Ag Science 5.03

A. Water Resources 1. Potable Water- though most of the Earth’s surface is covered with water, our bodies can survive only a few days if our supply of potable (drinkable-free from harmful chemicals and organisms) water is cut-off. Most of the Earth’s water is not fresh water.

2. Water is considered the universal solvent because as a material it dissolves otherwise changes most other materials

3. Water Cycle (p. 146) – is the cycling of water between water sources, atmosphere, and surface areas. a. Precipitation – moisture from rain or snow. b. Evaporation – changing from a liquid to a gas..

4. Watershed – a large land area in which water is absorbed from rain or melting snow and from which water drains. It acts as a storage system by absorbing excess water and releasing it slowly throughout the year.

5. Water Table - the level below which soil is saturated or filled with water.

6. Types of Groundwater a. Capillary – water that plant roots can absorb. b. Free (gravitational) – water that drains out of a soil after it has been wetted. c. Hygroscopic – water that is held too tightly for plant roots to absorb.

b. Free (gravitational) – water that drains out of a soil after it has been wetted. c. Hygroscopic – water that is held too tightly for plant roots to absorb.

7. Conserving Water and Improving Water Quality a. Ask the right questions 1) How can we reduce water pollution? 2) How can soil erosion be reduced? 3) What is the most productive use of water and soil without polluting or losing these essential resources?

b. Some good practices: 1) Save clean water (ie. turn off water faucet while brushing teeth). 2) Dispose of household products carefully and appropriately. (ie. never pour paint down the drain as it will eventually enter the water supply). 3) Care for lawns, gardens and farmland carefully. (ie. only till soil that will not erode excessively and don’t over fertilize).

B. Soil (worlds’ largest sponge) 1. Soil Profile a. A Horizon- topsoil 1) Surface layer of soil approximately 6” deep. 2) Usually contains more organic matter than other horizons and is typically darker colored because of it. 3) Generally the layer that has the greatest influence on crop production (plant growth).

b. B Horizon – subsoil 1) Subsurface layer. 2) Most subsoil has an increase in clay content. 3) Generally has the greatest influence on urban uses such as building sites, septic systems, etc.

c. C Horizon – parent material (bedrock). 1) Releases water to the upper soil layers. 2) Contains larger soil particles including gravel and large rocks.

2. Soil texture and Structure a. Texture refers to the size of soil particles 1) Sand – largest soil particle. a) Sandy soils have problems holding enough water for good plant growth, but they do drain well. b) Individual particles can be seen with the naked eye.

2) Silt – Intermediate size soil particle that can’t be seen with naked eye. 3) Clay – smallest soil particle- clayey soils hold lots of water but may be airtight, infertile for root growth, and associated with wet soils.

b. Structure refers to the tendency of soil particles to cluster together and function as soil units called aggregates that leave pore space to store air, water, nutrients, and allow root penetration.

1) Single grain - associated with sandy soils. 2) Granular – particles cling together to form rounded aggregates- very desirable for all soil uses. 3) Blocky – particles cling together in angular aggregates –typical of soils with high clay content.

3. Soil Classification a. Land capability maps are based on the physical, chemical, and topographical aspects of the land.

b. Land Capability classes are designated by Roman Numerals I – VIII. 1) Class I and II land is the best land for the most intensive cultivation of field crops with the fewest limitations and can be planted year after year. 2) Class VII land is very steeply sloping and best used for planting trees. 3) Class VIII land is best suited for wildlife and recreation.

4. Soil Conservation a. Two types of erosion 1) Sheet – removal of layers of soil from the land. 2) Gully – removal of soil that leaves trenches.

b. “No till” is a cropping technique used to reduce soil erosion. 1) Crops are planted directly into the residue of a previous crop without plowing or disking. 2) An effective means of erosion control.

c. Conventional Tillage- uses tillage system that disturbs the soil surface by plowing, disking and/or harrowing.

d. Conservation Tillage – intermediate tillage system conventional and no-till.

