Calibração de tanques evaporímetros de baixo custo sob diferentes diâmetros em ambiente protegido

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Resposta de cultivares de feijão-caupi a calagem

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Influência do Extrato Pirolenhoso no desenvolvimento e crescimento de plantas de milho

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Armazenamento de água no solo em sequências de culturas de verão e inverno sob semeadura direta

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Chemical and biological properties of phosphorus-fertilized soil under legume and grass cover (Cerrado region, Brazil)

The use of cover crops has been suggested as an effective method to maintain and/or increase the organic matter content, while maintaining and/or enhancing the soil physical, chemical and biological properties. The fertility of Cerrado soils is low and, consequently, phosphorus levels as well. Phosphorus is required at every metabolic stage of the plant, as it plays a role in the processes of protein and energy synthesis and influences the photosynthetic process. This study evaluated the influence of cover crops and phosphorus rates on soil chemical and biological properties after two consecutive years of common bean. The study analyzed an Oxisol in Selvíria (Mato Grosso do Sul, Brazil), in a randomized block, split plot design, in a total of 24 treatments with three replications. The plot treatments consisted of cover crops (millet, pigeon pea, crotalaria, velvet bean, millet + pigeon pea, millet + crotalaria, and millet + velvet bean) and one plot was left fallow. The subplots were represented by phosphorus rates applied as monoammonium phosphate (0, 60 and 90 kg ha-1 P2O5). In August 2011, the soil chemical properties were evaluated (pH, organic matter, phosphorus, potential acidity, cation exchange capacity, and base saturation) as well as biological variables (carbon of released CO2, microbial carbon, metabolic quotient and microbial quotient). After two years of cover crops in rotation with common bean, the cover crop biomass had not altered the soil chemical properties and barely influenced the microbial activity. The biomass production of millet and crotalaria (monoculture or intercropped) was highest. The biological variables were sensitive and responded to increasing phosphorus rates with increases in microbial carbon and reduction of the metabolic quotient.

Magnetic susceptibility in the prediction of soil attributes in two sugarcane harvesting management systems

This study aimed to investigate the potential use of magnetic susceptibility (MS) as pedotransfer function to predict soil attributes under two sugarcane harvesting management systems. For each area of 1 ha (one with green sugarcane mechanized harvesting and other one with burnt sugarcane manual harvesting), 126 soil samples were collected and subjected to laboratory analysis to determine soil physical, chemical and mineralogical attributes and for measuring of MS. Data were submitted to descriptive statistics by calculating the mean and coefficient of variation. In order to compare the means in the different harvesting management systems it was carried out the Tukey test at a significance level of 5%. In order to investigate the correlation of the MS with other soil properties it was made the correlation test and aiming to assess how the MS contributes to the prediction of soil complex attributes it was made the multiple linear regressions. The results demonstrate that MS showed, in both sugarcane harvesting management systems, statistical correlation with chemical, physical and mineralogical soil attributes and it also showed potential to be used as pedotransfer function to predict attributes of the studied oxisol.

Peanut mechanized digging regarding to plant population and soil water level

The largest losses in mechanical harvesting of peanuts occur during the stage of digging, and its assessment is still incipient in Brazil. Therefore, the aim of this study was to evaluate the quantitative losses and the performance of the tractor-digger-inverter, according to soil water content and plant populations. The experiment was conducted in a completely randomized block design with a factorial scheme 2 x 3, in which the treatments consisted of two soil, water content (19.3 and 24.8%) and three populations of plants (86,111, 127,603 and 141,144 plants ha-1), with four replications. The quantitative digging losses and the set mechanized performance were evaluated. The largest amount of visible and total losses was found in the population of 141.144 plants ha-1 for the 19.3% soil water content. The harvested material flow and the tractor-digger-inverter performance were not influenced by soil water content and plant population. The water content in the pods was higher in 24.8% soil water content only for the population of 86,111 plants ha-1; the yield was higher in the populations of 141.144 and 127.603 plants ha-1, in the 19.3 e 24.8% soil water content, respectively.

