Gram Of Organic Matter Research Articles

Effects of multispecies and monoculture forages on nutrient digestibility and fermentation responses using an in vitro rumen simulation technique (RUSITEC)

Enteric methane (CH4) emissions are a major contributor to global greenhouse gas emissions. A number of different CH4 mitigation strategies have been proposed, and the inclusion of alternative forages into grazing systems could be a practical and feasible option. Multispecies swards comprise a mixture of forage species and can increase grassland productivity, reduce nitrogen fertiliser requirements, and reduce fertiliser-associated nitrous oxide emissions. This study investigated the potential benefit of multispecies swards in reducing ruminal CH4 production. Using the in vitro rumen simulation technique, we compared the effects of different forages (perennial ryegrass, timothy, red clover, white clover, chicory, ribwort plantain and their equi-proportional mixture) on CH4 and gas production, ruminal fermentation parameters and nutrient digestibility. We also compared these responses to perennial ryegrass produced with a higher nitrogen application rate (300 N). The experiment was conducted over 21 d, with the initial 14 d allowed for dietary adaptation. Over the subsequent 7 d, there were significant effects of forage type on CH4 production, ruminal fermentation and digestibility. Ribwort plantain, chicory and white clover showed lower CH4 production; with chicory producing 73% and 57% less CH4 (mmol d−1) compared to 300 N perennial ryegrass and 150 N perennial ryegrass incubation, respectively. Chicory had 72% lower CH4 produced per gram of organic matter digested (mmol g−1) than that of 300 N perennial ryegrass. Chicory and 300 N perennial ryegrass had greater (P < 0.01) organic matter and nutrient digestibility (DM, CP, NDF, and ADF) than other forages. Greater ammonia nitrogen concentration was observed in chicory and both clover species, compared to the other forage species (P < 0.01). In general, the response of the six-species mixture was not significantly different to the average response of the six component monocultures. Thus, from these data, the performance of multispecies swards for these responses (in general) was predictable from the performance of the component monocultures. These results showed that different grassland forages, especially chicory and white clover, have the potential to reduce ruminal CH4 emissions and could be a promising anti-methanogenic alternative to chemical CH4 inhibitors and feed additives. More generally, the relatively wide variation in CH4 abatement potential across a small sample of plant species suggests the merit of wider screening to identify grassland species with high CH4 abatement potential in vitro.

Effect of urease enrichment degree of multiple sources of urease on bio-cementation efficacy via enzyme-induced carbonate precipitation

This study aims to investigate the effect of the urease enrichment degree of high-purity commercial urease and plant-derived crude ureases from sword bean (SWCU), soybean (SCU), and pigeon pea (PCU) on bio-cementation efficacy via enzyme-induced carbonate precipitation. The urease enrichment degree is defined as the urease activity per gram of organic matter in the urease solution. Bio-cementation efficacy was evaluated by the distribution and morphology of the precipitates and unconfined compressive strength. The results show that the urease enrichment degrees of the high-purity commercial urease, SWCU, PCU, and SCU are 1.08, 1.05, 0.57, and 0.31 mmol/min/g, respectively. The urease enrichment degree is the dominant factor influencing the pattern of CaCO3 distribution by affecting the organic matter distribution. The high-purity commercial urease-treated sand has the smallest calcite crystals (13–23 µm) and the lowest strength (172 kPa). For the plant-derived crude urease, with the decrease of the urease enrichment degree, the generated crystals become smaller, the CaCO3 distribution becomes less uniform, and the soil strength decreases. The SWCU-treated sand exhibits the best bio-cementation efficacy and is recommended to enhance soil strength.

Interspecies and seasonal variations in macroalgae from the Nordic region: Chemical composition and impacts on rumen fermentation and microbiome assembly

