Food & AgricultureFood & Agriculture

Chapters 11 & 12Chapters 11 & 12

APESAPES

20082008

Is there enough food?Is there enough food? As population has increased, our food supply has As population has increased, our food supply has

increased.increased. There is enough food for everyone but it is not There is enough food for everyone but it is not

distributed equally.distributed equally. We in US are overnourished- consume too many We in US are overnourished- consume too many

caloriescalories Some countries have overcome food shortfallsSome countries have overcome food shortfalls

– EX: Indonesia used to largest importer of rice, now they EX: Indonesia used to largest importer of rice, now they are the biggest producers of rice.are the biggest producers of rice.

– Why? irrigation, fertilizers, pesticides, use high yielding Why? irrigation, fertilizers, pesticides, use high yielding crop varieties of rice.crop varieties of rice.

Other countries are still undernourished (don’t get Other countries are still undernourished (don’t get enough calories)enough calories)– Sub-Saharan Africa- drought, war, governmental Sub-Saharan Africa- drought, war, governmental

mismanagement have kept people starving in poverty.mismanagement have kept people starving in poverty.

In developing countries, In developing countries, 800 million people are 800 million people are chronically hungry. 200 chronically hungry. 200 million of them are kidsmillion of them are kids

Undernourishment during Undernourishment during childhood results inchildhood results in– Stunted growthStunted growth– Mental retardationMental retardation– Social/developmental Social/developmental

disordersdisorders Undernourished more Undernourished more

susceptible to infectious susceptible to infectious disease & diarrhea.disease & diarrhea.

Poverty is the greatest threat to food Poverty is the greatest threat to food security- ability to get food everyday.security- ability to get food everyday.

1.4 billion that live on $1/day can’t 1.4 billion that live on $1/day can’t buy food or have no means to grow it buy food or have no means to grow it for themselves.for themselves.

In many families the males get In many families the males get largest & most nutritious share- largest & most nutritious share- females & kids have poorest diet.females & kids have poorest diet.

MalnourishmentMalnourishment Not only need calories, but also Not only need calories, but also

specific nutrientsspecific nutrients Malnourished-Malnourished- lack of necessary lack of necessary

nutrients (protein, vitamins, nutrients (protein, vitamins, minerals)minerals)

Kwashiorkor-Kwashiorkor- protein deficiency protein deficiency but has enuf calories; but has enuf calories; reddish/orange hair, discolored reddish/orange hair, discolored skin, swollen belly, susceptible to skin, swollen belly, susceptible to infectious diseaseinfectious disease

Marasmus-Marasmus- diet low in calories & diet low in calories & protein; thin, shriveled, protein; thin, shriveled, susceptible to infectious diseasesusceptible to infectious disease

Most countries eat maize (corn), Most countries eat maize (corn), rice, manioc (tapioca) but these rice, manioc (tapioca) but these food lack essential vitamins like…food lack essential vitamins like…– Folic acid (for fetal brain Folic acid (for fetal brain

development)development)– Vitamin A (for good vision)Vitamin A (for good vision)– Iron (for strong blood)Iron (for strong blood)– Iodine (for making of thyroxine- Iodine (for making of thyroxine-

which regulates metabolism & which regulates metabolism & brain fxn)brain fxn)

FamineFamine Large-scale food Large-scale food

shortages, massive shortages, massive starvation, social starvation, social disruption, economic chaosdisruption, economic chaos

Usually mass migrations to Usually mass migrations to refugee camps in search of refugee camps in search of food & medical carefood & medical care

Can be caused by…Can be caused by…– Environmental Environmental

conditions- drought, conditions- drought, insect infestationsinsect infestations

– Politics & War- political Politics & War- political boundaries can prevent boundaries can prevent people from following people from following traditional routes to flee traditional routes to flee environmental disasterenvironmental disaster

What you need to be What you need to be healthy…healthy…

Major CropsMajor Crops Wheat & rice are staple Wheat & rice are staple

foods for 5 billion people foods for 5 billion people in developing countries.in developing countries.

In mountainous areas- In mountainous areas- potatoes, barley, oats & potatoes, barley, oats & rye (N. Europe, N. Asia)rye (N. Europe, N. Asia)

In warm, wet areas- In warm, wet areas- cassava, sweet cassava, sweet potatoes, roots/tubers potatoes, roots/tubers (Amazonia, Africa)(Amazonia, Africa)

In dry regions- Millet & In dry regions- Millet & sorghum (Africa)sorghum (Africa)

Meat, Milk, PoultryMeat, Milk, Poultry N. America, Europe, Japan N. America, Europe, Japan

make up 20% of world make up 20% of world population. We consume population. We consume 80% of milk & meat.80% of milk & meat.

LDC have 80% of LDC have 80% of population, raise 60% of population, raise 60% of meat, but consume only meat, but consume only 20% of that meat. Most is 20% of that meat. Most is exported.exported.

