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Amending soil with manure from cattle fed biochar (BC) (biochar–manure [BM]) is a potential best management practice to improve plant nutrition in the circular economy. Yet, information concerning the agronomic performance of BM under temperate field conditions is scarce. A 2‐year study on a Gray Luvisol was conducted to determine the effect of BM on the crop growth of spring wheat (Triticum aestivum L.), followed by canola (Brassica napus L.), soil fertility, and microbial function. Treatments included (i) no amendments (control), (ii) BC at 5 and 10 Mg·ha−1 (BC5 and BC10), (iii) regular stockpiled manure (RM) at 100 kg total N·ha−1, (iv) stockpiled BM at 100 kg total N·ha−1, and (v) BC and RM (BC+RM) or BC and BM (BC+BM) at the aforementioned rates. During the wheat growing season in 2020, which had high precipitation, grain yield was 2.4 times greater in BM+BC10 than in BM alone (1416 vs. 579 kg·ha−1, p < 0.001), highlighting synergistic effects of BM together with BC application on agronomic performance. Conversely, lower precipitation and warmer temperatures in the canola growing season in 2021 hampered any statistical differences among treatments. While soil microbial biomass did not change by the end of the experiment, shifts toward amino acid utilization with BC additions in both crops potentially influenced crop growth and nitrogen‐use efficiency. In summary, BM+BC at 10 Mg·ha−1 performed best in this study during the first cropping season under cold and rainy conditions. Core Ideas: Biochar and biochar–manure additions increased wheat production.There were shifts toward amino acid utilization with biochar additions.Precipitation and temperature played an essential part in level of biochar addition benefits. [ABSTRACT FROM AUTHOR]

Decades of acidic deposition have depleted soil calcium (Ca) stocks over large areas of eastern Canada. The recovery of soil Ca levels has been limited despite substantial reductions in acidic deposition and will likely take many decades because rates of loss (owing to soil leaching, timber harvesting, and forest regeneration) may equal or exceed those of supply (via atmospheric input and natural mineral weathering). As low soil Ca levels may adversely affect local biota with relatively high Ca requirements, affected sites may benefit from supplementation with an alternative Ca source. A growing body of evidence suggests that the application of wood ash to Ca-deficient forest soils can help counteract the loss of Ca and other nutrients from the soil while boosting forest productivity. Yet the use of wood ash as a forest soil amendment is currently restricted in Canada, and the costs of obtaining permits and transporting/applying the ash make landfilling a more economically viable option. Here, we explore the potential of wood ash amendments in terms of their risks and benefits, dose and application frequency, time to see benefits, and longevity of benefits. After considering these topics in the context of Ca-deficient, acidified forest soils across eastern Canada, we propose that the potential benefits of ash amendments in these areas likely outweigh the risks. Future studies are needed to clarify both the short- and long-term effects of wood ash addition on different tree species in both natural and managed forests, as well as the potential benefits for carbon capture and implications for Ca-deficient aquatic ecosystems. [ABSTRACT FROM AUTHOR]

There is interest in utilizing wood ash as an amendment in forestry operations as a mechanism to return nutrients to soils that are removed during harvesting, with the added benefit of diverting this bioenergy waste material from landfill sites. Existing studies have not arrived at a consensus on what the effects of wood ash amendments are on soil biota. We collected forest soil samples from studies in managed forests across Canada that were amended with wood ash to evaluate the effects on arthropod, bacterial and fungal communities using metabarcoding of F230, 16S, 18S and ITS2 sequences as well as enzyme analyses to assess its effects on soil biotic function. Ash amendment did not result in consistent effects across sites, and those effects that were detected were small. Overall, this study suggests that ash amendment applied to managed forest systems in amounts (up to 20 Mg ha−1) applied across the 8 study sties had little to no detectable effects on soil biotic community structure or function. When effects were detected, they were small, and site-specific. These non-results support the application of wood ash to harvested forest sites to replace macronutrients (e.g., calcium) removed by logging operations, thereby diverting it from landfill sites, and potentially increasing stand productivity. [ABSTRACT FROM AUTHOR]

• Wood ash may be self-hardened to alter physical and chemical properties. • Ash may be exposed to acidity during disposal, storage or use as a soil amendment. • Acidification increases leachability of many trace elements of concern. • Self-hardening reduces leachability of many trace elements over a wide pH range. Bioenergy systems that utilize clean wood feedstocks are becoming more common in western Canada to produce heat and electricity. But, wood combustion leads to ash residuals that need to be managed. Although there is growing interest in value-added uses for these wood ashes, large quantities of wood ashes are currently stockpiled or landfilled. Wood ash may be self-hardened as a pretreatment strategy to improve handling and reduce reactiveness prior to land application. This study determined aqueous concentrations of constituents released from wood bottom ash (BA) and hardened wood bottom ash (HBA) when subjected to increasing levels of acidity (pH 10 to 4). Such acidic conditions are not common but may exist during some storage, landfilling or land reclamation scenarios. Acidification of BA and HBA increased aqueous concentrations of B, Ca, Cd, Co, Cu, Mg, Mn, Ni, Sr, and Zn, whereas Cr, Hg and Mo showed decreased concentrations. Hardening reduced aqueous concentrations of As, Ca, Co, Fe, Ni, P, and Pb, in HBA compared to BA over a pH range. When properly managed, hardened and non-hardened bottom ashes generated from the combustion of clean wood should pose minimal risk to the environment. [ABSTRACT FROM AUTHOR]

