bluuebunny/crossref_metadata_2025 huggingface dataset:
The Biology of Canadian Weeds. 137. Brassica napus L. and B. rapa L.
Authors: Gulden R. H. , Warwick S. I. , Thomas A. G.
Published: April 2011

Brassica napus and B. rapa are native to Eurasia. In Canada, these species are commonly referred to as volunteer canola, while feral populations of B. rapa are referred to as birdrape. Brassica napus and B. rapa have been grown commercially for their seed oil content in western Canada since the middle of the last century and volunteer populations are common in fields. Escaped populations of both species are also found along roadways, railways and in waste areas; however, only B. rapa is known to have naturalized, self-sustaining feral populations in these habitats in eastern Canada. Despite these escaped and feral populations, B. napus and B. rapa are mainly a concern in agricultural fields where their combined relative abundance has increased over the past few decades. In the mid 1990s, herbicide-resistant genotypes of B. napus were released for commercial production. Herbicide-resistance and the stacking of genes in volunteer populations conferring resistance to multiple herbicides have contributed to increased difficulties in controlling volunteer B. napus in some crops. However, yield loss resulting from volunteer populations is not well documented in Canada. Key words: Brassica napus, Brassica rapa, herbicide resistance, transgene escape, volunteer canola, weed biology
Characterization of fitness traits in thickspike wheatgrass
Authors: Robins J. G. , Jensen K. B.
Published: April 2011

Poor seed production and stand establishment are limitations to the use of thickspike wheatgrass [Elymus lanceolatus (Scribn. & J.G. Sm.) Gould] in rangeland re-vegetation projects. This study assessed the heritability of seed production, rhizome proliferation, and biomass production and genotypic correlations among these traits in a population of half-sib thickspike wheatgrass families at a site near Nephi, UT, USA during 2005 and 2006. Heritability estimates were ~ 0.6 for seed production and rhizome spread, but non-significant for biomass production. Genotypic correlations among the traits were all low or non-significant. Key words: Biomass production, genotypic correlation, heritability, rhizome, seed production, thickspike wheatgrass
Vegetative establishment of Kura clover
Authors: Sheaffer C. C. , Mathison R. D. , Seguin P.
Published: April 2011

Kura clover (Trifolium ambiguum M. Bieb.) is a rhizomatous perennial legume that is often challenging to establish from seed. Our objectives were to evaluate the effect of planting date (early April, late April, and mid-May), plant material (rhizomes and rhizomes with buds), and rhizome planting density (11, 44, and 178 plants m-2) on establishment of Kura clover. Establishment of the clover was enhanced by early April planting using rhizomes with buds. Kura clover populations increased with increased rhizome planting densities. Establishment of Kura clover at a rhizome density of 178 rhizome m-2 has the potential to provide yield and stands similar to broadcast seeding. Key words: Kura Clover (Trifolium ambiguum M. Bieb.), vegetative propagation
Empirical verification of heterogeneous DNA fragments generated from wheat genome-specific SSR primers
Authors: Chen Qijiao , Zhang Lianquan , Yuan Zhongwei , Yan Zehong , Zheng Youliang , Sun Genlou , Liu Dengcai
Published: April 2011

Due to the high polymorphisms between synthetic hexaploid wheat (SHW) and common wheat, SHW has been widely used in genetic studies. The transferability of simple sequence repeats (SSR) among common wheat and its donor species, Triticum turgidum and Aegilops tauschii, and their SHW suggested the possibility that some SSRs, specific for a single locus in common wheat, might appear in two or more loci in SHWs. This is an important genetic issue when using synthetic hexaploid wheat population and SSR for mapping. However, it is largely ignored and never empirically well verified. The present study addressed this issue by using the well-studied SSR marker Xgwm261 as an example. The Xgwm261 produced a 192 bp fragment specific to chromosome 2D in common wheat Chinese Spring, but generated a 176 bp fragment in the D genome of Ae. tauschii AS60. Chromosomal location and DNA sequence data revealed that the176 bp fragment also donated by 2B chromosome of durum wheat Langdon. These results indicated that although a single 176 bp fragment was appeared in synthetic hexaploid wheat Syn-SAU-5 between Langdon and AS60, the fragment contained two different loci, one from chromosome 2D of AS60 and the other from 2B of Langdon which were confirmed by the segregating analysis of SSR Xgwm261 in 185 plants from a F2 population between Syn-SAU-5 and Chinese Spring. If Xgwm261 in Syn-SAU-5 was considered as a single locus in genetic analysis, distorted segregation or incorrect conclusions would be yielded. A proposed strategy to avoid this problem is to include SHW’s parental T. turgidum and Ae. tauschii in SSR analysis as control for polymorphism detection. Key words: Synthetic hexaploid wheat, microsatellite, segregation distortion, Xgwm261, transferability
Effect of forest harvesting and slash piling on microbial biomass and respiration in Newfoundland boreal forests
Authors: Moroni Martin T , Carter Paul Q , Strickland Dean W , Makeschin Franz , Parkinson Don-Roger , Kahnt Linda
Published: April 2011

Clearcutting Newfoundland boreal forests significantly reduced organic layer fungal and total microbial biomass in clearcut areas with and without slash cover, compared with forested plots. However, aerobically incubated respiration rates were highest in organic layers from clearcut areas under slash, intermediate under forests, and lowest from clearcut areas without slash. Key words: Carbon, ergosterol, fumigationextraction, fungal biomass, harvest slash, nitrogen
Evaluation of two process-based models to estimate soil N2O emissions in Eastern Canada
Authors: Smith W N , Grant B B , Desjardins R L , Rochette P. , Drury C F , Li C.
Published: April 2011

