bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of annual legume green-manure crops as a substitute for summerfallow in the Peace River region
Authors: Rice W. A. , Olsen P. E. , Bailey L. D. , Biederbeck V. O. , Slinkard A. E.
Published: April 2011

Field studies were conducted on a Landry clay-loam soil (Black Solod) to evaluate the effects of green manuring Tangier flatpea (Lathyrus tingitanus 'Tinga'), lentil (Lens culinaris 'Indianhead') and alfalfa (Medicago sativa 'Moapa') on subsequent barley (Hordeum vulgare 'Galt') crops. Each trial consisted of separate legume phases planted in 1984, 1985 and 1986 and barley phases in each of the subsequent years. The flatpea and lentil were incorporated (green manured) in late July or in late August to early September. The alfalfa was incorporated in late August to early September. The 3-yr mean dry matter (DM) yields of lentil and Tangier flatpea varied from 1047 to 2308 kg ha−1, with considerable variability from year to year. Alfalfa, used as an annual legume, produced 812 kg DM ha−1. Dinitrogen fixation by the annual legumes, as assayed by acetylene reduction was 16 kg N ha−1 or less. Soil moisture measurements following the legumes showed 2–3 cm less water in the profile to a depth of 120 cm following alfalfa and late-incorporated Tangier flatpea than following summerfallow and early-incorporated lentil and Tangier flatpea. Ammonium-N levels in the soil were similar following the various legume green-manure treatments. Nitrate-N levels following the legumes were variable, but the levels of nitrate-N in the plots following legume incorporation generally followed the order: fallow > early incorporation > late incorporation. The grain and N yield of barley following early-incorporated lentil and flatpea were equal to or only slightly less than the yield following fallow, suggesting that annual legumes have a good potential as green-manure crops in place of fallow in Black Solod soils of the Peace River region. Key words: Legume plow-down, soil conservation, dinitrogen fixation, soil moisture, nitrate-N
Phosphate sorption and desorption as affected by addition sequences of ammonium lignosulphonate and diammonium phosphate in a clay soil
Authors: Xie R. J. , O'Halloran I. P. , MacKenzie A. F. , Fyles J. W.
Published: April 2011

A study was carried out to evaluate the effect of ammonium lignosulphonate (NH4LS) addition on the retention and desorption of P in a clay soil. High rates of NH4LS and diammonium phosphate (DAP) were added in four experiments: (1) simultaneous NH4LS and DAP addition, (2) DAP addition as a pretreatment followed by NH4LS addition, (3) NH4LS addition as a pretreatment followed by DAP addition, and (4) incubation of the soil with NH4LS for 15 d as a pretreatment followed by DAP addition. Both NH4LS and DAP increased Ca dissolution (CaD) when added alone, but DAP decreased CaD in the presence of NH4LS. Simultaneous addition of NH4LS and DAP, or incubation of NH4LS with soil decreased dissolution of Ca. Formation of Ca-P compounds accounted for part of the increases in P retention especially at high rates of P additions. Additions of NH4LS reduced P retention, except when DAP alone was added initially to the soil. This suggests that lignosulphonate competed with phosphate ions for adsorption sites when NH4LS was added either before or simultaneously with DAP. Phosphate desorption increased with increased P retention and was greater with simultaneous additions of NH4LS and DAP. In summary, NH4LS improved the efficiency of P fertilizers through increasing P solubility. Key words: Phosphate precipitation, Ca dissolution, phosphate potential, line potential
Iron extractability from iron-humate complexes by a siderophore and a mixture of organic acids
Authors: Piccolo A. , Pietramellara G. , Celano G.
Published: April 2011

Two well-characterized humic acids (HA), extracted from a volcanic soil and a leonhardite, were used to synthesize insoluble Fe complexes. The complexes were treated at different concentrations and contact times with a siderophore (deferoxamine mesylate) and a mixture of simple organic acids (citric, oxalic, tartaric, and ketoglutaric acids) naturally occurring in root exudates in order to evaluate the capacity of the extracting solutions to desorb Fe from the humic complexes. Results showed that iron can be extracted from the complexes according to the concentrations and pH of the extractants. The mixture of organic acids was generally a better extractant than the siderophore at the high concentration because of lower solution pH. Despite constant differences in solution pH, the extracting capacity of the two extractants was similar at lower concentrations. However, the extent of desorption varied with HA characteristics. Iron appeared to be more easily released from complexes with HA rich in aliphatic carbons than from those with HA rich in aromatic carbons. These findings were attributed to the stereochemical complexity of highly aromatic humic substances that prevents natural chelators to easily reach the Fe complexing sites. Key words: Humic substances, iron, siderophores, organic acids, plant chlorosis
Effect of formulation upon movement and dissipation of 14C-metolachlor and atrazine in field lysimeters
Authors: Bowman B. T.
Published: April 2011

One set of 12 lysimeters (75 cm × 15 cm, packed with 70 cm of Plainfield sand) was treated with 14C-labelled metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methyl ethyl)acetamide] in an emulsifiable concentrate (EC) while a second set was treated with a 25% granular (25G) formulation. Atrazine [2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine] was applied to all lysimeters as an internal reference. Duplicate soil cores from each treatment were removed and frozen at 1, 2, 4, 8, 12, and 21 wk following application. All lysimeters received supplementary water throughout the study, simulating 25-yr return storms on days 2 and 9, followed by a simulated irrigation practice thereafter. Soil cores were cut into seven 10-cm segments to obtain persistence data and concentration profiles. No metolachlor and only a few traces of atrazine appeared in the effluent throughout the study. Metolachlor EC disappeared more rapidly than metolachlor 25G, with 50% disappearance times of 2.2 and 4.0 wk, respectively. After 1 and 2 wk, 14.0 and 28.7% more metolachlor 25G than EC, respectively, remained in the top 10-cm layer. No metolachlor was detected below 40 cm in any soil core. Up to 22.3% of applied 14C accumulated in the effluent after 21 wk, with traces appearing in the effluent on day 2, following a 50-mm watering. 14C recovery in the lysimeter systems decreased to 78% after 21 wk, which may be partially ascribed to volatilization losses. Key words: Leaching, degradation, radioisotope, mobility, herbicide
The influence of hexazinone on carbon dioxide evolution and mineralization of nitrogen, phosphorus and sulfur in a forest soil
Authors: Maynard D. G.
Published: April 2011

