Sawdust Treatment Research Articles

Comparative short-term effects of different quality organic resources on maize productivity under two different environments in Zimbabwe

Major challenges for combined use of organic and mineral nutrient sources in smallholder agriculture include variable type and quality of the resources, their limited availability, timing of their relative application and the proportions at which the two should be combined. Short-term nutrient supply capacity of five different quality organic resources ranging from high to low quality, namely Crotalaria juncea, Calliandra calothyrsus, cattle manure, maize stover and Pinus patula sawdust were tested in the field using maize as a test crop. The study was conducted on two contrasting soil types at Makoholi and Domboshawa, which fall under different agro-ecological regions of Zimbabwe. Makoholi is a semi-arid area ( 750 mm yr−1) soils are sandy-clay loams with 220 g kg−1 clay. Each organic resource treatment was applied at low (2.5 t C ha−1) and high (7.5 t C ha−1) biomass rates at each site. Each plot was sub-divided into two with one half receiving 120 kg N ha−1 against zero in the other. At Makoholi, there was a nine-fold increase in maize grain yield under high application rates of C. juncea over the unfertilized control, which yielded only 0.4 t ha−1. Combinations of mineral N fertilizer with the leguminous resources and manure resulted in between 24% and 104% increase in grain yield against sole fertilizer, implying an increased nutrient recovery by maize under organic–mineral combinations. Maize biomass measured at 2 weeks after crop emergence already showed treatment differences, with biomass yields increasing linearly with soil mineral N availability (R2 = 0.75). This 2-week maize biomass in turn gave a positive linear relationship (R2 = 0.82) with grain yield suggesting that early season soil mineral N availability largely determined final yield. For low quality resources of maize stover and sawdust, application of mineral N fertilizer resulted in at least a seven-fold grain yield increase compared with sole application of the organic resources. Such nutrient combinations resulted in grain harvest indices of between 44% and 48%, up from a mean of 35% for sole application, suggesting the potential of increasing maize productivity from combinations of low quality resources with mineral fertilizer under depleted sandy soils. At Domboshawa, grain yields averaged 7 t ha−1 and did not show any significant treatment differences. This was attributed to relatively high levels of fertility under the sandy-clay loams during this first year of the trial implementation. Differences in N supply by different resources were only revealed in grain and stover uptake. Grain N concentration from the high quality leguminous resources averaged 2% against 1.5% from sawdust treatments. We conclude that early season soil mineral N availability is the primary regulatory factor for maize productivity obtainable under poor sandy soils. Maize biomass at 2 weeks is a potential tool for early season assessment of potential yields under constrained environments. However, the likely impact on system productivity following repeated application of high N-containing organic materials on different soil types remains poorly understood.

Flooring in Front of the Feed Bunk Affects Feeding Behavior and Use of Freestalls by Dairy Cows

In 2 experiments we assessed how preferences, time budgets, and feeding behavior of dairy cows change in response to flooring surfaces in front of the feed bunk. In Experiment 1, 12 nonlactating dairy cattle were individually housed with access to 2 standing platforms filled with either concrete or sawdust. In Experiment 2, 24 nonlactating dairy cattle were given access to either concrete or Animat rubber flooring in front of the feed bunk. In Experiment 1, cows preferred the sawdust to the concrete flooring. In both experiments, cows provided with a softer floor in front of the feed bunk spent more time standing near the feed bunk without eating (Experiment 1: 67 vs. 40min/d on sawdust vs. concrete, respectively, SEM = 5.6min/d; Experiment 2: 176 vs. 115min/d on Animat vs. concrete, respectively, SEM = 20.5min/d) compared with when they were kept on concrete. The increased time spent at the feed bunk was due to a combination of more frequent eating and standing bouts, indicating that cows were more willing to move on nonconcrete flooring. Total time spent eating was significantly greater on the softer floor in Experiment 2, but not in Experiment 1 (Exp. 1: 289 vs. 275min/d on sawdust and concrete, respectively, SEM = 7.3min/d; Exp. 2: 330 vs. 289min/d on Animat and concrete, respectively, SEM = 15.4), although feed intake was increased on the sawdust treatment in Experiment 1. Cows spent significantly more time lying in the feed alley when the flooring was rubber (219 vs. 53min/d on Animat and concrete, SEM = 53.6min/d), perhaps because the lying area in Experiment 2 was inadequate. In conclusion, cows prefer to stand on softer flooring in front of the feed bunk, and are more willing to move on and spend more time standing in front of the feed bunk when provided with softer flooring. These results indicate that cows find softer flooring surfaces more comfortable to stand on than concrete, and highlight the importance of evaluating the comfort of the entire facility.

