98 resultados para Sugar cane bagasse ash
Resumo:
The status of zinc in sugar cane, variety Co 419, troughout its life cyle, was studid in samples cut monthly, from the 6th to 15th month, from an experiment carried on under the conditions of soil and climate prevailing in Piracicaba, State of São Paulo, Brazil. The experiment consisted of 6plots, 3 fertilized and 3 unfertilized. The fertilized ones received 40 kg of N (ammonium sulfate), 100 kg P2O5 (superphosphate) and 40 kg K2O (potassium cloride) per hectare, just before planting. The zinc content was determined by the Zincon method, after separation of zinc from other ions by means of the ion Exchange Resin III, Merck. The results obtained show that there was a tendency to decrease the zinc level in the stalks, whereas it kept more or less constant in the leaves; there was an exception in January, when the zinc level in the stalks had a sharp raise: 38-90-20 and 28-60-23 ppm for the fertilized an unfertilized treatments. There was a parallelism in the absorption of zinc by the plants from 4 hills of both treatments, through the whole - plantcycle but, the total amount taken up was higher with the fertilized plot due to its greater mass production.
Resumo:
The authors carried out 3 experiments on the sampling of sugar cane for technological determinations, one with each of the varieties Co 419, CB 40-69 and CB 41-58, in Piracicaba, State of São Paulo, Brasil. The main intent of the project was to compare 2 methods of sampling, namely: 1) Method A, where the sample is a hill (CATANI et al, 1959) or, more generally, 20 stalks all together in a randomly selected point of the furrow; 2) Method B, where 20 stalks are taken, from 20 points evenly spread but on the whole plot. Coefficients of variation for 20 stalk samples Variety Characteristic 20 stalks per hill 1 stalk per hill Brix 4.8% 1.9% Pol 6.4% 2.5% CB 40-69 Coefficient of purity 2.1% 0.83% Available sucrose 7.3% 2.7% Weight 6.6% 6.9% Brix 5.3% 1.8% Pol 7.6% 2.6% Co 419 Coefficient of purity 2.9% 1.0% Available sucrose 8.6% 3.0% Weight 21.2% 6.5% Brix 2.8% 1.4% Pol 4.1% 1.9% CB 41-58 Coefficient of purity 1.8% 0.8% Available sucrose 5.0% 2.2% Weight 10.9% 6.2% For the 3 varieties studied and for the data on Brix, pol, coefficient of purity, available sucrose and weight, analyses of variance were carried out. Further computations led to the following coefficients of variation. For available sucrose, which is probably the most important characteristic studied, the average coefficient of variation for the 3 varieties was 2.7%, for the case of method B, that is, 20 stalk samples, one stalk per hill. Assuming this coefficient of variation, in a trial with 5 treatments and 6 replications, in randomised blocks, the least significant difference among treatment means, at the 5% level, would be 4.7% of available sucrose by Tukey's test, and 3.3% by the t test. For the case of method A the average coefficient of variation is 7.0% and, in similar conditions, the least significant difference would be 15.1% by Tukey's test, and 12.1% by the t test. Since differences of available sucrose among treatments in experiments with fertilizers seldom are higher than 3 or 4% of the mean (PIMENTEL GOMES & CARDOSO, 1958), method B with a 20 stalk sample per plot gives more or less the minimum amount of cane to be sampled for technological determinations. In experiments with varieties, however, where differences may be assumed to be higher, a sample of 10 to 20 stalks one per hill, can be enough.
Resumo:
This paper describes the results obtained from the determination of iron in sugar cane according to the age of the plant, in the soil and climate conditions of the state of S. Paulo, Brazil. The iron was determined by 1-10- phenanthroline method, in samples cut monthly from 7th to 15th month from an experiment consisted de 3 plots fertilized with amonium sulfate, superphosphate and potassium cloride. The concentration of iron in the stalks and in the leaves varies according to the age of the plant. A ton of fresh stalks 15 months old contains 78,71 g of iron.
Resumo:
I. This paper deals with an experiment carried out to evaluate the effect of sugar cane upper end on the composition of the stalks and juice of sugar cane harvest as a raw material for the sugar industry. The variety studied was CB 41-76. The data were collected from plant cane at intervals of a two weeks, always from the same field, from a small central area of 3.000 square meters approximately, 60 stalks were cut in each occasion, randomly chosen from the whole area. They were afterwards separated into three groups of 20 stalks one for each of the treatments, namely: a) Complete stalk, with no leaves or sheaths. b) Stalks harvested by the technique of REYNOSO, that is, as usually done in practice. c) Stalks with the tops completely cut out, that is, cut by the techinique of REYNOSO and then with 3 other top internodes eliminated. The treatments caused significant differences on the weight of cane and coefficient of purity of juice, but the percentual differences between the average treatments a and c is 13% and 2%, respectively. II. Treatment differences for cane pol, cane fibre, brix, juice pol, reducing sugars, juice ashes, glucose coefficient, saline coefficient and available sucrose (pol) per cent were not significant. III. Time of harvest was an important factor affecting the composition of the cane and the juice. This paper shows that there is no sound basis for the heavy fines applied some sugar mills to planters who do not cut low enough the tops of the cane stalks.
