Browsing by Author "Biederbeck, V.O."
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Item The benefits of a wheat-lentil rotation for the Brown Soil Zone(1997-02-20) Zentner, R.P.; Campbell, C.A.; Biederbeck, V.O.; Selles, F.; Sonntag, G.J.; Fernandez, M.; Miller, P.R.Item A bioenergy success story: the energy savings implications of the increase in legumes in rotations since 1990(1996-02-22) Coxworth, E.; Biederbeck, V.O.; Campbell, C.A.; Entz, M.H.; Zentner, R.P.The energy savings achieved by the increase in field peas and lentil production in western Canada between 1990 and 1995 were calculated to be 4.46 PJ (petajoules) per year, equivalent to 1.7 % of the total energy costs of agriculture production in Alberta, Saskatchewan and Manitoba, and equivalent to 7.5 % of 1990 nitrogen fertilizer use. A modem ethanol-from-grain industry would have had to produce 380 million litres of ethanol to achieve the same net energy gain. The increase in soybean production hectares in Ontario since 1990 was calculated to be saving 3.92 PJ per year, equivalent to an ethanol industry of 330 million litres. The combined energy savings from these legumes in rotations in Ontario and western Canada were calculated to be 8.38 PJ, equivalent to an ethanol industry of 710 million litres. This is much larger than the existing 31 million L/year Canadian fuel ethanol industry, and equivalent to 17.7 % of present U.S. ethanol production. In addition, the energy costs of producing grain crops after a legume in the rotation were reduced. These reductions in energy costs of grain production would also reduce the overall energy costs of ethanol production.Item Changes in soil biological and physical properties under reduced tillage systems(1996-02-22) Curtin, D.; McConkey, B.; Biederbeck, V.; Campbell, C.; Schoenau, J.J.; Wang, H.; Lafond, G.; Moulin, A.; Zentner, R.; Brandt, S.Interest in reduced tillage systems has increased in recent years, though important questions remain as to the impacts of such systems on soil quality and nutrient cycling. We examined the effects of tillage on soil biochemical (N and C mineralization, microbial biomass, and light fraction of organic matter) and physical (aggregate stability and size distribution) attributes at seven long-term sites in Saskatchewan, representing a range of soil types and crop rotations. Reduction in tillage increased mineralizable N at most sites, though the effect of tillage was usually not as strong as that of crop rotation (continuous cropping vs. wheat-fallow). Other indicators (microbial biomass N, light fraction N) also provided evidence of improved N fertility under reduced tillage. These findings are in apparent conflict with recent reports that adoption of reduced tillage can reduce N uptake and protein content of wheat. This anomaly remains to be resolved. Wet aggregate stability was improved by reduction in tillage and by elimination of summer fallow on a sandy loam and a silt loam, but treatment effects were small or absent in the heavy textured soils. Aggregate stability increased between spring and fall and decreased during winter. On a sandy loam, where wind erosion was a perennial threat, cropping intensity did not affect the wind-erodible fraction (aggregates < 0.84 mm) but reducing tillage did decrease erodibility of the fallow phase. Data collected between 1982 and 1994 showed that wind erodibility varied considerably from year to year, but there was no discernible relationship with weather or residue amounts from the previous crop.Item Crop rotation effects on soil microbial populations, biomass, and diversity under wheat in a brown loam(1999-02-25) Biederbeck, V.O.; Lupwayi, N.Z.; Rice, W.A.; Hanson, K.G.; Zentner, R.P.Item Decomposition of crop residue in the landscape(1996-02-22) Moulin, A.P.; Biederbeck, V.O.; Beissler, H.J.; Beckie, H.J.Decomposition of spring wheat (Triticum aestivum L.), flax (Linum usitutissimum L.) and pea (Pisum sativum L.) residue placed at the soil surface, was measured at four slope positions: upper, upper-middle, lower-middle and lower, in the landscape. Slope position did not significantly affect decomposition or microbial populations in crop residue placed at the surface under a cereal leaf canopy. Decomposition of pea residue was significantly higher than for wheat and flax, due to differences in carbon to nitrogen ratios. Over-winter loss of crop residue varied considerably between crops. Microbial populations in residue were highest in pea residue compared to wheat and flax, and were independent of slope position. Microbial populations in the soil were affected by slope position but not residue. The most active phase of residue decomposition occurred from late, spring to early summer, and was correlated with high yeast populations.Item Development of selective growth media for isolation and enumeration of biodegraders from