Nitrogen mineralization, N 2 O production and soil microbiological properties as affected by long-term applications of sewage sludge composts

A field study was conducted to investigate the long-term effect of surface application of sewage sludge composts vs chemical N fertilizer on total N, total C, soluble organic C, pH, EC, microbial biomass C and N, protease activity, deaminase activity, urease activity, gross and net rates of N mineralization and nitrification, CO2 evolution, and N2O production. Soil samples were taken from five depths (0–15, 15–20, 20–30, 30–40, and 40–50 cm) of a long-term experiment at the University of Tokyo, Japan. Three fields have been receiving sewage sludge composted with rice husk (RH), sawdust (SD), or mixed chemical fertilizer NPK (CF), applied at the rate of 240 kg N ha−1 each in split applications in summer and autumn since 1978. Significantly higher amounts of total N and C and soluble organic C were found in the compost than in the CF treatments up to the 40-cm soil depth, indicating improved soil quality in the former. In the CF treatment, soil pH values were significantly lower and electrical conductivity values were significantly higher than those of compost-treated soils of up to 50 cm depth. Soil microbial biomass C and N, CO2 evolution, protease, deaminase, and urease activities were significantly higher in the compost than in the CF treatments due to greater availability of organic substrates that stimulated microbial activity. Gross N mineralization rates determined by 15N dilution technique were eight and five times higher in the SD and RH treatments than in the CF treatment, respectively, probably due to high levels of microbial and enzyme activities. Net N mineralization rates were also significantly higher in the compost treatments and were negative in the CF treatment indicating immobilization. Net nitrification rates were higher in compost treatments and negative in the CF treatment. Nitrous oxide productions from compost treatments were higher than the CF treatment due to the greater availability of mineral N as a result of higher mineralization and nitrification rates and soluble organic C in the former. Most of the measured parameters were highest in the surface soil (0–15 cm) and were significantly higher in the SD treatment than in the RH treatment.

Soil Nutrients and Microbial Biomass Following Weed-Control Treatments in a Christmas Tree Plantation

Control of competing vegetation in Christmas tree plantations is an important part of management, as uncontrolled weed growth can affect the growth and form of lower branches. Herbicide application is the most common weed-control strategy, but some Christmas tree growers prefer organic mulches. Although both herbicides and other weed-control strategies are available, there is little information about their effects on soil nutrients and microbial biomass, which determine long-term site productivity. A field experiment was conducted in a Christmas tree plantation in eastern Kentucky to examine the effects of four weed-management strategies-sulfometuron methyl herbicide (methyl 2[[[[(r,6-dimethyl-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]benzoate) (Oust) at two application rates, sawdust mulch, and rubber-tire mulch-on soil nutrients and microbial biomass. We tested the cumulative (3 yr) and re-treatment effects of the four treatments. Soil organic matter, moisture content, and total N were significantly higher in the sawdust-treated soils than in all other treatments. Inorganic N and extractable P were higher in the Oust-treated soils. The Oust and rubber-tire mulch treatments generally had negative cumulative and re-treatment effects on soil cations and pH. Significantly higher microbial biomass occurred in the sawdust treatment. This was most likely due to increased soil water content under the sawdust mulch and coincided with higher total N and soil organic matter for the cumulative and re-treatment periods. Sawdust was the best of the four weed-control strategies for long-term Christmas tree production because of the positive effects on soil physical, chemical, and biological characteristics, an important consideration for growers choosing a weed-control strategy for use on land expected to produce Christmas trees for many years.

Effects of Soil Nitrogen Reduction on Nonnative Plants in Restored Grasslands

AbstractWe studied the cumulative effects of 3 years of carbon amendments on previously disturbed mixed‐grass prairie sites near Boulder, Colorado. Analysis of soil inorganic nitrogen during the third field season indicated statistically significant but short‐term nitrogen reduction in response to addition of a combination of sugar and sawdust treatments. Plant foliage production was significantly reduced by these carbon amendments and averaged 377 g/m2/year on control plots versus 219 g/m2/year on treated plots. Undesirable species such as Centaurea diffusa (diffuse knapweed) exhibited a similar biomass response. But after three years of treatment there is little evidence to suggest a relative increase in desirable, reseeded species such as Agropyron smithii (western wheatgrass). We suggest that the carbon amendment treatment alone is an inadequate remediation technique in areas exposed to extensive seed rain by exotic species.

