Chapter 14 Envir: Soil Resources

Crop rotation

Planting a series of different crops in the same field over a period of years

Soil Texture

Relative proportion of sand, silt and clay Sand: 2mm-0.05mm Silt: 0.05mm-0.002mm Clay: >0.002mm Soil texture affects soil properties

Acid precipitation (primarily from industrial emissions)

Sulfuric and nitric acids Alters soils, need to add calcium to reverse

How does CRP enrollment work?

Initially based on erodibility. Now based on a more complex index - the EBI:EBI weights have changed through time (eg now carbon is a factor) This is the largest program

Soil Acidity

Measured using pH scale pH of most soils range from 4-8 Affects solubility of certain plant nutrients Optimum soil pH is 6-7, because nutrients are most available to plants at this pH

Composting and Mulching

Make your own compost Degrade organic waste materials Add to property to naturally increase fertility Mulch Weed control Reduces evaporation Natural mulches can add to soil organic content

Inorganic fertilizers

Manufactured from chemical compounds Soluble Fast acting, short lasting Mobile- easily leach and pollute groundwater

Soil

Uppermost layer of earth's crust that supports plants, animals and microbes. Soil deliver ecosystem services that enable life on earth

Soil is composed of: mineral particles all of these water organic materials air

all of these

Soil Conservation

conservation tillage crop rotation contour plowing strip cropping terracing cover cropping

Cover crops

crops grown between seasons of other crops

The 1930's Dust Bowl in the western United States is an example of:

prolonged drought and accelerated wind erosion caused by use of marginal land for agriculture

Soil water

provides water to roots

Conservation Tillage

residue from previous years left in place

What is the best way to have soil reclamation?

shelter belts: Row of trees planted to reduce wind erosion of soil

Which of the following is a type of contour plowing? crop rotation grasslands reserve program native prairie seizure sod busting strip cropping

strip cropping

Pore space

50% of soil volume

Strip cropping

Alternating strips of different crops along natural contours

Organic fertilizers

Animal manure, crop residue, bone meal and compost Nutrient available to plants only as material decomposes

Soil Conservation Act 1935

Authorized formation of Soil Conservation Service, now called Natural Resource Conservation Service (NRCS) Assess soil damage and develop policies to improve soil

Mudslide in Oso, WA (2014)

Caused by heavy rainfall in erosion prone area.logging and poor management of area. Certain topographic areas need different management. 41 people died in mudslide Soil as a resource and in need of protection For our benefit, as well

Soil erosion

Caused primarily by water and wind Wearing away or removal of soil (usually topsoil). This is a problem because Causes a loss in soil fertility as organic material and nutrients are eroded More fertilizers must be used to replace nutrients lost to erosion.

Conservation funding

Conservation funding has been reduced from initial levels mandated by previous Farm Acts.

Terracing

Creating terraces on steep slopes to prevent erosion. very expensive to build and harder to implement

Cover cropping

Crops grown between seasons of other crops Otherwise soil lies bare

Ecosystem services soil organisms provide

Decaying and cycling organic material Castings - from gut of earthworms Breaking down toxic materials Cleansing water Soil aeration Mycorrhizae

Desertification

Degradation of once-fertile rangeland, agricultural land, or tropical dry forest into nonproductive desert

CRP

Environmental benefits may not be diminishing as quickly as the drop in enrolled acreage might suggest. CRP has shifted rapidly from enrolling whole fields or farms (through general signup) to funding high-priority, partial-field practices, including riparian buffers, field-edge filter strips, grassed waterways, and wetland restoration (through continuous signup).

Food Security Act (Farm Bill) 1985

Farmers with highly erodible soil had to change their farming practices Instituted Conservation Reserve Program Pays farmers to stop farming highly erodible land

Ecosystem services of soil

Food Fuel Water purification

Crop Production on Native Sod ("sodsaver")

For producers who choose to till native sod, provision would reduce crop insurance premium subsidies and limit the yield or revenue guarantee available during the first 4 years of crop production on native sod that had not been previously tilled. Applies to 6 states

Oxisols

Found in tropical and subtropical areas with high precipitation Very little organic material accumulation due to fast decay rate B-horizon is highly leached and nutrient poor

Spodosols

Form under coniferous forests Cold, ample precipitation, good drainage O-horizon composed of decaying needles E-horizon is ash-gray under thin A-horizon Not good farmland- too acidic

Aridisols

Found in arid regions of all continents Low precipitation preclude leaching and growth of lush vegetation Development of salic (salty) horizon possible

Mollisols

Found in temperate, semi-arid grassland Very fertile soil Thick, dark brown/ black A-horizon Soluble nutrients stay in A-horizon due to low leaching Grow most grains Deep rooting grasses help form

Agricultural Conservation Easement Program (ACEP)

Funding for long-term easements for the restoration and protection of on farm wetlands and protection of eligible agricultural land from conversion to nonagricultural uses. ACEP consolidates the functions of the Wetlands Reserve Program, the Grassland Reserve Program (easement portion), and the Farmland Protection Program.