Marine macroalgae may serve as sustainable feed resources for ruminant production due to their nutritional attributes, and enteric methane (CH 4 ) mitigating potential. We aimed to characterize the anti-methanogenic properties of 12 Nordic macroalgae species (eight brown, three red, and one green). Differences in the chemical composition across two harvesting seasons and impacts of addition of macroalgae (20% dry matter basis) on in vitro rumen fermentability of maize silage (MS) and associated changes in the rumen microbiome composition were also evaluated. Green and red macroalgae contained twice as much crude protein (CP) as compared to brown macroalgae. The latter had higher mineral and total polyphenol content (TPC: 10 to 20 times). In some brown species, ash and CP contents were up to twice as high in spring than in autumn, but TPC was highest in autumn. The TPC content was inversely correlated with in vitro rumen fermentation characteristics: organic matter (OM) degradability (r = −0.85; P < 0.001), production of total gas (r = −0.79; P < 0.001), total volatile fatty acids (r = −0.78; P < 0.001) and CH 4 (r = −0.53; P < 0.03) per gram of OM. The polyphenol-rich brown species, Fucus vesiculosus and Ascophyllum nodosum , caused a significant reduction in feed degradability (∼25%) due to the suppression of cellulolytic bacteria ( Ruminococcus spp., Lacnospiraceae spp., Rikenellaceae RC9 gut group) in the rumen fluid after fermentation. Interestingly, autumn-harvested samples of those two macroalgae decreased the CH 4 production by 62.6% and 48.2%, respectively, and reduced rumen methanogenic archaea (e.g., Methanobrevibacter spp.), although the reduction was not directly correlated with TPC. Thus, Nordic macroalgae, depending upon their species-specific unique properties, could be utilized as anti-methanogenic feed additives or feeding resources for ruminants. In vivo studies are needed to establish the implications of feeding with these macroalgae on overall animal performance. • Macroalgae generally had greater protein and mineral contents in the spring. • Including 20% macroalgae with a low polyphenol content did not reduce in vitro feed degradability. • Polyphenol-rich brown algae reduced feed degradation by inhibiting cellulolytic microbes. • Brown alga, Fucus vesiculosus mitigated 62.6% of in vitro CH 4 production at 20% inclusion in feed.

Net methylmercury production in 2 contrasting stream sediments and associated accumulation and toxicity to periphyton.

Periphyton uptake of bioaccumulative methylmercury (MeHg) may be an important entryway into the food web of many stream ecosystems where periphyton can be dominant primary producers. The net production of MeHg in stream sediment, its bioaccumulation in periphyton, and the potential toxicity of divalent Hg (Hg[II]) and MeHg in sediment to periphyton were investigated with a 67-d in situ incubation experiment using chemical exposure substrates containing either a fine-grained, organic-rich or a sandy, low-organic sediment, each amended with varying concentrations of mercuric chloride. Methylmercury was produced in sediment, and concentrations increased with greater amounts of added Hg(II); however, the net production of MeHg was inhibited in the highest Hg(II) treatments of both sediments. The range of total Hg concentrations that inhibited MeHg production was between approximately 80 000 ng Hg and 350 000 ng Hg per gram of organic matter for both sediments. Periphyton colonizing substrates accumulated MeHg in proportion to the concentration in sediment, but periphyton exposed to the sandy sediment accumulated approximately 20-fold more than those exposed to the organic-rich sediment relative to sediment MeHg concentrations. Toxicity of either Hg(II) or MeHg to periphyton was not observed with either periphyton organic content, net primary production, or respiration as endpoints. These results suggest that in situ production and bioaccumulation of MeHg in stream ecosystems can vary as a function of sediment characteristics and Hg(II) loadings to the sediment. Environ Toxicol Chem 2016;35:1759-1765. © 2015 SETAC.

Effects of nutrition on digestion efficiency and gaseous emissions from slurry in growing pigs: III. Influence of varying the dietary level of calcium soap of palm fatty acids distillate with or without orange pulp supplementation

The aim of this study was to establish the relationships between faecal fat concentration and gaseous emissions from pig slurry. Five diets were designed to meet essential nutrient requirements: a control and four experimental feeds including two levels (35 or 70g/kg) of calcium soap fatty acids distillate (CSP) and 0 or 200g/kg of orange pulp (OP) combined in a 2×2 factorial structure. Thirty growing pigs (six per treatment) were used to measure dry matter (DM) and N balance, coefficients of total tract apparent digestibility (CTTAD) of nutrients, faecal and urine composition and potential emissions of ammonia (NH3) and methane (CH4). Increasing dietary CSP level decreased DM, ether extract (EE) and crude protein (CP) CTTAD (by 4.0, 11.1 and 3.5%, respectively, P<0.05), but did not influence those of fibrous constituents. It also led to a decrease (from 475 to 412g/kg DM, P<0.001) of faecal concentration of neutral detergent fibre (aNDFom) and to an increment (from 138 to 204g/kg, P<0.001) of EE in faecal DM that was related to greater CH4 emissions, both per gram of organic matter (P=0.021) or on a daily basis (P<0.001). Level of CSP did not affect N content in faeces or urine, but increased daily DM (P<0.001), and N (P=0.031) faecal excretion with no effect on urine N excretion. This resulted in lesser (P=0.036) NH3 potential emission per kg of slurry. Addition of OP decreased CTTAD of EE (by 7.9%, P=0.044), but increased (P<0.05) that of all the fibrous fractions. As a consequence, faecal EE content increased (from 165 to 177g/kg DM; P=0.012), and aNDFom decreased greatly (from 483 to 404g/kg DM, P<0.001), which in all resulted in a lack of effect of OP on CH4 potential emission. Inclusion of OP in the diet also led to a significant decrease of CP CTTAD (by 6.85%, P<0.001), and to an increase of faecal CP concentration (from 174 to 226g/kg DM, P<0.001), with no significant influence on urine N content. These effects resulted in higher N faecal losses, especially those of the undigested dietary origin, without significant effects on potential NH3 emission. No significant interactions between CSP and OP supplementation were observed for the gaseous emissions measured.

