The Soil Biology Primer is an introduction to the living component of soil and By Dr Elaine Ingham Introduction to the Soil Foodweb – downloadable mp3s. Soil Biology Primer. Front Cover. U.S. Department of Agriculture, Natural Resources Conservation Service, – Soil biology. The online Soil Biology Primer is an introduction to the living component of soil and Elaine R. Ingham; Andrew R. Moldenke, Oregon State University; Clive A.

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Fundamentals of Soil Ecology. These differences are the result of soil, vegetation, and climate factors, as well as land management practices Figure 2. Burrowing changes the physical prop- erties of soil, including porosity, water infiltration rate, and bulk density. Whether pollutants reach groundwater depends on a number of factors, including the location of pollutants on the surface or within soil, the quantity and intensity of rain, how well water moves into and through other parts of the soil, and characteristics of the burrows.

They may produce a com- pound that inhibits the growth of pathogens or reduces invasion of the plant by a pathogen.

Soil Biology Primer |

Some herbivores, including rootworms and symphylans, can be crop pests where they occur in large numbers, feeding on roots or other plant parts. Earthworms perform a number of beneficial functions. These resources include a vast knowledgebase of inguam information, experienced technical support and an extensive seed bank focused on highly beneficial underutilized plants.

As they feed, arthro- pods aerate and mix the soil, regulate the population size of other soil organ- isms, and shred organic material. Forests tend to have fungal-dominated food webs. The active fraction changes more quickly than total organic matter in response to management changes. There is good evidence that earthworm activity affects the spatial distribution of soil microarthropod communities in the soil.


Soil Biology Primer

At any time, only a small subset of species is metabolically active – only those capable of using the resources currently available. Some species make permanent burrows deep into the soil. Organic matter such as humus or lignin-containing material that few soil organisms can decompose.

Organic compounds that can be used as food by microorganisms. The United States has only one or two known native species of lumbricids. If grazer populations get too dense the opposite effect can occur — popula- tions of bacteria and fungi will decline. When foraging, springtails walk with 3 pairs of legs like most insects, and hold their tail tightly tucked under the belly. Certain row- crop soils contain several dozen species Soil is.

These may be potential biocontrol agents. Rugose harvester ants are scavengers rather than predators. Active organic matter is the portion available to soil organisms.

Citation for the first edition of the booklet: Stable aggregates improve water infiltration and the soil’s water- holding ability. Successful land management requires approaches that protect all resources, including soil, water, air, plants, ani- mals and humans. Citation for this web page: Fungi are more important in degrading these compounds at low pH. Protozoa play an important role in nutrient cycling by feeding intensively on bacteria.

The NRCS thanks many individuals. A few fungal-feed- ers. There is evidence that plants produce certain types of root exudates to encourage the growth of protective bacteria. Stimulate the succession of species.

As organisms decompose complex materials, or consume other organ- isms, nutrients are converted from one form to another, and are made avail- able to plants and to other soil organ- isms.


Nematodes are food for higher level predators, including predatory nema- todes, soil microarthropods, and soil insects. I hope you enjoy reading about the fascinating diversity of soil life under our feet and gain a deeper appreciation of the intrinsic value of soil organisms to sustainable civilizations.

When organisms consume food, they create more of their own biomass and they release wastes. Fecal pellets are a highly concentrated nutrient resource, and are a mixture of the organic and inorganic substances required for growth of bacteria and fungi.

Some hitchhike under the ;rimer of beetles. Soil organisms prey on crop pests and are food for above-ground animals. Most people become familiar with these soft, slimy, invertebrates at a young age.

The Basics Tropical Agriculture Development: Discounts are available for orders of 85 or more. A mixture of soil and organic zoil within an earthworm burrow. Casts at the soil surface are evidence that earthworms are shredding, mixing, and burying surface residue.

Holmes, Oregon State University, Corvallis. Several hundred yards in deciduous forests. They are generally harmless to people, but most millipedes protect themselves ifrom predators by spraying an offensive odor from their skunk-glands.

Soil Biology Primer |

Soil Landscape and the An incredible diversity of organisms make up tlie soil food web. Forests have been observed to increase in productivity as fungal biomass increases.

That is, there must be a healthy and diverse food web.