Chantigny, M. H., Angers, D. A., Rochette, P., Pomar, C. and Pelster, D. E. 2014. Evidencing overwinter loss of residual organic and clay-fixed nitrogen from spring-applied,¹⁵N-labelled pig slurry. Can. J. Soil Sci. 94: 1-8. In northern areas, it is assumed that soil residual mineral N measured at harvest represents the pool at risk of environmental loss during the non-growing season. Using ¹⁵N-tracing techniques we determined (i) the distribution of side-dressed pig slurry N in the mineral, organic and clay-fixed N pools of sandy loam and clay soils, and (ii) whether ¹⁵N found in each individual pool at harvest is retained or lost during the non-growing season. Pig slurry labelled with ¹⁵N was side-dressed to corn (four-leaf stage; 100 kg ha^-1 total N) and traced in soil (0-60 cm) and plants for 2 yr. Pig slurry contained 60% of its N as NH₄. During the growing season, applied N accumulated in the clay-fixed N pool in the clay soil, and in the organic N pool in both soils. At harvest, less than 5% of side-dressed N was present as soil mineral N, whereas 60 to 65% was in the organic and clay-fixed pools. Although these forms are considered immobilized, one-third to one-half was lost during the non-growing season. This work provides evidence that the soil organic and clay-fixed N pools contribute to the loss of soil N during the non-growing season in cold areas, which should be included in future indicators for the risk of soil N loss.

Li, Y., Han, J., Wang, S., Brandle, J., Lian, J., Luo, Y. and Zhang, F. 2014. Soil organic carbon and total nitrogen storage under different land uses in the Naiman Banner, a semiarid degraded region of northern China. Can. J. Soil Sci. 94: 9-20. Accurate investigation of soil organic carbon (SOC) and total nitrogen (TN) storage at a regional level is important for detecting changes in the C and N sequestration and emission potentials induced by land-use and cover type changes. In a degraded semiarid region of northern China's Horqin Sandy Land, we selected 208 locations and calculated SOC and TN storage to a depth of 100 cm for the main land-use and cover types. The productive cropland on former grassland had the highest level of SOC and TN storage (6613 g C m^-2 and 709 g N m^-2). The corresponding storage values were 3758 g C m^-2 and 402 g N m^-2 in degraded grassland, 3449 g C m^-2 and 373 g N m^-2 in afforested dunes, 2674 g C m^-2 and 320 g N m^-2 in unproductive cropland on former dunes, and 1109 g C m^-2 and 129 g N m^-2 in sand dunes (from mobile to fixed). The average soil bulk density was highest in sand dunes, with a value of 1.59 g cm^-3, and lowest in productive cropland on former grassland, with a value of 1.39 g cm^-3. The conversion of severely degraded sandy land into other land-use and cover types therefore has considerable potential to partially offset the SOC and TN loss during the past century that has resulted from desertification in the Horqin Sandy Land.

Harrison, D. J. and Maynard, D. G. 2014. Nitrogen mineralization assessment using PRS™ probes (ion-exchange membranes) and soil extractions in fertilized and unfertilized pine and spruce soils. Can. J. Soil Sci. 94: 21-34. Several assay approaches that measure mineralizable nitrogen (N) have been used, with varying success, to assess the N supply power of soil. We compared Plant Root Simulators (PRS™ probes, Western Ag Innovations, Inc., Saskatoon, SK) with chemical extractions in an incubation to evaluate how these methods quantify N-mineralization activity of forest soils. Nitrogen mineralization was compared in spruce- and pine-forest soils that had varying N status and had been subjected to 14 yr of N-based fertilization. We paired the assays to determine how the measures co-varied after 1, 2, 4, 6, 8, 10 and 12 wk of incubation. Significant correlations existed between PRS probes and extractable ammonium () in the spruce (r=0.567, P<0.001) and pine (r=0.730, P<0.001) soils, although trendlines differed by soil type. Nitrate ()- PRS relationships were evident only in the spruce soils (r=0.916, P<0.001), as the pine soils produced minimal . Both assays provide opportunities for assessing N-mineralization processes in forest soils and differences between assays appear to be related to soil N availability. The PRS probes responded primarily to factors affecting ion mobility because of the cumulative nature of the PRS probes; whereas the static soil extractions were more sensitive to variations in mineralization and immobilization fluxes.

