humus
Slightly soluble residue of undigested or partially decomposed organic material in topsoil. This material helps retain water and water-soluble nutrients, which can be taken up by plant roots.
Subject:
Chapter 10 - Geology: Processes, Hazards, and Soils
gully reclamation
Restoring land suffering from gully erosion by seeding gullies with quick-growing plants, building small dams to collect silt and gradually fill in the channels, and building channels to divert water away from the gully.
Subject:
green manure
Freshly cut or still-growing green vegetation that is plowed into the soil to increase the organic matter and humus available to support crop growth. Compare animal manure.
Subject:
geology
Study of the earth's dynamic history. Geologists study and analyze rocks and the features and processes of the earth's interior and surface.
Subject:
erosion
Process or group of processes by which loose or consolidated earth materials are dissolved, loosened, or worn away and removed from one place and deposited in another. See weathering.
Subject:
earthquake
Shaking of the ground resulting from the fracturing and displacement of rock, which produces a fault, or from subsequent movement along the fault.
Subject:
divergent plate boundary
Area where earth's lithospheric plates move apart in opposite directions. Compare convergent plate boundary, transform fault.
Subject:
desertification
Conversion of rangeland, rain-fed cropland, or irrigated cropland to desert like land, with a drop in agricultural productivity of 10% or more. It usually is caused by a combination of overgrazing, soil erosion, prolonged drought, and climate change.
Subject:
crust
Solid outer zone of the earth. It consists of oceanic crust and continental crust. Compare core, mantle.
Subject:
crop rotation
Planting a field, or an area of a field, with different crops from year to year to reduce soil nutrient depletion. A plant such as corn, tobacco, or cotton, which removes large amounts of nitrogen from the soil, is planted one year. The next year a legume such as soybeans, which adds nitrogen to the soil, is planted.
Subject:
Pages
Need Help?
We hope your visit has been a productive one. If you're having any problems, or would like to give some feedback, we'd love to hear from you.
For general help, questions, and suggestions, try our dedicated support forums.
If you need to contact the Course-Notes.Org web experience team, please use our contact form.
Need Notes?
While we strive to provide the most comprehensive notes for as many high school textbooks as possible, there are certainly going to be some that we miss. Drop us a note and let us know which textbooks you need. Be sure to include which edition of the textbook you are using! If we see enough demand, we'll do whatever we can to get those notes up on the site for you!