Growing Shiitake Mushroom on Hardwood Sawdust in the Greenhouse

Seven strains of shiitake mushroom [Lentinula edodes (Berk.) Pegler] produced spawn in culture vessels containing hardwood sawdust amended with YVMBS (yeast extract, multigrain oatmeal, brown sugar) broth within 35 to 45 days after mycelia inoculations. Under greenhouse conditions, shiitake basidiocarps (mushroom fruit) appeared from 1 to 3 months after spawn inoculations of the hardwood sawdust amended with YVMBS broth. The shiitake mushroom strains LE2, LE1, LE6, and LE5 had 10.4, 7.3, 2.5, and 1.6 times more fresh harvested basidiocarps, respectively, on the amended hardwood sawdust compared to the controls. The amount of basidiocarps produced by the shiitake strains LE3, LE4, and LE7 was the same on both hardwood sawdust treatments. The basidiocarps of LE1, LE2, LE3, LE4, and LE5 were averaged 5 inches (12.7 cm) in diameter, however, the basidiocarps of LE6 and LE7 were averaging only 2 inches (5.1 cm) in diameter. The only pests of the shiitake basidiocarps in the greenhouse were slugs, but they were easily controlled by applying table salt. The start up cost of inoculating 100 shiitake spawn blocks on hardwood sawdust on one bench in the greenhouse was $77. The start up cost of inoculating shiitake spawn on 100 logs was $1,329.75. In 1 year, shiitake strains LE1, LE2, LE5, and LE6 produced 19.5, 20.2, 7.9, and 4.5 lb (8.8, 9.2, 3.6, and 2.0 kg), respectively, of harvested fresh basidiocarps on amended hardwood sawdust in the greenhouse. The mushrooms retail for $3.20 to $4.20/lb ($7.05 to $9.26/kg). The use of the hardwood sawdust amended with YVMBS broth for shiitake production in the greenhouse has considerable economic potential for shiitake mushroom growers.

Effects of Carbon, Fertilizer, and Drought on Foliar Chemistry of Tree Species in Interior Alaska

Changes in foliar chemistry resulting from changes in forest‐floor and mineral‐soil moisture availability, forest‐floor microbial energy supply, and nitrogen availability were investigated across the successional sequences in both upland and floodplain landscape positions. Three amendments, sugar, sawdust, and nitrogen fertilizer (NH4NO3) were applied to a series of three upland and four floodplain successional sites. The sugar and sawdust treatments were designed to increase the carbon: nitrogen ratio (C/N) of the forest floor to values typical of black spruce sites (C/N = 50). The nitrogen fertilizer treatment was designed to equal estimated yearly N mineralization in an attempt to double available nitrogen in the forest floor. A moisture exclusion treatment was designed to remove all summer rainfall from the treatment plots. Foliar phosphorus concentrations were higher in the upland sites than on the floodplain. No consistent differences were reported among successional stages within a landscape unit. The effect of either sugar or sawdust treatment was to decrease foliar phosphorus concentrations. Sugar produced more significant differences than did sawdust. Sugar treatments decreased foliar nitrogen in all tree species except for white spruce, while fertilizer tended to increase foliar nitrogen. In the second year following treatment there was not an increase in foliar nitrogen concentration resulting from fertilizer treatment.

Organosolv pulping-VII: Delignification selectivity of formic acid pulping of Eucalyptus grandis

Eucalyptus grandis wood was ca. 80% delignified in 79–92% (v v −1 formic acid containing 0.22% (w v −1) HCl as a catalyst under reflux and mechanical stirring for 90 min. Pulps obtained under these conditions presented pulp yield, Kappa number and Klason lignin in the ranges of 44–52%, 30–40 and 8–10%, respectively. The presence of water in the experiments with the more diluted formic acid concentration (79%) showed a beneficial effect on the pulp fiber length and pulp yield. Formic acid sawdust treatments were carried out under the best chip pulping conditions. Plots of yield versus lignin loss show comparable delignification selectivity for sawdust and chips. The most selective pulping experiments were those with 79% formic acid employing a mechanical stirrer blade of polytetrafluorethylene (PTFE) and those with 99% formic acid using a stainless steel blade.