The effect of hexazinone (applied as Velpar L.) on carbon dioxide (CO2) evolution, nitrogen (N), phosphorus (P), and sulfur (S) mineralization in a surface organic layer (L–H horizons) of a forest soil was followed during a 150-d laboratory incubation. Hexazinone was applied at recommended field rates equivalent to 2 and 4 kg a.i. ha−1 and at a higher rate, 8 kg a.i. ha−1. A bioassay determined that hexazinone at 4 and 8 kg a.i. ha−1 affected the root and shoot biomass of oats for up to 63 d after application. Hexazinone had no effect on CO2 evolution, ammonification, nitrification or net S mineralization in the L–H horizons. An increase in extractable P was found in the hexazinone-treated soils at the end of the incubation. Hexazinone applied at recommended field rates of 2 and 4 kg a.i. ha−1 would have little direct impact on nutrient-cycling processes in the L–H horizons of mixed-wood cutovers. Key words: Hexazinone, carbon dioxide evolution, nitrogen, phosphorus, sulfur, forest soils
Soil properties associated with formation of barren areas on formed dykelands cropped to forage
Authors: Rodd A. V. , McRae K. B. , Harnish J. B. , Kolstee H. W.
Published: April 2011

Acadia or dykeland soils have produced forages successfully for centuries. The formation of barren areas within very productive forage stands has been noted recently in some land-formed fields, indicating either poor germination or poor growing conditions. A survey was undertaken in 1988 to determine the differences in soil attributes between barren and productive areas, namely: topographical position, resistance to penetration, bulk density, pH, plant-available P2O5, -K2O, Ca, and Mg, salt content (as measured by conductivity and sodium adsorption ratio), and exchangeable and soluble Ca, Mg, K and Na. Barren areas had greater: plant-available P2O5, resistance to penetration (the differential ranged from 480 to 1440 kPa), bulk density (in the top 15 cm), salt and sodium content than the productive ones. The exchangeable and soluble Na:Mg and Na:Ca ratios were higher on barren areas than on productive areas. Organic matter content was lower on barren than on productive areas. Values for topographic position, pH, particle size classes and plant-available K2O, Ca, and Mg were similar between the productivity areas. The results of this survey indicate that the formation of barren areas appears to be mainly due to accumulation of excess salts, especially sodium. Reasons for salt accumulation in these areas are discussed. Key words: Acadia soils, dykeland, salt, sodium, organic matter, resistance to penetration
Estimating soil loss from changes in soil cesium-137
Authors: Kachanoski R. Gary
Published: April 2011

A simple power-function equation was developed to relate changes in soil 137Cs with time to an average annual soil-loss rate. The equation accounts for tillage dilution of the concentration of 137Cs in the surface plow layer and for enrichment in the eroding soil. The predictions from the relationship were similar to values for a more complicated model and to measured values given in previous studies. Key words: Erosion rate, prediction, cesium-137
Nitrogen accumulations and relative rates of mineralization in two soils following legume green manuring
Authors: Jans-Hammermeister D. C. , McGill W. B. , Jensen T. L.
Published: April 2011

The distribution and dynamics of N following green manuring of full bloom field pea (Pisum sativum ’Sirius’) were investigated in the soil mineral, microbial and non-microbial organic (NMO N) fractions at two contrasting field sites in central Alberta; one on a Chernozemic (Dark Brown) soil near Provost and the other on a Luvisolic (Gray Luvisol) soil near Rimbey. Soils were sampled four times during a 1-yr period. The accumulations of N in the whole soil and in the soil mineral and microbial fractions were similar between sites. Net mineralization rates under controlled environments were strongly influenced by pre-incubation soil conditions. The short-term dynamics of N were distinguished best between the two soils by mineralization rates normalized to selected soil fractions rather than on the basis of N accumulation in these fractions. Net N mineralization rates expressed on the basis of soil N, microbial N or NMO N were greater in the Luvisolic soil indicating a more rapid internal N cycling system and greater activity of microbial biomass. These observations were consistent with the hypothesis that higher rates are associated with soils of lower clay content. Key words: Soil N dynamics, N mineralization rate, legume green manuring, Chernozemic, Luvisolic
Monosaccharide status of pre-Mazama Ahb horizons in Alberta, Canada
Authors: Dormaar J. F.
Published: April 2011

Palaeosols, formed prior to deposition of Mazama tephra (6600 yr B.P.), are widespread in Alberta. Palaeo-Ahb horizons are readily identifiable, with colors ranging from very dark gray to gray and brown. Establishment of fundamental and stable properties of the original organic matter would facilitate the classification of these buried soils. Use of a suite of eight monosaccharides divided the 15 palaeosols examined in this study into one group of three, possibly formed under Brown Chernozemic soil-forming conditions or drier, and the remainder, possibly formed under Black Chernozemic soil-forming conditions. The former had C/N ratios approaching those of microorganisms and low xylose to mannose ratios. It is concluded that, because of the long time-window of surface stability between deglaciation and the Mazama tephra fall, pre-Mazama palaeosols can only be studied on a site-specific basis. Grouping these palaeosols, based on their pre-Mazama tephra deposition only, is not realistic. Synthesis of a unified hypothesis of palaeoenvironmental conditions is, therefore, not possible using only their monosaccharide status. Key words: Holocene soils, palaeosols, buried soils, monosaccharides, landscape
Effect of KCl on bioavailability of manganese
Authors: Tu S. , Racz G. J.
Published: April 2011

