree interference. The ICLF system is relevant to increase the delivery of ecosystem goods and services in Northwestern Paraná, though technological adjustments are needed to increase its economic and environmental gains.

Selectivity and efficiency of herbicides in weed control on sweet sorghum.

A carência de herbicidas registrados para o controle de plantas daninhas, em sorgo sacarino, torna-se fator limitante à produção. Objetivou-se avaliar a seletividade de herbicidas em sorgo sacarino e a eficiência no controle de plantas daninhas. O delineamento experimental foi de blocos ao acaso, com quarto repetições. Os tratamentos incluíram cultivares de sorgo sacarino (BRS 506, BRS 509 e BRS 511) e herbicidas aplicados isoladamente em pré-emergência (atrazine - 1.500 g ha-1; atrazine + s-metolachlor - 1.665 g ha-1 + 1.035 g ha-1; flumioxazin - 50 g ha-1; s-metolachlor - 1.440 g ha-1) e pós-emergência (tembotrione - 100,8 g ha-1) e de forma sequencial em pré e pós-emergência (atrazine + s-metolachlor + tembotrione - 1.665 g ha-1 + 1.035 g ha-1 + 100,8 g ha-1; atrazine + tembotrione - 1.500 g ha-1 + 100,8 g ha-1; flumioxazin + tembotrione - 50 g ha-1 + 100,8 g ha-1), mais duas testemunhas, uma capinada e outra sem capina. A fitotoxicidade ao sorgo foi de 98,0 %, 98,0 % e 100 % de tembotrione; 100 %, 98,7 % e 100 % de flumioxazin + tembotrione; 100 %, 100 % e 100 % de atrazine + s-metolachlor + tembotrione; e 98,7 %, 98,7 % e 99,7 % de atrazine + tembotrione, respectivamente para as cultivares BRS 509, BRS 506 e BRS 511. Tembotrione, flumioxazin + tembotrione, atrazine + s-metolachlor + tembotrione e atrazine + tembotrione apresentaram bom controle de Ipomoea indivisa, Digitaria ciliaris e Urochloa plantaginea, porém, não demonstraram seletividade às cultivares de sorgo. O atrazine, de modo geral, apresentou maior seletividade aos componentes de rendimento das cultivares BRS 509 e BRS 506.

Influência de sistemas de manejo integrados em um latossolo amarelo no desenvolvimento da soja.

O cultivo da soja destaca-se por ser a principal atividade responsável pela expansão da fronteira agrícola no País, sendo assim, necessário a utilização de sistemas que torne seu cultivo sustentável. Objetivou-se avaliar o desenvolvimento da soja cultivada em diferentes sistemas. O experimento foi realizado na fazenda Vitória, município de Paragominas, Pará. Segundo Köppen, o clima do município é classificado como mesotérmico e úmido, tipologia climática Aw. O delineamento experimental utilizado foi o de blocos casualizados, com quatro repetições. Os tratamentos foram compostos por três sistemas de cultivo de soja, sendo em sistema iLPF (consórcio com Brachiaria ruziziensis e intercalado com eucalipto), sistema Santa Fé (consórcio com Brachiaria ruziziensis) e sistema Convencional manejado com técnicas tradicionais de preparo do solo (aração e gradagem) e controle fitossanitário. Foram avaliadas a produtividade de grãos da cultura, teor de umidade dos grãos (%); Stand de plantas, altura de planta e de inserção da primeira vagem. As médias dos tratamentos foram comparadas pelo teste de Tukey (p<0,05). Os valores de altura de planta e inserção da primeira vagem e produtividade de grãos não apresentaram diferença significativa entre os sistemas em estudo. A soja cultivar sambaiba em consórcio com Brachiaria ruziziensis nos sistemas integração Lavoura-Pecuária-Floresta e Santa Fé não sofreram redução na produtividade de grãos por área e de grãos por indivíduo quando comparados ao sistema Convencional.

Manejo de cultivo do paricá (Schizolobium amazonicum) em um Latossolo amarelo distrófico no sistema de integração lavourapecuária-floresta no Nordeste Paraense.

