Food Farming Agriculture

LECTURE 17

Lecture: Professor Webb returns next week! Lab: Exploring an Environmental Issue – continue to work in groups, bring together various delegated individual tasks (from proposal), advance overall project, ask questions

ENVIRON201 SCHEDULE

HUMAN EXPERIENCE

FOOD

  Agriculture: Yield –   Varieties   Pest Control   Soil  Water   Fertilizer

  Agriculture: Energy   Case Study: UM Sustainable Food Program

  Supply of land for agriculture use is limited   In 2011, 1.5 billion hectares are already under cultivation   Or, 3.7065x109 acres

  This number is projected to increase over the next 50 years, especially in developing nations with less stable food production

AGRICULTURE: LAND

source: indianagrain.com

AGRICULTURE: LAND

The Millennium Ecosystem Assessment: -  Commissioned by UN Secretary General

Annan in 2000 -  Goal: To assess the consequences of

ecosystem change for human well-being and the scientific basis for action needed to enhance the conservation and sustainable use of those systems and their contribution to human well-being

-  Anthropocentric

 In the past 50 years, humans have changed ecosystems more rapidly and extensively than in any comparable period of time in human history

-Mi l lennium Ecosystem Assessment

AGRICULTURE: LAND

More land was conver ted to cropland in the 30 years af ter 1950 than in the 150 years between 1700 and 1850 Cul t ivated systems cover 25% of Ear th ’s ter restr ia l sur face

AGRICULTURE: LAND

  Agriculture: Land

  Agriculture: Energy   Green Revolution   Agriculture: Subsidies   Agriculture: Climate Change   Organic Farming and Beyond

FOOD

 With less and less land available for food production, there is pressure to intensify

 But there are competing goals of multifunctional agriculture

AGRICULTURE: YIELD PRESSURE TO USE LESS LAND IN FUTURE

  Avoid farming marginal lands   Restore grasslands on steeper slopes   Restore wetlands for water quality improvement   Allow for 100-300 f t riparian stream buffers   Increase crop diversity   5-year crop rotations   Row crops planted with cover crops  Managed intensive rotational grazing

Boody et a l . 2005 BioSci . Vol . 55(1) ;27-38

AGRICULTURE: YIELD COMPETING GOALS

slash-and-burn ag in South America

Terraced A gr icul ture Common in As ia Eros ion Hard to maintain

RESTORE GRASSLAND ON SLOPES

Wet lands prov ide humans with natural water pur i f icat ion Habi tat for rare species Poor land for agr icul ture ( low y ie ld) Good to incorporate preser ved wet lands wi th buf fer zone

RESTORE WETLANDS

Wetland that was farmed upon then abandoned Poor habitat for farming, but available

P lant species af fect so i l composi t ion d i f ferent ly Rotate what you p lant to let so i ls re juvenate Lots of techniques – need to know what k ind of so i l you’ re working wi th

CROP ROTATION

Less intense d i rect sunl ight Covered crops require less f requent water ings Manage soi l fer t i l i ty Mit igate pests , d iseases, weeds, eros ion of so i ls

IMPLEMENT COVER CROPS

Rotat ion of animals to a l low for regrowth Can be used with cows, sheep, goats , p igs , ch ickens, ducks Some farmers have temporar y fences

MANAGED INTENSIVE ROTATIONAL GRAZING

 CAFO – Concentrated Animal Feeding Operation  Animal feeding facility

with no natural vegetation (feed)

 Animals grow (fattened) in confined space for > 6 weeks

 Increase in yield

AGRICULTURE: YIELD MAKING LAND WORK HARDER

ENVIRONMENTAL IMPACTS OF CAFOS

Point-source pollution from CAFO

CAFOs replacing small-scale farms

 Europe and US – concerns for animal welfare

 Developing markets – less/no concern

 Unlikely to meet global meat demand without CAFOs (TechnoGarden scenario, MEA)

AGRICULTURE: YIELD SOCIAL CONTEXT OF YIELD

  https://www.youtube.com/watch?v=-LjW6eIFYpo

  A happier alternative (for the animals AND environment): https://www.youtube.com/watch?v=z9HF93LfBDw

  Visit Niman Ranch website for more information: http://www.nimanranch.com/Index.aspx

