bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies of Cu(II) in soil by X-ray absorption spectroscopy
Authors: Frenkel A I , Korshin G V
Published: April 2011

Based on original data for copper, this paper evaluates the use and advantages of X-ray absorption fine structure (XAFS) in studies of heavy metals in soils. The structural parameters of the Cu2+ target were quantified for soil exposed to copper and the same soil eluted with 0.1 M HCl. Experimental data were obtained using synchrotron sources of second and third generations.X-ray absorption near edge structure (XANES) indicated that the copper in both samples is likely to be predominantly bound by oxygen-containing functional groups. Extended X-ray absorption fine structure (EXAFS) analysis showed that the equatorial Cu-O distances were similar to those seen for Cu2+-humic complexes in aqueous solutions, but the axial distances for both samples were longer than in water. In the axial direction, this may indicate a type of ligation dissimilar to that in solutions. The magnitude of the mean square deviation of the axial Cu-O distance in the 0.1 M HCl eluted sample indicated a stronger bond compared with that in the sample containing both extractable and tightly bound copper. The results indicate that careful examination of structural data for sequentially eluted soils in combination with the development of new radiation sources to improve the sensitivity and quality of the data are likely to improve insight into the nature of interactions between heavy metals and soil. Key words: Soil, copper, humic, speciation, extended X-ray absorption fine structure, X-ray absorption near edge structure
Interactive effects of management practices on water-stable aggregation and organic matter of a Humic Gleysol
Authors: Bissonnette Nicole , Angers Denis A. , Simard Régis R. , Lafond Jean
Published: April 2011

In many soils, the content and quality of organic matter (OM) control water-stable aggregation, which in turn preserves soil surface integrity. The effects of management practices on soil OM and aggregation remain to be determined for certain soils and climatic conditions. We assessed the effects of eight management systems involving two crop sequences: [barley ( Hordeum vulgare L.) monoculture (M) and barley in rotation (R) with a forage mix of red clover ( Trifolium pratense L.) and timothy ( Phleum pratense L. ‘Champ’)], two fall tillage [moldboard plowing (MP) and chisel plowing (CP)] and two nutrient sources [liquid dairy manure (LDM) and mineral fertilizers (MIN)] on soil aggregation and OM fractions of a silty clay Humic Gleysol. Soil samples from the 0–7.5 cm layer were taken periodically during 7 yr, and the total C and N, microbial biomass C (MBC) and carbohydrate (AHC) contents, alkaline phosphatase activity (APA), and water-stable aggregation were determined. By the 7th yr, initial total C and N contents of the surface soil had increased by 35 and 45%, respectively, in R-CP-LDM. They were slightly increased in R-CP-MIN an d R-MP-LDM, whereas they decreased by an average of 19% in R-MP-MIN and all monoculture plots. Increases in C contents were attributed to higher annual C inputs from forage residues and LDM, less frequent tillage in the rotation, and shallower tillage with CP. The MBC, APA, AHC and aggregation generally responded faster and to a greater degree to conservation management practices than total C and N. Overall, conservation tillage and manure applications resulted in greater improvement in surface soil conditions when used in a rotation system rather than in a monoculture. The rapid rate of changes in soil properties suggests that the surface quality of this cold silty clay soil can be improved relatively quickly with selected management combinations. Key Words: Cropping systems, total soil C, microbial biomass, carbohydrate, alkaline phosphatase, soil aggregation, liquid dairy manure, reducted tillage, rotations
Autumn and spring applications of ammonium nitrate and urea to bromegrass influence total and light fraction organic C and N in a thin Black Chernozem
Authors: Malhi S S , Harapiak J T , Nyborg M. , Gill K S , Flore N A
Published: April 2011

An adequate level of organic matter is needed to sustain the productivity, improve the quality of soils and increase soil C. Grassland improvement is considered to be one of the best ways to achieve these goals. A field experiment, in which bromegrass (Bromus inermis Leyss) was grown for hay, was conducted from 1974 to 1996 on a thin Black Chernozemic soil near Crossfield, Alberta. Total organic C (TOC) and total N (TN), and light fraction organic C (LFOC) and light fraction N (LFN) of soil for the treatments receiving 23 annual applications of 112 kg N ha-1 as ammonium nitrate (AN) or urea in early autumn, late autumn, early spring or late spring were compared to zero-N check. Soil samples from 0- to 5- cm (layer 1), 5- to 10- cm (layer 2), 10- to 15- cm (layer 3) and 15- to 30-cm depths were taken in October 1996. Mass of TOC, TN, LFOC and LFN was calculated using equivalent mass technique. The concentration and mass of TOC and LFOC, TN and LFN in the soil were increased by N fertilization compared to the zero-N check. The majority of this increase in C and N occurred in the surface 5-cm depth and predominantly occurred in the light fraction material. In layer 1, the average increase from N fertilization was 3.1 Mg C ha-1 for TOC, 1.82 Mg C ha-1 for LFOC, 0.20 Mg N ha-1 for TN and 0.12 Mg N ha-1 for LFN. The LFOC and LFN were more responsive to N fertilization compared to the TOC and TN. Averaged across application times, more TOC, LFOC, TN and LFN were stored under AN than under urea in layer 1, by 1.50, 1.21, 0.06 and 0.08 Mg ha-1, respectively. Lower volatilization loss and higher plant uptake of surfaced-broadcast N were probable reasons from more soil C and N storage under AN source. Time of N application had no effect on the soil characteristics studied. In conclusion, most of the N-induced increase in soil C and N occurred in the 0- to 5-cm depth (layer 1) and in the light fraction material, with the increases being greater under AN than urea. Key words: Bromegrass, light fraction C and N, N source, soil, total organic C and N
Effects of deep ripping and organic matter amendments on Ap horizons of soil reconstructed after coal strip-mining
Authors: Bateman J C , Chanasyk D S
Published: April 2011