soil(1997-02-20) Hanson, K.G.; Biederbeck, V.O.; Geissler, H.J.; Moulin, A.P.Cellulose and lignin are the main components of crop residues that must be decomposed by heterotrophic microbes either on the surface (zero-tillage) or in the soil (conventional tillage) to release plant nutrients and sustain humus formation. This study was conducted to develop and evaluate improved agar media for the selective enumeration and isolation of a wide range of cellulolytic and ligninolytic microbes from field samples. An existing cellulose-Congo Red agar was modified by replacing the cellulose powder with carboxymethylcellulose (CMC) and by doubling the concentration of soil extract. The new medium (CMCCRA) for cellulolytic bacteria was evaluated, in comparison with the traditional minimal salts-CMC agar (MSCMCA), by spreadplating of dilutions from samples of three, surface-placed crop residues (wheat, pea and flax) and the underlying soil, collected in spring 1996 from a field study at Melfort. Cellulolytic activity was easy to detect on CMCCRA plates due to the distinct zones of clearing around all active colonies, that are clearly visible against a deep red background without having to flood the agar with a liquid reagent as is necessary when using the MSCMC agar. Thus, counts of cellulose degrading bacteria on crop residues and in soil were consistently higher on CMCCRA and also less variable than on MSCMCA. By adding streptomycin we made the CMCCR agar more selective for fungal growth and used it to reliably enumerate cellulolytic fungi, which - as a group - accounted for about 30% of total number of viable fungi in the surface soil. We also explored the feasibility of using a polymeric dye agar (with Poly R-478) as selective medium for the primary detection of ligninolytic organisms and their subsequent isolation from enrichment cultures.Item Dynamics of carbon dioxide evolution from decomposing wheat straw(1997-02-20) Curtin, D.; Selles, F.; Campbell, C.A.; Wang, H.; Biederbeck, V.O.Increasing concentration of CO2 in the atmosphere is a concern because of the potential for global warming. Carbon exchange between soil and the atmosphere has an important role in the global C cycle, but partitioning soil CO2 emissions by source (soil organic matter mineralization, crop residue decomposition, root respiration) is difficult. Our objective was to determine the contribution of decomposing wheat straw to CO2 emissions from a Swinton silt loan under controlled conditions (constant 20°C). Two types of straw (i.e., fresh straw collected shortly after harvest and standing stubble that had ‘weathered’ in the field for a year) were either incorporated or placed on the surface of soil (contained in polythene-lined, wooden boxes 10 cm deep with area of 1363 cm2) at a rate equivalent to 2,800 kg ha-‘. One set of soils was watered every two or three days to 90% of field capacity and a second set was allowed to dry (from 90% field capacity) to permanent wilting point before watering. Emissions of CO2 were measured every two or three days using a vented chamber connected to a portable CO2 analyzer. Within 2 d, incorporation of straw increased CO2 flux from 0.3 to about 1.5 umol CO2 mm2 s-1. Surface straw significantly (P < 0.05) increased fluxes, but the effect was small compared with incorporated straw. Straw type had little effect on emissions. Total CO2-C emitted from continuously moist soil in 77 d was 3.3 g box-’ (no straw added), 5.5 g box-’ when straw was placed on soil surface and 9.6 g box-’ when straw was incorporated. In all, 37% of incorporated straw C and 13% of surface straw C was emitted as CO2. Moisture limitation in soil subjected to moist/dry cycles reduced emissions to 34-59% of those observed under continuously moist conditions. Fluxes from soil with incorporated straw were least sensitive to moisture availability. In the absence of straw, CO2-C emitted during the experiment was about equal to the amount by which light fraction C decreased, suggesting that this labile fraction of organic matter was the main source of respired C.Item Effect of cropping and fertilization on soil microflora in an oily waste amended loamy sand(2000-02-22) Hanson, K.G.; Biederbeck, V.O.A field study to assess the impact of oily waste application on soil properties and crop production was conducted on a highly erodible, loamy sand near Richmound, SK between 1997 and 1999. The oily sludge from the CCRL Upgrader in Regina was applied to alleviate erosion and build soil organic matter thus improving soil quality while utilizing an industrial waste product. Fertilizer and cropping treatments were used to assess their impact on oily waste bioconversion. Oil-related fertilization has been reported to encourage microbial biodegradation of hydrocarbons thus speeding up reclamation and allowing cereal crop production to reach levels similar to the unoiled