Process-based models play an important role in the estimation of soil N2O emissions from regions with contrasting soil and climatic conditions. A study was performed to evaluate the ability of two process-based models, DAYCENT and DNDC, to estimate N2O emissions, soil nitrate- and ammonium-N levels, as well as soil temperature and water content. The measurement sites included a maize crop fertilized with pig slurry (Quebec) and a wheat-maize-soybean rotation as part of a tillage-fertilizer experiment (Ontario). At the Quebec site, both models accurately simulated soil temperature with an average relative error (ARE) ranging from 0 to 2%. The models underpredicted soil temperature at the Ontario site with ARE from −5 to −7% for DNDC and from −5 to −13% for DAYCENT. Both models underestimated soil water content particularly during the growing season. The DNDC model accurately predicted average seasonal N2O emissions across treatments at both sites whereas the DAYCENT model underpredicted N2O emissions by 32 to 58% for all treatments excluding the fertilizer treatment at the Quebec site. Both models had difficulty in simulating the timing of individual emission events. The hydrology and nitrogen transformation routines need to be improved in both models before further enhancements are made to the trace gas routines. Key words: Nitrous oxide, process-based model, DNDC, greenhouse gas emissions, soil
Comparison of three simple field methods for ammonia volatilization from manure
Authors: Smith E. , Gordon R. , Bourque C. , Campbell A.
Published: April 2011

Land application of swine manure can result in a loss of nitrogen (N) through ammonia (NH3) volatilization. Accurate NH3 loss assessments are essential to support the development of regional and global emission factors and identify best management strategies for reducing losses. The objectives of this study were to simultaneously assess the reliability and applicability of three simple NH3 flux measurement techniques and their effectiveness and usefulness for the measurement of emissions from surface-applied swine manure. Ammonia losses from two chamber systems were compared: (i) static and (ii) wind tunnel chamber, as well as the (iii) micrometeorological theoretical profile shape (TPS) method. A series of field tests was performed at the Agriculture and Agri-Food Canada (AAFC) Research Farm in Harrington, Prince Edward Island (PE) on a sandy loam, stubble field that was surface applied with 100 kg NH4-N ha-1 of liquid swine manure. After application the three NH3 emission techniques were established and measurements were performed over a 5-d period. Ammonia losses from the wind tunnels were comparable with those from the TPS method. The static chambers were found to underestimate NH3 emissions (by ~95–99%), compared with both the wind tunnel and TPS methods. It is therefore recommended that either the TPS or wind tunnel approaches be used to more accurately quantify NH3 losses for field systems. Key words: Ammonia volatilization, flux measurements, swine manure, micrometeorology, static chambers, wind tunnel
Nitrogen transformations and ammonia volatilization losses from 15N-urea as affected by the co-application of composted pig manure
Authors: Choi Woo-Jung , Chang Scott X , Kwak Jin-Hyeob , Jung Jae-Woon , Lim Sang-Sun , Yoon Kwang-Sik , Choi Soo-Myung
Published: April 2011

Co-application of composted manure (compost) and urea is considered an environment-friendly fertilization practice; however, the high urease activity in compost may stimulate NH3 volatilization and cause N loss from co-applied urea. To test the above hypothesis, we investigated the fate of urea co-applied with compost in a loam-textured soil through two laboratory incubation experiments. Urea (150 mg N kg-1) was co-applied with 0, 4.9, 9.8, and 14.6 g of compost (oven-dry basis) kg-1 of soil, designated as treatments UC0, UC1, UC2, and UC3, respectively. Co-application of compost and urea enhanced urea hydrolysis and increased the 1st order rate constant of urea hydrolysis from 0.047 h-1 in the UC0 to 0.139 h-1 in the UC3 treatments. Soil pH increased from 7.0 for UC0 to 7.6 for UC3, leading to greater NH3 volatilization (up to two times more) in the soils receiving 9.8 g kg-1 or more of compost. Compost co-application also increased the immobilization of urea-derived N, probably because the organic matter added in compost stimulated microbial growth or NH4+ fixation. Between 15 and 17% of urea-N was not recovered at the end of the incubation, but there was no difference in N loss among the treatments resulting from the contrasting effects (NH3 volatilization vs. NH4+ immobilization) of compost on N losses. Our results clearly show that application of compost with high urease activity increases NH3 volatilization loss of N from the co-applied urea, but the total amount of N lost is also affected by immobilization of NH4+ by the organic matter added to the soil through the applied compost. Key words: Ammonia volatilization, nitrogen dynamics, nitrogen-15 recovery, organic carbon, urease activity
Soil water regimes of annual and perennial forages during drought years in the Aspen Parkland ecoregion of Alberta
Authors: Bradshaw D L , Chanasyk D S , Baron V S , Naeth M A
Published: April 2011

