Exchangeable basic cations and nitrogen distribution in soil as affected by crop residues and nitrogen

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

Phosphorus and potassium balance in soil under crop rotation and fertilization

The use of crop rotation and manure application can provide sustainability for an agricultural production system by improving soil quality and increasing nutrient use efficiency. This study aimed to evaluate the effect of mineral, organic and mineral+organic fertilization on grain yield and on soil phosphorus and potassium balance, in two crop systems under no-till, with and without rotation of cover crops. The experiment was carried out from 2006 to 2008 on a clayey Rhodic Hapludox in Marechal Candido Rondon, Parana State, Brazil. The cropping sequence in the rotation system involving cover crops was black oat + hairy vetch + forage turnip/corn/pigeon pea/wheat/mucuna + brachiaria + sunn hemp, and in the succession system was wheat/corn/wheat/soybean. Organic and mineral+organic fertilizations consisted of the application of solely manure and manure combined with mineral fertilizer, respectively. Soil P and K balances were calculated after the second year of the experiment, up to a depth of 0.40 m. First year corn yields were higher in the crop succession system accompanied by mineral fertilization. In the second year, wheat and soybean yield did not vary between crop systems and nutrient sources, demonstrating the residual effect of crop rotation and manure use. Crop rotation with cover crops resulted in an increase in soil K levels by promoting the recycling of this nutrient in the soil. In both crop systems, the application of mineral and organic fertilizers - either in isolation or in combination - resulted in a negative soil P and K balance in the short term. This represents a threat to the sustainability of the agricultural production system in the long term, due to the depletion of soil nutrient reserves.

Nitrogen content identification in crop plants using spectral reflectance and artificial neural networks

The accurate identification of the nitrogen content in crop plants is extremely important since it involves economic aspects and environmental impacts. Several experimental tests have been carried out to obtain characteristics and parameters associated with the health of plants and its growing. The nitrogen content identification involves a lot of nonlinear parametes and complexes mathematical models. This paper describes a novel approach for identification of nitrogen content thought spectral reflectance of plant leaves using artificial neural networks. The network acts as identifier of relationships among pH of soil, fertilizer treatment, spectral reflectance and nitrogen content in the plants. So, nitrogen content can be estimated and generalized from an input parameter set. This approach can be form the basis for development of an accurate real time nitrogen applicator.

Damage Detection in Flexible Plate Using Lamb Waves

This paper presents an experimental technique for structural health monitoring (SHM) based on Lamb waves approach in an aluminum plate using piezoelectric material as actuators and sensors. Lamb waves are a form of elastic perturbation that remains guided between two parallel free surfaces, such as the upper and lower surfaces of a plate, beam or shelf. Lamb waves are formed when the actuator excites the surface of the structure with a pulse after receiving a signal. Two PZTs were placed in the plate surface and one of them was used to send a predefined wave through the structure. Thus, the other PZT (adjacent) becomes the sensor. Using this methodology, this paper presents one case of damage detection considering the aluminum plate in the free-free-free-free boundary condition. The damage was simulated by adding additional mass on the plate. It is proposed two damage detection indexes obtained from the experimental signal, involving the Fast Fourier Transform (FFT) and the power spectral density (PSD) that were computed using the output signal. The results show the viability of the presented methodology to damage detection in smart structures

Straw decomposition of nitrogen-fertilized grasses intercropped with irrigated maize in an integrated crop-livestock system

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nitrogen fertilization and soil management of winter common bean crop

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

Analysis and functional annotation of an expressed sequence tag collection for tropical crop sugarcane

To contribute to our understanding of the genome complexity of sugarcane, we undertook a large-scale expressed sequence tag (EST),program. More than 260,000 cDNA clones were partially sequenced from 26 standard cDNA libraries generated from different sugarcane tissues. After the processing of the sequences, 237,954 high-quality ESTs were identified. These ESTs were assembled into 43,141 putative transcripts. of the assembled sequences, 35.6% presented no matches with existing sequences in public databases. A global analysis of the whole SUCEST data set indicated that 14,409 assembled sequences (33% of the total) contained at least one cDNA clone with a full-length insert. Annotation of the 43,141 assembled sequences associated almost 50% of the putative identified sugarcane genes with protein metabolism, cellular communication/signal transduction, bioenergetics, and stress responses. Inspection of the translated assembled sequences for conserved protein domains revealed 40,821 amino acid sequences with 1415 Pfam domains. Reassembling the consensus sequences of the 43,141 transcripts revealed a 22% redundancy in the first assembling. This indicated that possibly 33,620 unique genes had been identified and indicated that >90% of the sugarcane expressed genes were tagged.