Malhi, S. S., Johnson, E. N., Hall, L. M., May, W. E., Phelps, S. and Nybo, B. 2014. Effect of nitrogen fertilizer application on seed yield, N uptake, and seed quality ofCamelina sativa. Can. J. Soil Sci. 94: 35-47. Camelina [Camelina sativa (L.) Crantz] is a new crop to western Canada, and research information on its response to nitrogen fertilizer is lacking. Two field experiments were conducted from 2008 to 2010 in Saskatchewan and Alberta, Canada, to determine the effect of N fertilizer application on camelina plant establishment, seed and straw yield, total N uptake in seed and straw, seed oil and protein concentration, N fertilizer use efficiency (NFUE) and percent recovery of applied N (%NR) in seed. Nitrogen fertilizer rates ranged from 0 to 160 kg N ha^-1 in exp. 1 and from 0 to 200 kg N ha^-1 in exp. 2. There was generally no detrimental effect of high N rates on plant establishment, with the exception of 1 site-year in which there was a slight linear decline in plant density as N rate increased. Seed yield, total N uptake in seed, NFUE and %NR responded to applied N rates at most site-years. Seed yield and total N uptake in seed usually increased while seed NFUE and %NR decreased with increasing N rate. Response trends of yield and total N uptake of straw to applied N were similar to that of seed at the corresponding site-years. Seed oil concentration decreased while protein concentration increased with increasing N rate. In exp. 1, fertilizer rates were not high enough to attain a maximum seed yield; however, maximum seed yields of 2013 kg ha^-1 were achieved at an N rate of 170 kg N ha^-1 in exp. 2. In conclusion, camelina responded to fairly high rates of applied N similar to responses reported for Brassica juncea on the Canadian prairies.

Rees, H. W., Chow, T. L., Zebarth, B., Xing, Z., Toner, P., Lavoie, J. and Daigle, J.-L. 2014. Impact of supplemental poultry manure application on potato yield and soil properties on a loam soil in north-western New Brunswick. Can. J. Soil Sci. 94: 49-65. The effect of timing of supplementary poultry manure applications on potato (Solanum tuberosum L.) yield and quality and soil properties of degraded soils in the New Brunswick potato belt were assessed. Four treatments on an 11% slope consisted of a control (11% - Ctrl) and applications of 4 Mg ha^-1 of fresh broiler poultry manure applied either in late fall (11% - F), pre-planting (11% - PP) or pre-hilling (11% - PH). Similar treatments were set out on an 8% slope with exception of the pre-planting treatment. Manure applications enhanced potato plant N status as measured by petiole concentration. Over the 3-yr experiment, poultry-manured treatments averaged 13 to 17% more annual total tuber yield and 19 to 34% more annual marketable tuber yield than the unmanured control. Poultry-manured treatments had fewer tubers in the small category and increased the proportion of tubers in the No. 1 and 10 oz. categories. Tuber yields were similar with fall-applied manure and with manure applied at pre-hilling. Manure did not induce either scab or hollow heart. Manure reduced tuber specific gravity. After three annual applications of poultry manure, soil P, K, B, Cu, Na, S and Zn increased significantly. Soil organic carbon did not change significantly after three annual poultry manure applications, but there was an increase in soil CO₂ concentrations, earthworm populations and infiltration. Repeated manuring did not improve saturated hydraulic conductivity, matrix bulk density, field capacity, available-water-holding capacity or wet aggregate stability, and no consistent response in soil temperature or soil water content occurred. We conclude that low, repeated applications of poultry manure would benefit tuber yield and soil biological properties, but soil physical properties would be slower to change.

Lafond, J. 2014. Fertilisation calcique et magnésienne dans la production du bleuet nain sauvage au Québec. Can. J. Soil Sci. 94: 67-76. L'accroissement de la productivité du bleuet nain sauvage (Vaccinium angustifolium Ait.) a eu pour conséquence de diminuer les concentrations foliaires en calcium (Ca) et en magnésium (Mg) sous les seuils minimaux de suffisance assurant une croissance optimale des plantes. Ainsi, les objectifs de l'étude ont été de déterminer l'impact de l'apport d'amendements calcique et magnésien sur la productivité du bleuet et sur les propriétés physico-chimiques du sol. Quatre doses de sulfate de Ca (0, 540, 1080 et 2160 kg ha^-1) et de sulfate de Mg (0, 31,5, 63 et 94,5 kg ha^-1) ont été appliquées au printemps de l'année de végétation. Le pH a augmenté significativement de 0,4 et 0,1 unité avec les apports de Ca dans les couches de sol 0-5 et 5-20 cm respectivement. Des accumulations significatives de 746 et de 53 mg kg^-1 de Ca et de Mg respectivement ont été mesurées dans la couche de sol de surface à la suite des applications des amendements comparativement au témoin. Des augmentations de Ca ont été également mesurées dans la couche 20-40 cm indiquant qu'une partie du Ca a été lixiviée. Les concentrations en N, P, K et Ca dans les feuilles ont augmenté significativement avec les apports de Ca. Les apports de Mg ont augmenté la concentration en Mg dans les feuilles. Le rendement moyen en fruits a été de 3042 kg ha^-1 mais n'a pas été significativement influencé par les traitements. La densité de tige a diminué avec les apports de Mg tandis que le nombre de bourgeons floraux et la taille des plants n'ont pas été influencés. Quoique les apports de Ca et de Mg aient permis d'accroître les concentrations en éléments nutritifs dans les feuilles et dans le sol, la productivité de la culture n'a pas augmenté.