Salinization

Gradual accumulation of salt in the soil, usually due to improper irrigation techniques Often in arid and semi-arid areas Salt concentrations get to levels toxic to plants

American Dust Bowl

Great Plains has low precipitation and is subject to drought 1930-1937 severe drought No natural vegetation roots to hold soil in place Replaced by annual crops Winds blew soil as far east as NYC and DC. Farmers went bankrupt

Crop rotation and strip cropping alternate crops such as corn and wheat. The difference is:

In strip cropping, the crops are alternated by row. In crop rotation, the crops are alternated by years

Soil erosion increases movement of sediment among ecosystems...

Into streams and waterways Increases water pollution Degradation of water infrastructure (ex: dams)

Iowa landforms

Most of the deposits underlying today's land surface are composed of materials known as drift that were moved here by glaciers 12,000 to 14,000 years ago.

Contour plowing

Plowing around hill instead of up-down.

Fine textured soil (high in clay)

Poor drainage Low oxygen levels in soil Due to negatively charged surface, able to hold onto important plant nutrients (K+, Ca2+, NO2-)

Environmental Quality Incentives Program (EQIP)

Program continues financial assistance to producers to install and maintain conservation practices on eligible agricultural and forest land.

Conservation Stewardship Program (CSP)

Program continues financial assistance to producers who meet stewardship requirements on agricultural and forest lands. This is a farm wide program. Pays farmers to change their productive practices on all of their farm fields

Conservation tillage

Residues from previous year's crops are left in place to prevent soil erosion. A major drawback of conservation tillage is more weeds so we use more pesticides. Some benefits are the residues left also provides benefit for habitat for animals in the winter. If you don't use machinery on the field, you have energy savings.

Soil Taxonomy

Separates soils into 12 orders in U.S. Subdivided into more than 20,000 soil series that vary by locality Variations in soil forming factors cause variation in soils around globe

Five common soil orders

Spodosols, alfisols, mollisols, aridosols, oxisols

2 steps of Soil Reclamation

Stabilize land to prevent further erosion Restoring soil to former fertility

Alfisols

Temperate deciduous forests Brown to gray-brown A-horizon Precipitation high enough to leach most organics and nutrients out of O-, A- and B-horizons Soil fertility maintained by leaf litter

Conservation Compliance (CC)

The 2014 Farm Act adds crop insurance premium subsidies to the list of benefits that could be withheld for noncompliance with conservation provisions. Producers who fail to apply approved soil conservation plans on highly erodible cropland or who drain wetlands could become ineligible for a number of agricultural programs, including commodity programs, conservation programs, disaster assistance, and now crop insurance premium subsidies.

Nutrient cycling

The pathway of various nutrient minerals or elements from the environment through organisms and back to the environment

Soil organisms

There are millions of microorganisms in 1 tsp of fertile agricultural soil Soil organisms provide ecosystem services: Important environmental benefits that ecosystems provide

National Resources Conservation Service estimates erosion (5 year intervals)

Water erosion in grain belt (large rainstorm can remove ~1mm, but can add up) Annual loss of 75 billion metric tons of topsoil? Problems from loss and problems from where it goes

Soil Farming Factors

Weathering of parent material Time Climate Organisms Topography

Ecosystem service benefits: cultural...

aesthetic spiritual educational recreational

Humus

black organic matter remaining after most decomposition. Collective name for many different organic compounds

Healthy soil

chemical properties: pH near neutral, optimal nutrient levels, no harmful chemicals, low levels of salts biological properties: extensive biodiversity, plentiful beneficial organisms, low pest pressure physical properties: good tilth, surface structure porous and stable, no subsoil layers restricting roots, good aeration, water storage, drainage

Ecosystem service benefits: regulating...

climate regulation flood regulation disease regulation water purification

Increased soil erosion may be caused by all of the following except: construction of buildings construction of shelterbelts agriculture clearcutting large forested areas construction of roads

construction of shelterbelts

Which of the following outlines a typical crop rotation planting schedule for conservation purposes? corn → corn → corn → corn corn → soybean→ oats →alfalfa oats → soybean → oats → corn corn → soybean → corn→ soybean

corn → soybean→ oats →alfalfa

Coarse textured soil (sandy)

excellent drainage

Ecosystem service benefits: provisioning....

food freshwater wood and fiber fuel

Terrain characteristics of Des Moines Lobe

fresh glacial till no loess cover bands of knob and kettle terrain areas of level terrain poor surface damage natural lakes, wetlands

Terrain characteristics of the Iowan surface

gently rolling terrain thin, discontinuous loess or loam over glacial drift bedrock near surface local karst conditions scattered glacial boulders integrated drainage network isolated elongate hills (paha) This relaxed, open topographic style is free of the strong expressions of glacier surges, silt-laden winds, or erosional sculpture that identify the Des Moines Lobe, the Loess Hills, and the Southern Iowa Drift Plain. Like southern Iowa, the hillslopes of the Iowan Surface can be described as having multi-leveled or stepped surfaces.