Studies were conducted to determine whether KCl application alone or in combination with Mn fertilizer would increase the bioavailability of indigenous and applied Mn and to study the mechanisms by which KCl could enhance Mn uptake by crops. The effect of rates of application (0, 50, 100 and 300 μg K g−1) of two KCl carriers (fertilizer grade and reagent grade KCl), as well as the effects of various salts (KCl, MnSO4, K2SO4, K2CO3, KCl + MnSO4, and KCl + MnSO4 + KI) on Mn uptake by wheat were examined. The effect of KCl on the solubility of soil Mn and applied Mn and the effect of K2SO4 on solubility of soil Mn were examined in calcareous and noncalcareous soils.The two KCl carriers behaved similarly in affecting Mn uptake by wheat. On the calcareous soil only the highest rate of KCl significantly enhanced Mn uptake, whereas on the slightly acidic soil both 100 and 300 μg K g−1 treatments significantly increased Mn uptake. Different salts differed significantly in affecting Mn uptake by wheat, and their effect was observed in the order KCl > K2SO4 > > K2CO3 in both soils, with Mn uptake with K2CO3 being less than in the control. Application of KCl alone, at the higher rates, was as effective as MnSO4 alone in increasing Mn uptake by wheat. Mn uptake by wheat with dual application of MnSO4 and KCl was greater than with separate applications of MnSO4 or KCl. Addition of KCl to MnSO4 fertilizer bands increased amounts of water-soluble Mn in the fertilizer bands. K2SO4 was almost as effective as KCl in increasing water-soluble Mn in MnSO4 fertilizer bands but only for short periods of time (1–3 d). In contrast, KCl increased Mn solubility in the MnSO4 bands for periods up to 56 d. Key words: KCl fertilizer, KCl-enhanced Mn uptake, Mn availability, Mn solubility
SHORT COMMUNICATION: Distribution of cesium-137 in uncultivated Black Chernozemic landscapes
Authors: Pennock D. J. , Anderson D. W. , Jong E. de
Published: April 2011

The spatial distribution of cesium-137 was examined at two uncultivated sites in the Black soil zone of Saskatchewan. Although considerable variability occurred at both sites, the variability was not systematically related to landscape position. Between 9 and 16 samples need to be taken from uncultivated grassland sites to reliably estimate the mean 137Cs concentration at such sites. Key words: Cesium, soil redistribution, landscape
Changes in forms of soil zinc after 23 years of cropping following clearing of a boreal forest
Authors: Soon Y. K.
Published: April 2011

The long term effects of cropping systems on changes in forms of soil Zn following clearing of a poplar (Populus sp.) forest were determined by a sequential extraction procedure. Another objective was to determine from these changes the forms of available soil Zn. Four cropping systems were imposed on the broken land in 1968: (i) continuous barley, (ii) continuous bromegrass, (iii) continuous legume (alfalfa or red clover) and (iv) barley-hay rotation (3 yr each in barley and bromegrass-red clover hay). Only N and P fertilizers were applied annually. Soil (0–15 cm depth) samples taken in the spring of 1968 and in the autumn of 1977 and 1990 were extracted sequentially with (a) 1 M MgCl2, (b) 0.2 M CuCl2, (c) 0.1 M NH2OH.HCl (pH 3.0), (d) 0.2 M (COONH4)2 at pH 3.0 and (e) 0.2 M (COONH4)2 + 0.1 M ascorbic acid at 100 °C. The extracted Zn was assumed to be, respectively, exchangeable (ZnEX), chemisorbed by organic matter and hydrous oxides (ZnADS), associated with reducible Fe and Mn oxides (ZnRO), occluded by amorphous Fe and Al oxides (ZnAMO), and occluded by or coprecipitated with crystalline Fe and Al oxides (ZnCRO). The following changes in soil Zn were observed: (i) ZnEX and ZnADS decreased, (ii) ZnRO and especially ZnAMO increased, (iii) ZnCRO remained constant. Labile (DTPA) Zn decreased, but total extractable Zn increased. Zinc removed in the harvested crop was considerably less than the decrease in labile Zn. Therefore, it is concluded that (i) agricultural cropping mobilized soil Zn in the order forage legume > grass and cereal crops; (ii) only ZnEX and ZnADS were readily plant-available; and (iii) some available Zn changed to less available forms (oxide-associated). Key words: Available Zn, crop type, labile Zn, sequential extraction, Zn fractions
Response of Kochia scoparia to nitrogen fertilization on a saline soil
Authors: Steppuhn H. , Green D. G. , Knipfel J. E. , Coxworth E. , Kernan J. A.
Published: April 2011

