Volvariella-treated Eucalyptus sawdust stimulates wheat and onion growth

Conversion of sawdust, a major waste generated by the timber industry, to an agricultural supplement was explored. Beds made with a mixture of Eucalyptus sawdust and soil reduced the chlorophyll content and the growth rate of wheat seedlings. However, following treatment with Volvariella volvaceae and urea, the sawdust in growth beds enhanced both the chlorophyll content and growth of wheat seedlings. Application of treated sawdust to soil increased the biomass of both bulb and foliage of onion. This represents a small beginning in the conversion of an industrial solid waste into a soil conditioner for enhancing agricultural productivity.     

Volvariella-treated Eucalyptus sawdust stimulates wheat and onion growth

Conversion of sawdust, a major waste generated by the timber industry, to an agricultural supplement was explored. Beds made with a mixture of Eucalyptus sawdust and soil reduced the chlorophyll content and the growth rate of wheat seedlings. However, following treatment with Volvariella volvaceae and urea, the sawdust in growth beds enhanced both the chlorophyll content and growth of wheat seedlings. Application of treated sawdust to soil increased the biomass of both bulb and foliage of onion. This represents a small beginning in the conversion of an industrial solid waste into a soil conditioner for enhancing agricultural productivity.     

The effect of methods of application of sawdust on plant growth,plant nutrient uptake and soil chemical properties

Summary Sawdust fromCanarium schweinfurthii (Engl.), a common source of timber in the rainforest zone of Nigeria was subjected to various treatments to improve the nutrient content and aid the decomposition of the otherwise highly-lignified material. The treatments were then either incorporated into the soil or added to the soil surface as a mulch in both greenhouse and field studies. The greenhouse studies involved two six-week sowings in the same soil while the field study involved 3 season sowings (2 rainly, one dry season) using maize (Zea mays L.var. Western yellow) as a test crop.Results indicated that in the greenhouse, incorporation of untreated sawdust led to significant reductions in maize growth, dry matter yield and uptake of N and other nutrients. While the incorporated inorganically amended sawdust treatment produced significantly higher dry matter yield, that produced by the surface-applied organically amended treatment was significantly higher than the incorporated treatment. Except for untreated sawdust, the incorporation of organically and inorganically amended sawdust increased the contents insoil of N, available P, and exchangeable K.     

Lysis of mycelium ofFusarium oxysporum f. sp.udum in soil amended with organic matters

Summary Autoclaved or natural field soil amended with 0.1 to 5.0 per cent (W/W) of margosa cake, rice husk and sawdust with or without supplemental nitrogen were tested for lytic activity and bacterial numbers. Generally, non-amended autoclaved soil caused little or no lysis of mycelium ofF. oxysporum f. sp.udum; non-amended natural soil caused more lysis. Amendment of soil with margosa cake, rice husk or saw-dust with or without supplemental nitrogen greatly enhanced its lytic effect on the fungus. The degree of lysis depended on the dosage of amendment used and the stage of its decomposition in the soil. The extent of lysis increased as the bacterial population increased. Amongst bacteria,Bacillus subtilis was very common in most lytic zones.     

Carbon Addition as a Countermeasure Against Biological Invasion by Plants

Increased nitrogen availability is known to favor invasion by non-native plants into natural grasslands. This suggests that decreasing nitrogen availability might serve as a countermeasure against invasion. One way to at least temporarily decrease nitrogen availability to plants is to increase microbial nitrogen uptake by adding carbon to the soil, and sawdust is a carbon source whose low cost could make it a practical conservation tool. To test whether adding sawdust to soil can counter the tendency of nitrogen enrichment to promote invasions by non-native plants, we hand-tilled 1.5kg sawdust/m² into the upper soil of the bare, nitrogen-rich patches left by dead shrubs of the nitrogen-fixing shrub Lupinus arboreus in two nearby areas with contrasting levels of invasion in a coastal grassland in northern California. After two years, in both areas, patches with sawdust had 40% less biomass of non-native plants than patches without sawdust, whereas biomass of native plants was not affected by sawdust addition. The more negative effect of sawdust on non-native species was specifically due to an effect on non-native grasses; adding sawdust increased the frequency of both native and non-native forbs. Results suggest that adding carbon as sawdust to soil can help counter invasion of grassland by non-native plants when invasion is being promoted by increased nitrogen availability, especially when the major invasive species are grasses.     