C. Wildlife Management 1. Benefits of Wildlife to humans a. Hunting/Fishing b. Viewing c. Photography d. Environmental Indicator

2. Wildlife Environments a. Farm – wildlife management on farms is usually a by-product of the farming operation. Leaving crop residue standing can increase food supply. Creating brush piles when harvesting trees provides shelter and cover. b. Forest – difficult to manage. Plans should be developed so that timber and wildlife can exist in populations large enough to be sustained and harvested.

c. Wetland – No area of U.S. land is more important to wildlife than wetlands (land that is poorly drained- swamps, bogs, marshes, etc.). Wetlands are the most productive wildlife management area. d. Stream – difficult to manage due to continuous flow of water.

e. Ponds/Lakes – easier to manage than streams due to water standing and not flowing. f. Backyards (urban wildlife) – birds, butterflies and small mammals can be attracted through use of feeders, houses and proper landscaping.

3. Importance of Carrying Capacity a. The number of wildlife each habitat can support throughout the year.

b. More wildlife than habitat can support will result in problems for both the wildlife and the habitat. 1) Wildlife is affected by malnutrition, disease, and a reduction in the reproduction cycle. 2) Habitat quality decreases. A pond with a carrying capacity of 20 fish will decrease if 50 fish are competing for the same food, habitat and oxygen.

4. Role of Hunting and Fishing with regards to Wildlife Management a. Helps to maintain the proper carrying capacity. b. Prevents overpopulation, which results in malnutrition, disease, and reduction in reproduction, which will result in decreased wildlife population.

5. Examples of Wildlife in North Carolina a. Hunted Species – deer, ducks, bear, quail, doves, rabbits b. Songbirds – Cardinal, robin, chickadee, Eastern bluebird c. Birds of prey – Red- tailed hawk, Turkey and black vulture d. Fish (freshwater) – largemouth and smallmouth bass, bream, catfish, crappie

D. Forest Management 1. Forest Regions of North America include 8 major regions (map p. 199), of which the a. Northern coniferous forest is the largest region and produces large amounts of pulpwood.

b. Pacific Coast Forest is the most productive of the forest regions and has some of the largest trees in the world. Douglas Fir is one of the most important commercially grown trees.

c. Southern forests’ most important trees are conifers but some hardwood trees have economic importance as well. It has the most potential for meeting the future lumber and pulpwood needs of the US. 1) Conifers – Virginia, loblolly, shortleaf, longleaf and slash pines 2) Hardwoods – Oak, poplar, maple and walnut

2. Importance of Forests a. Recreation – hunting, hiking b. Wood products (p. 198) – lumber, pulpwood, etc. c. Wildlife habitat – (see Wildlife 5.03) d. Filter – water and air

3. Silviculture – scientific forest management techniques a. Managing growing timber 1) Prescribed thinning is recommended to remove some trees when competition slows the growth of all trees. 2) Prescribed burning is used to reduce the risk of wildfires by eliminating forest litter (fuel).

b. Harvesting Timber 1) Clear cutting is a system of harvesting trees where all of the trees in an area are removed. 2) Selection cutting is the harvesting method recommended for a forest of trees consisting of different ages and species.

c. Replacing trees 1) Replanting seedlings is a surer method of replacing trees. 2) Natural seeding is the least expensive method to replace harvested trees.

Identification and Uses of Important Tree Species in NC

a. Conifers (softwoods) – needle-type evergreens 1) Frazier fir a) Use- Most important commercially grown Christmas Tree in NC (mountains) b) ID – dark green ½-1” long singular needle

2) Loblolly pine a) Use – pulpwood and plywood b) ID – 3 needles/bundle, needles 6- 9” long needles

3) Longleaf pine a) Use – lumber, pulpwood and plywood b) ID – 3 needles/bundle, 8-18” long needles

b. Hardwoods – deciduous trees

1) Ash a) Use – baseball bats, handles b) ID – opposite pinnately compound leaves

2) White oak a) Use – flooring, furniture b) ID – alternate, pinnately lobed leaves,

3) Red Maple a) Use – lumber, veneer, cabinets b) ID – opposite, palmately lobed,3-5 lobed

6. Measurement of Trees and Lumber a. Pulpwood - DBH, merchantable height in feet, cords b. Sawtimber – DBH, 16 foot logs, board feet c. Lumber – 1 board foot = 144 cubic inches