The inclusion of rapeseed meal in fattening pig diets, as a partial replacer of soybean meal, alters nutrient digestion, faecal composition and biochemical methane potential from faeces

The effects of including rapeseed meal (RSM) as an alternative source of vegetable protein in pig diets on animal performance, nutrient digestibility and methane production from faeces was investigated. A total of 96 pigs of 42.4 (±4.04) kg of body weight (BW) were allocated into two dietary treatments (48 animals/treatment). One group was fed a conventional diet (C) and the other with a diet containing RSM (R). The level of RSM in the R diet was 120g/kg during the growing phase (40–70kg BW; days 1–34 of study) and 200g/kg during the finishing phase (70–114kg BW; days 35–76 of study). Average daily gain (ADG), average daily feed intake and feed conversion ratio were measured throughout the study. During the finishing phase, faeces were collected and analysed for dry matter (DM), organic matter (OM), crude protein (CP), crude fat, fibre fractions, pH, volatile fatty acids and biochemical methane potential (B0). Additionally, the coefficient of total tract apparent digestibility (CTTAD) of nutrients was measured using the acid-insoluble ash method. At slaughter (114±12.2kg BW), the main carcass and meat quality characteristics were registered and the fatty acid (FA) profile of the subcutaneous fat and muscle was analysed. During the growing phase, R animals showed lower ADG compared with C animals (818 vs. 890g/d; P<0.05). These differences disappeared during the finishing phase. Faeces from treatment R showed a lower B0 compared to those from treatment C (308 vs. 351mL methane/g OM). Animals from R group showed a lower DM, OM and CP CTTAD than C animals (0.790, 0.826 and 0.729 vs. 0.832, 0.865 and 0.818, respectively; P<0.05) and tended to show lower fibre digestion rates. Consequently, animals from R group showed a higher amount of these components in faeces. However, fat digestion was not affected. No differences were found between treatments on most carcass characteristics. Overall, the inclusion of high levels of RSM in pig diets decreased final BW and nutrient digestibility (except fat) in the finishing phase. However, faeces from animals fed RSM were less degradable, producing less methane per gram of OM.

Preliminary Study on Ethanol Production by Using Macro Green Algae

In order to estimate the potential of ethanol production from the macro green algae, we collected 10 species of macro green algae in Thailand, Vietnam and Japan, classified into 3 families; and determined the neutral monosaccharides compositions. The contents of neutral monosaccharides differed in the same family, however those compositions were almost same. Cheatomorpha aereas collected in Vietnam was the most glucose-rich sample of these samples, about 300 mg of glucose per gram of organic matter. The experiments of enzymatic saccharification and the ethanol fermentation were carried out by using Ulva spp. collected in Japan. The glucose yield was about 95% by using Acremonium cellulase after the pretreatment of autoclave (120&deg.C, 20min.). The efficiency of ethanol fermentation by using S. cerevisiae IR-2 after the enzymatic saccharification was about 90%. Over 4 % (w/v) of NaCl concentration inhibited the ethanol fermentation, while the effect of NaCl concentration for the saccharification was small.