Identification of a mycorrhizal fungus in Epipogium roseum (Orchidaceae) from morphological characteristics of basidiomata

A mycorrhizal fungus, ME1-1, isolated from an achlorophyllous orchid, Epipogium roseum, was identified as Coprinellus disseminatus (≡ Coprinus disseminatus) based on characteristics of basidiomata that were artificially induced. Spawn of ME1-1 cultivated on a medium that consisted of sawdust and wheat, sandwiched between two mats of volcanic soils, which was incubated at 20.0° ± 0.5°C in 80.0% ± 0.5% relative humidity in the dark. The basidiomata were formed on the soil after 2 months. Morphological and anatomical characteristics of the basidioma mostly accorded with those of Coprinellus disseminatus. We therefore concluded that C. disseminatus is one of the mycobionts of E. roseum.     

Promoting effect of wood vinegar compounds on fruit-body formation ofPleurotus ostreatus

The promoting effect of wood vinegar compounds on the fruiting ofPleurotus ostreatus (Japanese name, Hiratake) was investigated. Not only crude wood vinegar but its components, 3,5-dimethylphenol, 2-methoxyphenol, butanoic acid and 1-pentanol, had the ability to promote fruit-body formation on liquid medium. For use of these promoters industrially, a test for practical cultivation was carried out using a commercial sawdust medium. The addition of 100 µg/ml butanoic acid and 100 µg/ml 2-methoxyphenol into the sawdust medium after removal of the surface mycelial layer (kinkaki in Japanese) produced 29 and 23% higher yields of fruit-bodies than the control cultures (137.2 g/bottle), respectively. The addition of the crude wood vinegar as a medium component into sawdust substrates in the concentration range of 0.1–6% increased yields of fruit-bodies by 21–42% over the control.     

Can Carbon Addition Increase Competitiveness of Native Grasses? A Case Study from California

There is growing interest in the addition of carbon (C) as sucrose or sawdust to the soil as a tool to reduce plant‐available nitrogen (N) and alter competitive interactions among species. The hypothesis that C addition changes N availability and thereby changes competitive dynamics between natives and exotics was tested in a California grassland that had experienced N enrichment. Sawdust (1.2 kg/m) was added to plots containing various combinations of three native perennial bunchgrasses, exotic perennial grasses, and exotic annual grasses. Sawdust addition resulted in higher microbial biomass N, lower rates of net N mineralization and net nitrification, and higher concentrations of extractable soil ammonium in the soil. In the first year sawdust addition decreased the degree to which exotic annuals competitively suppressed the seedlings of Nassella pulchra and, to a lesser extent, Festuca rubra, both native grasses. However there was no evidence of reduced growth of exotic grasses in sawdust‐amended plots. Sawdust addition did not influence interactions between the natives and exotic perennial grasses. In the second year, however, sawdust addition did not affect the interactions between the natives and either group of exotic grasses. In fact, the native perennial grasses that survived the first year of competition with annual grasses significantly reduced the aboveground productivity of annual grasses even without sawdust addition. These results suggest that the addition of sawdust as a tool in the restoration of native species in our system provided no significant benefit to natives over a 2‐year period.     

Cultivation of Oudemansiella tanzanica nom. prov. on agricultural solid wastes in Tanzania

The edible mushroom Oudemansiella tanzanica nom. prov., which is new to science, has been studied as a potential crop to reduce agricultural solid wastes and increase domestic mushroom production. The substrates sawdust, sisal waste and paddy straw supplemented with chicken manure resulted in the highest biological efficiencies of any mushroom cultivated in Tanzania so far. In addition, the mushroom has one of the shortest cultivation cycles at 24 d. Despite the fact that the mushroom extracts substantial amounts of nutrients, the spent substrate can be used as fodder, as a soil conditioner and fertilizer and in bioremediation.     

