Oven-dry Basis Research Articles

Conventional kiln drying and equalization of Western hemlock ( Tsuga heterophylla (Raf.)[Sarg]) to Japanese equilibrium moisture content

Density sorted, matched-samples of Western hemlock were dried in order to quantify the physical changes of conventionally kiln dried wood when exposed to the equilibrium moisture contents of a typical Japanese winter. Physical changes were monitored for 14 weeks by sampling board weight, dimensions, shell and core moisture contents (oven-dry basis) and warp. The difference of 7% in equilibrium moisture content between Tokyo and Vancouver is large enough to elicit a response in shell moisture content, dimensions and warp. However, the responses found should be expected when wood is examined in context of its natural variability. Drying 105 mm by 105 mm Western hemlock to 19% moisture content at the core should be considered the maximum target moisture content. A target moisture content of 15% at the core would balance drying time and end-use stability as the lumber is equalized to Japanese conditions.

Intra- and Inter-Tree Variability of Moisture Content in Standing Sessile Oak (Quercus petraea Liebl.)

Summary Knowledge about the moisture content of trees in the forest or wood yard is scarce. The variation of moisture content within and between 20 boles of sessile oak was investigated using 1543 measurements performed at three heights in each tree and along 4 radii. Five radial positions were defined: sapwood, outer, intermediate and inner heartwood, and the core piece including the pith. Results show that the average moisture content is highly dependent on the individual. The average moisture content was around 80%(oven-dried basis), but it ranges from 65% to 100%depending on the tree. This “tree” effect is discussed and examined using some general characteristics of the trees (region, stand structure, site quality, dendrometric and densitometric traits). Apart from age counted from pith, and the ratio of tree height vs. diameter, no strong correlation appears. Moderate variations in moisture content with radial position and height are also brought to the fore. The specific role of sapwood, which exhibits a more variable moisture content is discussed.

Feasibility of a Harvesting System for Logging Residues as Unutilized Forest Biomass

The concept of a “harvesting system for unutilized forest biomass by a processor and a forwarder” is examined for the purpose of constructing a system to harvest logging residues (or slashes) as a new resource for energy. The rate of slash harvesting, α, and the energy input rate of hauling slashes,p (%), are defined as indices of the possibility of harvesting slashes and the utilization of slashes for energy, respectively. From an analysis of the field experiment, both the volume of logs hauled by the forwarder per day,EF (m3/day), andp are expressed as functions of the hauling distance,L(m). The productivity of the processor,EP (m3/day), andL were used to calculate α. Results showed that α was approximately 0.95 for the experiment site, indicating that almost all the slashes could be hauled. It was recognized that the energy utilization of slashes was feasible for this site becausep was less than 1 %. The hauling cost per unit weight of slashes was calculated as 15.4 yen/kg on an oven-dry weight basis. This high cost clarified that the cost must be reduced by taking measures such as enhancing the hauling efficiency of the forwarder.

Bioconversion of mixed solids waste to ethanol.

A mixed solids waste (MSW) feedstock, comprising construction lumber waste (35% oven-dry basis), almond tree prunings (20%), wheat straw (20%), office waste paper (12.5%), and newsprint (12.5%), was converted to ethanol via dilute-acid pretreatment followed by enzymatic hydrolysis and yeast fermentation. The MSW was pretreated with dilute sulfuric acid (0.4% w/w) at 210 degrees C for 3 min in a 4-L steam explosion reactor, then washed with water to recover the solubilized hemicellulose. The digestibility of water-washed, pretreated MSW was 90% in batch enzymatic hydrolysis at 66 FPU/g cellulose. Using an enzyme-recycle bioreactor system, greater than 90% cellulose hydrolysis was achieved at a net enzyme loading of about 10 FPU/g cellulose. Enzyme recycling using membrane filtration and a fed-batch fermentation technique is a promising option for significantly reducing the cost of enzyme in cellulose hydrolysis. The hexose sugars were readily fermentable using a Saccharomyces cerevisiae yeast strain that was adapted to the hydrolysate. Solid residue after enzyme digestion was subjected to various furnace experiments designed to assess the fouling and slagging characteristics. Results of these analyses suggest the residue to be of a low to moderate slagging and fouling type if burned by itself.

