Advertisement Upgrade to remove ads

the lesson learned by the schroeder brothers on their iowa farm is that

erosion and soil nutrient losses are reduced with no-till agriculture

the practice of planting large areas with a single type of crop, monoculture

is a development of industrial agriculture

agricultural practices, where the members of a farming family produce only enough food for themselves and do not make use of large-scale irrigation, chemical fertilizer or machinery and technology is called

subsistence agriculture

industrial agriculture

increased the ability to obtain more food from the same area

which of the following particles is smallest

clay

which soil horizon is most depleted through erosion

A

desertification of soil

can be caused by overgrazing

which of the following practices leads to the greatest amount of soil erosion from one location

clear-cutting trees from hillsides

what occurs when salts build up in the surface of soil

salinization

humus is

composed of organic compounds and is necessary for fertile soils and for holding soil moisture

during most of our species 160,000 year existence and until about 10,000 years ago, we depended on

hunting and gathering

factors involved in soil formation are

weathering of parent material, freezing/thawing, growth of tree roots

leaching

removes water soluble nutrients from soil

the O horizon is

primarily composed of organic materials

oxidation of minerals, warm and wet conditions, reactions of water with parent material are all components of

chemical weathering of soils

sachiko and her husband, fred, recently bought a farm that had been left idle for over 20 years. to understand the best uses of the land, they should first investigate

the horizons, texture, structure, pH, slope, and prior erosion history

pH influences

plant growth

how does the conservation reserve program try to protect soil for future agriculture

the CRP pays farmers not to grow crops on land that is not very well suited for crop production

weather can dramatically affect a farmers yield. government subsidies to farmers can compensate for this rick but may lead to

environmental sustainability

how has the US government changed its views of wetlands over the past 40 years

historically we have encouraged the draining of wetlands to make room for agriculture. recently we have reversed this policy and are trying to restore wetlands

we lose 5 to 7 million ha of productive cropland per year to

erosion, over-irrigation and other factors

when surface water flows downhill and removes topsoil in uniform layers

sheet erosion

leaching and the rate of movement of water would be greatest in a soil classified as

sandy

the consequences of over-fertilization can include

eutrophication in nearby waters

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set