Natural Resource Ecology Laboratory (NREL)
Permanent URI for this communityhttps://hdl.handle.net/10217/195540
These digital collections include faculty publications, presentations, reports, and datasets from the Natural Resource Ecology Laboratory (NREL). Included here are individual datasets for the Ethiopia Project, Shortgrass Steppe-Long Term Ecological Research (SGS-LTER), Riparian Habitat and Invasive Species in the Colorado River Basin, and Yellowstone Willows LTREB. Also included is a collection of publications by Eldor A. Paul, a Senior Research Scientist at the Natural Resource Ecology Laboratory and a Professor in the Department of Soil and Crop Sciences.
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Item Open Access SGS-LTER GIS layer with detailed information on CPER boundary on Central Plains Experimental Range, Nunn, Colorado, USA 2012(Colorado State University. Libraries, 1939-2012) Kaplan, NicoleThis data package was produced by researchers working on the Shortgrass Steppe Long Term Ecological Research (SGS-LTER) Project, administered at Colorado State University. Long-term datasets and background information (proposals, reports, photographs, etc.) on the SGS-LTER project are contained in a comprehensive project collection within the Repository (http://hdl.handle.net/10217/100254). The data table and associated metadata document, which is generated in Ecological Metadata Language, may be available through other repositories serving the ecological research community and represent components of the larger SGS-LTER project collection.Item Open Access SGS-LTER standard met data: Monthly precipitation totals and temperatures from the Central Plains Experimental Range, Nunn, CO 1940-1973(Colorado State University. Libraries, 1941-1973) Parton, WilliamThis data package was produced by researchers working on the Shortgrass Steppe Long Term Ecological Research (SGS-LTER) Project, administered at Colorado State University. Long-term datasets and background information (proposals, reports, photographs, etc.) on the SGS-LTER project are contained in a comprehensive project collection within the Repository (http://hdl.handle.net/10217/100254). The data table and associated metadata document, which is generated in Ecological Metadata Language, may be available through other repositories serving the ecological research community and represent components of the larger SGS-LTER project collection. The objective of this study is to collect baseline meteorological data for the CPER. Datasets auto12_climdb and man11_climdb have been processed for quality and missing values.Item Open Access Behavior of free amino acids in soil(Colorado State University. Libraries, 1960-03) Putnam, H. D., author; Schmidt, E. L., author; Paul, Eldor A., author; Soil Science Society of America, publisherThe behavior of a mixture of amino acids in a soil environment was studied. Extractions were made with 80% ethanol. The extract was concentrated and then was analyzed for amino acids by gradient elution chromatography. After 1 hour of soil contact in the cold, at least some of each amino acid could be recovered, but the extraction was not efficient. Replicate soil flasks to which amino acids had been added were incubated at 28° C. under conditions that allowed for both CO2 and amino acid analysis of the same flask. After 24 hours, substantial degradation had occurred but at least trace amounts of each of the added amino acids except threonine could still be detected. Beta alanine appeared on the 24-hour chromatogram although it was not among the amino acids added initially. Results of both chromatographic analysis and CO2 collection suggested that nearly all of the added amino acids were degraded by the end of 96 hours. Separate studies using microbiological assay failed to confirm the persistence of threonine in soil as reported in the literature. The possibility that the beta alanine found in the soil environment was formed from aspartic acid decarboxylation was explored, but large additions of aspartic acid to soil did not result in substantial increases in beta alanine.Item Open Access Extraction of free amino acids from soil(Colorado State University. Libraries, 1960-05) Paul, Eldor A., author; Schmidt, E. L., author; Soil Science Society of America, publisherAlternatives to extraction with ethanol were examined in order to obtain more effective removal of free amino acids from soil. Ba(OH)2 was a promising extractant and proved to be very effective in recovering a mixture of 17 amino acids that had been added to soil. Resolution of the extract by elution chromatography was followed by colorimetric analysis; 73 to 121% of the acidic and neutral components