control within one year (Toogood et al. 1977). Microbial populations or activities have been used to evaluate hydrocarbon biodegradation and bioconversion to stable humus although they are not direct measurements of bioconversion (Bossert and Kosson 1997). The objective of this portion of the study was to evaluate the effect of oily waste sludge, oil-related fertilization, cropping and crop type on various soil microbial populations and microbial activity over the course of the field study.Item Effect of phosphorus fertilization on legume green fallow and subsequent wheat(1998-02-19) Biederbeck, V.O.; Selles, F.; Hanson, K.G.; James, D.C.A greenhouse study was conducted to determine effects of P fertilization on green manure and N production by chickling vetch, cv. AC Greenfix, in a degraded Brown sandy loam and to assess if P applied to the legume and N fixed during vegetative growth will be re-mineralized during partial fallow to adequately supply a subsequent crop of spring wheat. The soil from a stubble field near Cadillac, SK was placed in large plastic tubs which were randomized for the seven green fallow treatments consisting of Rhizobium inoculated and uninoculated AC Greenfix, each at three P levels (0,36 and 72 kg P ha-t), plus an uninoculated high N control fertilized with 72 kg P ha-t and 100 kg N ha-t. At full bloom, the legume top growth was coarsely chopped and soil incorporated. Then the green-manured soil was managed for 12 weeks as ‘partial fallow’ with occasional watering and periodic soil sampling to monitor available nutrients. Thereafter, all green-manured tubs plus tubs with the ‘conventional fallow’ control were seeded to spring wheat, cv. AC Barrie, which was harvested 14 weeks later when all treatments had reached maturity. Despite suboptimal legume growth due to midwinter light deficiencies in the greenhouse there was still a positive response to P fertilization. On a DM per plant basis, high P fertilized inoculated and uninoculated treatments produced 35% and 30% more green manure biomass than the respective unfertilized controls. Fertilization with P tended to enhance symbiotic N2 fixation while N fertilization at 100 kg ha-t resulted in complete inhibition of root nodule formation. Upon soil incorporation, legume decomposition in the greenhouse proceeded so rapidly that much of the green manure P and N was re-mineralized within the first three weeks of fallowing. Green fallow P fertilization accelerated the maturity of subsequent spring wheat by 12 to 18 days but it had no effect on grain yield. Grain protein and P contents were generally also unaffected by preceding P fertilization. This lack of green fallow P fertilization response in the greenhouse, in terms of wheat yield and quality, points to the need for a similar study under natural field conditions and greater crop nutrient demands. Nevertheless, all green fallow treatments in the greenhouse effected significant wheat yield increases over the yield on conventional fallow. Thus, benefits of green manuring per se on wheat were confirmed by an average 54% increase in grain and 20% increase in straw production. Green fallowing also increased the efficiency of grain production (e.g. harvest index) and it improved grain quality with an average 29% increase in kernel size and 14% increase in protein content. These results imply that legume green fallowing per se was more important to wheat production in the greenhouse than the rate of legume fertilization.Item Effect of tillage on selected soil biochemical characteristics in a coarse- and medium-textured soil in southwestern Saskatchewan(1997-02-20) Campbell, C.A.; Biederbeck, V.O.; McConkey, B.G.; Curtin, D.; Peru, M.R.; Hahn, D.L.Characterization of soil organic matter is valuable for identifying the overall quality of soils. Crop management will influence soil quality. Some changes may become apparent more quickly than others and may depend upon soil texture and environmental conditions under which production is conducted. We assessed the impact of tillage [no-tillage (NT) vs conventional mechanical tillage (CT)] and fallow frequency [continuous wheat (Triticum aestivum L.)