Kochia scoparia (L.) Schrad. naturally invades mechanically disturbed soils in the Brown and Dark Brown soil zones of the Canadian Prairies and offers potential as a forage crop in saline environments. A 3-yr study conducted on severely saline soil (~ 11 dS m−1) near Swift Current, Saskatchewan, evaluated the production of kochia forage and plant-N uptake following applications of 0, 56, 112 and 168 kg N ha−1 of ammonium nitrate. The yield response in aboveground, dried forage (Y) followed a curvilinear function based on the quantity of nitrogen applied (N): Y = 4740 + 38.5N − 0.121N2. The N-fertilizer requirement to produce 7500 kg ha−1 of dried forage (96% of the function maximum) equalled 110 kg N ha−1 and reflected average growing conditions at the study site during 1987–89. The kochia assimilated protein N (Kjeldahl) within its tissue in direct proportion to the fertilizer dosage applied, reaching theoretical maxima which varied yearly: 18 g kg−1 in 1987, 12 g kg−1 in 1988 and 22 g kg−1 in 1989. Although NO3-N concentrations increased with each addition of fertilizer N, the maximum accumulation of NO3 N (0.5 g kg−1) among all the tests and treatments was within the safe limit of 1.1 g kg−1 to avoid livestock poisoning. The efficiency with which the fertilizer N was assimilated by the kochia ranged between 44 and 69% over the test years and fertilizer treatments. Key words: Saline soil, N fertilization, kochia forage, soil fertility, salinity
Effect of various sources of selenium fertilization on the selenium concentration of feed crops
Authors: Gupta Umesh C. , MacLeod J. A.
Published: April 2011

This study was conducted in Prince Edward Island (PEI) Canada to determine the effect of various sources of selenium (Se) (i) sodium selenate (ii) selcote (iii) selcote 2 year and (iv) lime coated Se-granules on the Se concentration in cereals, forages and soybeans. All sources were applied to the soil at 10 g Se ha−1. For soybeans, sodium selenate was also applied as a foliar spray. All sources, in the year of application, proved effective in raising the feed crop Se to more than 100 μg Se kg−1, the minimum level required to prevent Se deficiency diseases in livestock. Lime coated Se granules resulted in much lower Se in all crops than other Se sources. Selenium concentration in soybean grain was higher than in cereals and forages treated with Se. Selenium concentration in soybean grain was higher following foliar applications of sodium selenate (3005 μg kg−1) than following soil application (1930 μg kg−1). Experiments conducted at a second location produced similar results. In most cases, soybean grain contained higher Se than either the whole plant or leaves. Selcote resulted in significantly higher Se, during the first year in soybean and forages, than selcote 2 year. This relationship was not consistent on cereals. Selenium concentrations in the second year crop of soybeans were below the minimum required level of 100 μg kg−1 needed to prevent Se deficiency in livestock for all Se sources except for the selcote 2 year source. Only the latter Se source resulted in a Se concentration of > 100 μg kg−1 for 2 yr. Soybeans fertilized with Se should prove to be an excellent feed crop for enriching grain with Se. Key words: Podzol soils, selcote, sodium selenate, barley, oat, forages, soybeans, crop Se
The effects of tillage systems and crop rotations on soil chemical properties of a Black Chernozemic soil
Authors: Grant C. A. , Lafond G. P.
Published: April 2011

The effects of zero (ZT), minimum (MT) and conventional tillage (CT) systems and three 4-yr crop rotations on soil total C and N, mineralizable N, NO3-N, P, K and SO4-S accumulation and distribution in the soil profile were determined after one 4-yr cycle of crop production on Black Chernozemic Indian Head heavy clay soil. The distributions of available P and K in the profile were not affected by tillage or rotation. Total C and N in the 0–5 cm depth was higher in the reduced tillage systems than in CT, but differences in the 5–10 cm and 10–15 cm depths were not significant. Nitrate concentration was higher in the 15–30 cm and 30–60 cm depths under CT than under reduced tillage. Inclusion of fallow increased accumulation of NO3-N in the deeper soil depths, while inclusion of winter wheat in the rotation reduced deep movement of NO3-N. Nitrate-nitrogen accumulation after field pea production was comparable to that after winter wheat, but a greater proportion of the NO3-N was present near the soil surface after winter wheat, reducing the potential for leaching below the rooting zone. Potential for movement of NO3-N below the rooting zone may be increased by fallow and decreased by production of winter wheat and by reduced tillage systems. Key words: Tillage, rotations, nitrate, sulphate
Cation exchange capacities of upland soils in eastern Canada
Authors: Meyer W. L. , Arp P. A. , Marsh M.
Published: April 2011

Relationships between cation exchange capacity (CEC), clay and organic carbon contents and soil pH were analyzed by way of multiple regressions for upland soils in eastern Canada (mostly Ontario, with additional data for New Brunswick). This was done by vegetation type in an attempt to explain some of the otherwise unexplained CEC variations. Data were taken from about 2000 soil horizons (organic L, F, and H horizons as well as A, B, and C mineral soil horizons) under broadleaves (mostly maples, beech, birch or aspen as dominant species), conifers (mostly fir, spruces and/or pines), and grass vegetation. For the organic forest floor horizons (or L, F, and H horizons), both organic carbon content (%) and pH were highly significant for predicting CEC, i.e.,CEC (L, F, and H of broadleaves) = −38 + 0.71 × org. C (%) + 10.3 × pH (R2 = 0.69), andCEC (L, F and H of conifers) = −31 + 0.34 × org. C (%) + 12.1 × pH (R2 = 0.58).For the mineral soil, clay and organic carbon contents (%) and pH were highly significant for predicting CEC. Soils with forest vegetation were found to have lower contributions of organic matter to CEC than grassland soils, i.e.,CEC (forest soils) = −7.0 + 0.29 × clay (%) + 0.82 × org. C (%) + 1.4 × pH (R2 = 0.72),CEC (wooded grasslands) = −6.0 + 0.31 × clay (%) + 1.31 × org. C (%) + 1.0 pH (R2 = 0.74), andCEC (grasslands) = −8.3 + 0.24 × clay (%) + 2.14 × org. C (%) + 1.3 × pH (R2 = 0.79).Relationships that were developed from Ontario data for specific vegetational types (maple sites, strongly podzolized conifer sites, grasslands/croplands) were tested by comparing CEC predictions with reported values for similar sites in New Brunswick and Quebec. The predictions were consistent with the general trends for maple sites and grasslands/croplands, but CEC values were strongly overpredicted for Podzolic subsoils on conifer sites.Literature information of the CEC dependency on in situ pH is sparse. Existing information that is based on buffering grassland/cropland soil samples from pH 2.5 to 8 appears to mimic this dependency quite well. Key words: Cation exchange capacity, clay, organic carbon, soil pH, forests, grasslands
Effects of potato hilling on water runoff and soil erosion under simulated rainfall
Authors: Chow T. L. , Rees H. W.
Published: April 2011