Arbuscular mycorrhizal fungal communities and soil aggregation as affected by cultivation of various crops during the sugarcane fallow period

Management systems involving crop rotation, ground cover species and reduced soil tillage can improve the soil physical and biological properties and reduce degradation. The primary purpose of this study was to assess the effect of various crops grown during the sugarcane fallow period on the production of glomalin and arbuscular mycorrhizal fungi in two Latosols, as well as their influence on soil aggregation. The experiment was conducted on an eutroferric Red Latosol with high-clay texture (680 g clay kg-1) and an acric Red Latosol with clayey texture (440 g kg-1 clay) in Jaboticabal (São Paulo State, Brazil). A randomized block design involving five blocks and four crops [soybean (S), soybean/fallow/soybean (SFS), soybean/millet/soybean (SMS) and soybean/sunn hemp/soybean (SHS)] was used to this end. Soil samples for analysis were collected in June 2011. No significant differences in total glomalin production were detected between the soils after the different crops. However, total external mycelium length was greater in the soils under SMS and SHS. Also, there were differences in easily extractable glomalin, total glomalin and aggregate stability, which were all greater in the eutroferric Red Latosol than in the acric Red Latosol. None of the cover crops planted in the fallow period of sugarcane improved aggregate stability in either Latosol.

Soil uses during the sugarcane fallow period: influence on soil chemical and physical properties and on sugarcane productivity

The planting of diversified crops during the sugarcane fallow period can improve the chemical and physical properties and increase the production potential of the soil for the next sugarcane cycle. The primary purpose of this study was to assess the influence of various soil uses during the sugarcane fallow period on soil chemical and physical properties and productivity after the first sugarcane harvest. The experiment was conducted in two areas located in Jaboticabal, São Paulo State, Brazil (21º 14' 05'' S, 48º 17' 09'' W) with two different soil types, namely: an eutroferric Red Latosol (RLe) with high-clay texture (clay content = 680 g kg-1) and an acric Red Latosol (RLa) with clayey texture (clay content = 440 g kg-1). A randomized block design with five replications and four treatments (crop sequences) was used. The crop sequences during the sugarcane fallow period were soybean/millet/soybean, soybean/sunn hemp/soybean, soybean/fallow/soybean, and soybean. Soil use was found not to affect chemical properties and sugarcane productivity of RLe or RLa. The soybean/millet/soybean sequence improved aggregation in the acric Latosol.

Componentes agronômicos e índices fisiológicos da mandioca correlacionados ao preparo do solo

Pós-graduação em Agronomia (Agricultura) - FCA

Adubação potássica e desenvolvimento de clones de eucalipto cultivados em Luís Eduardo Magalhães-BA

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Phosphorus fertilization of 'Fuyutoyo' cabbages in phosphorus-rich Eutrustox soil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Biodegradation and Phytotoxicity of Biodiesel, Diesel, and Petroleum in Soil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of Resin Cement Type on the Microtensile Bond Strength to Lithium Disilicate Ceramic and Dentin Using Different Test Assemblies

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Applying boron to coconut palm plants: effects on the soil, on the plant nutritional status and on productivity boron to coconut palm trees

Boron, one of the micronutrients frequently found in low levels in tropical soils affects nutrition and productivity of coconut palm trees essentially cultivated in tropical climates. The objective of this research study was to evaluate the effect of boron on the nutritional status of the plant and its productivity when artificially applied to the culture soil. The experiment was carried out in a four year old, artificially irrigated, dwarf coconut palm orchard in Brazil, between January, 2005 and October, 2006. The soil was a red yellow Latosol (B: 0.18 mg dm(-3)). The treatments consisted in the application of five boron dosages: zero, 1, 2, 4, and 6 kg ha(-1). In the field, the treatments were arranged according to a completely randomized block design, with four replications. Boron (borax) dosages were applied in equal halves directly into the soil in the months of January and February of 2005. Boron concentration in the soil and plant and plant productivity were evaluated. The higher palm tree production was associated to levels of 0.6mg dm(-3) of B in the soil and 23.5mg kg(-1) in leaves. Ninety five percent of palm trees maximum production was obtained with the use of a boron dosage of 2,1kg ha(-1).