Fractionation of Sugar Cane with Hot, Compressed, Liquid Water

Sugar-cane bagasse and leaves (10−15 g oven-dry basis) were fractionated without size reduction by a rapid (45 s to 4 min), immersed percolation using only hot (190−230 °C), compressed (P > Psat), liquid water (0.6−1.2 kg). Over 50% of the biomass could be solubilized. All of the hemicellulose, together with much of the acid-insoluble lignin in the bagasse (>60%), was solubilized, while less than 10% of the cellulose entered the liquid phase. Moreover, recovery of the hemicellulose as monomeric sugars (after a mild posthydrolysis) exceeded 80%. Less than 5% of the hemicellulose was converted to furfural. Percolation beyond that needed to immerse the biomass in hot liquid water did not result in increased solubilization. The yield of lignocellulosic residue was also not sensitive to the form of the sugar cane used (bagasse or leaves) or its moisture content (8−50%). Commercial applications for this fractionation process include the pretreatment of lignocellulosics for bioconversion to ethanol and the production of pulp and paper products.

A computer program to express the properties of gypsiferous soils

Data from gypsiferous soils on an oven-dry basis cannot be compared with similar data from nongypsiferous soils because gypsum loses most of its crystal water on drying at 105 °C. A short computer program that uses the successive-approximation technique was developed to convert percent gypsum values determined on an air-dry basis or on an oven-dry basis into percent gypsum values determined on an oven-dry basis plus crystal water of gypsum. Percent gypsum and percent moisture of the analyzed soil samples are the required input data. The program calculates the corrected percent moisture and the percent gypsum on an oven-dry basis plus crystal water of the gypsum. The output of the program allows a comparison of gypsum contents, and any other properties, of gypsiferous soils after obtaining the correct moisture contents of the gypsiferous soils and makes these properties comparable with those of nongypsiferous soils. Key words: Percent gypsum, computer program, water content, gypsiferous soils

Elementary composition, humus composition, and decomposition in soil of charred grassland plants

Abstract Charred plant residues collected after the burning of grassland vegetation in which Susuki plants predominated (Eulalia, Miscanthus sinensis A.), were divided into 5 particle size fractions of >2, 1-2, 0.5-1.0, 0.25-0.5, and <0.25 mm using sieves. 1) The percentage distribution of organic matter in the charred plant residues was higher in the larger particle size fractions, and the reverse was true for the distribution of ash. 2) The contents of carbon, hydrogen, and oxygen of each fraction on an oven-dried basis decreased with decreasing particle size, but the ash content showed an inverse relationship. No regular trend was found between the nitrogen content and the particle size. 3) The atomic H/C and O/C ratios of each fraction and other data suggested that dehydrative condensation took place during the burning of the grassland vegetation studied. 4) The amounts of NaOH-extractable materials from each fraction which were very small significantly increased after the HNO3 treatment of the fractions. The extraction ratio of organic matter, amounts of humic and fulvic acids, and ratio of humic acid in the NaOH-extractable organic matter decreased with decreasing particle size. The humic acids produced belonged to A type, and their absorption curves were similar to those of A type soil humic acids. 5) When several fractions were separately added to a sample of volcanic ash soil and incubated at 25°C under moist conditions, their fractions were hardly decomposed by microorganisms even after 40 weeks.