Soil air

good for aeration

Planting the same crop year after year:

increases damage by insects and disease

Which of the following represents an "ecosystem service" performed by soil organisms? contributing to desertification by removing excess moisture from the soil altering topography by amplifying erosion maintaining soil fertility by decaying and cycling organic material providing minerals by assisting in weathering preserving toxic materials by situating toxins into encapsulated structures

maintaining soil fertility by decaying and cycling organic material

Soil erosion: may result in decreased water quality for fishes and other aquatic organisms is never responsible for or related to water pollution is not affected by the extent of plant cover is exclusively linked to human activities does not reduce the fertility of the soil, just the quantity

may result in decreased water quality for fishes and other aquatic organisms

"Typical Soil" composition

mineral particles (45%): weathered rock organic martial (5%): litter, animal dung, dead remains of plants and animals, humus water (25%) air (25%)

Terrain characteristics of the Southern Iowa Drift Plain

moderate loess cover weathered glacial drifts with paleosols integrated drainage network bedrock exposed in deeper valleys Grant Wood emphasized the steeply rolling character of this landscape in many of his paintings. The landforms of this region, like those of the DML, are composed primarily of glacial drift, older by hundreds of thousands of years than those that occupied the north-central area of the state.

Terrain characteristics of the Northwest Iowa Plains

moderate to thick loess over glacial till gently rolling terrain integrated drainage network Gently rolling landscapes reminiscent of the low, uniform relief seen on the Iowan Surface. A well-established branching network of streams, provides effective drainage and a uniformly creased land surface.

_________ describes the pathway of various nutrient minerals or elements from the environment through organisms and back to the environment.

nutrient cycling

Ecosystem service benefits: supporting...

nutrient cycling soil formation primary production

Soil horizons

o-horizon: accumulation of plant litter a-horizon: accumulation of organic matter and humus e-horizon: heavily leached b-horizon: accumulation of clay and nutrient minerals c-horizon: weathered pieces of rock soil parent material: bedrock

Which of the following is not true of conservation tiling? there are several types including no tilling over 70% of US farmland was planted using conservation tilling in the early 2000s a method of cultivation in which residues from previous crops are left in the soil residues are partially covering soil and helping it to hold seeds all these are false

over 70% of US farmland was planted using conservation tilling in the early 2000s

Worldwide, 75 billion metric tons (83 billion tons) of topsoil is lost annually, primarily due to:

poor agricultural practices

Soil degradation is primarily attributed to:

poor agricultural practices, overgrazing and deforestation

Of the following, which has the greatest permeability? humus loam clay silt sand

sand

Soil problems

soil erosion accelerated by poor soil management practices (not just agriculture) nutrient mineral depletion salinization desertification

The soils of tropical rain forests tend to be nutrient-poor due to:

the fact that nutrient minerals are stored primarily in the vegetation

Terrain characteristics of the Alluvial Plains

thick alluvium level terrain along valleys include stream channels, floodplains, oxbow lakes, terraces, alluvial fans, sand dunes Rivers construct distinctive, flat-floored corridors known as alluvial plains which are underlain by water-transported deposits. These topographic corridors weave throughout the state's other landform regions, & together they constitute the last of Iowa's seven physiographic regions, the Alluvial Plains

Terrain characteristics of the Paleozoic Plateau

thick loess cover isolated patches of glacial drift bedrock-dominated terrain plateau-like uplands integrated drainage network deeply-entrenched valleys karst topography (sinkholes, caves, springs) A different Iowa. The most striking differences include abundant rock outcroppings, a near absence of glacial deposits, many deep, narrow valleys containing cool, fast-flowing streams, and more woodlands.

Terrain characteristics of the Loess Hills

thick loess cover sharply rigid terrain high drainage density rapid surface runoff gully development vertical road cuts The western boundary is very abrupt as distinct and well defined as a coastline. The bluffs of steeply pitched, prairie-covered ridges and wooded back-slopes stand boldly apart from the lower, flat-lying cultivated fields of the Missouri River valley floor