Periodic and prolonged drought can be devastating to pasture production, which increases the financial risk for grazing enterprises. A study was conducted during 2 drought years (2002 and 2003) in the aspen parkland at Lacombe, Alberta, Canada, to compare the soil water regime of meadow bromegrass (Bromus riparius Rhem.), alfalfa (Medicago sativa L.), and annual [oat (Avena sativa L.) and winter triticale (X Triticosecale Wittmack)] pastures with a naturalized, old grass pasture consisting of quackgrass (Elytrigia repens L.), smooth bromegrass (Bromus inermis Leyss.), and Kentucky bluegrass (Poa partensis L.). The pasture soil was an Orthic Black Chernozem of fine sandy loam to loam texture. Soil water measurements were conducted between May and October over 2 yr using a neutron scattering hydroprobe to a depth of 1.6 m. Annual and meadow bromegrass had similar and highest cumulative and volumetric water contents and old grass had the lowest. All pastures tended to use all water available by the end of the season, but annual pasture had higher soil water in spring and early summer due to delayed canopy development. Soil in the upper 40 cm of annual and meadow bromegrass pastures was at wilting point 5 to 10% of all measurement times compared with 65 to 71% of measurement times for alfalfa and old grass. Annual and meadow bromegrass pastures did not extract water below 1.2 m, while the other pastures did, and on the basis of soil water regimes, appear to be lower risk options than status quo old grass and alfalfa pastures during drought. Key words: Soil water, forages, rotational grazing, drought, wilting point, field capacity
Effects of different soil management practices on soil free-living nematode community structure, Eastern China
Authors: Dong Daofeng , Chen Yun-Feng , Steinberger Yosef , Cao Zhi-Ping
Published: April 2011

An investigation was conducted in a Shouguang agroecosystem, Shandong Province, Eastern China, in order to determine the long-term (10–15 yr) disturbances of three different agricultural management practices. In this study, the main focus was on free-living soil nematodes, as a tool which will help differentiate between treatments according to their sensitivity to physical, chemical, and biota composition. In this study, three treatments were implemented in each of a total of four investigated sites: greenhouses, conventional farmlands, and fallows. Diversity, maturity (MI) and weight indices were used to assess the nematode community. The results indicated that greenhouses have a lower richness (SR), diversity, modified maturity index (ΣMI), modified maturity index for all nematodes with c-p = 2–5 [ΣMI (2–5)], plant parasite index (PPI), PPI/MI values, and fungi-feeding/bacteria-feeding (F/B) ratio, as well as lower basal index (BI) and channel index (CI) and higher dominance. These results elucidated the difference between the three treatments, where the greenhouses were an enriched disturbed system compared with the other treatments and were dominated by bacterivorous nematodes, the fallows were a relatively infertile and stable system dominated by plant parasites, and the conventional farmlands can be positioned between the above two treatments. Key words: Agricultural management, nematode, disturbance, indices
Modelling nitrogen leaching in Prince Edward Island under climate change scenarios
Authors: De Jong R. , Qian B. , Yang J Y
Published: April 2011

Projected climate change in Canada and its impact on crop yield and production have been studied, but the impacts on soil and water quality are less well known. The objective of this study was to model and evaluate the potential impacts of climate change on soil nitrogen (N) leaching in Prince Edward Island. Residual soil nitrogen (RSN), the quantity of inorganic soil N at the time of harvest, was calculated from an annual N budget, based on Census of Agriculture data. RSN was "added" to the soil in the fall and subject to leaching until the start of the next growing season. Water and N movement in and through the soil were calculated with a modified version of the Versatile Soil Moisture Budget. The provincial averages of RSN and N leaching under historic (1971–2000) climate and management conditions were calculated to be 30.8 kg N ha-1 and 27.9 kg N ha-1, i.e. , 91% of the RSN was lost via leaching. With no changes in agricultural practices, N leaching under four climate change (2040–2069) scenarios remained very similar (± 1%) to that simulated under historic climatic conditions. With agricultural intensification, in response to climate change and economic conditions, RSN levels increased to 35.7 kg N ha-1 and estimates of soil N leaching increased by 5 to 30% beyond historic levels. Key words: Residual soil nitrogen, versatile soil moisture budget, climate change impacts, agricultural adaptation, water contamination
Effect of municipal and pulp mill effluents on the chemical properties and nutrient status of a coarse-textured Brunisol in a growth chamber
Authors: Patterson S L , Chanasyk D S , Naeth M A , Mapfumo E.
Published: April 2011

Maximizing productive use and minimizing the environmental impacts of effluents require research on application rates. This study evaluated the effect of effluents from a Kraft pulp mill [a final effluent (KPME) and a waste activated sludge (WAS)], a municipality (ME) and tap water (TPW) applied at rates of 1.5, 3 and 6 mm d-1 on reed canarygrass (Phalaris arundinacea L. cv. Vantage) and hybrid poplar (Populus deltoides × P. petrowskyana var. Walker). The two pulp mill effluents significantly increased soluble soil SO4, Na and Cl. Soil solution electrical conductivity (EC) and sodium adsorption ratio (SAR) increased with pulp mill effluents compared with ME and TPW. Soil solution SAR increased from less than 1 to a range of 2.7 to 4.0 for the municipal effluent and 8.4 to 14.0 for the two pulp mill effluents. Soil solution EC increased from 1.1 to 2.3 dS m-1 to a range of 1.8 to 3.4 dS m-1 for municipal effluent and 5.1 to 6.1 dS m-1 as a result of pulp mill effluent applications. Under reed canarygrass, soils had lower concentrations of cations and anions than those under hybrid poplar, suggesting crop uptake and leaching. Thus, salt loadings of soils must be considered when determining application rates of effluents for irrigation. Key words: Electrical conductivity, hybrid poplar, effluent irrigation, sodium adsorption ratio
Seasonal nitrate levels in the soil solution of an organic pasture managed for nature conservation
Authors: Bouman O T
Published: April 2011