90% of N. American grain 90% of N. American grain is used to feed livestock. is used to feed livestock. What a waste of energy!What a waste of energy!

Meat vs. GrainMeat vs. Grain

Every 16 kg of grain Every 16 kg of grain fed to cows produces fed to cows produces 1 kg of edible meat.1 kg of edible meat.

The other 15 kg are The other 15 kg are used by the animal for used by the animal for energy.energy.

If we ate grain If we ate grain directly, we would get directly, we would get 21x more calories & 21x more calories & 8x more protein than 8x more protein than by eating the meat it by eating the meat it produced.produced.

Fish & SeafoodFish & Seafood Important source of protein in Important source of protein in

many countriesmany countries Oceans & major rivers are Oceans & major rivers are

overharvested or habitats are overharvested or habitats are destroyeddestroyed

Radar, sonar, remote sensing, Radar, sonar, remote sensing, GPS, longlines with 60,000 hooks, GPS, longlines with 60,000 hooks, trawl nets large enough to engulf trawl nets large enough to engulf a jumbo jet, make it possible to a jumbo jet, make it possible to exhaust entire populations in just exhaust entire populations in just a few years.a few years.

1 in 4 animals caught in nets are 1 in 4 animals caught in nets are “by-catch” or non-target animals “by-catch” or non-target animals (diving birds, marine mammals)(diving birds, marine mammals)

According to UN, 70% of world’s According to UN, 70% of world’s edible ocean fish, crustaceans, & edible ocean fish, crustaceans, & mollusks are declining & in urgent mollusks are declining & in urgent need of managed conservation.need of managed conservation.

Aquaculture- controlled fish Aquaculture- controlled fish farming- is becoming more farming- is becoming more popularpopular

Importance of SoilImportance of Soil

Important resource for growing Important resource for growing crops!crops!

An ecosystem (See Ch. 12 page 219-An ecosystem (See Ch. 12 page 219-222)222)

What nutrients are important in What nutrients are important in soil?soil?

1. Nitrogen- (N)1. Nitrogen- (N)– Need for making chlorophyll for leavesNeed for making chlorophyll for leaves– Rapid plant growth and healthy leaves.Rapid plant growth and healthy leaves.– Important for leafy veggies- spinach, Important for leafy veggies- spinach,

lettuce, cabbage, soybeans, cornlettuce, cabbage, soybeans, corn– Deficiency results in yellow or reddish Deficiency results in yellow or reddish

leaves.leaves.

2. Phosphorus- (P)2. Phosphorus- (P)– Needed for root development & growth.Needed for root development & growth.– Helps produce flowers & fruitHelps produce flowers & fruit– Deficiency results in darkening of leaves Deficiency results in darkening of leaves

then reddish tinge around edges.then reddish tinge around edges.– Important for beets, potatoes, carrots, & Important for beets, potatoes, carrots, &

radishes.radishes.

What nutrients are important in What nutrients are important in soil?soil?

3. Potassium- (K)3. Potassium- (K)– Also called potashAlso called potash– Deficiency results in puckering & yellow-Deficiency results in puckering & yellow-

brown leaves.brown leaves.– Needed for Needed for

Rapid cell growth at root tipsRapid cell growth at root tips Resistance to disease Resistance to disease Makes stems strong Makes stems strong

Important for potatos, beets, carrots, radishes, bud crops (asparagus, broccoli, cauliflower)

What nutrients are important in What nutrients are important in soil?soil?

Why should we know about soil Why should we know about soil pH?pH?

pH of soil can affect pH of soil can affect how plants absorb N, P, how plants absorb N, P, KK

Most plants like neutral Most plants like neutral to slightly acidic soil to slightly acidic soil (6.0-6.8)(6.0-6.8)

Some carnivorous Some carnivorous plants like more acidicplants like more acidic (4.0-5.0)(4.0-5.0)

To adjust soil pH…To adjust soil pH…– Add lime to make more Add lime to make more

basicbasic– Add alum to make more Add alum to make more

acidicacidic

Prefer Prefer neutralneutral

(6.0-6.8)(6.0-6.8)

Prefer Prefer slightly slightly acidicacidic

(5.0-6.5)(5.0-6.5)

Prefer Prefer strongly strongly acidicacidic

(4.0-5.0)(4.0-5.0)

GrainsGrains HollyHolly SundewSundew

VeggiesVeggies OrchidsOrchids Pitcher Pitcher plantsplants

EvergreenEvergreen Venus fly Venus fly traptrap

StrawberrStrawberriesies

AzaleaAzalea

PotatoPotato RhododenRhododendrondron

CarrotCarrot camelliacamellia

What do those numbers mean What do those numbers mean on a bag of fertilizer?on a bag of fertilizer?

Indicates % of N, P, K in Indicates % of N, P, K in the fertilizerthe fertilizer

Different plants have Different plants have different nutrient needs.different nutrient needs.