The practice of planting potatoes (Solanum tuberosum) in rows and hilling the plants at some stage of growth has been universally adopted. Using a rainfall simulator and runoff-erosion plots (0.9 m wide × 1 m long), the effects of hilling on runoff, infiltration, and soil loss were examined on an Orthic Dystric Brunisol. Tests of the rainfall simulator revealed that variations in operating pressure (36.5–62.1 kPa) and soil slope conditions (0–15%) did not significantly (P < 0.05) affect the intensity and spatial uniformity of the simulated rainfall. The potato hills studied were 90 cm apart with heights of approximately 25 cm, row-sideslopes of 35° and furrow widths of 10 cm, which are similar to those used in commercial production. Although not significantly different at P < 0.05, the runoff rate from the hilled plots was approximately 20% higher than that from the unhilled plots. Hilling resulted in a significant reduction in infiltration rate (P < 0.05). Average soil loss from the hilled plots was approximately four times higher than from the unhilled plots. For runoff rates below a critical value of 0.93 L min−1, the rate of soil loss correlated linearly with the runoff rate, whereas a non-linear exponential equation was generated for the entire range of runoff with r = 0.94. The increase in soil loss as a result of hilling was adequately predicted from row-sideslope gradients using an existing equation derived from erosion data obtained from fields having conditions similar to that of potato hills. Key words: Universal soil loss equation, slope steepness, cover and management factor, row-sideslope, spatial uniformity, infiltration
SHORT COMMUNICATION: Sorption of benzene, toluene, and o-xylene by collagen compared with non-protein organic sorbents
Authors: Xing B. , McGill W. B. , Dudas M. J.
Published: April 2011

Our previous work has demonstrated a relationship between polarity index and organic carbon referenced partition coefficients (Koc) of organic chemicals. Here we compare sorption of benzene, toluene, or o-xylene by protein with non-protein organic sorbents. Koc for benzene, toluene, or o-xylene sorption by collagen was much higher than by lignins, humic acid, chitin, or cellulose. Sorption of benzene, toluene, or o-xylene was not only influenced by organic sorbent polarity and functionality (e.g., aromaticity), but also by additional properties which we inferred related to physical conformation of the organic sorbents. In this respect, collagen exhibits unique sorptive behavior toward removal of nonpolar organic chemicals in the aqueous phase, which was not shared by humic acids of similar C, O or N content. Key words: Sorption, collagen, lignin, polarity, hydrophobic domains
Availability of manure slurry ammonium for corn using 15N-labelled (NH4)2SO4
Authors: Paul J. W. , Beauchamp E. G.
Published: April 2011

The NH4+ fraction of animal manure slurry is often considered to be as available as fertilizer N to a crop; however, immobilization and losses via denitrification and NH3 volatilization may be higher in manured than in fertilized soil. The apparent N recovery and the 15N recovery methods were used for corn (Zea mays L.) grown in soil amended with dairy cattle slurry and NH4+ fertilizer to determine the source of the N taken up by corn plants. Manure slurry or (NH4)2SO4 fertilizer were applied at rates equivalent to 100 kg NH4+–N ha−1 in the greenhouse and the field. In the greenhouse, the apparent NH4+–N uptake by corn was 76 and 85% with animal manure slurries and NH4+ fertilizer, respectively. In the field, apparent N recovery of NH4+ from dairy cattle slurry and (NH4)2SO4 was 43 and 58%, respectively, whereas 15N recovery from the same treatments was 15 and 29%, respectively. The lower 15N recovery values compared with the apparent recovery values suggest that mineralization-immobilization turnover (MIT) occurred, and that MIT was greater in manured soil than in fertilized soil. A laboratory incubation study showed greater microbial biomass and more 15N immobilization in soil amended with dairy cattle slurry than in soil amended with fertilizer. Key words: Animal manure slurry, nitrogen, corn, N recovery, 15N microplots
The relative importance of oxalate and pyrophosphate extractable aluminum to the acidic leaching of aluminium in Podzol B horizons from the Precambrian Shield, Ontario, Canada
Authors: LaZerte Bruce D. , Findeis Joe
Published: April 2011

Four Bf and one Bhf Podzol horizon samples from the Precambrian Shield, Ontario, Canada were leached with pH 3 solutions in three different experiments to determine which soil aluminum fraction was primarily responsible for the aluminum leached into solution. For the Bf horizons, it was primarily the oxalate-extractable aluminum fraction (corrected for pyrophosphate, Alo–Alp); for the Bhf horizon it was equally the pyrophosphate (Alp) and Alo–Alp. A comparison with other studies suggests that when the ratio (Alo–Alp)/Alp is above 0.3–0.7, the oxalate-extractable fraction will be most important, and at lower ratios the pyrophosphate fraction becomes most important. The pattern of fluoride leaching in these experiments suggests that F was concentrated primarily on the surface of the amorphous aluminum fraction. Key words: Aluminum, silica, fluoride, Podzol, acid deposition
SHORT COMMUNICATION: Herbicides in surface runoff and groundwater under surface irrigation in southern Alberta
Authors: Miller J. J. , Foroud N. , Hill B. D. , Lindwall C. W.
Published: April 2011