Extensive management of pastures is considered as an option to enhance nature conservation in agricultural landscapes. Partial reduction of the grazing frequency from four to two rotations and discontinuing the tending of sod and sward have been tested for extensive management of a mixed pasture at the Nova Scotia College of Agriculture in Truro since 2004. It is not well known how extensification affects the N cycle of organic pastures without mineral fertilizer or manure applications. Moisture and temperature of the topsoil and nitrate content of the leachate extracted with ceramic suction cups at 0.5 m depth were monitored prior to grazing and during sward regrowth in the first and second rotation in spring of 2005 and 2006. In each year, more than 75 % of all samples contained less than 2.5 mg NO3-N L-1. A significant seasonal nitrate dynamic suggests that plant N uptake reduces nitrate leaching in the first rotation, while soil biological activity increases N supply due to soil warming in excess of plant uptake, thus raising the nitrate level in the second rotation. Extensification significantly reduced soil temperature with a concomitant albeit small decrease of nitrate levels in the soil leachate. The pasture cycled nitrogen very tightly with little room for leakages as a result of imposed treatments during the spring season. Key words: Pasture, organic, temperature, nitrogen, leaching
Nutrient and trace element changes during manure composting at four southern Alberta feedlots
Authors: Larney Francis J , Olson Andrew F , DeMaere Paul R , Handerek Brian P , Tovell Bonnie C
Published: April 2011

Interest in composting as a means of handling the large volumes of manure generated by southern Alberta beef cattle feedlots has increased in recent years. We measured concentrations of 19 elements (C, N, P, Na, Ca, Mg, K, S, Al, Fe, Mn, Zn, Cu, Cr, Ni, P b , Co, Mo and Cd) in fresh manure, interim-composted manure and finished compost, at four commercial feedlots. Thirteen elements showed increased concentrations (by 26–73%) with composting, while four (C, Cr, Ni and Mo) showed concentration declines. Of the remaining two, the trend in N concentration was feedlot dependent, while Pb was largely unaffected. Total mass loss during composting averaged 54%, which represents a substantial decrease in haulage requirements. Overall average C losses were 61% and N losses 33%. On an equivalent wet weight basis ("as-is"), composting allowed haulage of 56% more N, 84% more P, 91% more Zn, and 76% more Cu than fresh manure, which is advantageous in terms of moving nutrients and trace elements from high to low-loading areas. Our study quantifies nutrient and trace element behaviour during composting, provides comparative data with fresh manure, and helps tailor end-use decisions (e.g., haulage distance, application rate) on the compost product. Key words: Manure, compost, beef cattle feedlots, nutrients, trace elements
Toxicity thresholds for oat (Avena sativa L.) grown in Ni-impacted agricultural soils near Port Colborne, Ontario, Canada
Authors: Dan Tereza , Hale Beverley , Johnson Dallas , Conard Bruce , Stiebel Bill , Veska Eric
Published: April 2011

This study established Ni phytotoxicity thresholds for oat (Avena sativa L.) in four soil types, each created by blending a low and a high Ni soil, to generate a range of concentrations. The first quartile effective concentration (EC25) for soil and shoot tissue Ni concentration and reduction in shoot dry weight (DW) was determined using a Weibull function. The EC25 (for soil Ni concentration) was 1350, 1950, 1880 and > 2400 mg Ni kg-1 soil, for sand, till clay, heavy clay and organic muck, respectively. The EC25 (for shoot Ni concentration) was 71, 21, 52 and > 35 mg Ni kg-1 shoot DW, for sand, till clay, heavy clay and organic muck, respectively. Total soil Ni concentration, soil pH and soil cation exchange capacity (CEC) accounted for 70% of the variation of Ni accumulation in tissue when the data for all four of the soils were combined; this was similar to the amount of variation accounted for by fitting Ni concentration in tissue to ammonium oxalate extractable soil Ni. Manganese deficiency may have impaired plant growth at higher soil Ni concentrations in the clay soils. Speciation of Ni was similar in all soils studied, and the relationship between Ni concentrations in soil and in tissue was less closely related to chemically extracted soil Ni than it was to a combination of total soil Ni, soil pH and CEC. These are the soil characteristics known to influence both equilibrium among metal species in soil solution, and uptake of cations by plants. Key words: Avena sativa L., EC25, Ni, oat
Bromide redistribution as influenced by landscape morphology and pedogenic properties in a variable glacial till landscape: A qualitative examination
Authors: Whetter D A , Bullock P R , Fuller L G
Published: April 2011