Influence of feeding regime and finishing system on lamb muscle fiber and meat quality

Avaliou-se a influência dos níveis nutricionais da ovelha antes do parto, da idade à desmama e do sistema de terminação sobre as fibras musculares e a qualidade da carne dos cordeiros. Utilizaram-se matrizes mestiças Ile de France × Bergamacia criadas a pasto. As ovelhas foram divididas em dois grupos: um com suplementação alimentar 30 dias antes do parto e outro sem suplementação. Os animais (ovelha e cordeiros) foram subdivididos de acordo com a idade à desmama (45 ou 60 dias de idade) e os cordeiros desmamados foram submetidos a três sistemas de terminação: confinamento com dieta completa; confinamento somente com feno; e confinamento somente no pasto. O abate dos cordeiros foi realizado aos 30 kg de peso vivo ou aos 150 dias de idade. As características de carcaça analisadas foram morfofisiologia da fibra do músculo longissimus dorsi, fragmentação miofibrilar pós-morte (maturados nos dias 0, 3 e 7 pos mortem) e redução do pH e da temperatura da carne pós-abate. Não houve efeito da suplementação às ovelhas ou da idade à desmama sobre nenhuma das características avaliadas. A composição em fibras de contração lenta e oxidativa, contração rápida e oxidativa ou contração rápida e glicolítica não foi alterada pelos fatores em estudo, mas a área transversal das fibras foi menor nos cordeiros terminados com feno, assim como os valores de pH, temperatura e as medidas dos fragmentos de miofibrila. Com o aumento do tempo de maturação de 0 para 3 e 7 dias post mortem, houve redução do comprimento dos fragmentos de miofibrilas. O sistema de terminação de cordeiros em confinamento somente com feno interfere mais intensamente na qualidade da carne que o sistema de terminação a pasto ou em confinamento com dieta completa.

Determination of the optimal quantity of crop residues for energy in sugarcane crop management using linear programming in variety selection and planting strategy

The aim of this work was to present organizational models for optimizing the reduction of crop residue generated by the sugarcane culture. The first model consisted of the selection of varieties of sugarcane to be planted meeting the mill requirements and, at the same time, to minimize the quantity of residue produced. The second model discussed the use of residue to produce energy. This is related to the selection of variety and quantity to be planted, in order to meet the requirements of the mill, to reduce the quantity of residue, and to maximize as much as possible the energy production. The use of linear programming was proposed. The two models presented similar results in this study, and both may be used to define the varieties and areas to be cultivated. (C) 2001 Published by Elsevier B.V. Ltd.

Game theory in sugarcane crop residue and available energy optimization

This work proposes a mathematical model to aid variety selection and planting quantity of sugarcane in order to reduce crop residues, maximize energy generated by this residue, and satisfy all the supply of the mill. We propose Linear Programming with two objective. The conflict between these objectives allows the use of the Nonzero-sum Game Theory. (C) 2003 Elsevier B.V. Ltd. All rights reserved.

Identification and expression analysis of microRNAs and targets in the biofuel crop sugarcane

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

Green lacewings (Neuroptera: Chrysopidae) associated with Melon Crop in Mossoró, Rio Grande do Norte State, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Upland rice yield as affected by previous summer crop rotation (soybean or upland rice) and glyphosate management on cover crops

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Microbiological counting in lamb carcasses from an abattoir in São Paulo, Brazil

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

WATER NEEDS FOR WINTER BEAN CROP

Um estudo sobre o uso de água do feijoeiro de inverno (Phaseolus vulgaris L. cv. Carioca) foi realizado num solo Latossol Vermelho Amarelo de textura argilosa. Um sistema de sulcos de infiltração foi usado para proceder a irrigação com o intuito de manter o solo em potenciais de água superiores a -40,0 KPa. Duas doses de aplicação de N em cobertura (0 a 30 Kg N/ha) foram colocados 25 dias após o plantio. Os principais objetivos do estudo foram: avaliar a interação entre as duas doses de N com a evapotranspiração e medir os coeficientes de cultura (Kc). A evapotranspiração média máxima (ETm) foi 1,71 mm/dia, ou 157,16 mm nos 92 dias de observações; os valores de ETm para as fases vegetativa (1), florescimento (2) e formação de vagens (3) foram 1,48; 2,35 e 1,50 mm/dia, respectivamente, para a dose de 30 Kg/ha e 1,48, 1,88 e 1,45 mm/dia para o tratamento sem aplicação de N em cobertura. Os coeficientes de cultura (Kc = ETm/ETo) foram 0,62 e 0,78 para a fase 1, 0,80 e 1,10 para a 2, 0,45 e 0,55 para a 3 e 0,61 e 0,80 para o ciclo todo, respectivamente, baseados no método de FAO-Penman e do Tanque Classe A. Este mostrou melhores resultados para estimar o máximo uso de água pelo feijoeiro de inverno. Os tratamentos de N não afetaram a evapotranspiração significativamente. Entretanto, a evapotranspiração, medida pelo método do balanço de água, foi 59,78 e 27,12% maior no estágio do florescimento que no estádio vegetativo, respectivamente, nas doses de 30 e 0 Kg N/ha.