Deep ripping is a common management technique used to shatter dense subsurface soil horizons that limit percolation of water and penetration of roots. Most studies have concentrated on the effects of deep ripping on subsoils, with few examining the effects on surface soil horizons. A study was conducted on reclaimed fields (undisturbed soil Albic Luvisol) at the Highvale coal mine approximately 80 km west of Edmonton, Alberta, Canada, with objectives to evaluate the effect of deep ripping, with and without the use of organic matter amendments, on the physical and chemical properties of Ap horizons of reconstructed minesoils. Significant treatment effects were identified for particle size distribution (all fractions), plasticity index and the October mean penetration resistance (PR), but effects on bulk density, soil water content at the time of sampling, water retention characteristics and modulus of rupture were non-significant. Soil chemical properties significantly affected included pH, soluble Ca and Mg, exchangeable Na and K, exchangeable Ca:Na ratio and loss of ignition. Addition of subsoil to the Ap horizon as a result of deep ripping likely caused the changes. They are expected to make the seedbed more difficult to cultivate and manage unless specific management practices such as organic matter additions are adopted to overcome the detrimental changes in soil properties that have occurred. Key words: Manure, peat, reclamation, soil properties, subsoiling, surface horizon, tilth
Changes in phosphorus fractions of a Humic Gleysol as influenced by cropping systems and nutrient sources
Authors: Zheng Zhiming , Simard Régis R , Lafond Jean , Parent Léon E
Published: April 2011

Information about the dynamics of soil P fractions is useful to predict their bioavailability and risk of P transfer from soils to surface waters. The objective of this study was to assess the effects of cropping systems and nutrient sources on P fractions in a Labarre silty clay (Humic Gleysol). Soil samples (0-15 cm) were collected in 1989, 1994 and 1997 from a field with four cropping systems, combining two crop rotations, barley (Hordeum vulgare L.) monoculture and 3-yr barley-forage rotation, with two tillage operations (chisel and moldboard plowing) as main plots, and two nutrient sources (mineral fertilizer and liquid dairy manure) as subplots. A modified Hedley sequential fractionation scheme was used. The inorganic P (Pi) fractions (resin-P, NaHCO3-Pi, and NaOH-Pi) increase with time in all cropping system and nutrient source combinations. Organic (Po) fraction (NaHCO3-Po and NaOH-Po) changes were related to C inputs and total soil C contents. The barley monoculture combined with mineral fertilizer slightly reduced NaHCO3-Po and NaOH-Po. The barley-forage rotation increased labile Po fractions. Rotation, chisel plowing and liquid dairy manure addition result in a buildup of labile P. A larger labile P increment per unit of P added, in surplus to plant exports, was observed with dairy manure than for mineral fertilizer, suggesting a higher risk of surface water contamination by P. Cropping systems and nutrient sources have a large influence on the changes in P fractions in this fine-textured Gleysolic soil. Key words: P fractions, crop rotations, liquid dairy manure, chisel plowing, moldboard plowing
Assessing physical quality of plastic soils of differing mineralogy and pre-stress history using mechanical parameters. I. Saturated compression tests
Authors: Joosse P. J. , McBride R. A.
Published: April 2011

The comparison of selected soil mechanical parameters measured on plastic soils under remoulded and structurally intact conditions may provide an opportunity to assess soil structural quality on a regional or even broader scale. This study was conducted to determine: (i) if existing pedotransfer functions developed for southwestern Ontario soils could be used outside this physiographic region, and (ii) if key mechanical parameters were sensitive to a range of land use conditions that are likely to influence soil structural quality. Soil profiles were sampled in natural (forested or grassland), agricultural and pipeline workspace areas (land use variable) located in southwestern Ontario, eastern Ontario, Alberta and Texas (mineralogy variable). Slurry consolidation and uniaxial compression tests were conducted on remoulded and structurally intact samples, the resulting void ratio-log stress [e(logσ')]data were fitted to linear or nonlinear model equations, respectively, and several key mechanical parameters were derived. The effective stresses at the liquid and plastic limits could not be adequately estimated for soils with smectitic mineralogy using existing pedotransfer functions because of the absence of a significant relationship with organic carbon content. The difference between void ratio intercepts for remoulded and structurally intact soils (e*1kPa–e0) was found to be a suitable indicator of physical soil quality because of the convergence of remoulded and structured compression lines in e(logσ') co-ordinates. Severely overconsolidated soils were identified when the (e*1kPa–e0) variable exceeded 0.40. This threshold also corresponded to soil conditions that could limit plant growth. Key words: Compression, consolidation, pedotransfer function, soil quality, Atterberg limits, remoulded, structured, pipeline, woodland
Soil physical properties of a Chernozemic clay loam after 24 years of beef cattle manure application
Authors: Miller J J , Sweetland N J , Chang C.
Published: April 2011