AGRICULTURE: LAND MAKING LAND WORK HARDER

  Yield = biomass achieved per unit area  Wheat:

  11,032 pounds/acre – best modern plants, best fertilizer, best husbandry

  5,511 pounds/acre – best yield from 1970s after Green Revolution   2,755 pounds/acre – typical practices in Argentina and India

AGRICULTURE: YIELD

  There are two sources of increasing crop yield without increasing amount of land used:   1) Increase in cropping intensities

  Shorter fallow periods

  2) Modify system through increased inputs   More biomass via increased nutrient inputs, denser plantings WHICH OF THESE COULD POTENTIALLY HAVE AN ECOLOGICAL ISSUE ASSOCITED WITH ITS IMPLEMENTATION?

AGRICULTURE: YIELD

  Yield depends on:   Crop/livestock variety – species and traits

  New varieties generated through selective breeding, genetically modified organisms, and pests

  Soil   Micro-organisms in soil biomass > dirt biomass

 Water   Up to 80% may be wasted. Often subsidized. Over-watering water-logs

soils. Agricultural Runoff.

  Fertilizer   Responsible for > 50% of doubling of crop production in last 50 years.

Over fertilization leads to aquatic ecosystem pollution.

AGRICULTURE: YIELD

 Until recently there were numerous varieties from selective breeding by humans

 Selective breeding of battery chickens reduced input food requirement from 4kg of food/kg of eggs to just 2kg food/kg eggs!

 Turkeys so bloated they cannot walk. Chickens grow so fast they suffer stress fractures.

AGRICULTURE: YIELD VARIETIES

WHICH KIND OF EGGS DO YOU BUY FROM THE STORE?

 PROS  Accelerates genetic

modification by faster selection for desired traits

 Insertion of novel genes

 Increases yield, resistance to pathogens, ability to process fertilizers, freeze resistance

 CONS  Accelerates

development of pest resistance

 Higher herbicide use for GMO high tolerance varieties

 Reduce survival/growth and diversity of wildlife

 Gene jumping  Dilution of wild genome

and genetic diversity

AGRICULTURE: YIELD GENETICALLY MODIFIED ORGANISMS

READ: A GROWING THREAT DOWN ON THE FARM

 Ethical concerns:

 Are we tampering with nature?

 Where’s the stopping point?

 Lots of information out there on this topic – know what you’re reading!

AGRICULTURE: YIELD GENETICALLY MODIFIED ORGANISMS

INTERMISSION

  Direct advantage – increase yield by killing competitors (pests)

  Disadvantages –   Pesticide resistance and pest resurgence (pesticide treadmill)   Non-target species: 90% misses   New pests   Bioaccumulation (Rachel Carson, Silent Spring)

“But man is a part of nature, and his war against nature is inevitably a war against himself.” – Rachel Carson

AGRICULTURE: YIELD PESTICIDE USE

  Farming Practices:   Crop rotation   Green manure   Natural, organic fertilizers   Polyculture   Vary planting times   Burning before planting   Flooding before planting   Surrounding habitat

diversity

AGRICULTURE: YIELD ALTERNATIVES TO PESTICIDES?

Source: wikimedia commons

  Biological Control   Predators, pathogens attack pests   Interplanting with pest deterrents   Sterile males/females   Sex attractants to traps

  Integrated Pest Management   Organic Farming

AGRICULTURE YIELD: ALTERNATIVES TO PESTICIDES?

Source: wikimedia commons

>15,000 soi l types in US Accrue 10tons/acre , year Eros ion <25 mm/year

AGRICULTURE: YIELD SOIL

  Soil is easily exhausted by intensive agriculture

  Loss of organic matter requires 5-10 years to recover

  Low organic-matter soils left fallow for 8-10 years to recover

  Loss of top-soil takes centuries to replace

AGRICULTURE: YIELD SOIL

 Withdrawal – water diverted or withdrawn from a surface water or ground source that eventually returns to the system

  Consumption – water use that permanently draws water from its source; water that is no longer available because it has evaporated, has been consumed by humans or livestock, water that has been removed from the immediate environment

