Soil Biology & EcologyUnit 2.3 | Part 2 – 99 t *NNPCJMJ[BUJPOPGOVUSJFOUT
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necessarily compatible with crop needs. May result in leaching of water-soluble
nutrients, especially forms of N.
d) Earthworms
i. Most strongly affected (negatively) by fungicides and fumigants
ii. Herbicides
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- Food web structures
a) Fungi/bacteria ratio
b) Dominant microbe influences other trophic levels
- Interaction with fertility needs (also see Unit 1.1)
a) Measures of available nitrogen
i. Conventional cropping systems
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available to plants
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ii. Cropping systems based on organic matter management
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levels of N at any given time because much of soil N is immobilized
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conventional system
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incorporation of high-OM nutrient amendments, irrigation) by soil food web
becomes more critical
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Lecture 1: Soil Biology & Ecology