Robert Dallas, Eric Soper, Alex Elliott, Anna KarlinBlock 3

32.6 MICRO AND MACRO NUTRIENTS

Basic Knowledge•Autotrophs survive and grow on inorganic substances•Essential Element- element a plant needs to survive•Lack of nutrients cause stunted growth and discolored leaves in plants.•17 essential elements

Macro Nutrients•C, O, H, N, S, P, K, Ca, Mg•Calcium- gives structure to cell walls•Potassium- helps with osmosis•Magnesium- vital part of chlorophyll

Micro Nutrients•Cl, Fe, Mn, B, Zn, Cu, Ni, Molybdenun•Micro- only need small amounts to survive•For every sixty million atoms of hydrogen, the plant needs one micro nutrient to survive.•Micro nutrients help with catalysis

Amber YeasinChloe McMahon Marleah CampbellTheresa Bryant

32.8 FERTILE SOIL SUPPORTS PLANT GROWTH

Importance of Soil•Quality of soil determines plant’s growth•Good soil allows plants to absorb nutrients•Bacteria/algae break down a plant’s organic matter

Soil Horizons•A Horizon•Topsoil is subject to extensive weather

•B Horizon• contains fewer organisms

•C horizon•parent material for upper layers of soil

Cations and Anions•Cation exchange is mechanism• root hairs take up certain positively charged ions

•Cations(+) adhere to (-) charged surfaces•Cation exchange •root hairs release hydrogen ions into soil

•Anions usually not bound tightly by soil

Cations and Anions

Ions and Soil Fertility•Unbound ions drain out soil quickly•May take centuries for soil to become fertile •Loss of soil fertility = pressing environmental problem

Leah Knobel Madison Stewart

Scott RamboGurpreet Singh

32.9 - Soil conservation is essential to human life

Ways to save soil➔ Proper irrigation ➔ Prevention of erosion➔ Prudent fertilization

Preventing ErosionDefintion of Erosion: Blowing away or washing away soil

➔ Planting trees to block wind ➔ Contour planting patterns to catch

runoff water

Proper Irrigation• Too much irrigation can make the soil salty.• Modern irrigation uses perforated pipes that

drip water slowly closer to the roots, using less water.

More water is then absorbed by the plant= LESS WASTE

Prudent Fertilization• Fertilizers contain:

- nitrogen, phosphorus, and potassiumex. manure, fish meal, and compost

• Nutrients must be broken down by bacteria and fungi. • Organic fertilizer is slower, but lasts much longer.• Inorganic fertilizer attains the nutrients quicker, but

the minerals do not last as long. The minerals can runoff and cause pollution.

Jonathan DobsonLexie AllenArgel MoncayoJessi Sailer

ORGANIC SOIL & FARMING

32.9 Soil Conservation is Essential to Human Life• Our survival as a species depends on soil• Erosion and chemical pollution threaten

this vital resource throughout the world• 3 critical goals of soil conservation: proper

irrigation, prevention of erosion, prudent fertilization

32.9 continued…• Irrigation can make soil salty; too much so

for plants to tolerate• In order to prevent erosion, farmers can

take precautions such as planting rows of trees as wind breaks, terracing hillside crops, and cultivating in a contour pattern can prevent loss of top soil

• Manure, fish meal, and compost are common fertilizers

32.10 Organic Farmers Follow Principles of Sustainable Growth• To be “organic” food must be grown and

processed according to strict guidelines by the U.S. Dept. of Agriculture

• Goal is sustainable agriculture that is conservation minded, environmentally safe, and profitable

• Meant to sustain biological diversity, maintain soil quality, manage pests with little pesticides, little use of fertilizers, and to avoid genetically modified organisms

32.10 continued…• Over 2 million acres are used for organic

farming and industry is growing at 20% each year (0.3% of crop land and 2% of food market in U.S.)

• Ultimate aim is to restore as much to the soil as is drawn from it

• Protects environment and creates naturally produced foods

32.11Agricultural Research is Improving the Yields and Nutritional Value of Crops

• 800 million suffered from mal-nutrition• 40,000 people (including children) die each day

• The most limited source for food production is land• Human population increases while farmland decreases

• The commercial adoption by farmers of genetically modified crops has been one of the most rapid advances in the history of agriculture • Transgenic crops contain genes from the bacterium

(Bacillus-Thuriugiensis)• Genes encode for protein which controls a number of

serious insect pest• Transgenic plants (corns, soybeans, and wheat) are

tolerant to a number of herbicides

• This allows farmers to kill weeds without harming the transgenic plants• Researchers are also engineering plants with enhanced resistance to disease

• Nutritional quality of plants is being improved

• Gold + Rice = increased qualities of vitamin A • E.x.: Different varieties of corn, wheat, and rice that are enriched in protein. • Important because protein deficiency is the leading cause of mal-nutrition

Chris SharpClaire HugShawn Blake BensonKatherine Calhoun

32.12 Fungi and Roots

Fungus• Plants need large absorptive surface area

o Root hairs provide this area• Plants can absorb more water by

teaming with fungi• The roots that team with fungi are called

Mycorrhizao Mycorrhiza is covered in twisted mat of fungal

filaments

Fungus continuedFungi:• Benefits from sugars of the plant• Increases absorption surface area• Stimulates growth• Protects from pathogens in the soil

The Plant• Fungus symbiosis was possibly an

adaptation that allowed plants to colonize land evidence in fossil record• Roots can only transform into

Mycorrhiza if exposed to the correct type of funguso If seed drifts to foreign soil, it will not

grow

Bacteria• Nitrogen fixing bacteria provides a

source of ammonium.• Infects the plants nodules• Plant gives bacteria carbohydrates and

other organic compounds• Excretion of NH4

+ which increases soil fertility

Jamie KellyLogan RileyDeana SarkisovaLauren Scobee

32.15 Plant Parasites and Carnivorous Plants

• Many plants have symbiotic relationships

• Epiphytes absorb water and minerals from rain

• Parasites absorb sugars and minerals from their living hosts

• Some parasites tap into vascular tissue to absorb sugars

• Certain plants obtain nutrients, nitrogen and minerals by killing insects or small animals

• They live in soils with poor nitrogen and minerals such as acid bags