Soils KT#1-2

climate as a soil-forming factor

• water is the solvent, reaction environment, transport medium

• temp —> rate of chemical reactions and the intensity of biological activity

• freeze-thaw processes

• Wind —> erosion / deposition

organisms/vegetation as a soil-forming factor

• nutrient exchange

• increased rate of chemical weathering

• improves soil structure

• modify microclimate

parent material as a soil-forming factor

• influences texture (infiltration, depth of leaching, etc.), buffering capacity, CEC, minerology

topography as a soil forming factor

• elevation affects moisture (convex slopes —> drier)

macropores definition

large soil pores, usually between aggregates, that are generally greater than 0.08 mm

important soil functions related to soil structure are:

• sustaining biological productivity

• regulating and partitioning water and solute flow

• cycling and storing nutrients

ways that soil organic matter can be added to soil / lost

• addition: litter, microbial biomass, microbial synthesis

• loss: microbial respiration, erosion, leaching

major Sources of Soil Organic Matter

above ground plants, below ground plants, microfauna, macrofauna

benefits of soil organic matter

• structure / stability

• increased CEC

• increased buffering capacity

• habitat

• nutrient exchange

• infiltration

• reduces compaction

define soil organic matter

• mixture of living & nonliving components

• plant, animal, microbial derived residues at various stages of decomposition + new molecules synthesized by microbes

• interacts w/ minerals —> mineral complexes

2 sets of soil forming processes that modify initial structure

• additions, transformations, and mixing of organic matter

• physical processes (e.g. freezing/thawing)

effects of agriculture on soil

• soil organic carbon loss

• increased erosion

__% of the original soil organic carbon is lost when conversion from forest or grassland to cropland occurs

30

cumulic soils definition

soils where upper soil layer becomes unnaturally overthickened from deposition of eroded upslope soils

is temp or precip more importnat for carbon accumulation

temp (it limits decomposition)

effect of precipitation on soil organic matter

increases

effect of deeper roots on soil organic matter

more belowground soil organic matter

lower / north facing slopes effect on soil organic matter

more

what mineral soil order has highest carbon stock

cryosols

cryosols + organic soils hold about __% of the total carbon stocks contained in Canadian soils.

80

define paludization

the accumulation of thick organic layers on the mineral soil surface,

define humification

the formation of humic substances from the accumulation of organic matter

define melanization

the darkening of a soil color due to carbon addition

conversion of land to agriculture in canada has led to a ___% surface soil carbon loss

25

m*thods to improve soil carbon

1. low till

2. reduction of summer fallow

3. cover crops

4. adding organic matte

5. chemical fertilizers

6. afforestation and reforestation

wetlands store __% of terrestrial carbon

20

4 types of soil services

provisioning, supporting, regulating, cultural

Section 95 of the Constitution Act, 1867

establishes agriculture as a concurrent or shared jurisdiction between the federal government and the provinces.

why should traditional crop insurance be restructured

to encourage people to adopt regenerative and sustainable farming methods, instead of rewarding practices like planting canola on poor-quality land just to collect insurance payouts

what are the two types of carbon marketplaces in Canada?

regulated/compliance and voluntary/non-compliance carbon marketplaces

what’s a major barrier to building a credible soil-based carbon market in Canada?

lack of standardized, reliable measurement and verification tools for soil carbon makes it hard to prove value, reducing confidence from global buyers and investors.

why is there a push to treat soil health as a commodity in Canada’s carbon market?

• soil health stores carbon and can generate carbon credits

• experts argue it should be regulated and monetized to compete globally, support farmers, and attract private investment into sustainable agriculture.

what are some beneficial soil microorganisms

• micorrhyzal fungi

• pseudamonas bacteria

• protazoa

• nematodse, etc.

how do bacteria help plants

1. help prevent disease

2. protection from drought through biofilm

3. nutrients

how do plants recruit their little fungi buddies

they send signals and spore responds by growing in that direction, fungus penetrates root and builds structures for exchange

what is the most limiting abiotic factor to plant growth

water

hydrotropism

positive hydrotropism

phenomenon where plant roots grow towards water

root grows towards dry side to find water

effect of antibiotic soil pollution

resistant bacteria

policy problems for soil pollution regulation

• soils impact atmosphere but not covered by law - policy no-man’s-land

• need more federal guidance on PPCPs and PFAS

effects of oil/gas industry on soil

• decomissioned gas stations / lead paints / oil —> persistent pollutants

• disruption of contaminated sites —> pathogens / contagions

• lead contam on crops