of the mixture and 36 to 41% of the basic amino acids were recovered. A second extraction procedure, based on the use of NH4OAc, was developed to avoid any slight hydrolysis of amino acid polymers that may have occurred during preparation of Ba(OH)2 extracts. The NH4OAc extraction procedure was 31 to 83% effective in the recovery of added amino acids from soil. When both extraction techniques were applied in preliminary trials to characterize the free amino acids fraction of a soil, the NH4OAc extraction was considered the better. Both NH4OAc and Ba(OH)2 extractions yielded many more kinds of free amino acids in concentrations 5 to 25 times greater than that reported earlier in comparable studies using ethanol extraction.Item Open Access Formation of free amino acids in rhizosphere and nonrhizosphere soil(Colorado State University. Libraries, 1961-09) Schmidt, E. L., author; Paul, Eldor A., author; Soil Science Society of America, publisherUntreated samples of nonrhizosphere and soybean rhizosphere soils each contained about 15 identified free amino acids totaling 2 to 4 µg. per g. of soil; lysine was the most prevalent amino acid in each preparation. Numerous additional unidentified compounds occurred at concentrations estimated as 0.1 to 0.5 µg. per g. Treatment with glucose and potassium nitrate increased the amount of free amino acids to about 100 µg. per g. after 3 days. Concentrations declined after 3 days but still were 4 to 5 times that of the untreated control after 2 weeks' incubation. Glutamic acid was the dominant amino acid in all treated soils. Rhizosphere soil did not differ quantitatively from nonrhizosphere in samples treated with glucose, although a greater variety of ninhydrin reacting compounds was encountered in rhizosphere soil. Treated soils incubated at 20% field moisture capacity differed little in free amino acids from those held at 30%. The features of the free amino acid fraction are discussed.Item Open Access The influence of nitrogen on the decomposition of crop residues in the soil(Colorado State University. Libraries, 1962-08) Lueken, H., author; Hutcheon, W. L., author; Paul, Eldor A., author; Agricultural Institute of Canada, publisherAdditions of mineral nitrogen accelerated the initial decomposition rate of incorporated wheat straw, alfalfa hay and glucose when added to two soils differing widely in organic matter content. However, in the more advanced stages of decomposition the reverse was true, and over the total incubation period larger amounts of carbon were maintained in soils supplemented with nitrogen. In contrast to all other residues used, nitrogen additions to cellulose effected a continuous and substantial increase in residue decomposition. This was the only residue for which the mineralization of soil organic matter did not supply nitrogen adequate for its decomposition within 120 days. The very slow rate of decomposition of sphagnum peat could be attributed to its high lignin content, rather than to the nitrogen levels. Sulphacetolysis analysis, which measures the non-humified carbon, indicated the feasibility of separating non-humified crop residues from the more complex soil organic matter. Addition of organic amendments thus resulted in a drop in the soil humification quotient. Nitrogen resulted in the retention of a significantly higher percentage of the added residue, without a drop in the humification quotient for the high organic matter Melfort soil. Residue applications to soils produced a significant improvement of structural development, especially in the low organic matter soil (Arborfield).Item Open Access SGS-LTER GIS layer with detailed information on buildings on Central Plains Experimental Range, Nunn, Colorado, USA 2012(Colorado State University. Libraries, 1962-2012) Kaplan, NicoleThis data package was produced by researchers working on the Shortgrass Steppe Long Term Ecological Research (SGS-LTER) Project, administered at Colorado State University. Long-term datasets and background information (proposals, reports, photographs, etc.) on the SGS-LTER project are contained in a comprehensive project collection within the Repository (http://hdl.handle.net/10217/100254). The data table and associated metadata document, which is generated in Ecological Metadata Language, may be available through other repositories serving the ecological research community and represent components of the larger SGS-LTER project collection.Item Open Access Measurement of the polysaccharide content of soils(Colorado State University. Libraries, 1963-01) Acton, C. J., author; Paul, E. A., author; Rennie, D. A., author; Agricultural Institute of Canada, publisherThe polysaccharide content of