Redistribution of water and associated solutes in undulating to hummocky landscapes affects crop yield via losses of valuable nutrients and negatively impacts groundwater quality. The objective of this study was to determine the influence of qualitative soil-landscape complexes on vertical and lateral redistribution of solutes in a variable glacial till landscape under zero tillage agricultural management by employing a bromide tracer. Tracer plots were established in the fall of 1999 within three sites comprising three representative soil-slope associations. Values of soil development indicators (A horizon thickness, solum thickness, depth to CaCO3, profile development index and organic carbon) generally increased from crest to midslope to depression. Further to this, the occurrence and thickness of eluvial and illuvial horizons increased from crest to midslope to depression. Well-developed, clay-coated blocky Bt horizons with vertical cracking and overlying Ae horizons in depressions appeared to have favoured rapid, downward vertical bromide redistribution. Crest positions were the least anisotropic and vertical redistribution was more important than lateral redistribution at this position. A combination of topographic and pedologic factors resulted in more lateral redistribution at the midslope position relative to crests and depressions. Bromide recovery rates in the top 60 cm of the soil profile indicated that most of the recovered bromide remained within that depth following spring runoff, but had mostly leached below that depth after the growing season, particularly at the depression position. Low bromide recovery rates in the top 30 cm following spring runoff, indicated that reduced availability of fall-applied nutrients for early crop growth could be expected at crest and depression positions following spring runoff. Bromide redistribution was important during both spring recharge and over the growing season at the depression position. Bromide movement below crop rooting depths and into shallow groundwater sources provides evidence that fall-applied nutrients can enter groundwater following both spring melt and growing season runoff in depressional landscape positions, especially in recharge areas. Management practices to reduce over-application of soluble nutrients and surface water accumulation, or both, in depressional areas may be an effective means to lower the risk of groundwater contamination with soluble nutrients without jeopardizing crop yield potential across the majority of the landscape positions in undulating to hummocky glacial till terrain. Key words: Solute redistribution, bromide tracer, soil properties, topography, landscape
Effect of preceding crop management on crop yield and soil properties assessed using standard erosion plots
Authors: Edwards Linnell , Burney Jack
Published: April 2011

Using blanket crops of ryegrass and under-seeded barley (with red clover) super-imposed on standard erosion plots just coming out of potatoes, this study assessed the influence of preceding soil-and-crop management treatments viz., straw mulch, compost and liquid pig manure (LPM) (antecedent input variables) on crop yield, soil physical properties and erosion amounts (subsequent response variables). There were no significant carry-over effects on erosion amounts, and effects on yield were limited to red clover. However, soil properties (reflecting compactability, structure and soil water retention) were affected throughout - showing general improvements of up to 46%. Thus, soil water content (SWC) was 9.4% greater with compost amendment than it was for the control. SWC with compost was also greater than it was with straw mulch by 7.9%. Soil organic matter (SOM) showed a 13% increase with compost amendment relative to the control. SOM also showed a 5% increase with compost relative to straw mulch. Compost uniquely gave yield increases in red clover, double that of the control, while LPM gave unique increases in hydraulic conductivity and SOM under red clover to the extent of 60 and 24% (respectively) relative to the control. Key words: Soil physical properties, soil erosion, organic amendments, potatoes, barley, red clover
Soil organic carbon and nitrogen pools as affected by compost applicationsto a sandy-loam soil in Québec
Authors: Whalen Joann K , Benslim Hicham , Jiao You , Sey Benjamin K
Published: April 2011

Compost contributes plant-available nutrients for crop production and adds partially decomposed carbon (C) to the soil organic carbon (SOC) pool. The effect of compost applications and other agricultural practices on SOC and total nitrogen (N) pools was determined in a sandy-loam Humic Gleysol at the Research Farm of McGill University, Ste-Anne-de-Bellevue, Quebec. Experimental plots with continuous silage corn (Zea mays L.) and silage corn-soybean (Glycine max L. Merr.) production were under conventional tillage (CT) or no-tillage (NT) management. Composted cattle manure was applied each spring at rates of 0, 5, 10 and 15 Mg (dry weight) ha-1 and supplemental NPK fertilizers were added to meet crop requirements. The C input from crop residues was affected by tillage, crop rotations and compost application, but differences in the SOC and total N pools were due to compost applications. After 5 yr, compost-amended plots gained 1.35 to 2.02 Mg C ha-1 yr-1 in the SOC pool and 0.18 to 0.24 Mg N ha-1 yr-1 in the total N pool, as compared with initial pool sizes when the experiment was initiated. These gains in SOC and total N were achieved with agronomic rates of compost and supplemental NPK fertilizers, selected to match the phosphorus requirements of silage corn. Such judicious use of compost has the potential to increase the SOC and total N pools in agroecosystems under annual crop production. Key words: Composted cattle manure, corn silage, mineral fertilizer, plant-available nitrogen, soil organic carbon
Ammonia volatilization following application of pig slurry increases with slurry interception by grass foliage
Authors: Rochette P. , Guilmette D. , Chantigny M H , Angers D A , MacDonald J D , Bertrand N. , Parent L -É , Côté D. , Gasser M O
Published: April 2011

Efficient liquid manure application systems that minimize ammonia volatilization are required for use on perennial forage grasses. Ammonia volatilization was monitored using wind tunnels for 10 d after three pig slurry applications using four boom-mounted applicators: a broadcast splash-plate system, a trailing-shoe system and a drag-hose system with and without previous soil aeration. Average losses of 32, 20 and 15% of the total ammonia-N (TAN) applied to plots were observed for the splash-plate, the trailing-shoe and the drag-hose systems, respectively. The grass canopy intercepted, on average, 14% of pig slurry TAN using the splash-plate system compared with 4% for the trailing-shoe and 5% for the drag-hose systems. Reductions in canopy interception explained 58% of differences in volatilization rates among the application systems. On two of three application dates, NH3 volatilization was lower using the drag-hose than the trailing-shoe system. This was attributed to the sealing of the soil surface by the passage of the trailing-shoe, which decreased slurry infiltration rate. Ammonia volatilization was not reduced by soil aeration prior to slurry application using a drag-hose system likely because aeration did not increase slurry infiltration into the soil. Producers could be advised to reduce volatilization losses by using a simple drag-hose system to avoid application of slurry to leaf canopies. Key words: Ammonia volatilization, liquid hog manure, pig slurry, application method, ammonium
Emissions of nitrous oxide after application of dairy slurry on bare soil and perennial grass in a maritime climate
Authors: Bhandral R. , Bittman S. , Kowalenko C G , Friesen A. , Hunt D E
Published: April 2011