Full-Scale Cocomposting of Hair Wastes from the Leather Manufacturing Industry and Sewage Sludge

A full-scale cocomposting experiment using hair wastes from the leather manufacturing industry and sewage sludge as cosubstrates was carried out with the aim of producing compost that may be used as an organic amendment in agriculture. A 1:1 weight ratio of hair wastes and sewage sludge was used based on experiments at smaller-scale. The resulting mixture was then amended with pruning wastes acting as bulking agent in a 1:1 volumetric ratio (mixture:pruning wastes). The experiment was carried out using the windrow composting technology with a weekly turning frequency. Thermophilic range of temperature was quickly achieved and maintained for more than 8 weeks. This fact ensured the sanitation of the compost according to international requirements. Additionally, the quality of the product obtained expressed in stability terms was very high (Self-heating test grade: V; respiration index: 0.83 mg O2 per gram of organic matter per hour). The nitrogen content in the final product was also high (5.6%, dry basis). In conclusion, the recycling of hair wastes produced in the leather manufacturing industry using the composting technology is feasible and a valuable organic fertilizer may be obtained.

Supplementation of a tropical grass diet with forage legumes and Sapindus saponaria fruits: effects on in vitro ruminal nitrogen turnover and methanogenesis

In two in vitro experiments with the RUSITEC-apparatus, Brachiaria dictyoneura was tested alone and with legumes at dietary proportions of 1/3, 2/3, or 3/3 of Arachis pintoi (Expt 1) and 1/3 of Arachis pintoi, Cratylia argentea, or Calliandra calothyrsus (Expt 2). In Expt 2, all diets were evaluated with and without 80 mg/g diet of Sapindus saponaria fruits. In Expt 1, the stepwise replacement of the grass by A. pintoi curvi-linearly increased rumen fluid concentrations of ammonia, volatile fatty acids, bacteria, and protozoa. Methane release rates were 1.7, 7.3, 8.8, and 9.0�mmol/day. With increasing legume proportion, more organic matter and protein were degraded, the latter being only partially recovered as ammonia. In Expt 2, 1/3 of A. pintoi basically had the same effects as in Expt 1. Cratylia argentea was less effective in modifying the fermentation pattern. In association with a higher nutrient degradation and rumen ammonia concentration, C. argentea and A. pintoi increased methane release to about 3- and 4-fold levels. Calliandra calothyrsus reduced nutrient degradation and methane release per gram of organic matter degraded. Tannins, predominant in C. calothyrsus, might have affected methanogenesis. Sapindus saponaria reduced methanogenesis by 11% on average in grass-alone and legume-supplemented diets.

Influence of exotic earthworm invasion on soil organic matter, microbial biomass and denitrification potential in forest soils of the northeastern United States

Formerly glaciated regions of the northeastern United States have few native earthworm species and the region is dominated by exotic earthworms from Europe and Asia. Earthworms of the Asian Megascolecid genus Amynthas, common in many forests of the southeastern US, are invading new habitats in north of their reported range in the northeastern US. At the Cary Arboretum in Millbrook, NY (approximately 42° N latitude, 74° W longitude), we discovered distinct patches of forest soil invaded by Amynthas hawayanus which were adjacent to areas of forest soil with no earthworms. We sampled soil within and just outside of the worm patches to assess the influence of earthworm invasion on the following soil chemical and biological characteristics: soil NO − 3 and NH + 4 concentrations, microbial biomass carbon (C) and nitrogen (N), readily-mineralizable C, organic matter content, pH and denitrification enzyme activity (DEA). Soil patches with earthworms had greatly increased fractions of active and readily-mineralizable soil organic matter compared with patches lacking worms. Readily-mineralizable and microbial biomass C, expressed per gram of soil organic matter, were 1.4-fold greater within the worm patches than outside the patches. Microbial biomass N per gram of organic matter was 2.4-fold greater, and DEA was 2.7-fold greater, in the worm patches than in surrounding soil. Earthworms apparently decreased the organic matter content of the O horizon by 36%. Our results strongly suggest that invasion of forests in the northeastern US by these exotic earthworms increases both C and N flux, with potentially important long-term consequences for nutrient cycling in these ecosystems.

Epiphytes: photosynthesis, water balance and nutrients

Epiphytes are plants adapted to living in the canopy and can be classified as facultative, hemiepiphytes or obligatory depending n the period spent in the canopy and if the species also occur as soil-rooted plants. Epiphytes are subjected to same environmental pressures as soil-rooted plants, such as demand water, light and nutrients, although environmental fluctuation tend to be more frequent. Epiphytes do not show any exclusive photosynthesis pathway, even though CAM is relatively common within this group, specially among orchids. In general, epiphytes are slow growing plants with high water use efficiency. This trait can be less competitive in environments with more favorable conditions where competition is more pronounced. Yet, among other epiphytes the vegetative growth phase coincides with the rain season. These plants can spend as much as 1.000g water per gram of organic matter produced, whereas among plants with high water use efficiency typical rates are 100:1. This variety of strategies demonstrates that, as in soil-rooted plants, a more parsimonious use of water does not necessarily represent the best mechanism to compromise water economy and growth.