Pros of commercial Pros of commercial fertilizer:fertilizer:– Greatly increases crop yieldGreatly increases crop yield– Greatly increase crop Greatly increase crop

qualityquality Cons of commercial Cons of commercial

fertilizer:fertilizer:– Pollute & degrade soilPollute & degrade soil– Cause eutrophicationCause eutrophication

New CropsNew Crops We have used around 3,000 We have used around 3,000

different crops as food source different crops as food source but now currently use about but now currently use about 16 different species.16 different species.

Some New Crops…Some New Crops…– Winged beans- completely Winged beans- completely

edible, resistant to disease, edible, resistant to disease, enrich soil, like warm climateenrich soil, like warm climate

– Tricale- cross betwn wheat & Tricale- cross betwn wheat & rye, likes light, sandy infertile rye, likes light, sandy infertile soil, drought resistant, tested soil, drought resistant, tested for growth in salty soil (might for growth in salty soil (might be able to irrigate with ocean be able to irrigate with ocean water?)water?)

Green RevolutionGreen Revolution About 50 years ago, new About 50 years ago, new

strains of high yielding strains of high yielding wheat & rice were wheat & rice were developed through cross developed through cross pollinationpollination

If given optimum levels If given optimum levels of fertilizer, water, of fertilizer, water, protection from pests protection from pests these will yield lots of these will yield lots of product.product.

Poor farmers however, Poor farmers however, cannot afford the cannot afford the fertilizers, seeds, fertilizers, seeds, equipment, etc so did not equipment, etc so did not help out in LDC.help out in LDC.

Gene RevolutionGene Revolution Genetic engineering- altering genes by Genetic engineering- altering genes by

splicing genes of desirable traits & splicing genes of desirable traits & inserting into food crop.inserting into food crop.

Potential forPotential for– Engineering crops to withstand salty, Engineering crops to withstand salty,

waterlogged, or low nutrient soilwaterlogged, or low nutrient soil– ““grown-in” pesticides so no sprayinggrown-in” pesticides so no spraying– Make food more nutritiousMake food more nutritious

1/3 of all corn & soybean is transgenic; 1/5 1/3 of all corn & soybean is transgenic; 1/5 of all cottonof all cotton

70% of all processed food is made with 70% of all processed food is made with transgenic materialtransgenic material

Pest ResistancePest Resistance Bacillus thuringiensisBacillus thuringiensis (Bt)- (Bt)-

bacterium that is lethal to bacterium that is lethal to butterflies & beetles.butterflies & beetles.

Bt was transgenically inserted in Bt was transgenically inserted in potatoes, cotton, & corn. Bt gives potatoes, cotton, & corn. Bt gives off poison all growing season not off poison all growing season not just when needed.just when needed.

Now scientists worried this is Now scientists worried this is creating “superbugs” or Bt-resistant creating “superbugs” or Bt-resistant pests.pests.

By planting non-Bt crops with Bt By planting non-Bt crops with Bt crops allows some pests to “hide-crops allows some pests to “hide-out” and munch (keeping them out” and munch (keeping them “wild”, while others die.) By “wild”, while others die.) By breeding “wild-type” and Bt breeding “wild-type” and Bt exposed, may dilute recessive exposed, may dilute recessive resistance gene.resistance gene.

Negatives- can kill “non-target” Negatives- can kill “non-target” organisms (Monarch butterflies) if organisms (Monarch butterflies) if pollen moved by air to milkweed pollen moved by air to milkweed plantplant

Weed ControlWeed Control Making plants with Making plants with

herbicide resistant herbicide resistant genes means you can genes means you can spray heavy doses of spray heavy doses of herbicide and kill herbicide and kill weeds but not crop.weeds but not crop.

Pros- don’t have to till Pros- don’t have to till so can leave crops to so can leave crops to fall over & prevent soil fall over & prevent soil erosionerosion

Cons- may create Cons- may create “super-weeds”“super-weeds”

Sustainable AgricultureSustainable AgricultureSoil Conservation important in Soil Conservation important in

maintaining arable land.maintaining arable land.1.1. Land management- Land management-

terracing, strip farming, terracing, strip farming, contour plowing help contour plowing help prevent water & wind prevent water & wind erosionerosion

2.2. Using cover crops (rye, Using cover crops (rye, alfalfa) after harvest alfalfa) after harvest prevents erosion & returns prevents erosion & returns N to soil. Also use mulch.N to soil. Also use mulch.

3.3. Use reduced tillage systemUse reduced tillage systema.a. Minimal till Minimal till b.b. Conserv-tillConserv-tillc.c. No- till planting- best; keeps No- till planting- best; keeps

all cover plant in place and all cover plant in place and pushes crop seed into soilpushes crop seed into soil

d.d. Cons of these systems- Cons of these systems- must use more herbicide to must use more herbicide to keep weeds low.keep weeds low.