  Up to 80% of water can be wasted:   Often subsidized   Over-watering water-logs soils, can promote salinization (build up of salts in soils, can be toxic, bad for future water uptake)

WATER

WATER

From the Webber reading: “More Food Less Energy” A)  Drip irrigation could save thousands of megawatt-hours of electricity nationwide

every year. B)  Drip irrigation consists of long, narrow tubes placed at the tops of plants in order

to water each plant locally with little loss to evaporation C)  Center-pivot sprinklers provides more crop per drop by spraying water into the air

where a major fraction effectively waters crops D)  Drip irrigation consists of long, narrow tubes placed at the bottoms of plants in

order to water each plant locally with little loss to evaporation E)  Both A and B F)  Both A and D

  It takes ~ 132 gallons of water to produce 1 lb of cereal grain   ~ 5,679 gallons/lb of beef   90% of infectious diseases in developing countries

transmitted by polluted water (often from agriculture)   This is going to become a big problem when agricultural system

expand in these nations

 Water footprint:   http://environment.nationalgeographic.com/environment/

freshwater/change-the-course/water-footprint-calculator/

AGRICULTUE: YIELD WATER

  Solutions?   Drip-feeding can reduce water usage by 40%, which increases overall

yield (READ MORE FOOD LESS ENERGY)

  No-till agriculture reduces water loss through evaporation and run-off, and also reduces soil temperature about 1°C (offset global warming)   Carbon sequestration – holds organic material underground and isn’t lost

to the atmosphere   Save tilling time – grow extra crop in some countries   Less erosion of top soil

AGRICULTURE: YIELD WATER

 Flows of biologically available N in terrestrial ecosystems have doubled since 1960 (flows of P have tripled)

 >50% of all synthetic N fertilizer ever used has been used since 1985

 60% increase in the atmospheric concentration of CO2 since 1750 has taken place since 1959

 What’s happening?

AGRICULTURE: YIELD FERTILIZERS

 Plants also need phosphorus in small amounts, but these elements are also limiting

 Effects of runoff with nutrient loads of N & P

 DEAD ZONES

AGRICULTURE: YIELD FERTILIZER

Lake Erie

  Gulf of Mexico Case Study   https://www.youtube.com/watch?v=ahOmeTOIrRg

AGRICULTURE: YIELD DEAD ZONES

FORMATION OF DEAD ZONES

  Over-fertilization   Produces “yield insurance”, add more to ensure maximum current

yield   Excess enters water table – “Blue baby alerts” in Iowa

  Salinization   Toxic   Soils untenable

  Dead Zones   Hypoxia – excessive O2 demand   Eutrophication – nutrients are single biggest water quality problem

worldwide (Carpenter et al., Ecol App 1998)   Non-functioning ecosystem

AGRICULTURE: YIELD FERTILIZER

  Alternatives?   Animal manure   Interplanting (legumes = N fixers)   Crop rotation   Green manure

AGRICULTURE YIELD: FERTILIZERS

  Alternatives?   Use animal waste as fertilizer/soil improvement   Interstate regulations limit the transport of wastes and toxic material  Would reduce odor, dust, and escape of waste into system

AGRICULTURE YIELD: FERTILIZERS

  Agriculture:   Agriculture: Yield

  UM Sustainable Food Program

FOOD

Which of the following is an example of direct energy use involved in the processing and distribution of farm products? A.  The manufacturing of fertilizer B.  Storage of the products C.  Running the farm machinery

to harvest the products D.  Cooking the food E.  Eating the products

AGRICULTURE: ENERGY

  Energy is another raw material used for farming   Two types of use:

  Direct   Indirect

AGRICULTURE: ENERGY

  Another Raw Material for Farming - Energy   Fossil fuel – key ingredient for increased global food production and

distribution.   Direct use that is going to become more and more expensive as oil

becomes a very limited resource!

“The U.S. expends roughly 10 units of fossil energy to produce one unit of food energy.” -Webber 2012. More Food, Less Energy. Scientific American Jan, pp. 74-79

AGRICULTURE: ENERGY

 DIRECT USE  Operating machinery  Lights, and heating on

the farm

 INDIRECT USE  Fertilizer manufacturer  Pesticide

manufacturer  Storage  Cooking  Distribution

AGRICULTURE: ENERGY