Limited information exists on the influence of long-term application of beef cattle manure on soil physical properties in the Canadian prairies. A site on a clay loam soil (Dark Brown Chernozem) at Lethbridge was used to determine the effect of increased rates of manure application on selected soil physical properties in 1997 and 1998. The manure (from an unpaved feedlot) was applied annually in the fall for 24 yr at one, two and three times the 1973 recommended rates under dryland (0, 30, 60, 90 Mg ha-1 wet basis) and irrigation (0, 60, 120, 180 Mg ha-1). There was a significant (P < 0.05) decrease in the sand content of soil (0–10, 10–20 cm) with increased rates of manure application; and an increase in clay content for the 60 and 120 Mg ha-1 rates compared to the control under irrigation. There was a significant and negative linear relationship between increased rates of manure application and bulk density (0–5, 10–15 cm) for most seasons, and season affected bulk density values for a given manure rate. Penetration resistance (0–14 cm) was unaffected by increased rates of manure application under dryland. Under irrigation, it was significantly reduced at only the 3.5 cm and 10.5 cm depths in 1997, and at only the 3.5 cm depth in 1998. Air permeability was generally unaffected by increased rates of manure application, except for the 0–5 cm depth under irrigation, where it was significantly lowered at the highest application rate. Soil temperatures (0, 10, 20 cm) were lower under increased rates of marnure application at the 10 and 20 cm depths in the spring and summer under dryland, and they were higher at these two depths in the winter. Under irrigation, soil temperatures were lower with increased rates of manure application at the 20-cm depth in the spring, and they were higher at the 20-cm depth in the fall, and at the 0- and 20-cm depths in the winter. Overall, soil physical properties generally had a neutral or positive response to 24 yr of annual manure application at high rates, and should not cause any detrimental effects to the soil's physical condition. Key words: Manure rate, physical properties, bulk density, penetration resistance, air permeability, temperature
Soil fertility effects on carbon fluxes under two spring wheat rotations in a semiarid agroecosystem
Authors: Curtin D. , Wang H. , Selles F. , Campbell C. A. , Zentner R. P.
Published: April 2011

Changes in soil C storage due to management practices are important in relation to soil quality and to the broader issue of atmospheric C sequestration. Our objective was to evaluate the effects of soil fertility management on C fluxes under two spring wheat (Triticum aestivum L.) rotations in semiarid southwestern Saskatchewan, i.e., continuous wheat (Cont W) and a rotation that included summerfallow every third year (F-W-W). Continuous wheat was grown under two fertility regimes since initiation of the experiment in 1967, i.e., fertilization with N+P (no nutrient limitation) or with P only. In F-W-W there were three fertility treatments: N+ P, N only, and P only. We measured soil CO2 emissions under all fertility treatments and rotation phases during the 1995 and 1996 cropping seasons (emissions were measured at about weekly intervals between spring and freeze-up in autumn). Inputs of C in straw were measured and a root:straw ratio of 0.59 was used to estimate root C inputs. Alleviation of nutrient limitations generally had a positive effect on wheat growth (and thus on C inputs), particularly in 1995, the wetter of the 2 yr (precipitation 14% greater than average). For example, C inputs in 1995 under Cont W were estimated at 2700 kg ha-1 in the N+P treatment compared with 1500 kg ha-1 in the P only treatment. Fertility treatments had little effect on CO2 emissions; e.g., for Cont W the mean flux for the 1995 monitoring period was 2.7 mmol CO2 m-2s-1 where N + P was applied and 2.6 mmol CO2 m-2s-1 where P only was applied. Greater C inputs, but similar outputs of CO2-C for the N + P treatment vs. the systems receiving N or P only, suggest that proper fertilization resulted in a gain in soil C. However, quantifying the fertility-induced C gain is problematic because of uncertainty regarding effects of fertility on several components of the C budget, particularly root-C inputs and the contribution of rhizosphere respiration to the measured CO2 flux. Key words: Carbon sequestration, N and P fertilization, CO2 emissions, C inputs in crop residues, spring wheat, summerfallow
Effect of fall-applied manure practices on runoff, sediment, and nutrient surface transport from silage corn in south coastal British Columbia
Authors: van Vliet L J.P. , Zebarth B J , Derksen G.
Published: April 2011

Runoff from manured cropland during the wet fall and winter season, when 70% of the annual rainfall occurs, is a surface water quality concern in the Lower Fraser Valley of British Columbia. This study compares different fall-manure application strategies on runoff and contaminant transport from silage corn (Zea mays) land. The treatments were (i) a control, which did not receive manure in the fall; (ii) manure broadcast in the fall on corn stubble; and (iii) manure broadcast in the fall on corn stubble with an established relay crop. Runoff, solids, and nutrients loads from natural precipitation were measured on replicated experimental plots (0.0125 ha) from 1996 to 1998. Fall-applied manure on 3–5% sloping silage cornland without a relay crop resulted in a high risk to surface water quality, due to high suspended solid loads of between 7 and 14 Mg ha-1 yr-1 and high nutrient transport with mean annual total Kjeldahl N (TKN) P, and K loads of 98, 21, and 63 kg ha-1, respectively. Compared with no relay crop, intercropping silage corn with a relay crop of Italian ryegrass (Lolium multiflorum) reduced the mean annual runoff and suspended solid load by 53 and 74%, respectively, TKN load by 56%, P load by 42%, K load by 31%, and Cu load by 57%. Even though total nutrient loads were lower with the relay crop treatment, all fall manure treatments including the relay crop resulted in nutrient loads above guidelines for the first three runoff events immediately following application. Key words: Runoff, suspended solids, nutrient loads, relay crop, cover crop, silage corn, manure
Effect of rate, frequency and method of liquid swine manure application on soil nitrogen availability, cropperformance and N use efficiency in east-central Saskatchewan
Authors: Mooleki S P , Schoenau J J , Hultgreen G. , Wen G. , Charles J L
Published: April 2011

