AGRO study guide pt 1

What is the dominant narrative around need the for industrial agriculture? 

Other forms of agriculture are not as productive meaning if they were used there would not be enough food to feed everyone. The notion that food insecurity is primarily the result of insufficient food/production AND increasing production and efficiency will solve the issue. 

Why does vic believe it is a flawed narrative? 

It simplifies food and agriculture issues to avoid complexity. Generalizing to avoid context. Presuming that the status quo is justified by its existence (aka system justification). Asking questions that give answers for the wrong problems. 

Proximate versus Ultimate 

proximate cause refers to a phenomenon which is usually short term or immediately causes some observed outcome. In contrast an ultimate cause, it is usually the “root” cause for an observe outcome.

Nikolai Vavilov

The father of seed banks and identified the importance of “centers of origins” for crop species, these regions harbor the highest percentage of genetic diversity per taxa 

Why did Vavilov stress the importance of maintaining seed diversity? 

Lack of diversity makes seeds more vulnerable.

What were some of the governmental responses to the dust bowl? 

Soil conservation service, Economic policies and Market expansions 

Domestication Syndrome

Zero sum game - any change in an organism, plant or animal, to select for one trait will lead to some loss in other traits. Often many plants (and animals) become less defended and more susceptible to predations, herbivory and/or disease. 

What are some other ways that investment in yields and growth rates has made domesticated plants and animals less resilient?

narrowing the genetic diversity within populations

The Recipe for Evolution 

Variation provides the raw materials (traits) → Selection does the choosing → inheritability = passes trait onto the next generation.

Evolution

Descent with modification

Modification = change

Descent = Passed on through generation(s)

Change passed on through generations

Characteristics of healthy soil 

High Organic matter (keep it alive and spongy). Practices that add organic materials to the soil. Minimize losses of native soil organic matter.

Erosion Control (keep it there) 

Provide plenty of soil cover crops and/or surface residue. Soil Structure (keep it aerated and porous)  Minimize tillage and other soil disturbances. 

High Fertility (keep it healthy) 

Manage soil fertility status to maintain optimal pH levels for your crops and a sufficient supply of nutrients for plants without resulting in water pollution. 

How can you maintain or increase organic matter in the soil?

Growing cover crops help increase or maintain SOM. Most effective when combined with reduced tillage and erosion control

Why is drainage important for soil fertility? 

Drainage reduces soil and nutrient loss from runoff and can help avoid soil erosion

What conditions lead to denitrification and why? 

anaerobic conditions (low oxygen) with readily available organic matter and nitrate

How is organic matter lost from the soil? 

Co2 respiration of soil organisms, erosion 

What are the factors that determine the potential amount of soil organic matter? 

Temperature, rainfall, soil type, soil drainage, type of vegetation. 

How does tillage affect organic matter? 

Tillage DECREASES organic matter and water holding capacity. Tillage aerates the soil causing a large increase in oxygen which leads to an overabundance of bacteria that "burn-up" the organic material. 

What are cover crops and how do they support soil organic matter? 

They help maintain soil organic matter. They are like a sponge, soaking up nutrients and storing them helps prevent nutrient runoff in spring thaw/rain. The plants hold on to the soil, preventing leeching. 

What is soil made up of?

Soil is 45% inorganic mineral matter, 25% water, 25% air, and 5% organic matter (microorganisms and macroorganisms).

Soil Organic matter components

Living organisms <5%. Fresh residue <10%. Decomposing organic matter (active fraction) 33-50%. Stabilized organic matter (humus) 33-50%

Organic matter in soil % of total soil mass

Organic matter is 1-6% of total soil mass