Effect of nitrogen on partitioning and yield in grain sorghum under differing environmental conditions in the semi-arid tropics

Abstract The effect of nitrogen (N) supply on the relative contributions of pre- and post-anthesis net above-ground biomass accumulation and N uptake to grain-yield and grain N concentration was examined in four contrasting environments in semi-arid tropical Australia. The four environments had different radiation and temperature regimes, and varying levels of water deficit. The grain-yield achieved under high N supply ranged from 156 to 621 g m−2 (on an oven-dry basis). In all but the lowest-yielding environment, there was substantial biomass accumulation during grain-filling and it increased with N application. Only in the lowest-yielding environment was there substantial mobilization of pre-anthesis biomass to grain. Biomass mobilization was not affected by N application. Nitrogen uptake during grain-filling was unresponsive to N application, and was small relative to total N uptake during the life-cycle. Mobilization of pre-anthesis N to the grain was much more significant. In all but the lowest-yielding environment, N mobilization increased with N application. Grain-yield under variable N supply and differing environmental conditions was not dependent on the proportions of pre- and post-anthesis growth. However, grain-yield was proportional to biomass at maturity over the entire yield range in this study and variability in biomass accounted for 95% of the variance in grain-yield. Similarly, grain N concentration was not related to the proportions of pre- and post-anthesis N uptake, but variability in total N uptake accounted for 92% of the variance in grain N accumulation. Consequently, there was no differential effect of N supply or environmental factors on yield physiology that could not be explained by their effect on biomass and N uptake.

Numerical characterization of forest soils using biological and biochemical properties

To find if surface soils could be grouped by their biological and biochemical properties, soil samples (0–5 cm) were collected at 4-week intervals for 56 weeks from 48 woods in and around the English Lake District, and pH, loss-on-ignition (LOI), moisture content, oxygen uptake, and cellulase and phosphatase activities were measured. Results expressed on a loss-on-ignition basis were more informative than those on an oven-dry basis. In a principal component analysis of each property over the 14 samplings, the first component values represent “smoothed” between-plot differences; other components identify plots which behave differently from the majority at certain times. Analysis of variance showed very highly significant differences between plots for all the properties. pH and loss-on-ignition showed the smallest, but significant, differences between samplings. On a loss-on-ignition basis, the only significant correlations between first component values, and between plot means, were phosphatase with oxygen uptake and cellulase with pH. It is concluded that no individual physiological property can be used as a measure of soil bioactivity, which supports the conclusions of other authors. None of the principal component analyses of individual or combined properties showed any evidence of the existence of distinct clusters of plots. On a loss-on-ignition basis, a priori groups based on (1) pH 5.0, showed no significant difference in moisture content. However, oxygen uptake was significantly lower in (1) than in (2). Cellulase activity was significantly greater in (3) than in (1) and (2). Phosphatase activity was significantly lower in (1) than in (2), and there appeared to be a peak at pH 3.8 – 5.0.

SULFATE SORPTION BY ACID FOREST SOILS

The kinetics of sulfate adsorption and the effects of temperature and moisture on sulfate sorption of two acid forest soils have been investigated. Sulfate adsorption in both soils was time-dependent and showed an excellent fit, accounting for more than 99% of the variation, by a two-constant rate equation x = K/sub a/C/sub o/t/sup 1/m/ where x = adsorbed sulfate, C/sub o/ = initial sulfate concentration, K/sub a/ = rate coefficient, t = time, and 1/m = constant. The average rate coefficients of sulfate adsorption over a period of 1152 h were 0.462 and 0.167 h/sup -1/ for the iron-podzol and brown-earth soils, respectively. Thus the relative rate was faster in the iron podzol than in the brown earth. The rate of sulfate adsorption was faster initially (up to 4 h), but decreased drastically with increased time. Sulfate adsorption over a period of 1152 h in both soils showed the best fit, accounting for more than 99.9% of the variation, by a multiple-order kinetic equation dx/dt = Kx/sup n/ where x and t are the same as in the rate equation, and K and n are constants. Sulfate adsorption in both soils increased over a temperature range of 4 to 24/supmore » 0/C, but it decreased when the moisture content of the soils was raised from 5 to 100% on an oven-dry weight basis. The percentage of sulfate desorbed decreased with increase in time and temperature, but it increased with increased moisture content. These results indicate that longer contact between soil and sulfate ions and higher temperature will result in immobilization of atmospherically deposited sulfate in these soils, whereas increased moisture content will result in mobilization of sulfate and cations. 23 references, 5 figures, 2 tables.« less