A study was initiated in the fall of 1996 in the Black soil zone in east-central Saskatchewan (parkland region) to examine the soil and crop response to application of liquid swine manure at different rates, frequencies and methods of application. Low, medium and high rates of liquid swine manure (equivalent to approximately 100, 200 and 400 kg total N ha-1, respectively) were applied annually and in reduced frequency applications using injection and broadcast/incorporated placement over a 4-yr period. Crops grown during this period were Argentine canola (Brassica napus L.) in 1997, hard red spring wheat (Triticum aestivum L.) in 1998, hulless barley (Hordeum vulgare L.) in 1999, and Argentine canola in 2000. Under an annual application regime, a significant elevation of pre-seeding available N in the 0–60 cm soil depth and increased grain yield and protein content with increasing application rates of liquid swine manure were observed. Under a reduced frequency application regime, elevation of pre-seeding available N, grain yield and protein content observed in the year of application declined in the second year, and were significantly diminished by the third year. Cumulative N use efficiency (NUE) was highest (50–60%) for low annual application and lowest (10–30%) for high annual application rates that were injected. Generally, injection of liquid swine manure into the soil resulted in better enhancement of pre-seeding available N, higher grain yield and protein content, and better NUE than broadcasting and incorporation. Type of opener used to inject swine manure had no significant effect on either crop response or available N. This study showed that in the Black soil zone of the parkland region of Saskatchewan, annual application of low to medium rates (100 to 200 kg total N ha-1) of liquid swine manure are sufficient for high grain yield and grain protein, without leaving excess nitrates in the soil. In contrast, annual application of high rates (400 kg total N ha-1) of liquid swine manure has no agronomic advantage over the lower rates, but may result in higher residual nitrates in the soil, increasing potential for environmental pollution. Key words: Swine manure, N availability, manure management, N use efficiency
Diversity of symbiotic rhizobia resident in Canadian soils
Authors: Prévost and E. S P. Bromfield D.
Published: April 2011

The dependency of agriculture on nitrogen fertilizer inputs is associated with adverse effects on the environment and human health. The importance of biological nitrogen fixation by rhizobia in symbiotic association with legumes is underscored by its potential to reduce or replace chemical fertilizer inputs. This paper reviews research on the diversity of the symbiotic rhizobia resident in Canadian soils. Research has focussed on phenotypic and genotypic variation (e.g., nitrogen fixing efficacy, nodulating competitiveness, host range, adaptation to cool climate) within rhizobial species with the objective of selecting efficient strains for use in inoculants for legume crops. The genetic diversity of rhizobia resident in Canadian soils has been reported only for Sinorhizobium meliloti, Rhizobium leguminosarum and Mesorhizobium spp. There is a need for further studies on populations of other rhizobial species, particularly those associated with native legumes. Exploiting the diversity present in natural soil populations via selection and genetic manipulation should permit the development of superior strains for use in legume inoculants. Other rhizobial traits that may be exploited include plant growth-promoting activity and ability to degrade pollutants. Key words: Symbiotic rhizobia, diversity, Canadian soils
Spatial and temporal variation in soil inorganic n concentration, and soil test P and K, in red raspberry fields and implications for soil sampling strategies
Authors: Zebarth B J , Dean D M , Kowalenko C G , Paul J W , Chipperfield K.
Published: April 2011

Fertilizer is commonly applied as a band in red raspberry (Rubus idaeus L.) fields, resulting in complex spatial and temporal variation in soil inorganic N concentration, and in soil test P and K. The objectives of this study were to determine the spatial and temporal distribution of soil inorganic N in red raspberry fields receiving different N fertility treatments, to use the data to determine the most appropriate sampling strategies for estimating the quantity of soil inorganic N at various times during the growing season, and to evaluate the same sampling strategies for soil test P and K. Treatments were a control that received no manure or fertilizer N, 55 kg N ha-1 as urea or as Duration T60, a slow release N fertilizer, banded in mid-April, or 100 kg total N ha-1 as solid broiler manure broadcast or banded in early March, or banded in mid-April. Soil inorganic N was sampled at 10 inter-row locations 8, 23, 38, 53, 68, 83, 98, 113, 128, and 143 cm from the crop row, and for 0–15, 15–30, and 30–60 cm depth, for four sampling dates for the control and urea treatments, and for 0–15 and 15–30 cm depth on one sampling date for the remaining treatments. Random sampling and four systematic sampling strategies were evaluated for their bias in estimating soil inorganic N concentration and soil test P and K, and with respect to the number of soil cores required to achieve a given precision and probability level combination. The random sampling strategy gave unbiased estimates of soil inorganic N and soil test P and K, however, the number of cores required to obtain a given precision at a given probability level were generally greater than for the systematic sampling strategies. The systematic sampling strategy involving sampling only in the crop row and in the centre of the inter-row, the current industry standard, gave expected values that could sometimes be substantially lower than the true value, and was therefore not recommended for use in raspberry fields. The best systematic sampling strategy used samples collected from the crop row, from the fertilizer band, from the centre of the inter-row, and from midway between the fertilizer band and the centre of the inter-row. Key words: Rubus idaeus, nitrate leaching, nitrification, nitrate, ammonium
Characterizing organic matter retention for surface soils in eastern Canada using density and particle size fractions
Authors: Carter M. R. , Angers D. A. , Gregorich E. G. , Bolinder M. A.
Published: April 2011