Objetivou-se avaliar o (Schizolobium amazonicum) no sistema de Integração Lavoura-Pecuária-Floresta (ILPF) e no sistema homogêneo para recuperar áreas de pastagens degradadas. O cultivo de grãos foi realizado com milho (BRS 1030), a forragem utilizada foi Urochlroa ruziziensis e a espécie florestal foi o paricá. O crescimento do paricá foi mensurado até o quinto ano e a circunferência à altura do peito (CAP) foi mensurada a partir do segundo ano da instalação do sistema ILPF. Na avaliação dos 5 anos, as plantas de paricá no ILPF apresentaram menores valores de altura de planta e maiores valores de CAP, quando comparadas com o sistema homogêneo. O excesso de chuva nos meses de fevereiro a maio de 2009 causou prejuízos na produtividade e na qualidade dos grãos de milho (Zea mays). Mesmo assim, apresentou bons resultados no consórcio com forragem intercalado com paricá. Houve recuperação e manutenção da capacidade produtiva do solo, redução de carbono (C), fósforo (P), saturação por bases e aumento no teor de alumínio trocável (Al3+) com o aumento da profundidade do solo. Essas peculiaridades do iLPF implicam em diferentes estratégias de manejo da fertilidade do solo. Para tanto, as recomendações devem ser mais bem estudadas, respeitando as situações especificamente.

Annual crop rotation of tropical pastures with no-till soil as affectedby lime surface application.

Soil acidity and low natural fertility are the main limiting factors for grain production in tropical regionssuch as the Brazilian Cerrado. The application of lime to the surface of no-till soil can improve plant nutrition, dry matter production, crop yields and revenue. The present study, conducted at the Lageado Experimental Farm in Botucatu, State of São Paulo, Brazil, is part of an ongoing research project initi-ated in 2002 to evaluate the long-term effects of the surface application of lime on the soil?s chemical attributes, nutrition and kernel/grain yield of peanut (Arachis hypogaea), white oat (Avena sativa L.) and maize (Zea mays L.) inter cropped with palisade grass (Urochloa brizantha cv. Marandu), as well as the forage dry matter yield of palisade grass in winter/spring, its crude protein concentration, estimated meat production, and revenue in a tropical region with a dry winter during four growing seasons. The experiment was designed in randomized blocks with four replications. The treatments consisted of four rates of lime application (0, 1000, 2000 and 4000 kg ha−1), performed in November 2004. The surface application of limestone to the studied tropical no-till soil was efficient in reducing soil acidity from the surface down to a depth of 0.60 m and resulted in greater availability of P and K at the soil surface. Ca and Mg availability in the soil also increased with the lime application rate, up to a depth of 0.60 m. Nutrient absorption was enhanced with liming, especially regarding the nutrient uptake of K, Ca and Mg by plants.Significant increases in the yield components and kernel/grain yields of peanut, white oat and maize were obtained through the surface application of limestone. The lime rates estimated to achieve the maximum grain yield, especially in white oat and maize, were very close to the rates necessary to increase the base saturation of a soil sample collected at a depth of 0?0.20 m to 70%, indicating that the surface liming of 2000 kg ha−1is effective for the studied tropical no-till soil. This lime rate also increases the forage dry matter yield, crude protein concentration and estimated meat production during winter/spring in the maize-palisade grass inter cropping, provides the highest total and mean net profit during the four growing seasons, and can improve the long-term sustainability of tropical agriculture in the Brazilian Cerrado.

Differences between root traits of early- and late-successional trees influence below-ground competition and seedling establishment.

The competitive influence of the root system of the exotic grass Urochloa brizantha and the widespread forb Leonotis nepetifolia on the emergence, survival and early growth of the seedlings of eight tropical heliophilous herbaceous species, six early-successional woody species and five late-successional woody species from Brazil, grown in 3500-cm3 pots and in greenhouse without light restriction were assessed. The density of fine-root systems produced by the forb and the grass in pots were 6.8 cm cm-3 soil and 48.1 cm cm-3 soil, respectively. Seedlings survival of the heliophilous herbaceous, early- and late-successional woody species were 86%, 70% and 100% in presence of the forb root system and 12%, 14% and 100% in competition with grass root system, respectively. The competitive pressure applied by the grass root system on seedling growth of the heliophilous herbaceous, early- and late-successional woody species were 2.4, 1.9 and 1.4 times greater than the forb root system. Total root length of the heliophilous herbaceous, early- and late-successional woody species grown without competitors were 13, 33 and 5 times greater than in competition with forb, and were 66, 54 and 6 times greater than in competition with grass root system, respectively. The averages of fine-root diameter of plants grown without competitors were 209 microm for the heliophilous herbaceous, 281 microm for early-successional trees and 382 microm for late-successional trees. The root system of the forb did not avoid seedling establishment of most plant species, but the grass root system hampered more the establishment of heliophilous herbaceous and early-successional woody species than the seedling establishment of late-successional woody species. The different density of root systems produced in soil by the forb and the grass, and the distinct root traits (e.g. root diameter and root tissue density) of the early- and late-successional plant species can explain the differences in the establishment of seedlings of plant species belonging to different groups of tropical succession when exposed to below-ground competition.