EPTC ( s-ethyl N, N-dipropylthiocarbamate)-degrading microorganisms isolated from a soil previously exposed to EPTC

EPTC ( s-ethyl N, N-dipropylthiocarbamate)-degrading microorganisms isolated from a soil previously exposed to EPTC

Cultivars and experimental lines of a promising forage legume - Astragalus cicer. Evaluation for forage yield in Fort Collins

An evaluation of some new cultivars and experimental lines of cicer milk vetch ( Asparagus cicer L., Fabaceae) selected in the last decade for forage yield, seedling vigour and recovery after harvest are briefly summarized. The examined samples are promising especially in grazing conditions. The new cultivars have a better stand establishment, a good average forage yield of 13,27 MT/ha (oven-dry basis) and a high protein content. No injuries in grazing animals have been reported till now. The variability in forage yield between the cultivars and experimental lines suggests further possibilities of breeding.

Concept for Southern Pine Plantation Operation in the Year 2020

Abstract Fertilization, close spacing, very early thinning, and application of new harvesting and manufacturing technology could yield-over a 35-year rotation-146 tons per acre (ovendry basis) of pulp, 2-by-4 studs, random-length conventional lumber, millwork and structural laminated wood, long-wide structural lumber laminated from veneer, sheathing plywood, structural flakeboard, and animal food supplement (muka). At $200 per product ton (ovendry basis, 1979 dollars), each acre could yield a gross realization of about $29,200 of these products per 35-year rotation; additionally, about 47 tons (ovendry basis) of fuel would be harvested over the 35-year rotation.

The Effect of Nitrogen, Phosphorus and Potassium Fertilization on Chemical Content of Sheep Diets

The Effect of Nitrogen, Phosphorus and Potassium Fertilization on Chemical Content of Sheep Diets

Estimation of the Amount of Amorphous Materials for Characterizing Andosols

AbstractAn estimation method of amorphous inorganic materials in soils for characterizing andosols and tentative criteria for classification of andosols was proposed. Organic matter‐free fine earth is treated with 0.2N oxalic acid solution at 40°C for 6 hours under about 10,000 lux by a fluorescent lamp. The amounts of extracted silica, aluminum, and iron are highly correlated with values determined by the alternate dissolution method using hydrochloric acid and sodium hydroxide solutions.Andepts have more than 50% of amorphous inorganic materials in the clay fraction as determined by the pipette method after treated by ultrasonic vibration. The soils, derived from volcanic ash and/or volcanic ash influenced or redeposited, containing &lt; 50% of amorphous inorganic materials in the clay fraction and &lt; 20% on an ovendry basis, are included in Andeptic subgroups.

17—THE PREDICTION OF THE COMMERCIAL CARBONIZING YIELD OF WOOL

An investigation is reported in which the core-test yield was compared with the achieved mill yield for 90 commercial batches of Australian wool. Eight Australian mills participated in the trial. It was found that the wool base of the greasy wool (B g%) was directly proportional to the achieved mill yield. The carbonizing loss, which was on the average 3.05% (on an oven-dry basis), was negatively correlated with the vegetable-matter base of the greasy wool (VMB g%. The most precise prediction of the achieved mill yield was given by the equation: ECCY% = 1.1972 B g% + 0.1616 VMB g% − 5.12, where ECCY% is the estimated commercial carbonizing yield. For the 90 batches in the trial, the standard error of the prediction was 1.95%.