Interest in the storage of organic matter in terrestrial ecosystems has identified a need to better understand the accumulation and retention of organic C and N in soil. The proportions of C and N associated with clay and silt particles (i.e., “capacity level”), water-stable macro-aggregates (WSA) (>250 µm), particulate (POM) (>53 µm), and light fraction (LF) organic matter, for the 0- to 10-cm soil depth, were assessed at 14 agricultural experimental sites established on Gleysolic, Podzolic, Luvisolic , and Brunisolic soils in the cool, humid region of eastern Canada. Organic C and N in the clay plus silt particles was at or near the capacity level for soils with clay plus silt content < 40%. For soils with >60% clay plus silt, the degree of saturation was 65–70% indicating a potential for further organic C and N retention. The mean proportion of C and N found in the POM was 22 and 27%, whil e the LF organic matter contained 7 and 5% C and N, respectively. Mean soil WSA content, determined by wet-sieving analysis, was 42% for air-dry soil and 54% for wetted soil, and was significantly (P < 0.05) related to both soil clay plus silt (r = 0.65) and organic C (r = 0.54). Water-stable macro-aggregate C content was proportional to soil organic C (r = 0.96, P < 0.01). At four of the sites, where soil C and N were influenced by management, an increasing level of soil organic C and N was associated with both the clay plus silt particles and the POM fraction until the former was saturated. Once the capacity level was saturated, further organic C and N accumulation was associated with the POM fraction. Although stabilized organic C and N in soil exists as a continuum, both soil particle and particulate fractions provided a practical approach to monitor, quantify and differentiate the storage and retention of C and N in soils of eastern Canada. Key words: Soil organic matter, clay plus silt associated organic C and N, size fractions, particulate organic matter, light fraction organic matter, water-stable macro-aggregates, organic amendments, Canada
Effects of pulp fibre on soil physical properties and soil erosion under simulated rainfall
Authors: Chow T. L. , Rees H. W. , Fahmy S. H. , Monteith J. O.
Published: April 2011

Pulp fibre, a primary type of sludge of pulp and paper mills containing approximately 40% organic C, is usually disposed of in landfills causing a potential environmental problem. This material may be used as a soil amendment to restore the productivity of organic-matter-depleted potato-producing soils in Atlantic Canada. The effect of incorporating this material at rates equivalent to 0.5, 1.0, 2.0, and 4.0% organic matter in the plow layer of a gravelly loam soil on selected soil physical properties and soil erosion was evaluated. The objectives were to determine the effect of pulp fibre additions on selected soil properties, which are pertinent to water retention and movement and to evaluate its effectiveness in reducing runoff and soil loss, major contributing processes to soil degradation . Chemical analysis of pulp fibre revealed that all heavy metal concentrations were well below allowable concentrations for Category A compost. One year after incorporation, bulk density of the Ap horizon had decreased with increasing rates of organic matter addition. On the other hand, the saturated hydraulic conductivity and specific moisture content increased with increasing rates of treatments. Results on water-stable aggregates revealed that the organic matter in the pulp fibre combined smaller aggregates to form larger aggregates, resulting in a larger proportion of macropores as compared to micropores. In the 4% organic matter treatment, a 27% increase was found in the 1.0 to 5.0 mm-diameter aggregates whereas a 23% reduction was found in aggregates smaller than 1.0 mm diameter. In spite of the higher specific moisture content of the organic-matter-treated soils, soil moisture content measured immediately prior to the erosion test indicated that field soil moisture contents were lower than those of the control. Time of runoff initiation, rates of runoff and soil loss were greatly improved with the amendments. The beneficial effects of the 4% organic matter treatment include 2.1 times delay in runoff initiation, and 23 and 71% reduction in runoff and soil loss, respectively. Although the beneficial effects in soil and water conservation are apparent, a minor drawback appears to be lower field soil moisture content. Large-scale implementation of the addition of this material in potato fields should proceed only with caution. Key words: Saturated hydraulic conductivity, moisture retention, water stable aggregate, mean weight diameter, sediment yield, soil amendment
Influence of peatmoss on hydraulic properties and strength of compacted soils
Authors: Nusier Osama K.
Published: April 2011

Due to its high organic matter content, peatmoss can be highly beneficial to agricultural soil. In this research, the impact of varying organic matter contents at different compaction efforts on water retention, saturated hydraulic conductivity, and modulus of rupture of three soils (sandy loam, clay loam, and clay) has been investigated under laboratory conditions. Compaction changed the ability of the soils to hold water, increased modulus of rupture, and decreased the plant-available water-holding capacity of the soils. On the other hand, organic matter generally increased the ability of the soils to hold water, expanded the available water capacity, and decreased the modulus of rupture of compacted soils. Key words: Peatmoss, water retention, saturated hydraulic conductivity, modulus of rupture
Comparison of different phosphorus extraction and determination methods using manured soils
Authors: R. Wright Mingchu Zhang, , Heaney D. , Vanderwel D.
Published: April 2011