Manipulating the Quantity, Quality, and Manner of C Addition to Reduce Soil Inorganic N and Increase C4:C3 Grass Biomass

Applying C to soils has been proposed as a plant community restoration tactic because it has been shown to immobilize inorganic N, which should confer a competitive advantage to slower growing plants that are often key components of the desired plant community. Disparate experimental and survey results have led to questions about the appropriate quality and quantity of C to apply. We conducted a single‐season glasshouse experiment in three soil types to determine how the quality (sugar, sawdust, sugar + sawdust), quantity (1 and 5 kg sugar or sawdust/m²), and mode of application (surface applied or mixed into soil) of C affected soil inorganic N pools, net mineralization rates, and aboveground biomass of coexisting C3 and C4 plant species. Carbon applied as sawdust mixed into the soil resulted in the highest level of immobilization in the short term (6 weeks), but all combinations and rates of sugar and sawdust application resulted in immobilization over this period. In the long term (24 weeks), most amendments immobilized N and suppressed aboveground biomass of the C3 grass, Bromus inermis, but the high rate of sugar resulted in the strongest immobilization and C3 suppression. However, this treatment also maintained the highest soil inorganic N pool at season’s end, which calls into question its effectiveness if longer‐term benefits are desired. Neither net mineralization rates nor soil inorganic N pools were correlated to the ratio of C4 to C3 plant biomass at season’s end indicating that the mechanisms for favorable plant response to C addition are not understood.     

<Emphasis Type="Italic">Polyporus tenuiculus</Emphasis>: a new naturally occurring mushroom that can be industrially cultivated on agricultural waste

Polyporus tenuiculus is a naturally occurring species from Central and South America that is consumed by different ethnic groups in the region. To determine the optimal conditions for fruiting body production, two strains were assayed on wheat straw and sawdust with or without supplements. Sixty days of incubation at 25°C were needed to produce a solid block. The highest yield was obtained with strain ICFC 383/00 grown on supplemented willow sawdust. In a second experiment the strain ICFC 383/00 and different supplements were used to improve the biological efficiency (BE) and to determine the quality traits and its biodegradation capacity. The highest yields were obtained on sawdust with 25% of supplements reaching 82.7% of BE. Supplements raised the number of flushes, generally from four to five, contributing to increased yields. The type of substrate had a significant effect on fruiting body diameters of P. tenuiculus, and the largest mushrooms were harvested on supplemented substrate with the highest BE coinciding with the highest dry matter loss in substrates. P. tenuiculus showed a capacity to degrade sawdust, causing a decrease of 67.2–74.5% in cellulose, 80.4–85.7% in hemicellulose, and 60.6–66.2% in lignin content at the end of the cultivation cycle. The decrease in hemicellulose was relatively greater than that of cellulose and lignin on supplemented substrates. This is the first report of the cultivation of P. tenuiculus on lignocellulosic waste, and it is a promising species both for commercial production and for its potential use in the degradation of other biowastes.     

Sawdust Addition Reduces the Productivity of Nitrogen‐Enriched Mountain Grasslands

Anthropogenic nutrient enrichment of mountain grasslands has boosted grasses and fast‐growing unpalatable plants at the expense of slow‐growing species, resulting in a significant loss in biodiversity. A potential tool to reduce nutrient availability and aboveground productivity without destroying the perennial vegetation is carbon (C) addition. However, little is known about its suitability under severe climatic conditions. Here, we report the results of a 3‐year field study assessing the effects of sawdust addition on soil nutrients, aboveground productivity, and vegetational composition of 10 grazed and ungrazed mountain grasslands. Of particular interest was the effect of C addition on grasses and on the tall unpalatable weed Veratrum album. After 3 years, soil pH, ammonium, and plant‐available phosphorus were not altered by sawdust application, and nitrate concentrations were marginally higher in treatment plots. However, the biomass of grasses and forbs (without V. album) was 20–25% lower in sawdust‐amended plots, whereas the biomass of V. album was marginally higher. Sawdust addition reduced the cover of grasses but did not affect evenness, vegetation diversity, or plant species richness, although species richness generally increased with decreasing biomass at our sites. Our results suggest that sawdust addition is a potent tool to reduce within a relatively short time the aboveground productivity and grass cover in both grazed and ungrazed mountain grasslands as long as they are not dominated by tall unpalatable weeds. The technique has the advantage that it preserves the topsoil and the perennial soil seed bank.     

