Chapter 9: Soil and Agriculture

Soil texture

Clay consists of particles less than 0.002mm in diameter, silt is 0.002mm-0.05mm, sand 0.05mm-2mm. This depends on its mix of particle sizes.

Deposition

Occurs when eroded material is deposit dat a new location.

Weathering

Parent material is broken down by the physical, chemical and biological processes that convert large rock particles into smaller particles.

Humus

Partial decomposition of organic matter creates a dark, spongy, crumbly mass of material and up of complex organic compounds.

Cation exchange

Plant roots donate hydrogen ions to the soil in exchange for these nutrient ions(calcium, magnesium, and potassium), which the soil particles then replenish by exchange with soil water.

Land degradation

Refers to the general deterioration of land that diminishes its productivity and biodiversity impairs the functioning fo the ecosystems and reduces the ecosystem services it offers us. Regional soil differences affect how people farm.

Loam

Soil with and even mixture of the three particle sizes.

Summarize major policy approaches for pursuing soil conservation and sustainable agriculture

In the United States and across the world, governments are devising agricultural policies and programs for conservation, such as the Conservation Reserve Program, and other programs funded in the periodic U.S. farm bills.

Green revolution

Industrial agriculture spread form developed nations to developing nations in the 1950's, introducing new technology, crop varieties, and farming practices.

Desertification

Describes a form of land degradation in which more than 10% of productivity is lost as a result of erosion, soil, compaction, forest removal, overgrazing drought, salinization, climate change, water depletion, and other factors. When this is serve it can cause desire areas to expand.

Conservation tillage

Describes an array of approaches that reduce the amount of tilling relative to conventional farming; one common definition is any method of limited tilling that leaves more than 30% of crop residue covering the soil after harvest. No-til farming is the ultimate form of this.

Picture examples to conserve soil

Farmers adopted various strategies to conserve soil. Pg 227.

Crop rotation

Farmers alternate the type of crop grown in a given field from one season or year to the next.

Polycultures

"many type".

Monocultures

"one type".

Conservation districts

A agency that promotes soil conservation practices through county-based systems.

Top soil

A crucial horizon for agriculture and ecosystems is the A horizon. Consist mostly of inorganic mineral components, with organic matter and humus from above mixed in.

Sustainable agriculture

Agriculture we can practice in the same way in the same place far into the suture.

Industrial agriculture

Also boosted yields by intensifying irrigation and by introducing synthetic fertilizers.

Inorganic fertilizer

Are mined or synthetically manufactured mineral supplements.

Analyze the causes and impacts of soil erosion and land degradation

As the human population grows and consumption increases, pressures from agricultures are degrading earths soils, and we are losing 12-17 million acres of productive cropland annually.

Agriculture

As the practice of raising crops and livestock for human use and consumption.

Outline major developments in the history of agriculture

At least 10,000 years ago, people began crop breeding plants and domesticating animals through the process of selective breeding. Agriculture originated multiple times independently in different cultures across the world. Industrial agriculture is replacing traditional agriculture, which largely replaced hunting and gathering.

Soil color

Can indicate its composition and fertility. Black or brown soils are usually rich in organic matter, whereas a place color often indicates leaching or low organic content.

Soil formation are influcend by these five factors

Climate: Soil forms faster in warm, wet climates, because of heat and moisture speed physical, chemical, and biological process. Organisms: Plants and decomposers add organic matter to the soil. Topography: Hills and valleys affect exposure to sun, wind, and water, and they influence how the soil moves. Parent material: Its attributes influence properties of the soil. Time: Soil formation can take decades, centuries or millennia.

Mature soil

Consists of layers, or horizons, that have different compositions and characteristics.

Contour farming

Consists of plowing furrows sideways across a hillside, perpendicular to its slope and following the natural contours of the land.

Organic fertilizer

Consists of the remains or wastes of organisms and include animal manure; crop residues; fresh vegetation(green manure); and compost, a mixture produced when decomposers break down organic material such as food and crop waste in a controlled environment.

Cover crops

Crops planted to hold soil in place between times that main food crops are growing.

Soil degradation

Drier regions are becoming more difficult to raise crops and graze livestock because of the soil deteriorating in quality and the decline in productivity. This on drylands is due primarily to erosion by wind and water.