Soil test P (STP) methods were developed for fertilizer P recommendation in crop production. As soil P content of arable land increases due to manure application, the suitability of these STP methods for assessing P runoff potential from a field needs to be evaluated. The objective of this research was to evaluate various P extraction and determination methods using manured soils for their potential use as environmental P testing methods. Eighty one soil samples were taken in 1998 from various manured fields and research plots across Alberta. Phosphorus in the samples was extracted using deionized water, Miller-Axley (0.03 M NH4F + 0.015 M H2SO4), modified Kelowna (0.015 M NH4F + 0.25 M NH4OAc), and Mehlich 3 (M3) (1.5 M NH4F + 0.1 M EDTA) procedures. Phosphorus concentration in all extraction solutions was determined by the molybdenum blue colorimetric method in a Technicon II autoanalyzer. In addition, P content of the deionized water and M3 extractions was determined by an inductively coupled plasma emission spectroscopy (ICP) method. Soluble organic carbon content was measured in the deionized water extraction.

The extractable P concentration increased as the acidity of the extraction solution increased in the order: M3 > modified Kelowna > Miller-Alxey > deionized water. The P extracted by Miller-Axley and M3 was strongly related to the deionized water extractable P, suggesting that both methods may be useful in assessing potential P runoff from arable land. The P concentration by the ICP determination was much higher than with the colorimetric method in M3 and the deionized water. The P concentration difference between the two determination methods was largely correlated to the soluble organic carbon in the deionized water extraction (r = 0.828***), suggesting that the undetected P by the molybdenum blue colorimetric method may exist in organic forms. To asses P runoff risk from arable land, both soluble inorganic and organic P need to be considered, and the ICP method can determine the total P, which includes both. In developing a STP for environmental soil P management, both P extraction and P determination methods should be standardized, and our results suggest that M3 and Miller-Axley extraction, and ICP determination are suitable methods for assessing P runoff. Key words: Soil test P, colorimetric P, ICP-P, dissolved organic carbon, soluble organic P, manure application rate
Phosphorus fractions in soil amended with organic and inorganic phosphorus sources
Authors: Kashem Md. Abul , Akinremi Olalekan Oluwole , Racz Geza Joseph
Published: April 2011

Information on the P fractions in soils treated with different organic amendments is needed to better manage land application of organic amendments to agricultural soils. This study investigated the forms and distribution of P after 1, 4 and 16 wk in a Lakeland silty clay loam soil using a sequential fractionation procedure. Phosphorus was added at rates of 0, 123, 307 and 614 mg P kg-1 in the form of biosolids, hog manure, cattle manure and fertilizer P. The largest difference among the amendments was in the water-extractable P fraction, which was significantly lower in soil amended with biosolids. Regression analysis showed that the slope of P increment in the H2O fraction as a function of P application rate was four times lower for biosolids (0.06) than for hog manure (0.24) and seven times lower than for fertilizer (0.42) amended soils. In the biosolids-amended soil, there was a net increase of H2O-P, NaOH-Pi and HCl-P fractions at the expense of organic P (NaOH-Po) and residual P fractions after 16 wk of incubation, signifying net P mineralization. In hog manure amended soil, H2O-P decreased by 128 mg kg-1 with a corresponding increase in the NaHCO3-P, possibly due to P sorption during the 16 wk of incubation. The results for cattle manure indicated net immobilization of P as the H2O-P and NaHCO3-P declined while the inorganic P (NaOHPi), HCl-P and residual P increased with incubation time. The transformation of P in fertilizer-amended soil was similar to that of hog manure amended soil. The amount of labile P (defined as H2O-P plus NaHCO3-P) in amended soils followed the order of fertilizer P > hog manure > cattle manure > biosolids. Key words: Phosphorus fractions, sequential P extraction, incubation, organic amendments
Soil and plant response to wellsite rehabilitation on native prairie in southeastern Alberta, Canada
Authors: Hammermeister A. M. , Naeth M. A. , Schoenau J. J. , Biederbeck V. O.
Published: April 2011

Rehabilitation of disturbed native prairie is a challenge facing many in the petroleum industry, with implications for prairie ecology and productivity. The purpose of this research was to examine the relative influence of four rehabilitation strategies on biogeochemical processes (i.e., nitrogen availability, plant uptake of nitrogen, biomass production, carbon allocation, and soil biological activity). Seven petroleum wellsites were selected on Chernozemic and Solonetzic soils in southeastern Alberta. Undisturbed native prairie was compared with four seeding treatments: not seeded, a low diversity seed mix commonly used by industry, a low diversity mix of species more typically dominant in native prairie, and a diverse seed mix. Flux of NO3− and NH4+were measured in situ using ion exchange membranes. Soil total C and N were lower and available N higher as a result of disturbance. In the seeded treatments, biomass production was higher and soil nitrogen flux was lower due to higher plant uptake than in the unseeded treatment. Higher initial N availability favoured species with rapid growth and colonization rates, particularly Agropyron dasystachyum [(Hook.) Scribn.] and Agropyron trachycaulum [(Link) Malte]. Seed mix composition and species attributes were deemed to have greater influence on N cycling and biomass production than seed mix diversity. Key words: Nitrogen cycling, plant competition, secondary succession, wheatgrass, biodiversity, prairie
Properties of soils influenced by ectomycorrhizal fungi in hybrid spruce [Picea glauca × engelmannii (Moench.) Voss]
Authors: Glowa K. R. , Arocena J. M. , Massicotte H. B.
Published: April 2011