Desert succulents and their life strategies

A succulent is a plant with water storing tissue, but succulence clearly is a quality that can be possessed to a higher or lesser degree. This paper gives a definition of succulence and discusses problems concerning Delf's measure of succulence. A new measure, Succulence Quotient, is proposed. It measures the amount of water that a plant can store at the expenditure of one gram of organic matter. We demonstrate this measure on a number of plants from the Namib desert, southern Africa, and compare it with the measured caloric values of the plant tissues. We also discuss life cycles of desert succulents in terms of utilizable and structural biomass and water. We contrast the concepts of growth form, life form and life strategy, and propose, on the basis of life cycle characteristics, an outline classification of life strategies of desert succulents. One detail of this outline classification is further worked out and illustrated for succulents from the Namib desert.

Relationships Between Concentrations of Sedimentary Variables and Trophic State in Florida Lakes

Midlake sediment samples from 97 Florida lakes were analyzed for organic matter (LOI 550 °C), carbonate (LOI 550–990 °C), total C, N, and P, and pigment (SCDU665) content. We used simple correlation and multiple regression to examine relationships between concentrations of selected sediment constituents, or their ratios, and trophic state (Carlson's TSI) of the overlying waters. Simple concentrations of sediment variables are poor predictors of TSI. The best simple correlation relates N per gram of organic matter to TSI–Chl a but explains only 27% of the variance in trophic state. The best multiple regression model incorporates five independent sediment variables and accounts for 43% of the variance in TSI–Chl a. Reasons for the poor relationships include (1) interlake variation in the dilution of organic matter and pigments by allochthonous inorganics, (2) variation among lakes in the diagenesis of surface sediments, (3) differential contributions of insoluble, large particulate, inorganic P, and (4) failure of open-water TSI measures to account for contributions to sediments from littoral and allochthonous sources.

Climate, Time, and Organisms in Relation to Podzol Development in Michigan Sands: I. Site Descriptions and Microbiological Observations

AbstractDirect microscopic counts of microflora, nitrification patterns, and water‐soluble organic matter production in upper humic horizons of seven soils were studied in an attempt to determine the processes responsible for correlations between forest types and Podzol development in Michigan.The volume and surface area of fungal mycelia, the number of bacterial cells, and the length of actinomycete filaments per gram of organic matter were substantially greater in a mull humus horizon under 100% northern hardwoods than in a mor humus horizon under a forest stand dominated by hemlock.Maximum crenic acid production occurred in the mor humus horizons, these being associated with forest stands dominated either by hemlock or white pine. Leachates from these horizons contained no nitrate until incubated with periodic leaching for over 5 months. In a mull and a duff mull horizon, nitrification was nil during the period of maximum crenic acid production and the initial appearance of nitrate was closely accompanied by sharp decreases in pH of the leachates and sharply reduced production of crenic acid.Data obtained in these studies point to mor humus layers (Oh or O2 horizons) as a major site of production of water‐soluble organic materials having properties which suggest that they may be active agents in podzolization and contribute to the composition of Podzol illuvial horizons. Production of these materials is intimately linked with patterns of nitrogen transformation peculiar to forest soils, notably under conifers.

Kinetics of aerobic sludge stabilization

The aerobic decomposition of organic sludge solids, measured in volatile solids and bacterial mass (respiration rate, acetate decomposition activity) has been determined at different temperatures ( Tables 1 and 2). Based on the rates of respiration (which is directly proportional to the reaction constant of decomposition) the characteristics of temperature dependence have been determined ( Fig. 2). The equation of monomolecular reactions and the thermal relation of Van't Hoff-Arrhenius were found to be generally applicable. The change in the rate of reaction caused by a 10°C change in temperature is about two-fold. The oxygen consumption per gram of organic matter decomposed ranges from 1·0 to 2·2 g, averaging at 1·7 for batch fed and 1·3 for continuously fed systems. The influence of sludge elutriation on the specific resistance is considerable, this being smaller by an order of magnitude than in non-washed systems.