Resumo:
In this paper the authors describe the results obtained from the determination of molybdenum in sugar cane plant, grown in soils and climate prevailing in Piracicaba, State of São Paulo, Brazil. The molybdenum was determined in samples cut monthly from the 8th to 14th month, from an experiment consisting of 6 plots, 3 fertilized and 3 unfertilized. The fertilized treatment received 40 kg N (ammonium sulfate) 100 kg P2O3, (superphosphate) and 40 kg K2O (potassium chloride) per hectare, just before planting. Molybdenum was determined by thiocyanate-stannous chloride method, using carbon tetrachloride-butyl alcohol misture, for extrating the colored complex. The results obtained show a parallelism in the absorption of molybdenum by the plants of both treatments. The concentration of molybdenum in the stalks have a tendency to decrease, where as it kept more or less constant in leaves, with a exception in the 14° month when it rised probable because of a migration of molybdenum of the stalks to the leaves. The total amount molybdenum taken up was higher with the fertilized plot due its greater mass prodution.
Levantamento sôbre a composição química bromatológica de 39 variedades forrageiras de cana-de-açúcar
Resumo:
This paper deals with a survey on chemical compositions of 39 forage sugar cane varieties carried out at the Bromatology Laboratory of the E.S.A. "Luiz de Queiroz" (5th chair). Samples were taken at Sugar Cane Experimental Station "Jose Viziolli", Piracicaba, SP, and the material was analised by standard methods. The main conclusions can be summarised as follows: 1. All varieties showed low protein and mineral contents, but were high in crude fiber and nitrogen free extract fractions. 2. A small, but positive correlation was observed between crude fiber and protein content. 3. The amount of observed variation concerning the various nutrient fractions could be used to select better forage sugar cane varieties.
Resumo:
The composition and diversity of bees in an agricultural area in Rio Claro, state of São Paulo, Brazil, were studied from May 2003 to June 2004, using Moericke traps. The collection site, an area with 58.08 hectares, is characterized by grain production and direct planting, with 70% of the surrounding area planted with sugar cane. During the study, 456 bees were collected, distributed among 20 genera, pertaining to the families Andrenidae (4.8%), Apidae (40.8%) and Halictidae (54.4%). Specimens of genera Dialictus (38%) and Diadasia (30%) predominated in this area. The species diversity, assessed using the Shannon and Simpson indices, were H=1.88 and 1/ D= 4.15, respectively, and the Evenness index was 0.61.
Resumo:
This study had the purpose of evaluating the effects of two management types of sugarcane: harvesting of burnt cane (BCH) and mechanized harvesting of unburnt green cane (MCH), on some soil physical properties of a dystrophic Rhodic Haplustox. The data were then compared with results for the same soil type under native forest. A completely randomized design was used, with three treatments and 20 replications. The following characteristics were determined: organic matter, aggregate stability, soil bulk density, and porosity at depths of 0-0.20 m and soil penetration resistance. After 15 years of cultivation, there were some alterations in the soil under cane burnt before harvesting, evidenced by a drop in the weighted average diameter of stable aggregates in water and increased soil bulk density. Significant changes were also detected in total porosity and pore distribution under both harvesting systems. Critical values for penetration resistance were observed in the area under mechanized sugar cane harvesting, with a value of 4.5 MPa in the 40-55 cm layer. This value is considered high and could indicate compaction and restriction of root growth. Soil properties under the green cane (unburned) management system were closest to those of the soil under native forest.
Resumo:
Nitrogen fertilization is a major component of the cost of agricultural production, due to the high cost and low efficiency of fertilizers. In the case of urea, the low efficiency is mainly due to losses by volatilization, which are more pronounced in cultivation systems in which plant residues are left on the soil. The objective of this work was to compare the influence of urea coated with sulfur or boric acid and copper sulfate with conventional N fertilizers on N volatilization losses in sugar cane harvested after stubble burning. The sources urea, sulfur-coated urea, urea coated with boric acid and copper sulfate, as well as nitrate and ammonium sulfate, were tested at amounts containing N rates of 120 kg ha-1 N. The integration of new technologies in urea fertilization can reduce N losses by volatilization. These losses were most reduced when using nitrate and ammonium sulfate. The application of a readily acidified substance (boric acid) to urea was more efficient in reducing volatilization losses and nutrient removal by sugar cane than that of a substance with gradual acidification (elemental sulfur).