two soils, measured by precipitating and weighing the microbial gums from the fulvic acid fraction of soil organic matter, and by colorimetric analyses using anthrone, was increased appreciably during the incubation of samples with straw. Applications of nitrogen and phosphorus altered only slightly the amount of polysaccharides present. The polysaccharide content of the amended soils increased rapidly during the first week of incubation and then levelled off. Peptization of the soil with dilute alkali prior to acid hydrolysis substantially increased the carbohydrates measured with anthrone. The anthrone reagent which measures primarily hexoses indicated a soil carbohydrate content of 10–15 per cent occurring in a range of Saskatchewan soils. Thirty-five per cent more carbohydrate carbon was found using the less specific phenol-sulphuric acid reagent. The acetone precipitated fraction from the fulvic acids accounted for only 10 per cent of the soil carbohydrates and contained a large proportion of ash and other non-carbohydrate materials. The total acid-soluble base-soluble fraction, fulvic acids, contained 15–25 per cent; the remainder was distributed in the alkali insoluble humin — 55–70 per cent and the humic acid fraction 4–12 per cent.Item Open Access The influence of soil moisture, nitrogen fertilization, and temperature on quality and amino acid composition of Thatcher wheat(Colorado State University. Libraries, 1963-07) Hutcheon, W. L., author; Sosulski, F. W., author; Paul, E. A., author; Agricultural Institute of Canada, publisherThe protein content of Thatcher wheat grown in the growth chamber was increased by reduced water supply, nitrogen fertilization, and higher air temperatures. Soil moisture conditions had a greater influence on protein content at higher temperatures, while the largest responses to nitrogen fertilization were obtained at the medium moisture level. Changes in sedimentation value and mixing time were associated with protein content except for plants grown at 62°F. Apparently the low temperature had an adverse effect on gluten quality. The relative distribution of 9 amino acids was significantly correlated with changes in grain protein content. Only 6 amino acids gave similar high correlations with flour protein content and sedimentation value. These differences are explained on the basis of changes in the morphology of the wheat grain and the proportion of flour proteins.Item Open Access The relationship of polysaccharides to soil aggregation(Colorado State University. Libraries, 1963-07) Acton, C. J., author; Rennie, D. A., author; Paul, E. A., author; Agricultural Institute of Canada, publisherStudies were conducted on two soil types to determine whether variations in level of aggregation, induced by adding wheat straw were accompanied by significant changes in the polysaccharide content of the soils. The addition of finely ground wheat straw to the soils, followed by varying periods of incubation, markedly improved the level of aggregation in both soils. Where nitrogen was added together with the straw, the percentage of aggregates > 0.5 and 0.1 mm. diameter was reduced significantly as compared to the straw treatment alone. The data indicate that maximal structural improvement due to straw additions can only be attained where N is maintained at a relatively low level. The level of aggregation of the variously treated soils was shown to be approximately 35 per cent dependent on the 'microbial gum' content of the soil samples. This low level of correlation was due m part to the fact that the maximum level of aggregation was attained at a different sampling period than maximum accumulation of 'microbial gum'. Also, appreciable contents of polysaccharides were found in the humin and humic acid as well as the fulvic acid fractions of the soil organic matter. It is concluded that level of aggregation is a function, not only of the microbial gum content of the soil, but also of the carbohydrate carbon content of the numic acid-humin fraction.Item Open Access The effect of various clover management practices on gaseous N losses and mineral N accumulation(Colorado State University. Libraries, 1963-08) Aulakh, M. S., author; Rennie, D. A., author; Paul, E. A., author; Agricultural Institute of Canada, publisherA 2-yr field study was carried out to assess gaseous losses of N as N2O + N2 from two Black Chernozemic soils, where during year 1 wheat was underseeded to clover and in year 2, the clover in late June was (a) green-manured and the field fallowed, (b) harvested for hay and then fallowed, or (c) harvested for hay and allowed to regrow. Gaseous losses during year 1 were small and ranged from 1.3 kg N∙ha−1 (Blaine