Over half the slurry manure produced on dairy farms in the high-rainfall, coastal region of British Columbia (BC), Washington State and northern Oregon is applied from mid-February to early May. This study was conducted to compare the emissions of nitrous oxide (N2O) after manure application during this period on perennial forage grass or winter fallow land. The experimental site soil was moderately well- to well-drained medium-textured river deposit of the Monroe series. Treatments consisted of liquid dairy manure applied either at 270 (Early) or 450 (Late) Tsum (accumulation of average air temperatures above 0ºC from Jan. 01) on bare land or a perennial stand of tall fescue (Festuca arundinacea Schreb.) at a rate of 55.5 m3 ha-1 giving a total ammoniacal N (TAN) loading of 100 and 111 kg ha-1 in 2001 and 2002, respectively. An additional grass treatment consisted of split applications (Split) of manure at half the rate on each of the two application dates. Untreated (Control) bare and grass treatments were also included. Emissions were monitored for 105 d (28 Feb. to 12 Jun.) in 2001 and 121 d (26 Feb. to 26 Jun.) in 2002. Cumulative N2O emissions, during the measurement period (averaged over manure application times), from manured bare soil were 2.19 and 2.74 kg N ha-1 for 2001 and 2002, respectively and those from manured grass treatment were 0.21 and 0.58 kg N ha-1 for 2001 and 2002, respectively. Time of application altered seasonal emission pattern, but effect on total emission was inconsistent, probably due to conflicting effects of temperature and moisture. Significant differences in soil NO3-N levels between the grass and the bare soil treatments may explain the differences in N2O emission. Key words: Mineral N, herbage, water-filled pore space, winter fallow, Festuca arundinacea Schreb
Comparison of four prewetting techniques in wet aggregate stability determination
Authors: Dickson E. L. , Rasiah V. , Groenevelt P. H.
Published: April 2011

Variabilities in measured values of wet aggregate stability (WAS) of replicate samples of treatment exceeding that between treatments can create problems in interpreting treatment effects. The variabilities in WAS of replicate samples of treatment can be minimized by subjecting soil aggregates to a high vacuum fast prewetting technique. However, this technique is laborious and time consuming. In this paper the effect of four prewetting techniques: (1) and (2) high vacuum fast (HVFW) and slow (HVSW) wetting; (3) and (4) no vacuum (atmospheric) fast (NVFW) and slow wetting (NVSW) on the variations in WAS and coefficient of variation (CV) of WAS are reported. The measured values in WAS and CV of WAS for each soil varied with wetting rate and/or gas pressure used. The highest variation in WAS was found with NVFW, HVFW, NVSW and HVSW, respectively. For three out of four soils, the CV of WAS for NVSW technique was less than 2%, which was similar to that obtained under HVFW technique. Compared to HVFW technique, NVSW technique is simple, less laborious and less time consuming. Key words: Wet aggregate stability, prewetting techniques, vacuum wetting.
Evaluation of soil sampling schemes for geostatistical analyses: A case study for soil bulk density
Authors: Entz T. , Chang C.
Published: April 2011

Sixteen soil sampling schemes were evaluated in a case study using geostatistical analyses to determine their impact on directional sample variograms and kriging. Soil bulk density measurements for each sampling scheme were obtained from an intensively sampled grid, and kriging was used to estimate the bulk densities not included in the sampling scheme. The kriged bulk density estimates for all sampling schemes were verified using a minimum of 6168 observed values. Grid sampling for this study required more samples than stratified random sampling and the stratified-grid sampling schemes, but the accuracy of the kriged estimates was comparable for all sampling schemes. Key words: Kriging, variogram, soil density
Short-term and residual contribution of selected elemental S fertilizers to the S fertility of two Luvisolic soils
Authors: Janzen H. H. , Karamanos R. E.
Published: April 2011

A 3-yr program was carried out in central Alberta to evaluate the immediate and residual contributions of various fertilizer sulfur sources to the pool of plant-available sulfate in soil. Three elemental sulfur products, a finely-divided suspension and two elemental sulfur + bentonite products, and ammonium sulfate were applied at various rates (0–120 kg S ha−1) in factorial arrangement with various supplemental rates of sulfate (0–40 kg S ha−1). Temporal patterns of plant-available sulfur release varied significantly among fertilizer S sources, suggesting different agronomic niches for the various forms. While ammonium sulfate and the finely divided S suspension provided almost immediate correction of S deficiency, the S-bentonite products appeared be better suited to long-term maintenance of soil S fertility. The relatively slow release of plant-available S in the latter products was attributed to ineffective dispersion of the products in the soil. These slow-release characteristics need to be considered in the formulation of fertilizer recommendations on soils previously amended with S-bentonite products. Key words: Oxidation, plant availability, residual effect, S fertilizers
Crop response to elemental sulfur fertilizers in central Alberta
Authors: Karamanos R. E. , Janzen H. H.
Published: April 2011