(Cont W)vs fallow- wheat (FW)] on selected soil quality attributes on a Hatton fine sandy loam soil at Cantuar and a silt loam soil at Swift Current, in semiarid southwestern Saskatchewan. Measurements made in the 0-7.5 cm depth at 4-year intervals after the study was initiated are discussed. In the coarse-textured soil, significant treatment effects on total organic C and N were only observed after 11-12 years. In the coarse-textured soil, labile organic constituents, such as C and N mineralization (Cmin and Nmin showed treatment effects in 7 years, but microbial biomass-C (MB-C) and specific respiratory activity (SRA) (ratio Cmin/MB-C) only showed significant effects after 11 years. In the medium-textured soil, total organic C and N and MB-C were not significantly affected by treatment even after 12 years, and Cmin and SRA were only significantly affected after 12 years; Nmin was affected after 8 years. In the coarse-textured soil, soil quality attributes were generally greater in no-tillage (NT) systems than in conventional mechanical tillage (CT) or minimum tillage (MT), and greater in Cont W than in F-W systems. However, in the medium-textured soil, tillage did not influence the soil quality attributes, but cropping more frequently resulted in higher Cmin, Nmin, and SRA. In both soils the response of the labile soil attributes was generally a function of crop residues returned to the land. Of the soil quality attributes tested, Cmin and Nmin were the most sensitive to the agronomic treatments. More research is required to determine why changes in soil quality become apparent more quickly in the coarser-textured soil.Item Effects of crop rotation and fertilization on soil carbon sequestration in the semiarid region(2001-02-22) Campbell, C.A.; Zentner, R.P.; Biederbeck, V.O.; Selles, F.; Lemke, R.; McConkey, B.G.Item Field evaluation of two methods for assessment of nodulation and N-fixation by peas(2003-02-18) Biederbeck, V.O.; Zaychuk, K.; Bruins, R.A field experiment being conducted at Swift Current to evaluate the effectiveness of a commercial polymer-coating system in comparison with traditional pulse inoculation systems provided an opportunity to test side-by-side the utility of two differing methods for on-site assessment of nodule development and N-fixation potential. The first is the nodulation scoring method developed by Rice and Clayton at Beaverlodge, AB for peas that has also been used in recent years by other AAFC researchers in Alberta and Saskatchewan for in-field rating of not only peas but lentils and chickling vetch when grown as pulses or green manures. The other method is an adaptation from the BC Ministry of Forests Field Guide to assess forage legumes which was later modified by Grow Tec Seed Coatings Inc. for use in research trials with larges-eeded grain legumes. The results of our comparative study indicate that addition of above ground plant growth and vigour assessment to the excavation and assessment of root nodule colour, number, and position has rendered the Grow Tec / BC Ministry method much more precise than the Rice/Clayton method as it relates more closely to vegetative biomass production and also to final grain yields.Item Indian Head black lentil: a green manure crop for the Brown Soil Zone?(1996-02-22) Zentner, R.P.; Campbell, C.A.; Biederbeck, V.O.; Selles, F.Item Managing an annual legume green manure crop for fallow replacement in southwestern Saskatchewan(2003-02-18) Zentner, R.P.; Campbell, C.A.; Biederbeck, V.O.; Selles, F.; Lemke, R.; Jefferson, P.G.; Gan, Y.Some scientists have suggested that in the Brown soil zone an annual legume green manure crop (GM) could be used as a partial-fallow replacement to protect the soil against erosion and increase its N fertility, particularly when combined with a snow trapping technique to replenish soil water used by the legume. We assessed this possibility by comparing yields, N economy, water use efficiency, and economic returns of hard red spring wheat (W) grown in rotation with Indianhead black lentil (i.e., GM-W-W) vs. that obtained in a F-W-W system. Further, we assessed whether a change in management of the GM crop (i.e., moving to earlier seeding and earlier turn-down) was advantageous to the overall performance of this practice. The study was conducted over 12 years (1988-99) on a loam soil at Swift Current, SK. (wheat stubble was left tall to trap snow, tillage was kept to a minimum, and the wheat was fertilized based on soil tests). When examined after 6 years, the results suggested that by waiting for full bloom of the legume (usually late July or early August) to maximize N2 fixation, soil water was being depleted to the detriment of yields of the following wheat crop. However, the change in management of the GM crop since 1994 has resulted in wheat yields following GM equalling those after fallow. It also produced a significant increase (after one rotation cycle) in grain protein and N yields of aboveground parts of wheat in the GM-W-W compared to the F-W-W system, and lead to a gradual decrease in fertilizer N requirements of wheat in the GM system in the last 6 years. These savings in N fertilizer, together with savings in tillage and herbicide costs for weed control on partial-fallow vs conventional-fallow areas, and higher revenues from the enhanced grain protein, more than offset the added costs for seed and management of the GM crop. Thus, our results imply that, with proper management and given sufficient time, an annual legume GMcereal rotation is a viable option for area producers.Item The microbial ecology of a