Role of quinone groups in solubility and complexing of metals in sediments and soils

Benzoquinone which is thought to be present in humic acid along with other forms of quinone compounds, solubilized from 8.3 to 118.8 mg of Cu, Zn, Co, Mn and Ni per gram of organic matter as compared with 54.0 to 250.0 mg by humic acid. From 1.5 to 8.5% of the total metal-solubilizing capacity of humic acid appeared to arise from the reaction of quinones. The infrared analyses suggest that the quinone groups are participating in organometal reactions. The intensity of quinone absorption at 1650 cm −1 was reduced and shifted to lower frequency (1635 cm −1), when benzoquinone reacted with metals. The metal-solubilizing properties of quinones, together with their unusual stability in the geological column, may play a significant role in the concentration of metals in the substrate enriched with organic compounds containing quinone groups.

RECENT AND POSTGLACIAL PRODUCTION RATES OF A MARL LAKE1

Pigment degradation products were analyzed spectrophotometrically in postglacial, 14C‐dated sediments from the central depression and a marl lakemount of Pretty Lake in northeastern Indiana. Fluctuations in pigment products were examined in relation to the development of the productivity of the lake and to environmental parameters that might effect differential rates of preservation and deposition. Agreement was good between quantities of pigment degradation products and organic matter and other paleolimnological indices of productivity. There was a major peak of pigment products per gram of organic matter following the Boreal period, subsequent regression of productivity with several lesser peaks, especially during the millennium 6,500–5,500 B.P., and a slow increase in recent times. Contemporary rates of primary production were extrapolated to the inception of the lake. A general inverse relationship was evident between chlorophyll degradation products per unit organic content and carbonate levels. Changing levels of carbonate are discussed in relation to contemporary nutritional interactions and photosynthetic regulation.Rates of sedimentation at the central depression of the lake differed markedly from those of the littoral lakemount. While the rates in the central depression accelerated, those of the marl lakemount fluctuated sigmoidally, greatly accelerated during the interval 9,000– 7,000 B.P. The lakemount ceased accretion abruptly 1 m from the lake surface at 2,740 B.P. The probable ontogeny of marl lakemounts is discussed.

THE FLOW OF DIGESTA INTO THE DUODENUM OF SHEEP

A method is described to determine the volume of flow of digesta into the duodenum of sheep. A solution of polyethylene glycol 4000 was continuously infused into the abomasum via a cannula. The volume of digesta flowing was calculated from the dilution of polyethylene glycol in samples of digesta obtained from a duodenal cannula.Mature wethers were fed rations containing different amounts of straw and urea to give two levels of readily fermentable carbohydrate and two levels of nitrogen in a factorial arrangement. The sheep were fed once daily and there was a monophasic diurnal flow pattern with the highest rates occurring just prior to and during feeding and the lowest rates 6–12 hours after feeding. Both the composition of the ration and the quantity eaten affected the volume of flow which averaged 0.9 ml and 0.6 ml per hour per gram of organic matter consumed per day for the high straw and low straw rations respectively. Additional urea had no effect on flow volume.The average net disappearance, from the stomachs, of organic matter was 24.5 and 50.0% for the high straw and low straw rations, respectively. This difference was reflected in the overall digestibilities which were 57.2 and 78.5% for the high straw and low straw rations, respectively. Additional urea caused slight but not significant increases in digestibility.

SOME CHARACTERISTICS OF THE ORGANIC MATTER EXTRACTED BY DILUTE INORGANIC ACIDS FROM A PODZOLIC B HORIZON

Organic matter was extracted from the B21horizon of a podzol soil by both 0.5 per cent HF and 0.5 per cent HCl. Dialysis of the extracts against distilled water reduced the halogen content to less than 0.1 per cent and the iron plus aluminium to between two and three millimoles per gram of organic matter. Further treatment of this water-dialysed material with EDTA and 8-hydroxyquinoline removed almost all of the iron and about two-thirds of the aluminium.The number average molecular weight of the organic matter, as determined by osmometry, ranged between 47,000 and 53,800. Paper electrophoresis studies showed that this organic matter consisted chiefly of one component, negatively charged, dark-brown in colour and mobile over the pH range investigated (1.8 – 9.0). Only traces to small amounts of glucose, galactose, arabinose and xylose were detected by paper chromatography in both the HF and HCl extracts even after hydrolysis. In addition traces of rhamnose were found in the hydrolyzed HF extract.