Colonization of Sitka spruce stumps by decay-causing hymenomycetes in paired inoculations

Sitka spruce stumps were inoculated with decay fungi using colonized sawdust or dowel inoculum to investigate colonization in paired combinations. Estimates of domain sizes were made in the top 15 cm of stump after 13–14 or 21–23 months with sawdust or dowel inoculations, respectively. None of the co-inoculated species prevented colonization by Heterobasidion annosum; sapwood colonization by Resinicium bicolor may limit growth of H. annosum colonies out of heartwood, reducing the incidence of disease transfer at root contacts. H. annosum colonized stumps despite the presence of competing inoculum. Reduced colonization occurred in paired inoculations with R. bicolor, but not with other fungi. Co-inoculations with Stereum sanguinolentum increased colonization by H. annosum. R. bicolor largely remained in the upper 3–4 cm of stumps and reduced colonization by Melanotus proteus; growth of S. sanguinolentum was completely prevented. The results are discussed in relation to the colonization strategies of the decay fungi, their ability to colonize stumps in the presence of competitors and factors influencing development of communities of decay fungi in stumps.     

Optimization of culture media for solid-state culture of<Emphasis Type="Italic">Pleurotus ferulae</Emphasis>

In order to elucidate the possibility of artificial production ofP. ferulae by solid-state culture, the optimization of culture conditions was carried out. When NH₄H₂PO₄ and CaCO₃ were used in the cultures using test tube with 30 g ofPopulus sawdust at 25°C±1 in the dark, the favored mycelial growth was observed with 1% of NH₄H₂PO₄ and the production of polysaccharide was 7.85 mg/100 mg of mycelium with 1% of CaCO₃. The mixtures of 80% ofPopulus sawdust and 20% of rice bran at 60% of water content were determined to be optimal for the production of fruiting bodies in the sawdust culture. When three treatments containing various ratios of garlic powder were conducted, yields of fruiting bodies were drastically higher than those of synthetic mixture without garlic powder. The highest yield (143 g/bag) was obtained with 7% garlic powder. The yield of synthetic mixture containing 7% of garlic powder was 83% higher than that of sawdust culture. The reason why garlic powder did support growth was not clear but it is possible that garlic powder might contain effective components for the formation of fruiting body. The optimal synthetic mixture composition consisted of cotton seed 77%, lime 6.4%, K₂HPO₄ 0.2%, KH₂PO₄ 0.2%, CaHPO₄, 0.2%, corn flour 4%, wheat flour 5%, and garlic powder 7%.     

Effect of plant growth and addition of plant residues on the phosphatase activity in soil

Summary The phosphatase activity of the soil amended with roots and tops of clover (Trifolium repens) plant material (0.1% by weight) remained essentially constant in the absence of growing plants but changed considerably in the presence of plants (Avena sativa) grown for 10 weeks. There was a significant relationship between the phosphatase activity and organic and inorganic P in the soil solution only in the presence of growing plants. The differences in phosphatase activity between roots and tops amended soil were attributed to total C as well as differences in the degree of availability of C added through plant materials. This may also apply to the carpet grass (Axonopus affinis) amended soil.     

Altering Light and Soil N to Limit Phalaris arundinacea Reinvasion in Sedge Meadow Restorations

Efforts to eradicate invasive plants in restorations can unintentionally create conditions that favor reinvasion over the establishment of desired species, especially when remnant invasive propagules persist. Reducing resources needed by the invader for seedling establishment, however, may be an effective strategy to prevent reinvasion. Propagules of Phalaris arundinacea persist after removal from sedge meadow wetlands and reestablish quickly in posteradication conditions, hindering community restoration. A study was conducted in two experimental wetlands with controlled hydrologic regimes to determine if reducing light by sowing short‐lived, nonpersistent native cover crops or immobilizing soil N by incorporating soil–sawdust amendments can prevent Phalaris reinvasion, allowing native communities to recover. A 10‐species perennial target community and Phalaris were sown with high‐diversity, low‐diversity, or no cover crops in soils with or without sawdust, and seedling emergence, establishment, and growth were measured. High‐diversity cover crops reduced light, decreasing Phalaris and target community seedling establishment by 89 and 57%, respectively. Short‐term nitrogen reduction in sawdust‐amended soils delayed Phalaris seedling emergence and decreased Phalaris seedling establishment by 59% but did not affect total target community seedling establishment. The target community reduced Phalaris seedling establishment as effectively as cover crops did. In plots where the target community was grown, amending soils with sawdust further reduced Phalaris seedling growth but not establishment. Results show that use of cover crops can reduce seedling establishment of desired species and is counterproductive to restoration goals. Further, establishing target species is more important and practical for limiting Phalaris reinvasion than is immobilizing nitrogen.     

