Historically, drastically disturbed landscapes have been discussed in relation to the alteration of whole ecosystems with respect to nutrient and water cycling. Soil organic matter decline is seen as a key component in drastically disturbed lands, impacting ecosystem functions such as air and water quality, wildlife habitat condition and productivity. Recent focus has also been placed on the importance of drastically disturbed lands (especially those of resource development) contributing to the atmospheric CO2 emissions by soil disturbance and cleared biomass decomposition, and as such, provide an important opportunity to address ecosystem functions, carbon sequestration and general sustainability issues through restoration and reclamation.
Biochar is a promising amendment for ameliorating drastically disturbed soils due to its microchemcial, nutrient and biological properties as well as its stability in soil. Biochar is a carbon-rich product obtained when biomass is heated in a closed container with limited air and is produced with the intent of being applied to soil to improve soil productivity, carbon storage or remediation.
Due to the nature of production being dependent on both the feedstock and the process, biochar can be developed for site specific conditions to ameliorate a number of conditions:
|LIMITING FACTOR||VARIABLE||PROBLEM||SHORT-TERM TREATMENT||LONG-TERM TREATMENT||ROLE OF BIOCHAR|
|PHYSICAL||Soil Structure||Soil to compact||Rip of Scarify||Vegetation||Decreased soil bulk density, increased infiltration, decreased erodibility.
Increased water retention due to surface area and charge characteristics.
|Soil Erosion||High erodibility||Mulch||Re-grade, Vegetation|
|Soil Moisture||Too wet||Drain||Wetland construction|
|Too dry||Organic mulch||Tolerant species|
|NUTRITIONAL||Macronutrients||Nitrogen deficiency||Fertilizer||N-fixing plants e.g. leguminous trees or shrubs||Yield increases.
Slow nutrient release.
Soil organic matter stabilization.
Retention of released nutrients.
Increased microbial activity.
Habitat for mychorrhizal fungal hyphae
|Other deficiencies||Fertilizer||Fertilizer, Amendments, Tolerant species|
|TOXICITY||pH||Acid soils (<4.5)||Lime||Tolerant species||Designed for alkaline surface charge.|
|Alkaline soils (>7.8)||Pyritic waste, Organic matter||Weathering, Tolerant species|
|Heavy Metals||High concentrations||Organic matter, Tolerant cultivar||Inert covering, Tolerant cultivar||High surface area and cation exchange capacity allows for metal retention.|
|Salinity||EC >4.0 dS/m, pH<8.5, SAR<13||Gypsum, irrigation||Weathering, Tolerant species||Mixed with gypsum to reduce soil structural issues.
Nutritional values as described.
High CEC for Na retention
|Sodicity||EC <4.0 dS/m, pH>8.5, SAR≥13||Gypsum, irrigation||Weathering, Tolerant species|