Resumo:
The sampling scheme is essential in the investigation of the spatial variability of soil properties in Soil Science studies. The high costs of sampling schemes optimized with additional sampling points for each physical and chemical soil property, prevent their use in precision agriculture. The purpose of this study was to obtain an optimal sampling scheme for physical and chemical property sets and investigate its effect on the quality of soil sampling. Soil was sampled on a 42-ha area, with 206 geo-referenced points arranged in a regular grid spaced 50 m from each other, in a depth range of 0.00-0.20 m. In order to obtain an optimal sampling scheme for every physical and chemical property, a sample grid, a medium-scale variogram and the extended Spatial Simulated Annealing (SSA) method were used to minimize kriging variance. The optimization procedure was validated by constructing maps of relative improvement comparing the sample configuration before and after the process. A greater concentration of recommended points in specific areas (NW-SE direction) was observed, which also reflects a greater estimate variance at these locations. The addition of optimal samples, for specific regions, increased the accuracy up to 2 % for chemical and 1 % for physical properties. The use of a sample grid and medium-scale variogram, as previous information for the conception of additional sampling schemes, was very promising to determine the locations of these additional points for all physical and chemical soil properties, enhancing the accuracy of kriging estimates of the physical-chemical properties.
Resumo:
The present study shows that with liquid nitrogen stored inocula of Saccharomyces cerevisiae, and standardized experimental procedure, flow microcalorimetry can be a valuable tool for monitoring in real time the alcoholic fermentation processes on line. The avaliation of cultural conditions contained different carbon sources for alcohol fermentation (sucrose, glucose, fructose, manose, maltose, galactose, molasses, honey and sugar cane) and their effects on the heat output recording is discussed. Some examples of diauxic growth is given, where the microcalorimeters serves to detect the temporal order of succession of alternating metabolic pathways.
Resumo:
This paper describes variations in the profile of the main volatile organic compounds present in Brazilian sugar cane spirits distilled in copper and stainless steel distillers. The main organic compounds: aldehydes, ketones, carboxylic acids, alcohols and esters, were determined through High Performance Liquid Chromatography (HPLC) and High Resolution Gas Cromatography (HRGC). The spirits produced in copper distillers exhibit higher contents of aldehydes with respect to the ones produced in stainless steel. The inverse is true with respect to the higher alcohol and ester contents. No significant variation has been observed for the carboxylic acids.
Resumo:
A fast and direct method for the determination of Cr in milk and cane sugar suspensions using graphite furnace atomic absorption spectrometry with Zeeman-effect background correction is described. No sample pre-treatment was necessary, minimizing the risk of contamination. The concentration of chromium in cane sugar was evaluated using Cr reference solutions prepared in 1% v/v HNO3 solution. The milk samples were introduced into the furnace with a mixture of amines for avoiding the autosampler blockage and foaming of milk. Chromium determination in milk was based on the standard additions method (SAM). The limit of detection and characteristic mass for cane sugar sample (30 muL) were 0,13 ng/ml and 4,3 pg, and for milk sample (10 muL) were 0,23 ng/ml and 7,8 pg, respectively. The graphite tube lifetime was 300 firings for sugar-cane sample and 100 firings for milk sample. The heating program was implemented in 68 s.
Resumo:
Neural Networks are a set of mathematical methods and computer programs designed to simulate the information process and the knowledge acquisition of the human brain. In last years its application in chemistry is increasing significantly, due the special characteristics for model complex systems. The basic principles of two types of neural networks, the multi-layer perceptrons and radial basis functions, are introduced, as well as, a pruning approach to architecture optimization. Two analytical applications based on near infrared spectroscopy are presented, the first one for determination of nitrogen content in wheat leaves using multi-layer perceptrons networks and second one for determination of BRIX in sugar cane juices using radial basis functions networks.
Resumo:
The quantitative chemical analysis of the Brazilian sugar cane spirit distilled from glass column packaged with copper, stainless steel, aluminum sponge, or porcelain balls is described. The main chemical compounds determined by gas chromatography coupled with flame ionization (FID) and flame photometric (FPD) detectors and liquid chromatography coupled with diode array detector are aldehydes, ketones, carboxylic acids, alcohols, esters and dimethylsulfite (DMS). The spirits produced either in columns filled with copper or aluminum pot still exhibits the lowest DMS contents but the higher sulfate and methanol contents, whereas spirits produced in stainless steel or porcelain showed higher DMS concentration and lower teors of sulfate ion and methanol. These observations are coherent with DMS oxidation to sulfate, with methanol as by product, in the presence of either copper or aluminum.