Effect of organic amendment on phenolic content of soil and plant and response ofMeloidogyne javanica and its host to related compounds

Summary Amendment of soil with margosa cake or sawdust supplemented with NPK fertilizers increased its phenolic content. The concentration of total phenols was related to the amount of amendment used and varied with the length of decomposition period. Total phenols estimated in ether extract were more in margosa cake amended soil than in sawdust amended soil. Roots of tomato plants grown in amended soil showed presence of higher quantity of total phenols than those grown in non-amended soil. Exposure of females ofMeloidogyne javanica to benzoic, phenyl butyric, phenyl acetic and cinnamic acids significantly reduced their egg laying capacity. Suppression of larval motility was one of the main direct effects of these acids on the nematode. Exposure of tomato roots to different concentrations of phenyl acetic, benzoic, phenyl butyric and cinnamic acids imparted some resistance to invasion by the nematode. In such treated plants fewer larvae could penetrate the roots and develop into mature females and fewer eggs were produced. Research paper No.1455 through the Experiment Station G.B.P.U,A, & T., Pantnagar     

生物炭添加对不同水氮条件下芦苇生长和氮素吸收的影响

生物炭能改良土壤从而促进植物生长和氮素吸收,但其作用效果是否受水氮条件的影响尚不清楚。以湿地植物芦苇为研究对象,在3种氮添加水平（无添加,30 kg hm^-2 a^-1和60 kg hm^-2 a^-1）和两种水分（淹水和非淹水）条件下分别进行生物炭添加和不添加处理,结果表明：（1）生物炭添加能促进芦苇根系生长,在非淹水条件下根系生物量增加了40.5%,在淹水条件下根系生物量增加了20.1%。（2）生物炭添加能促进非淹水条件下芦苇的氮素吸收,能提高淹水条件下芦苇的氮素生产力。（3）生物炭添加加剧了土壤氮素损失,且在非淹水高氮条件下作用最强,可能是由于生物炭促进了芦苇的氮素吸收。芦苇氮素吸收速率与土壤氮损失之间存在显著的正相关关系。因此,在添加生物炭时,需要考虑土壤水分状况和氮素富集程度以及植物的氮素吸收偏好。该研究结果可为生物炭在湿地生态系统中的应用提供参考。     

Immobilization of soil nitrogen as a possible method for the restoration of sandy grassland

Abstract. Experiments were designed to test the applicability of nitrogen immobilization as a means of accelerating the recovery of an endemic open sandy grassland (Festucetum vaginatae danubiale) on old fields in the Great Hungarian Plain. Effects of various carbon sources (sucrose, starch, cellulose and sawdust) and their combinations in different quantities were studied in laboratory microcosms. Carbon addition decreased nitrogen availability in all cases, the intensity and timing of change being dependent on the type of carbon source applied. The combination of 2 g each of sucrose and polysaccharides (starch, cellulose, sawdust) per kg soil was found to be the most effective, as sucrose decreased available nitrogen content of soil intensively and the polysaccharides maintained the immobilized nitrogen for a longer period. In a follow‐up experiment, sucrose and sawdust were selected for field application to test their effectiveness in immobilizing N and accelerating restoration. The field experiment was established to test the importance of abiotic site differences in the immobilization of soil nitrogen. Selected sites were located along an elevation, moisture and productivity gradient. Soil organic matter, microbial biomass‐C and decomposition rate varied between sites depending on the elevation gradient. At two sites with lower soil moisture and organic matter levels carbon addition increased microbial activity and nitrogen immobilization significantly.