Horizon

Each layer of soil is known as this.

Subsistence agriculture

Farming families produce only enough food for themselves.

Parent material

Is the base of geologic material in a particular location.

Erosion

Is the removal of material from one place and its transport toward another by the action of wind or water. The rates from conventional agriculture are high. An example is that water erosion can readily remove soil form areas where soil is exposed such as farmland.

Soil

It is a complex system of disintegrated rock, organic matter, water, gasses, nutrients, and microorganisms.

Rangeland

Land or a pasture used for grazing livestock.

Cropland

Land used to raise plants for human use. Crop plants such s wheat depend on healthy soil for nutrients, organic matter, water retention, and proper root growth.

Shelterbelts

Or windbreaks, a widespread technique to reduce erosion from the wind to establish this.

Explain the importance of soil to agriculture

Our society's future depends on sustainable agriculture and soil integrity is a key component of this pursuit, successful agriculture requires healthy soil.

Intercropping

Planting different crops in altering bands or other spatially mixed arrangements.

Soil pH

Plants can die in soils that are too acidic or too alkaline so soils of intermediate pH values are best for most plants.

Natural Resources Conservation Service (NRCS)

Renamed in 1999 from SCS to this and it's responsibilities were expanded to include water quality protection and pollution control. Agricultural extension agents assist farmers by providing information on new research and techniques.

Fertilizer

Substances that contain essential nutrients.

Explain the principle of soil conservation and provide solutions to soil erosion and land degradation

The Dust bowl is an example of inspired scientists and farmers developing ways to conserve topsoil. NRCS help educate and assist farmers. Vegetation helps anchor and prevent erosion. Overgrazing can cause soil degradation on grasslands and diverse impacts to native ecosystems but herd rotation, razing limits and research cooperation are some pathways to sustainable grazing.

Irrigation

The artificial provision of water beyond that which crops revive from rainfall.

Salinization

The buildup of salts in a surface soil layers.

Soil profile

The cross-section as a whole, from surface to bedrock.

Bedrock

The mass of solid rock that makes up Earth's crust.

Leaching

The process whereby soil particles suspended or dissolved in liquid are transported to another location.

Dust Bowl

The southern Great Plains was the most affected region and became known as this because of the "black blizzards", forced thousand's of farmers off their land. Drought and poor agricultural practices devoted millions of U.S. farmers in the 1930's.

Delineate the fundamentals of soil science, including soil formation, and soil properties

The soil is a complex system and includes diverse biotic communities that decompose organic matter. Weathering and biological activity help from soil, influenced by climate, organisms, topography, parent material and time. Soil profiles consists of distinct horizons with characteristic properties. Soil properties differ among regions and affect plant growth and agriculture.

Traditional agriculture

The work of cultivating, harvesting, storing, and distribution crops was performed by human and animal muscle power, along with hand tools and simple machines.

Terracing

Transforms slopes into a series of steps like a staircase, enabling farmers to cultivate hilly land without losing huge amounts of soil to water erosion.

Describe techniques of watering and fertilizing crops, and offer more sustainable alternatives.

We can conserve water by using efficient irrigation techniques and choosing crops to match climates. Over irrigation can cause salinization and waterlogging, which lower crop yield and are difficult to mitigate. Overapplying fertilizers can lead to pollution problems, as leaching and runoff transport nutrients that affect ecosystems and human health. Fertilizer can be used more sustainable by targeting fertilizers directly to plants and monitoring when they are needed.

Waterlogging

When the water table rises to the point that water drowns plant roots depriving them of access to gasses and essentially suffocating them.

Overgrazing

When too many livestock destroys too much of the plant cover(vegetation that covers the soil), impeding plant regrowth and prevent the replacement of the biomass. It has ecological consequences. r

No-till farming

When you leave the crop residue atop their field after a harvest instead of blowing it over so the soil is covered with planet material at all times. Then to plant the crop, they cut a thing, shallow groove into the soil surface, drop the seeds in and then immediately cover it. By planting the new crop seeds through the old crop reside ensures that less soil erodes away, organic material accumulates, and the soil soaks up more water which all encourages better plant growth.

Conservation Reserve Program

Which pays farmers to stop cultivating damaged and highly erodible cropland and instead makes theses land conservation reserves planted with grasses and trees.