In 1991, up to 38 g L−1 hexazinone was found in 50% of surface runoff and 27% of groundwater samples at Lethbridge. No herbicides were detected in surface runoff from irrigation at Taber, but 2,4-D, bromoxynil, dicamba, mecoprop, MCPA and diclofop were found in 48, 34, 21, 16, 13 and 9%, respectively, of groundwater samples, and bromoxynil exceeded the Canadian drinking guideline (5.0 μg L−1) in 11% of samples. Key words: Herbicides, surface irrigation, surface runoff, groundwater
Onion response to ammoniated peat and ammonium sulfate in relation to ammonium toxicity
Authors: Abbès C. , Parent L. E. , Karam A. , Isfan D.
Published: April 2011

The objective of this study was to evaluate the effects of intermediate to high rates of granulated mineral or organo-mineral fertilizers on onion N uptake, nutrient balance, root growth and water influx. Ammonium sources were ammoniated peat (AP), ammonium sulfate (AS) and peat treated with ammonium sulfate (PAS). Onion was grown for 84 d in four soils at five N levels under growth-chamber conditions. Root length, N uptake, and root growth rate were influenced significantly by soil type, N source and N rate and were highest with 133 and 266 mg N kg−1 on loamy soils. On a sandy soil, maximum N uptake was obtained with 133 mg N kg−1. Water influx was influenced significantly by soil type and N application rate and reached its maximum value with 133 mg N kg−1. AP produced the greatest N uptake, root length and root growth rate. Except in the sandy soil, the highest water uptake was also obtained with AP. Compositional nutrient diagnosis (CND) indicated that plants fertilized with AP achieved a more adequate nutrient balance (or the lowest d value) over a larger range of N rates (133–266 mg N kg−1) than AS and PAS. AP, thus, attenuated ammonium toxicity to the crop more than AS and PAS. At AP rates exceeding 266 mg N kg−1, CND indicated a nutrient imbalance involving P or K deficiency. Key words:Allium cepa L., ammoniated peat, compositional nutrient diagnosis, root growth, water influx
Effect of selenium seed treatment on selenium concentrations in soybeans
Authors: MacLeod J. A. , Gupta Umesh C.
Published: April 2011

This study was conducted in Prince Edward Island (PEI), Canada, to determine the effect selenium (Se) treated seed on Se concentrations in soybean seed (Glycine max). Seed Se concentrations were also compared to those obtained with foliar applied Se. An application of 10 g Se ha−1 as seed treatment raised soybean Se concentrations to more than 0.5 mg kg−1. Soybeans with these Se concentrations, when included in rations at 200 kg t−1 with other low Se ingredients, would produce rations exceeding 0.1 mg Se kg−1, i.e., the minimum level required to prevent Se deficiency in livestock. Seed treatment with 100 g Se ha−1 produced soybean Se concentrations greater than 10 mg Se kg−1. When included in rations at 200 kg t−1 with other low Se feed sources, soybeans with such Se levels would produce rations in excess of the maximum tolerable dietary concentration of 2 mg Se kg−1 dry matter. Even higher soybean Se concentrations were obtained from equivalent Se rates when applied as foliar spray. In summary, treatment of soybean seed with Se has a potential for improving the Se status of rations that would be formulated with ingredients originating from Se deficient areas. Key words: Foliar applied Se, seed Se, sandy loam, Eastern Canada
A method for characterizing the effect of root-formed pores on growth of roots in a Chernozemic clay loam
Authors: Volkmar K. M. , Entz T.
Published: April 2011

Channels previously occupied by roots (biopores) may assist growth of roots through high-strength soils. This experiment was conducted to evaluate a method for determining the relationship between biopore frequency and root growth. Undisturbed cores were obtained from 5–10, 15–20, 25–30, and 35–40 cm depths of a conventionally tilled (CT) and a no-till (NT) Brown Chernozemic soil. The density distribution of small-diameter (200–500 μm), intermediate-diameter (500–1000 μm), and large-diameter (> 1000 μm) diameter pores was assessed visually. Pots containing wheat (Triticum aestivum L.) plants were placed on top of the cores and the number of roots that appeared at the bottom of the cores was measured after 120 and 168 h. Significantly fewer roots emerged from NT than from CT cores at all depths except 15–20 cm. Only pores in the 500–1000 μm (P-500) pore class correlated with root number. Root number correlated negatively with penetration resistance (PR). Path coefficient analysis revealed that the direct effects of P-500 pores and PR accounted for 24.7 and 19.3% of the variation in root number, respectively. The method described appears to be a useful tool for quantifying the relationship between pore density and root growth. Key words: Biopores, macroporosity, penetrometer resistance, root growth, soil strength, tillage
Carbon and nitrogen losses from undisturbed soil columns under short-term flooding conditions
Authors: Wang F. L. , Bettany J. R.
Published: April 2011