sustainable, long-term lentil-wheat rotation(2001-02-22) Hanson, K.G.; Biederbeck, V.O.; Lupwayi, N.Z.; Rice, W.A.; Zentner, R.P.Item Microbial response to amendment of an eroded brown loamy sand with an oily waste sludge(1999-02-25) Hanson, K.G.; Biederbeck, V.O.; Selles, F.; James, D.C.; Fonstad, T.A.Item Present and potential future nitrogen gains from legumes in major Soil Zones of the prairies(1996-02-22) Biederbeck, V.O.; Rice, W.A.; van Kessel, C.; Bailey, L.D.; Huffman, E.C.Two developments have enabled us to realistically estimate N, fixation and N credits from legume crops across the prairies: one is computerized processing of Statistics Canada’s Census of Agriculture crop data by Soil Climatic Zones (SCZ) rather than provincial borders; the other is availability of reliable field 15N data on N fixation (% Ndfa) for various legumes and on partitioning of N (PTN) into harvested and residual parts. Total N fixation for each legume and SCZ was computed on the basis of crop area and SCZ average yields, adjusted for abnormal precipitation, and then multiplied with crop-specific Ndfa and PTN factors. Future legume cropping and N gains were 'guesstimated' according to the most likely crop sequences for various SCZs to be in use by the year 2005. Bctwcen 1991 and 1994 legume hcctaragc increased 69%, due mainly to more pulse cropping, to a total of 2.4 million and is expected to reach 5.5 million by 2005. Dcspitc the increased pulse cropping, 85% of total N fixation in 1994 occurred still in the northern parklands and was overwhelmingly due to forage legumes. The average fixation rate was 104 kg/ha and the total 250 million kg N fixed is equal to 24% of all fertilizer N used in 1994 on 25 million ha of Prairie cropland. In comparison with recent fertilizer N costs the present legume N fixation can be valued at $220 million. Total N credit for 1994 was calculated to be 62 million kg N which is equal to 1/4 of total N fixation and suggests an average net gain of 26 kg N/ha of legume crop, although these amounts vary widely with legume type. Our N credit estimates ranged from a low of 0 kg N/ha for colored beans, to 9.4 for lentils, 18.1 for peas, 36.4 for forage hay legumes and a high of 65.4 kg N/ha for forage seed legumes. Through combination of the N credit effect with crop substitution and ‘rotation’ effects, the inclusion of forage, grain or green manure legumes in rotations can effect substantial energy savings for Prairie cropping systems. With continued expansion of legume crops and partial adoption of fallow replacement green manuring, N fixation is projected to total around 550 million kg N by 2005 with a residual N credit of about 190 million kg, indicating an average net gain of 35 kg N/ha. The N gains from legume cropping are forecast to provide most of the N required for reasonable yields by a following cereal or oilseed crop.Item Seasonal changes in soil biochemical characteristics as influenced by crop rotations and fertilizers(1996-02-22) Campbell, C.A.; Wen, G.; Biederbeck, V.O.; Lafond, G.P.; Zentner, R.P.; Schoenau, J.J.Item Using oil industry waste effectively to improve an eroded loamy sand(2000-02-22) Biederbeck, V.O.; Hanson, K.G.; Selles, F.; Schoenau, J.J.; Fonstad, T.A.; Kozak, L.M.; Kambeitz, B.As depletion of the easily recoverable oil reserves in western Canada accelerates, the volumes of waste generated during heavy oil production and processing are steadily increasing. The 600 million litres of heavy oil produced in 1998 accounted for 40% of total oil production, i.e. all across Canada plus offshore. The safe disposal of heavy oil wastes became an environmental issue when the conventional practice of ‘road oiling’ for dust suppression on rural roads could no longer accommodate the growing waste volumes (Biederbeck et al. 1993). We propose that agriculture may provide effective solutions for some oily waste disposal problems by utilizing such organic C-rich wastes to amend nearby areas of marginally productive cropland. Cultivated land on the Prairies includes >3 million ha of sandy soils (>50% sand) that are highly susceptible to degradation by wind and water erosion and are low in organic matter and productivity. Much of this marginal cropland could benefit from improvements in soil structure and humus content that can be realized through incorporation of organic, including petro-type, wastes (Biederbeck et al. 1997). Consequently, we conducted, with support from AFIF, a field experiment on a windy ridge at Richmound, SK to: (i) assess the impact of soil incorporation of a heavy oil processing sludge on soil and groundwater quality and on crop production, and (ii) generate benchmark data needed by regulatory agencies to develop guidelines for future use of suitable hydrocarbon wastes in an environmentally safe and agronomically beneficial manner on sandy cropland in Saskatchewan and Alberta.