Lake clay loam) to 4.7 kg N∙ha−1 (Hoey clay loam). Gaseous losses were somewhat higher during the second year, but differences between the various clover management practices were generally small. The contribution of lower soil horizons towards gaseous nitrogen losses were shown to be negligible. Soil moisture, mean air temperature, nitrate + nitrite, and ammonia N concentrations collectively accounted for 37–66% of the variations in N2O fluxes. It is concluded that incorporation of clover followed by a partial fallow results in substantially less gaseous loss of nitrogen than the standard summerfallowing practice, and at the same time significantly increases mineral nitrogen accumulation in the soil.Item Open Access Investigations of the dynamics of soil humus utilizing carbon dating techniques(Colorado State University. Libraries, 1964) Rennie, D. A., author; Campbell, C. A., author; Paul, Eldor A., author; McCallum, K. J., author; Pub. House of the Academy of the Socialist Republic of Romania, publisherThe radioactivity of naturally occurring C14 in soil humus when compared to the C14 activity of a standard of recent origin (carbon dating) can be used to estimate the mean residence time of the soil humus in studying problems in soil genesis, fertility and biochemistry. The apparent mean residence time of humus from a Black Chernozemic soil was approximately 1,000 years. The C14 activity of "Humin" and "Humic Acids" isolated from this soil was lower than that obtained from the whole soil. The fulvic acids, however, had a substantially higher activity and a corresponding lower mean residence time. A Grey Wooded Podzolic soil sample, developed under different vegetation than the chernozemic, had mean residence time approximately 1/3 that of the chernozemic soil. Carbon dating techniques can also be used to study the dynamics of soil organic matter under differing cultural techniques and in soil biochemistry investigations. When integrating these data, factors such as isotopic discrimination and variations in the C14 content of the atmosphere must however be taken into consideration in all studies using this technique.Item Open Access SGS-LTER GIS layer with detailed information on IBP vegetation on Central Plains Experimental Range, Nunn, Colorado, USA 2012(Colorado State University. Libraries, 1964-1972) Kaplan, NicoleThis data package was produced by researchers working on the Shortgrass Steppe Long Term Ecological Research (SGS-LTER) Project, administered at Colorado State University. Long-term datasets and background information (proposals, reports, photographs, etc.) on the SGS-LTER project are contained in a comprehensive project collection within the Repository (http://hdl.handle.net/10217/100254). The data table and associated metadata document, which is generated in Ecological Metadata Language, may be available through other repositories serving the ecological research community and represent components of the larger SGS-LTER project collection.Item Open Access Comprehensive network site description: Hays(Colorado State University. Libraries, 1965-1975) Tomanek, G. W. (Gerald Wayne), 1921-, author; Natural Resource Ecology Laboratory, Colorado State University, publisherItem Open Access Some concepts of modelling(Colorado State University. Libraries, 1965-1975) Swartzman, G. L. (Gordon L.), author; Beldsoe, L. J., author; Francis, R. C., author; French, N. R., author; Jameson, D. A., author; Smith, F. M., author; Van Dyne, G. M., author; Natural Resource Ecology Laboratory, Colorado State University, publisherItem Open Access Comprehensive network site description: Osage(Colorado State University. Libraries, 1965-1975) Risser Paul G., author; Natural Resource Ecology Laboratory, Colorado State University, publisherItem Open Access Comprehensive network site description: Dickinson(Colorado State University. Libraries, 1965-1975) Whitman, Warren C., 1911-, author; Natural Resource Ecology Laboratory, Colorado State University, publisherItem Open Access Comprehensive network site description: Pantex(Colorado State University. Libraries, 1965-1975) Huddleston, Ellis W., 1935-, author; Natural Resource Ecology Laboratory, Colorado State University, publisherItem Open Access Comprehensive network site description: Jornada(Colorado State University. Libraries, 1965-1975) Herbel, Carlton H., 1927-, author; Pieper, Rex D., author; Natural Resource Ecology Laboratory, Colorado State University, publisherItem Open Access Comprehensive network site description: Cottonwood(Colorado State University. Libraries, 1965-1975) Lewis, James K. (James Kelly), 1924-, author; Natural Resource Ecology Laboratory, Colorado State University, publisher