Short-term flooding (few days to several weeks) of usually well-drained soils — often occurring after snowmelt in spring and after heavy precipitation in summer — is a natural event in many regions of the world. Using incubation-leaching and gas sampling techniques in the laboratory, we examined the impact of flooding on the loss of carbon and leaching of nitrogen from five undisturbed soil columns. The soils varied in management, salinity and carbon content. After 8 wk of incubation, the amounts of soluble organic carbon leached by 0.001 M CaCl2 solution from flooded soils ranged from 153 to 630 mg C kg−1. In contrast, only 28–107 mg C kg−1 was leached from nonflooded soils. The amounts of soluble organic nitrogen leached from the flooded soils ranged from 10 to 30 mg N kg−1 compared with 5.9–12 mg N kg−1 from nonflooded soils. In the flooded soils, ammonium nitrogen dominated the total inorganic nitrogen leached (99.5–99.9%) whereas in nonflooded soils leachable N was mainly nitrate and nitrite (97.4–99.9%). Methane was emitted from the flooded soils (10–138 mg C kg−1 over 8 wk). The rate of carbon dioxide evolution in flooded soils increased linearly with time and total evolution ranged from 72 to 552 mg C kg−1, whereas CO2 evolution in the nonflooded soils was steady with total evolution ranging from 159 to 1279 mg C kg−1 after 8 wk. Key words: Prairie and forest soils, short-term flooding, C and N losses, methane emission
Field scale fertilizer recommendations: The spatial scaling problem
Authors: Kachanoski R. G. , Fairchild G. L.
Published: April 2011

Soil fertility may vary considerably within a field. The effects of variable soil fertility on the relationships among average crop yield response, average soil test, and fertilizer applied evenly to a field have not been examined. This paper develops stochastic equations to describe the average yield gain on a field basis from the application of a single constant rate of fertilizer, in fields with variable soil fertility. The equations are solved numerically for the specific case of nitrogen fertilizer on corn (Zea mays L.) in Ontario, Canada. The results suggest that since the relationships among yield response, soil test, and applied fertilizer are non-linear, a single soil test calibration cannot exist for fields with different spatial variability. Soil test calibrations obtained from sites with low variability (for example small plots) will not hold for sites with higher variability (for example farm fields). Calibrations obtained from sites with low variability will under-predict the optimum economic fertilizer rate for sites with low variability will under-predict the optimum economic fertilizer rate for sites with high variability. The results do not invalidate soil test calibration relationships per se. The challenge is to combine these calibrations with additional knowledge about the spatial distribution and field-scale variability of soil test values in order to maximize economic benefit. Key words: Spatial variability, soil test, fertilizer recommendation, yield, corn, field scale
SHORT COMMUNICATION: Estimation of microbial biomass by ninhydrin-reactive N using liquid chloroform
Authors: Mele P. M. , Carter M. R.
Published: April 2011

Ninhydrin-reactive N (NRN), which is a reliable and sensitive indicator of soil microbial biomass, was measured in extracts of three Australian duplex soils, under different tillage systems, fumigated using either vaporized or liquid CHCl3. Although the relationship between the two fumigation-extraction methods was influenced by soil type, the use of liquid CHCl3 appears to be a promising technique to allow greater ease and speed for releasing NRN in microbial biomass analysis. Key words: Duplex soils, tillage, microbial biomass, fumigation-extraction method
Soil solution chemistry and alfalfa response to CaCO3 and MgCO3 on an acidic Gleysol
Authors: Su Chunming , Evans L. J.
Published: April 2011

Soil acidity is a limiting factor for forage production. Liming is a common agricultural practice for acid soils, yet there is limited information on the effects of soil solution chemistry in response to liming. Soil from the Ap horizon of an Orthic Humic Gleysol was amended with 0, 2.5 or 5.0 g CaCO3 kg−1 and 2.1 or 4.2 g MgCO3 kg−1 to determine the changes due to liming in soil solution composition before planting and after three cuts of alfalfa (Medicago sativa L.). The soil solution samples were extracted by immiscible displacement with C2Cl4. The low equivalent rate of CaCO3 and MgCO3 decreased the concentrations of Fe from 889 to less than 22 μM, Mn from 286 to less than 6 μM, Al from 45 μM to undetectable level before plant growth. Soil pH, dissolved organic carbon (DOC), Cu and NH4-N concentrations in the soil solutions extracted after the third cut of alfalfa were increased compared with those measured before planting. Concentrations of Ca, Mg, K, Na, Mn, Zn, Fe, Al, NO3-N, SO4 and Si were all decreased after the third cut compared with those measured before planting. Step-wise multiple regression analysis indicated that the dry matter (DM) yield of the first cut was positively correlated to NO3-N and negatively correlated to Mn concentration in the soil solutions (R2 = 0.65**); whereas the DM yield of the second and third cuts and of the roots were negatively correlated with Mn concentrations (R2 = 0.75**, 0.63**, and 0.60**, respectively). The regression analysis supported visual Mn toxicity, suggesting that Mn toxicity, not Al concentration, was the main limitation to alfalfa growth in unlimed soil. Key words: Alfalfa, liming, soil solution chemistry, immiscible displacement, plant nutrition
Simulation of soil moisture and other components of the hydrological cycle using a water budget approach
Authors: Akinremi O. O. , McGinn S. M. , Barr A. G.
Published: April 2011