Sulfur deficiency has become a widespread limitation to crop production in western Canada. A variety of S sources are commercially available to alleviate these deficiencies but not all are equally effective. Three elemental S products (a finely-divided suspension and two elemental S + bentonite) and ammonium sulfate were compared over a 3-yr period in central Alberta. These products were applied to barley and canola at various rates (0–120 kg S ha−1) in a factorial arrangement with various supplemental rates of sulfate-S (0–40 kg ha−1) in two experiments Fertilizers affording effective and reliable alleviation of S deficiency in the year of application included sulfate forms and finely-divided elemental S products that can be readily mixed into the soil. The residual benefits of the various fertilizer products examined appeared to be comparable despite large differences in short-term availability. The absence of appreciable residual advantage of slow-release elemental S products was attributed to the short duration of S assimilation by canola and barley and the susceptibility to leaching of S oxidized after that period. Key words: Barley, canola, residual, rotation, S fertilizer, uptake, yield
Titratable acidity of organo-mineral complexes as affected by mode of preparation, drying and stability of aggregates
Authors: Buondonno A. , Violante A.
Published: April 2011

Hydroxy-aluminum-tannate-montomorillonite complexes, which were prepared at pH 4.5 by different addition sequences of hydroxy-Al, tannic acid and montomorillonite showed distinct differences in titratable acidity both before and after drying. Titratable acidity of the complexes depended on the feed rate of the base and on the presence and nature of neutral salts (KCl or CaCl2). The organo-mineral complexes showed acidity values in CaCl2 substantially higher than those determined in KCl or in water (in the order listed), probably because many weak acidic groups released H+ ions by complexation (tannate molecules) or adsorption (OH-Al-ions) of Ca2+ ions. The hydroxy-Al-tannate-montmorillonite complexes, which were washed differently (dialyzed or ultrafiltered) and dried (freeze-dried or air-dried) also showed remarkably different titratable acidity. All the complexes usually showed much lower acidity values when air-dried than when freeze-dried. After sonification the titratable acidity values of all the complexes increased, but some air-dried samples, even after four sonification treatments, showed titratable acidity lower than that of the same freeze-dried complexes before sonification. Key words: Organo-mineral complexes, aluminum, titratable acidity, potentiometric titrations
Sorption and desorption of orthophosphate and pyrophosphate by mineral fractions of soils, goethite, and kaolinite
Authors: Al-Kanani T. , MacKenzie A. F.
Published: April 2011

Sorption-desorption reactions of orthophosphate (OP) and pyrophosphate (PP) were studied in two size fractions of Quebec soils (St. Bernard and Dalhousie) and minerals (goethite and kaolinite). Soil and mineral samples were fractionated into two separates (20.0–2.0 μm and 2.0–0.2 μm). The soils had similar mineral suites, but the St. Bernard have more vermiculite, chlorite, and quartz in the coarser fraction than the Dalhousie soil, perhaps an indication of different origin of parent material. Soil and goethite samples sorbed more OP than PP whereas kaolinite sorbed small but similar amounts of PP and OP. The PP and OP sorption was found to be significantly correlated with acid ammonium oxalate extractable Fe, but not with dithionite extractable Fe. Kaolinite desorbed similar amounts of OP and PP whereas more OP than PP was desorbed from soil and goethite samples. The degree of subsequent desorption seemed to be related to degree of sorption. The lack of similarity between sorption and desorption isotherms may indicate that sorption isotherms are of limited value in P fertilizer studies especially with regard to the estimation of subsequent P release in fertilized soils. Smaller particle sizes and their larger specific surface area resulted in higher OP and PP sorption compared with the coarser particle sizes. For OP sorption, the Langmuir equation yielded the closest fit in comparison to Freundlich and Temkin equations; the Freundlich equation gave the closest fit for PP sorption data. The Langmuir equation failed to fit desorption data. Key words: Orthophosphate, pyrophosphate, sorption, desorption
Some cautions on the use of geographic information system (GIS) technology to integrate soil site and area data
Authors: Zhou H. Z. , MacDonald K. B. , Moore A.
Published: April 2011

GIS are ideal software tools for managing spatially referenced data. While such systems offer tremendous opportunities for efficient integration of land resource data, certain types of data combination and analysis are not appropriate. Data from the Soil Landscapes of Canada (SLC) Map for Alberta, detailed soil sites and long-term climate stations are used to demonstrate the importance of this consideration. Key words: Geographic information systems, GIS, soil sites, soil map
The nature and origin of nodules in Podzolic soils from Alberta
Authors: Arocena J. M. , Pawluk S.
Published: April 2011