Effects of Disturbance and Soil Amendments on Dissolved Organic Carbon and Organic Acidity in Red Pine Forest Floors

AbstractA site manipulation experiment was conducted to test the effects of timing, drought, fertilization, sawdust amendment, and root trenching on water‐soluble humic substances in the O horizon of a mature red pine (Pinus resinosa Ait.) stand in Maine. Concentrations of water‐extractable dissolved organic carbon (DOC) in the sawdust and root trenching treatments were approximately twice as high as DOC in the untreated controls and other treatments. Mean carboxyl group contents of DOC ranged from 4.8 to 6.3 mol/kg C among treatments and controls. Control and drought treatments contained the highest carboxyl contents, whereas the sawdust and fertilizer treatments had the lowest carboxyl densities. Synchronous scan fluorescence spectra for the water extracts contained major peaks at 350, 395, and 470 nm, and these peaks were similar to those obtained for reference humic and fulvic acid standards, as well as selected aromatic model compounds. Overall, the fertilizer treatment produced a 20% decrease, the root trenching generated a 70% increase, and the sawdust treatment yielded a 120% increase in the release of organic acid ligands as compared with the control plots. The twofold range of variation in DOC and organic acidity associated with different substrate conditions in this experiment was considerably smaller than the tenfold range of variation reported in the literature for sites from diverse geographic locations. This suggests that the quantitative fluxes of DOC and organic acidity from forest soil O horizons are determined by the interactive effects of substrate conditions, climate, and other local site factors.

Effect of pretreatment of cellulosic wastes on the production of cellulase enzymes by Trichoderma reesei

AbstractThe cellulosic wastes, bagasse and sawdust, were treated with different acidified solvents: chloroform, dioxan, ethanol, ethylacetate, dimethyl sulfoxide and dimethyl formamide; for increasing periods up to 36 h. The treated materials were delignified, dried and introduced in the fermentation media as inducing carbon source for Trichoderma reesei. The untreated materials and pure cellulose powder were used individually in control and reference media, respectively. The fermentation media containing bagasse treated for 8 h in chloroform or dioxan gave a promising cellulase activity, nearly the same as that from the reference medium. The untreated bagasse gave a markedly low cellulase activity.The media with treated sawdust gave a relatively higher enzyme activity but far below the reference medium. The sawdust treatment with the solvents mentioned resulted in a very mild effect because of its high content of admixtures, lighin and hemicellulose bonding cellulose.

THE EFFECT OF SAWDUST, STRAW, COMPOST AND MANURE ON THE YIELD AND CHEMICAL COMPOSITION OF STRAWBERRIES AND ON SOIL MOISTURE, ACIDITY AND ORGANIC MATTER CONTENT

Sawdust, straw, compost and manure were applied under dryland conditions to strawberry plantings at two locations. The effects on yield, leaf nutrient content, soil moisture, soil acidity and soil organic matter content were evaluated. Sawdust mulch and sawdust incorporation, the former being slightly better, produced highly significant increased yields over the check treatment and were superior to all other treatments. Soil moisture measurements showed that the sawdust treatments conserved soil moisture and this was regarded as the chief reason for the increased yields. The nitrogen, phosphorus, potassium, calcium and magnesium contents of leaves were affected somewhat by the treatments but the levels were considered adequate in all cases.Soil acidity was significantly increased in the sawdust plots but this was attributed to the additional nitrogen applied rather than to the sawdust per se. Sawdust incorporation, manure and compost treatments significantly increased soil organic matter content when compared to the check treatment.

Sahajauhopeitteen käytöstä omenapuuperusrunkojen suvuttomassa lisäyksessä

In 1958 a trial was layed out by using the sawdust for mounting up Malus robusta No 5-apple rootstock shoots in stool beds. The treatment was compared with that of ordinary soil beds. In both cases the mounting was repeated three times during the growing season. The sawdust was thoroughly wetted before the application. All the blocks in the trial were irrigated twice after the last mounting. The results of the trial are given in Tables 1—3. The sawdust has shown a very marked beneficial effect on the rooting of the shoots. More than twice as much well rooted shoots have been obtained from the sawdust blocks than from those stooled with soil. The sawdust treatment has given more roots per shoot. Moreover the rooted portion of the shoot as well as the total length of the roots in the shoots has been higher by using the sawdust stooling. The weight of the roots per shoot has been in sawdust bed twice of that grown in soil bed. The differences in the rooting quality of the shoots are obviously in the main due to better moisture conditions inside the sawdust than in the soil cover.

Field plot studies with sawdust for soil improvement

Heavy application of fresh and rotted sawdust to field plots in comparison to manure and untreated control plots showed no significant difference in yields of corn over a four year period. The soil type was coarse textured and poor in nutrients at the start. However, the total yields for the rotted sawdust plots were consistently greater each year than those for the other treatments, thus possibly indicating a trend of benefit for the rotted sawdust treatments. Total yields for the fresh sawdust were close to those for the controls. Heavy applications of fertilizer, especially nitrogen, were necessary the first three years, but only a rather light application was necessary the fourth year. Soil moisture determinations indicate that all of the organic materials tend to prevent pronounced fluctuations in moisture levels, the rotted sawdust most of all.