Ash from biofuels and nitrogen fertilizer are increasingly being used as soil amendments. While this can increase tree growth, it can also increase mammalian grazing and competition with vegetation. We applied moderate amounts of ash (1.5 t·ha−1·year−1) and urea (74 kg N·ha−1·year−1) in each of 2 years to a well-drained site in southeastern Manitoba, planted with Pinus banksiana Lamb. Subplots received deer browsing and (or) vegetation control. The ash resulted in an increase in pH in the upper 15 cm of mineral soil from ∼5.7 to 6.6, and the urea created short-term spikes in soil inorganic nitrogen (NH4 and NO3) levels. Urea combined with ash significantly increased seedling relative growth rates in the first 2 years, with seedlings being largest with urea, with or without ash. However, by the fourth year, seedling growth and size did not differ between the amendments. Urea application increased browsing damage to 91%, but only when vegetation was mowed. Browsing guards resulted in seedlings having 1.6 times greater shoot mass by the end of the fourth growing season. These results suggest that on sandy soils in the dry region of central Canada, P. banksiana may get little benefit from ash applications. [ABSTRACT FROM AUTHOR]

The contribution of forest biomass to Canada's energy production is small but growing. As the forest bioenergy industry in Canada expands, there is growing interest in more sustainably managing the wood ash that is generated as a by-product. Despite being rich in nutrients, wood ash is usually landfilled in Canada. Soil applications of ash in Canadian forests could be used to mimic some of the effects of wildfire, to replace nutrients removed during harvesting, to counteract the negative effects of acid deposition, and to improve tree growth. At present, the provincial and territorial processes for obtaining regulatory approval to use wood ash as a forest soil amendment can be challenging to navigate. Furthermore, the costs for obtaining approval and transporting and applying wood ash to the soil can render landfilling a more cost-effective method of ash management. To ensure that wood ash applications in Canadian forests are conducted safely, effectively, and efficiently, experience from European countries could provide a useful starting point for developing best practices. The results of Canadian research trials will assist policy makers and forest managers in refining management guidelines that encourage soil applications of wood ash as a forest management tool while protecting the ecology, water quality, biodiversity, and productivity of Canadian forests. [ABSTRACT FROM AUTHOR]

Abstract: In Canada, the influence of earthworms on soil is considered particularly important in the Southern regions where agriculture has developed. A field experiment was duplicated on a clay loam and a sandy loam soil in the Saint-Lawrence Valley. Both sites were enriched with urban compost or mineral amendment. The effects of amendments on soil properties and the earthworm community were evaluated by uni- and multivariate analyses at two soil depths (0–10 and 10–20cm) and after two growth seasons. Compost-amended plots had higher pH, wet aggregates stability, total N and C, OM, K and Ca in the 0–10cm soil layer than plots receiving mineral fertilizer. Two endogeic species, Aporrectodea caliginosa and Allolobophora chlorotica were dominant in both sites. Other species were all epigeic and were rare. Abundance and biomass of earthworms (0–10cm) were significantly higher in clay loam, with a similar proportion in A. caliginosa (263indm−2) and A. chlorotica (228indm−2). In sandy loam, A. caliginosa was the most abundant (18indm−2), A. chlorotica was scarce (1.3indm−2) and epigeic species were absent. The density and biomass of earthworms were significantly higher with compost amendment, up to 12 times in clay loam: A. chlorotica reached a mean density of 420indm−2 vs. 36indm−2 with mineral amendments, A. caliginosa 344indm−2 vs. 183indm−2 and epigeic earthworms 19indm−2 vs. 12indm−2. In co-inertia analysis, the main factors explaining data heterogeneity were soil texture (axis 1) and organic matter content (axis 2). A. chlorotica was associated with OM, while A. caliginosa was associated with silt and clay contents. Additionally, soil wet aggregate stability was the variable that best correlated with endogeic species. The overall earthworm population was low, which is common for tilled agricultural soils, but clearly benefited from the OM input from the urban compost, providing further evidence that fertilization based on organic residues, as implemented in organic agriculture, is highly beneficial for earthworms and soil quality. [Copyright &y& Elsevier]

The article cites a study about the efficacy of fish emulsion as a preplanting soil amendment for controlling the prevalence of soilborne diseases on eggplants and potatoes. The researchers conducted a test on 11 samples of soils from different commercial potato fields in Canada with a history of verticillium and scab. Results of the study concluded that treatment of fish emulsion significantly reduced the prevalence of the said plant diseases, though not on soils with high disease pressure.

Five experimental trials were established in commercial lowbush blueberry (Vaccinium angustifolium Ait.) fields in eastern Canada and monitored over two cropping cycles to determine the value of gypsum as a soil amendment. Lowbush blueberry plants were treated each cropping cycle with either: (1) no application (control), (2) 10-10-10 fertilizer applied at 300 kg/ha (268 lb/acre), (3) gypsum applied at 4 t/ha (3572 lb/acre), or (4) the combination of (2) and (3). In the first cropping cycle, the application of gypsum and gypsum with fertilizer significantly increased tissue concentrations of N, P, K, Ca, Mn, and S in comparison to the control and fertilizer only treatments. Tissue K, Ca, Mn, and S were significantly increased in the second cropping cycle with gypsum application. Soil pH was reduced in the second cropping cycle with gypsum application. Gypsum with fertilizer increased stem length, live buds, total buds, and total blossoms in the first cropping cycle in comparison to the control. The treatments had no significant effect on marketable yield. [ABSTRACT FROM AUTHOR]

Discusses the abstract of the article "Effect of soil amendments on common scab of potato and soil bacterial communities," by K. Prevost, B. Shipley and C. Beaulieu, submitted to the 2003 Canadian Phytopathological Society Annual Meeting in Montreal, Quebec.

Discusses the abstract of the article "Reduction of potato scab with volatile fatty acids and acidified liquid swine manure in soil amendments," by K.L. Conn, P.A. Abbasi, Y. Lin and G. Lazarovits, submitted to the 2003 Canadian Phytopathological Society Annual Meeting in Montreal, Quebec.