Soil properties of rhizosphere zones in coniferous forests are influenced by the presence of ectomycorrhizae. To elucidate the role of ectomycorrhizae (ECM) on the alteration of chemical and mineralogical properties of soils, soil pH, total C and N, cation exchange capacity, and the contents of mica, chlorite, and kaolinite, 2:1 type expandable clays, and amorphous minerals were compared in two soils, soils influenced by ectomycorrhizal fungi (ECS) and non-ectomycorrhizosphere soils (N-ECM) of Picea glauca x engelmannii (Moench.) Voss. Specifically, the two ECS soils were dominated by (1) Piloderma spp. (ECS-A) and (2) Inocybe lacera-like and Hebeloma-like morphotypes or where Piloderma spp. colonization was <1% (ECS-B). Our results showed that pH was lower in ECS compared to N-ECM samples. Total C and N were significantly higher in ECS soils than N-ECM samples. Cation exchange capacity as well as exchangeable K+, and Na+ were higher in ECS compared to N-ECM soils. X-ray diffraction analysis showed that the amount of 2:1 expanding clays (vermiculite and smectite) was higher in ECS than N-ECM samples and results suggest that there is an enhanced transformation of mica and chlorite to 2:1 type expandable clays in ECS samples when compared to N-ECM samples. The differences in chemical and mineralogical properties between ECS and N-ECM soils, in our study, support earlier studies that show ectomycorrhizal fungi can alter the properties of soils in the rhizosphere zone. Key words: ectomycorrhizosphere soils, soil properties, Piloderma spp.
Fertilizer response of barley silage in southern and central Alberta
Authors: McKenzie R. H. , Middleton A. B. , DeMulder J. , Bremer E.
Published: April 2011

Barley (Hordeum vulgare L.) silage is the foundation for cattle production on the Canadian prairies, but few studies have evaluated fertilizer requirements for the range of cultivars, soil types and environmental conditions in which it is grown. The objectives of this study were (1) to determine optimum N fertilizer rates for a range of barley cultivars when used for silage in southern and central Alberta and (2) to determine the frequency and impact of P, K and S deficiencies. Thirty-two field experiments were conducted from 1994 to 1996; 20 in southern Alberta under irrigated (8) or dryland (12) conditions and 12 in central Alberta under dryland conditions. Two semi-dwarf (CDC Earl, Tukwa) and three conventional (AC Lacombe, Leduc and Seebe) cultivars were tested. Fertilizer treatments included six rates of N (0 to 200 kg ha-1) and one rate each of P (13 kg ha-1), K (50 kg ha-1) and S (20 or 30 kg ha-1), compared to an appropriate unfertilized control. Optimum rates of N fertilizer ranged from 0 to 172 kg N ha-1. Irrigated sites had the highest N demand but the lowest economic optimum rate of N fertilizer (NFopt) due to high fertilizer N efficiency and high soil N availability. Dryland sites in southern Alberta had a lower N demand than irrigated sites, but NFopt was higher due to lower soil N availability. Sites in central Alberta had the least demand for N, but NFopt was similar to irrigated sites due to low N fertilizer efficiency. Nitrogen fertilizer efficiency frequently exceeded 80% in southern Alberta, particularly under irrigation. Soil N uptake increased with optimum barley yield, indicating that factors that increased crop growth also increased net mineralization and/or efficiency of soil N uptake. A good fit of NFopt was obtained in southern Alberta based on spring soil NO3-N levels and optimum yield. The best estimate of NFopt in central Alberta was the mean due to the lack of a relationship between soil N uptake and spring soil NO3-N. Barley response to P fertilizer was greatest in central Alberta and least in southern Alberta under irrigation. Few responses to K or S fertilizer were observed due to the generally adequate levels of these nutrients in Alberta soils. Fiber concentrations were not strongly affected by fertilizer treatment, while protein concentrations varied with the availability of N relative to demand. Improvements in prediction of fertilizer response for barley silage require better predictors of N fertilizer efficiency and soil N uptake, particularly in central Alberta. Key words: Hordeum vulgare, nitrogen fertilizer use efficiency, protein, fiber
Differentiation of four northern Great Plains soils using resin extraction
Authors: Hal Weiser Alan Olness, , Michael Lieser Bruce Kunze, , Rinke Jana
Published: April 2011