Jayasundara, S., Wagner-Riddle, C., Dias, G. and Kariyapperuma, K. A. 2014. Energy and greenhouse gas intensity of corn (Zea mays L.) production in Ontario: A regional assessment. Can. J. Soil Sci. 94: 77-95. Analysis of the environmental impact of corn (Zea mays L.) uses, such as biofuels and bioproducts, requires cradle to farm-gate life-cycle analysis of energy use and net greenhouse gas (GHG) emissions associated with corn production. Previous analyses have been based on case studies. Here we present an analysis based on census data for Ontario at the county level that was performed for three scenarios: (1) corn cultivated only for grain; (2) corn cultivated for grain and 30% stover harvest; and (3) corn cultivated for grain and cob harvest. Energy intensity of corn grain at the county level varied from 1.75 to 2.17 GJ Mg^-1 grain, with the largest proportions of energy being consumed for grain drying (33%), production and supply of nitrogen (N) fertilizer (30%) and diesel use for field work (17%). Overall GHG emission intensity of grain corn varied from 243 to 353 kg CO₂eq Mg^-1 grain, of which 72% were associated with N inputs [34% soil nitrous oxide (N₂O) from synthetic fertilizer N (SFN), 13% from SFN production and 10% from applied manure N]. Energy intensity of corn stover and cobs was 0.96 and 0.36 GJ Mg^-1 dry matter, respectively, with the largest proportion of energy associated with production and supply of replacement nutrients. Intensity of GHG emission was 79 and 31 kg CO₂ eq Mg^-1 dry matter for stover and for cobs, respectively. Counties with higher corn yields at lower N application rates and reduced tillage tended to produce corn with lower energy and GHG intensity per Mg grain.

Shi, W.-J., Shen, B. and Wang, Q.-J. 2014. Effect of ignoring parameterbon the maximum upward flux calculated from the Gardner rational model. Can. J. Soil Sci. 94: 97-103. The maximum upward flux (E_max) of groundwater evaporation can be predicted using the Gardner model. The model is often simplified by neglecting a soil parameter (b). The paper describes methods used to assess the impact of the b parameter on predictions of E_max including or eliminating b in the Gardner model. The results showed that ignoring b always resulted in a higher prediction of E_max; for the same soil, the calculated E_max ignoring b was higher than E_bmax including b, and the difference between the measured E_max and calculated E_bmax was smaller. For different soils, the difference between predicted E_max ignoring b and measured value increased as the soil mean particle size increased (when the water table depth was more than 1 cm). For layered soils, the measured E_max was always smaller than the calculated value, regardless of whether b was included or not. And the difference between the calculated and measured values increased with increasing distance from the sandy soil interlayer in the soil profile to the water table. The main reasons for the difference between the calculated E_bmax considering all parameters and the measured values are discussed based on previous research.

Moulin, A. P., Glenn, A., Tenuta, M., Lobb, D. A., Dunmola, A. S. and Yapa, P. 2014. Alternative transformations of nitrous oxide soil flux data to normal distributions. Can. J. Soil Sci. 94: 105-108. Non-normal distributions of soil N₂O fluxes are commonly log transformed prior to statistical analysis. These data are transformed to ensure that analysis of variance and regression based on least squares, meet the assumptions of normality for the distribution of data and equality of variances. Analysis of micrometeorological and static chamber-based fluxes of N₂O in Manitoba show that continuous functions such as the Johnson Su and Sl, Generalized Log or normal quantile may be useful as alternatives to the lognormal, which was relatively less effective in transforming data, though each transformation should be evaluated on a case-by-case basis.