Agriculture Inputs

Elements commonly used as fertilizer

phosphorus, potassium, nitrogen

Dangers of overuse of phosphate and nitrate fertilizer

aquatic ecosystem pollution and groundwater contamination

energy/fuel-intensive

food processing and distribution requires large amounts of fuel use

Agriculture depends on

water, nutrients, favorable climates, productive crop varieties, mechanical energy

Common limiting factor of plant growth

nitrogen

Role of nitrogen in plant growth

builds up proteins and DNA, in fertilizers to stimulate growth

Traditional pest evasion strategies

planting a mix of crops, rotating crops

Manure

an alternative to synthetic fertilizer use

Organophosphates

designed to prevent growth of broadleaf weeds or attack nervous systems of insect pests (most abundantly used pesticide)

Things used as pesticides

chlorinated hydrocarbons, fumigants, inorganics, botanicals

Crop rotation

changing the species of crops planted from one year to the next

Benefit of crop rotation

to reduce pests’ ability to build up populations over time

Chlorinated hydrocarbons

persistent and highly toxic to sensitive organisms; used extensively on corn

Fumigants

highly toxic gases used to kill fungus on low-growing crops

Inorganic pesticides

include arsenic and copper

Undesired effects of widespread pesticide use

need for stronger and more pesticides, creation of pesticide-resistant populations, destruction of nontargeted organisms

Pesticide treadmill

describes the cycle of increased pesticide application after new resistant strains aries

Modern farming is…

an energy-intensive process using fossil fuels for both fuel and fertilizers

Benefits of using synthetic fertilizer

immediate nutrient availability, support for high-demand crops, reduced land requirements (by higher yields), cost-effective and scalable

Problems of using synthetic fertilizer

soil degradation, water pollution, greenhouse gas emissions, health risks, high energy consumption

Impact of overfertilization

inhibits roots, degrades soil

Why atmospheric N2 is unavailable to most plants

the N-N triple bond is too strong

Pesticides

chemical/biological agents designed to kill or control pests

Benefits of pesticide use

increased crop yields, reduced post-harvest losses, lower labor costs, vector disease control, herbicide use for no-till farming

Problems with pesticide use

environmental contamination, non-target organism impact, human health risks, pesticide resistance, high costs for farmers

Commonly used pesticides

glyphosate (roundup), atrazine, neonicotinoids, 2,4-D, dicamba

Glyphosate

aka Roundup, most commonly used herbicide globally, inhibits enzyme pathway

Glyphosate and GMOs

Monsanto developed GMO crops resistant to glyphosate to allow farmers to use things like Roundup without harming or killing the crop itself (popularity spikes)

Genetically Modified Organisms (GMOs)

plants, animals, or organisms whose DNA has been artificially manipulated to modify their characteristics

Usage benefits of GMOs

increased crop yields, pest and disease resistance, drought and climate resilience, improved nutritional content, extended shelf life

Usage problems of GMOs

pest resistance, allergenicity and health risks, economic and ethical issues, loss of crop diversity and potential impact on non-target species

Short-stature corn

GMO corn to grow shorter makes them more resilient to storms and droughts due to shorter height and their extended root systems

Soil health principles

provide continuous living roots, minimize disturbance, maximize biodiversity, maximize soil cover

Impact of excessive tillage

disrupts soil structure and causes erosion

Cover crops

plants grown primarily to provide services rather than for harvest

Benefits of cover cropping

building soil health, nutrient retention, erosion control, weed reduction

Intercropping

increases in-season diversity

Three sisters farming

a traditional indigenous agriculture practice that involves planting corn, beans, and squash together in a symbiotic growing system

Legumes as cover crop

ex: clover; fixes N, provides N to the next cash crop

Grasses as cover crop

 ex: rye; winter hardy, scavenges remaining N in the soil, improves soil structure, reduces weed pressure

Brassicas as cover crop

ex: radish; breaks up soil compaction

Concentrated animal feeding operation (CAFO)

an intensive animal feeding operation where >1000 animal units are confined for over 45 days a year

Animal unit

1000 pounds of ‘live’ animal weight

Direct uses of energy in agriculture

operate machinery and equipment, heat/cool buildings, lighting on the farm, supplying water

Indirect uses of energy in agriculture

production off the farm and fertilizer and chemical use