Accurate simulation of soil moisture content at any time of the year is important to agriculture in dry regions due to the vital role soil moisture plays in crop production. In certain applications such as drought monitoring, other components of the hydrologic cycle such as runoff, snowmelt runoff, deep drainage and evaporative loss must also be accurately estimated. The goal of this study was to develop a model which accurately accounts for the major components of the hydrological cycle in order to simulate soil moisture content for drought monitoring and crop yield prediction. The versatile soil moisture budget (VSMB) was evaluated and modified to improve the prediction of soil moisture content runoff from rainfall and snowmelt, drainage of moisture out of the root zone and soil surface temperature. The modified components of the model were independently tested and validated using field and published data. The soil moisture output from our modified model correlated well with observed changes in soil moisture during the growing season under wheat, fallow and over the winter. The moisture content of the surface layer was simulated with greater accuracy than that of deeper layers. The soil moisture simulated by the modified model compares better with measured values than that simulated using the original version of the VSMB. The simulation of snow dynamics at Lethbridge, a chinook-dominated region, gave credibility to the snowmelt runoff predicted by the model. Key words: Soil moisture, modelling, runoff, evapotranspiration, snowmelt, Canadian prairies
Total elements in forest soils affected by acid deposition in southern Quebec
Authors: Lin Z. Q. , Hendershot W. H. , Schuepp P. H. , Kennedy G. G. , Dutilleul P.
Published: April 2011

Major and trace elements (Al, As, Ba, Ca, Cd Co, Cr Cs, Cu Eu Fe, Hf, K, La, Lu, Mg, Mn, Na, Ni, Pb, Rb, Sb, Sc, Si, Sm, Sr, Ta, Tb, Th, Ti, U, V, Yb and Zn) in forest soils from three acid-deposition-affected locations in southern Quebec were investigated. Total element concentrations in the surface layer (0–20 cm) of the Podzolic soils were mostly well within the range of element concentrations in Podzols reported worldwide but showed higher mean values for most elements. The mean concentrations of elements (except Zn, at 124 μg g−1) were also generally comparable to the respective elemental baseline data established for Canadian soils. Element concentrations (μg g−1) of Cs (6.2) Sc (19 8) V (106) Rb (194) K (26 500) and Al (76 900) in the surface soils were significantly higher at the 940-m elevation than the concentrations from the sites at 650 and 770 m along the Roundtop Mountain slope, but Ca (1120) and Ni (4.4) were lowest at the 940-m elevation A similar trend with elevation was not observed at the other mountain location (White Peak). Enrichment-factor (EF) analysis showed significant element enrichment (EF ≥ 10) for Cd, Rb and Sb but impoverishment (EF ≤ 0.1) for Ca, Cu and Ni in topsoils. Key words: Major and trace elements, surface soils, acid deposition
Impact of soil management systems on organic dwarf apple orchards and soil aggregate stability, bulk density, temperature and water content
Authors: Walsh Brice D. , MacKenzie Angus F. , Salmins S. , Buszard Deborah J.
Published: April 2011

With growing pressure to reduce pesticide use, fruit growers require an alternative to herbicidal control of weeds. One option is the use of mulches or permanent vegetative ground covers, which in turn may have advantages in promoting soil physical properties and improving growth. This study examined the short-term effects of ground cover management in two newly established dwarf apple orchards in Quebec. Effects of cultivation, composted manure mulch, straw mulch, grass cover crops, a cover crop mixture of lupin and wild carrot (mixed flora) and geotextile were determined, comparing soil aggregate stability, bulk density, temperature, volumetric water content and tree growth. Straw and geotextile mulches resulted in higher soil water contents and tree growth relative to soil under grass or mixed flora ground cover. Ground cover maintained soil aggregate stability. Soil temperatures were highest under cultivation and geotextile treatments in spring and summer months, and apple yields and growth rates were greater than for ground cover treatments. Straw mulch buffered soil from temperature variation. Little effect of mulch treatments on soil bulk density was observed. Given that soil water content was the primary factor related to optimum orchard production straw and geotextile mulches promoted soil water retention and could be considered superior management options for growers, depending on costs of establishment and maintenance of the mulches. Key words: Mulches, ground cover, bulk density, aggregate stability, soil temperature, volumetric water content
Banding urea and lignosulfonate in corn (Zea mays L.) production and 15N recovery
Authors: Alkanani Thamir , MacKenzie Angus. F.
Published: April 2011

The use of urea in corn (Zea mays L.) production is common. Under current N fertilizer recommendations for corn, urea may have adverse effects on corn growth when applied in a band. The effects of ammonium lignosulfonate (LS) on corn growth and on N uptake from the banded application of urea and diammonium phosphate (DAP) mixtures were investigated on two soils from eastern Quebec. Field experiments were initiated in the first week of May 1991 on an Ormstown silty clay and a Ste. Rosalie clay soils (fine, mixed, nonacid, mesic Typic Humaquepts). Treatments were two rates of urea (30 and 90 kg urea-N ha−1) in combination with DAP (14 kg N ha−1), with or without banded fertilizer solutions of LS (8 kg N ha−1) applied at planting 5 cm to the side and 3 cm below the seed. A no treatment control was included. The low rate of urea and DAP (no LS added) resulted in a 19 and 24% increase in grain yield at the Ste. Rosalie and Ormstown, respectively, when compared with the unfertilized plots. When compared with the unfertilized treatment, the high rate of urea and DAP (no LS added) caused 10% increase in grain yield. However, addition of LS to the high rate of urea and DAP increase grain yield by band 20%. In general, LS significantly increased corn N uptake from urea on both soils. Separate 15N field experiments were initiated in June 1991. Mean recovery of 15N in total dry matter (grain and stover) was 51.9% in Ormstown and 47.9% in Ste. Rosalie soil. Denitrification estimates, calculated as 15N not accounted for, were not affected by LS and the rate of banded urea-N. Immobilization of 15N ranged from 17.8% to 30.9% of the applied labelled urea. The rate of urea-N banded had no significant effect on immobilization, but LS resulted in significantly less 15N immobilized. These observations suggest that LS can reduce the biological immobilization of urea-N and increase the efficiency of urea fertilizer by reducing the negative effects of banding high levels of urea, while attaining benefits of band placement. Key words: Lignosulfonate, corn, urea, 15N