Resin extraction of soils has revealed sensitivities of crops to the extractable V:(V + P) and Mg:(Mg + Ca) molar ratios. Consequently, we examined the Barnes and Buse soils in the northern Great Plains of North Dakota, South Dakota, and Minnesota. Svea and Langhei soils were included in the survey because of their close association. Samples of A or Ap horizons suspended in 20% ethanol were extracted with cation-(Na+) and anion-(NO) exchange resin-extractors for a period of 5 d. After equilibration, extractors were eluted with 1 N HCl and eluates were analyzed using inductively coupled plasma-atomic emission spectroscopy. Analytical concentrations were log transformed and analyzed using SAS PROC GLM. Each soil produced a distinct suite of extractable ions. Mean pH values ranged from about 6.8 for the Svea soil to about 8.0 for the Langhei soils. Total resin extractable Ca ranged from about 150 to 28 000 nmol g-1 soil and total resin extractable Mg ranged from 110 to 5500 nmol g-1 soil; the least amounts were found in the Svea soil and the greatest amounts were found in the Langhei soil. The pH of the Barnes and Buse soils and the amounts of extractable Ca and Mg in the Barnes and Buse soils were intermediate to those of the Svea and Langhei soils. Trivial amounts of V were detected in extracts from a few samples of Buse soils. Large fractions of S, B, and As in the Langhei soil were extracted on cation exchange resins presumably due to complex formation with the much larger amounts of Ca and Mg. Amounts of Ba, Sr, Fe, Co, Cu, and Si, detected in the extracts differed between soils with more being extracted from the Langhei than from the other soils. Only resin extractable Li and K differed from the general trend in that the amounts associated with Langhei soils were among the least. Detectable amounts of Al, Ni, and Zn usually were obtained but without differences between soils. Resin extractable P was correlated with bicarbonate extractable P but slopes of the regression lines differed between soils and two groups of Barnes soils were clearly distinguished in these relationships. Key words: extractable, nutrients, toxic elements, varadium, sulfur, phosphorus
Phosphorus transformations in acid light-textured soils treated with dry swine manure
Authors: Khiari Lotfi , Parent Léon E.
Published: April 2011

Organic matter can sorb P in acid soils through metal-organic matter-phosphate complexes. The pyrophosphate extractable Al and Fe and soil C contents were hypothetized to influence P partitioning in Ferro-Humic Podzols. Reaction of added P may be mitigated by adding lime or organic matter as dry swine manure (DSM) together with mineral P fertilizers. Three soils had 40 to 50 g kg-1 of soil organic matter (SOM) content, and 76 to 140 mmol (Al + Fe)pyro kg-1. A peaty soil phase had 200 g SOM kg-1, and 58 mmol (Al + Fe)pyro kg-1. Rates of monoammonium phosphate were 0, 27, 69, and 144 kg P ha-1 in a simulated fertilizer band. Rates of DSM and lime were 800 and 185–369 mg per 35 mL of soil, respectively. After 6 wk of incubation, soil P was fractionated sequentially into aluminium bound P (Al-P), iron bound P (Fe-P), and loosely bound P. Total P, desorbed P and organic P were determined in separate subsamples. A proportion of 79–92% of added P was recovered as Al-P and Fe-P in the three low SOM soils, compared to 51–61% in the high SOM soil. The DSM increased loosely bound P from 25 to 34% in the high SOM soil and from 4.8 to 5.9% in low SOM soils. With DSM, the proportion of desorbed P was much higher in the high (70%) than in low SOM (22%) soils. Compared to the non-amended treatment, lime showed no significant effect on any P fraction but desorbed P. The DSM increased P availability in the fertilizer band considerably more in the soil having the lowest (Al + Fe)pyro/C ratio. Key words: P fractionation, organic ligand, P sorption, fertilizer band
A constant-head well permeameter method for measuring field-saturated hydraulic conductivity above an impermeable layer
Authors: Hayashi Masaki , Quinton William L.
Published: April 2011

Hydrologic understanding of mountainous and northern regions of Canada is poor owing to the lack of critical field data such as hydraulic conductivity. A portable field instrument, the Guelph permeameter (GP), is a promising tool for measuring field-saturated hydraulic conductivity in remote watersheds inaccessible by motorized vehicles. In order to extend the applicability of the GP method to relatively thin soils underlain by impermeable bedrock or permafrost, a new set of shape factors was determined by numerical simulation. The new shape factors gave accurate values of field-saturated hydraulic conductivity when tested in the laboratory. The impermeable layer causes flow around the auger hole to be primarily horizontal. Therefore, the GP method measures a predominantly horizontal field-saturated hydraulic conductivity in these thin soils. The measured conductivity represents a weighted average of the soil surrounding the submerged surface of the auger hole. In layered soil, the weight is greater for the layers close to the bottom of the hole than for those close to the top. Key words: Guelph permeameter, hydraulic conductivity, forest hydrology, permafrost, peat
Soil microbiological properties during decomposition of crop residues under conventional and zero tillage
Authors: Lupwayi N. Z. , Clayton G. W. , O’Donovan J. T. , Harker K. N. , Turkington T. K. , Rice W. A.
Published: April 2011

Field experiments were conducted to correlate decomposition of red clover (Trifolium pratense) green manure (GM), field pea (Pisum sativum), canola (Brassica rapa) and wheat (Triticum aestivum) residues, and soil organic C (SOC), under zero tillage and conventional tillage, with soil microbial biomass C (MBC), bacterial functional diversity and microbial activity (CO2 evolution). A greenhouse experiment was also conducted to relate crop residue quality to soil microbial characteristics. Zero tillage increas ed MBC only in the 0- to 5-cm soil layer. Soil MBC decreased more with soil depth than either microbial diversity or total SOC. Legume GM residues induced greater initial CO2 evolution than the other residues. This means that results that do not include the initial flush of microbial activity, e.g., by sampling only in the season(s) following residue placement, probably underestimate gas evolution from legume crop residues. Residue N, P and K contents were positively correlated with microbial functional diversity and activity, which were positively correlated with crop residue decomposition. Therefore, microbial functional diversity and activity were good indicators of microbial decomposition processes. Residue C/N and C/P ratios (i.e., high C content) were positively correlated with MBC, which was positively correlated with SOC. Therefore, soil MBC was a good indicator of soil quality (soil organic matter content). Key words: Biological soil quality, crop residues, crop rotation, microbial activity, microbial biomass, microbial diversity