A common pedological feature in Podzols and Podzolic-like soils in the forest region of Hinton, Alberta is the presence of nodules in the Bf horizons with diameters of 1—20 cm. The nature of these nodules was investigated through physical, chemical, mineralogical and micromorphological examinations. Results showed that the nodule microstructure is mainly bridged-grain type compared to dominantly pellicular type for the soil matrixes. The basic building blocks are (a) coarse components (> 5 μm): quartz, feldspars mainly albite, pseudo sands, sand-sized chlorites and small quantities of anthophyllite, sillimanite, andalusite and lithogenic hematite; (b) fine components (< μm): phyllosilicates (mainly hydroxy interlayered vermiculite, kaolinite, vermiculite, and small amounts of chlorite), quartz and organic matter. Imogolite is present in the very fine clays. The similarity in the mineral suites and the porphyric related distribution pattern between the Bf horizons and the nodules indicate an authigenic origin for the nodules through an eluviation/illuviation process. Fungal hyphae provide a framework for nodule aggregation. In situ XRD determinations revealed that sand-sized Fe concretions are goethite alone or in association with hematite. The omnipresence of quartz in infillings, coatings and opaque coarse components was also evident. Key words: Micromorphology, related distribution pattern, in situ mineral determination
The relation between movement of subsurface water and gaseous methane in a basin bog with a novel instrument
Authors: Buttler A. J. , Dinel H. , Lévesque M. , Mathur S. P.
Published: April 2011

A tubular metallic probe was built. Water and gases released into the sample chamber of the probe from the 45- to 60-cm depth could be collected in 1-min segments without exposure of the peat surface in the hole to the atmosphere. The evolved gases were identified and concentrations measured by gas chromatography. The water movement into the hole was found to vary by 3 orders of magnitude, apparently depending on whether the probe pierced a significant pocket of trapped (occluded) methane, or was close to, or away from any such pocket. It was concluded that the instrument developed would be suitable for characterizing the occurrence and movement of the gas-fluid mixture in peatland layers which would facilitate the development of new or modified mathematical models of gas and water transmission in peatlands. The study also indicated that methane, but not carbon dioxide, is occluded in the gaseous phase in amounts significant enough to influence water movement. Key words: Water movement, methane, bog
Variabilité des sols et stratégie d'échantillonnage dans les études pédologiques détaillées de la plaine de Montréal
Authors: Nolin M. C. , Caillier M. J. , Wang C.
Published: April 2011

In order to estimate variability of soil information presented in detailed soil surveys of the Montreal lowlands area, more than 2000 samples were collected along stratified random transects in 133 mapping units. The coefficient of variation (CV) was used as variability criteria. Variability of selected soil characteristics of the plow layer was studied according to phases of surface texture. The CV of clay, silt, pH, CEC and exchangeable cations decrease with an increase in clay content. The CV of sand content follows the opposite direction. Four modes of deposition (marine, fluvial, till and estuarine) were compared according to the variability within taxon (soil series or variant) of soil characteristics of the A, B and C horizons. More samples are needed to estimate the population mean value with the same relative error and the same confidence level for soils developed in fluvial deposits than in those formed in marine sediments. At the 90% confidence level, the allocation of 15 samples per map unit allows one to estimate the population mean with a relative error ranging from 5 to 30% for most soils and variables studied. Quality standards are proposed for soil sampling in future soil survey projects. Key words: Soil variability, accuracy, sampling, taxon, mapping unit
Solubility and retention of phosphate in soils of the northwestern Canadian prairie
Authors: Soon Y. K.
Published: April 2011

Phosphate solubility and sorption characteristics of 39 agricultural soils in the northwestern Canadian Prairie were studied to gain insights into the retention of fertilizer P added to soil. The soils were mostly acidic with base saturation of 59–95%. The solubility of P as determined by the equilibrium P concentration and phosphoric acid potential was low and appeared to be controlled by sorption of phosphate by soil components. The mean equilibrium solution P concentration was 0.03 mg L−1. Phosphorus concentration in saturation extracts was about one order of magnitude higher, but would have included organic and colloidal P since P analysis in these extracts was done by ICP. Sorption capacity of P as determined by Langmuir isotherm was greater for the Dark Gray and Black soils and gleysols, i.e., soils with higher amounts of organic matter, than the Gray Luvisolic and Solodic soils by about 30%. Partial correlation showed that clay content, Al-organic matter complexes (AlOM) and amorphous iron oxide (FeOX) were significantly correlated with P sorption capacity. When both topsoils and subsoils were considered, clay content was the most important soil property influencing P sorption capacity, followed by AlOM and FeOX (standard partial regression coefficients, b′, of 0.47, 0.39 and 0.38, respectively). When only topsoils were considered, AlOM and FeOX became more important than clay content in influencing P sorption (b′ = 0.47, 0.47, and 0.33, respectively). Native P, estimated by oxalate and anion-resin extractions, was associated with the hydrous iron oxides only, although soil pH also affected the resin-extractable P fraction. Key words: P retention, solubility, Luvisols, solodic soils
Nascent aggregates in the rhizosphere of perennial ryegrass (Lolium perenne L.)
Authors: Dormaar J. F. , Foster R. C.
Published: April 2011

Since there is little information on compound particles in the size range 2–20 μm, the genesis of the initial stages of soil aggregation was examined by transmission electron microscopy on ultrathin sections of the rhizospheres of Lolium perenne L. grown in attapulgite. Since attapulgite contains neither microorganisms nor organic matter, microorganisms were added as a soil suspension and all the organic matter was supplied by the ryegrass roots. Clusters were formed de novo by accumulation of attapulgite particles on root gel, on root cell fragments, and on microbial extracellular polysaccharides. Microaggregates were formed by the fusion of attapulgite-coated bacteria, colonies and cell remnants. Aggregates persisted after the death of the microorganisms. Key words: Microaggregates, clusters, soil ultrastructure, rhizosphere, extracellular polysaccharides