Analysis of the rotting process of sawdust barnyard manure

Abstract Sawdust barnyard manure was prepared by spreading sawdust in a loose-barn type cowshed. The manure was collected in a pile, kept undisturbed for more than a year, and used in this study. The vertical profile of the compost clearly showed six layers which seemed to indicate that differences in environmental conditions existed within the pile. Samples were collected from each layer and one of the dark brown layers was fractionated physically. The results obtained are as follows: 1) All samples collected from the compost pile had lower pll and EC (electrical conductivity) values and C/N ratios than fresh barnyard manure. The C/N ratios of the samples were all above 22. Samples near the surface of the pile showed lower pH and EC values and C/N ratios than did the inner samples. The most poorly aerated sample contained a large amount of ammonium-N. 2) The humus composition of air-dried samples showed differences with regard to the amount of extracted humus, percent of extracted humus (based on total humus content), and RF value. There were only slight differences in PQ and △logK values among the samples. The UV and visible absorption spectra of the humic acids showed lignin-like characteristics. The nitrogen content of the alkali-extracted residues was higher in the samples collected from the pile than in fresh manure. 3) Six size fractions were obtained by physical fractionation of the dark-colored layer. Generally, the total N and the amounts of extracted humus (H E/H T), humic acid and fulvic acid, on the ash-free oven-dried basis, wore higher, while the G/N ratio was lower, in the finer size fractions. The total nitrogen content and C/N ratio were negatively correlated with the amount of extracted humus. The water-soluble fraction showed properties notably different from the other fractions. Based on the results obtained for the fractionated sample, two unfractionated samples which were found to be highly aerated and moist (about 75% moisture content) were presumed to be of a higher degree of humification than the other samples.

RESPONSE FROM COPPER AND SELENIUM WITH VITAMIN E INJECTIONS TO CATTLE PASTURED ON MINERAL AND ORGANIC GROUNDWATER SOILS

An experiment, using a total of 127 cattle on one ranch over a 2-yr period and 82 cattle at two separate locations on a second ranch in 1 yr, tested injections of copper (Cu) and injections of selenium (Se) with vitamin E, separately and in combination. Injections of 100 mg Cu as copper calcium edetate resulted in an increased overall daily gain of 118 g or 22%. The injections of Se and vitamin E did not significantly increase gain and there was no synergistic effect when the two materials were given together. The crude protein, inorganic sulfate, S, P, Ca, K, Mg, Cu, Mo, Fe, Mn, Zn, and B concentrations were determined on grass from the experimental pastures and from grass growing in fields around one ranch. These latter forages were collected in seven paired locations with one member forage of each set being harvested from an organic groundwater soil and the other from an adjacent clay soil where there was good drainage. Forage growing on well-drained soils had a Cu/Mo ratio of 1.9, which was almost treble the 0.7 ratio found in forage grown on the groundwater soil. Cu levels in hair from cattle on ranch B, given only Cu injections, averaged 13.4 ppm Cu on an oven-dry weight basis, which was 54% higher in Cu than hair from the control cattle. The mean concentration of Se in hair of cattle receiving Se with vitamin E was 60 ppm, which was not significantly different from the control at 58 ppm.

QUANTITATIVE CATION REQUIREMENTS OF SEVERAL GREEN AND BLUE-GREEN ALGAE(2).

In contrast with studies which have based essential element requirements of algae on nutrient solution concentrations, in this investigation the requirements of each of 6 species of green and blue-green algae for calcium, magnesium, and potossium were quantitatively evaluated in terms of critical cell concentrations of the 3 cations. A critical cell concentration was considered the minimum cell content of an element which permitted maximum or near maximum total growth of an organism. In comparison with the needs of angiosperm crop plants, the requirements of all 6 species for calcium were extremely low (critical cell contents of 0.06% or less, oven-dry basis); requirements for magnesium were equal to or only slightly less than in higher plants (0.15-0.30%) with the exception of Scenedesmus quadricauda (0.05%); and the requirements for potassium varied greatly, from critical levels less than the average values established for higher plants (0.25-0.50%) to values equal to or in excess of higher plant averages (0.80-2.40%). The nutrition of S. quadricauda was of particular interest because of extremely low requirements for all 3 cations. The results provide a more precise and meaningful expression of the essential cation requirements of algae than have previous data. The results also suggest differences in the physiology and functions of cations in the algae studied and in angiosperms which seem worthy of further investigation.

A Hole on Moisture Content

AbstractIt is essential to distinguish between moisture content defined on a wet-weight basis and an oven-dry basis. The use of the suffixes w (wet) and d (dry) is proposed. The conversion from one form to the other is given, and the advantage, in attenuation calculations, of using the dry-weight basis is illustrated.