Title: Nutrient Cyclying, Pools, and Title: Transformations. What is the title of this lecture? Speaker: Speaker: Amit William Dhingra Pan Created by: (remove if same as speaker) online.wsu.edu
http://www.soccerassociation.info/globe.htm Unit 1, Lesson 3 Nutrient Cycling, Pools, and Transformations.
1.3 Learning Objectives Ecological nutrient cycling Soil nutrient cycling in place Soil nutrient pools and processes Plant nutrient availability Ion exchange Global nutrient flows
Overview life death soil Basic ashes to ashes, dust to dust 1 stuff of fertility life-mineral nutrients and the systems that influence nutrient availability to plants, including natural cycling in soils as well as the fate of organic and inorganic materials added to the soil-plant system. 1 'Ashes to ashes' derives from the English Burial Service. The text of that service is adapted from the Biblical text, Genesis 3:19 : "In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken: for dust thou art, and unto dust shalt thou return."
Origins of Life? So you re made of detritus [from exploded stars]. Get over it. Or better yet, celebrate it. After all, what nobler thought can one cherish than that the universe lives within us all Neil degrasse Tyson, American astrophysicist and science commentator
General Nutrient Cycling Broad perspective of nutrient cyclingcase #1 Read article by J. Miller on the connection of Maggots Cows Trout Humans Connect the dots by drawing arrows between organisms that shows the flow of nutrients.
Example of Nutrient Flow http://www.flickr.com/photos/btindrelunas/146340957/ http://organic.tfrec.wsu.edu/compost/imagesweb/compsys. html
Consider a farming system run by Ted Durfey. His system includes: Growing canola for making biodiesel from the oil and feed meal for dairy cows from the canola byproduct Using Seattle biosolids to fertilize the canola Composting dairy manure for making a soil amendment, fertilizer. Draw a diagram to describe this nutrient flow.
Assignment 1.3 Part 1. Hippo Dung Decline Nutrient Diagram Read Vanishing Hippo story in Wall Street Journal, Nov. 19, 2005. Draw a nutrient cycle cartoon connecting all key players Describe impacts of changes in the dynamics of the nutrient cycle that ripples through the system
Cycling of Essential Elements in Place Fertilizers Humans Plants Animals, Atmosphere microorganisms Mineral Reserves Mineral colloids Ions in Soil Solution Surface and Ground Water Soil organic matter
Nutrient Transformations and Flow In Soil-Plant Systems Solid Phase Solution Stable Organic Matter Mineral structures Slowly available Soluble precipitates Mineralizable Organic Matter Adsorbed Ions Moderate Chelated Ions Fast Plant Roots Free ions
Mineral Weathering: A long- term source of plant nutrients Primary minerals Formed under high temperature and pressure Secondary minerals + soluble plant nutrients Formed from physical and chemical weathering
Mineral Weathering: An example Primary minerals Biotite and Muscovite Micas, Orthoclase Secondary minerals Vermiculite, Smectite + Ca, Mg, K, Fe Kaolinite Fe, Al Oxides
Organic Matter Decomposition Humus Lignin Cellulose Soluble Proteins Lipids Amino Acids Soluble Ions
Nutrients locked in minerals and in stable fractions of soil organic matter are NOT available to plants over a single growing season. They are slowly available during long-term weathering. http://www.kings.edu/~chemlab/animation/clospack.html (ccp.gif)
Nutrient Availability: The accessibility of essential nutrients to plant roots Encompasses all factors: physical (e.g. bulk density, temp, water) Biological (e.g. organisms involved in nutrient transformations) chemical (weathering, precipitation/dissolution, exchange)
Moderately Available Nutrients Precipitates (chemical) Exchangeable ions (chemical) Mineralizable fraction of organic matter (biological) Nutrients in these pools can be made available to plants over the course of a single growing season.
Examples of readily soluble precipitates 2+ 2- CaHPO Ca + HPO 4 4 2+ 2- MgSO Mg + SO 4 4
Exchangeable ions Soil particles act like magnets for ions Soil Fertility Manual, PPI
Cation Exchange Capacity (CEC): the amount of (-) charge on soil colloids Soil Fertility Manual, PPI
Sources of Negatively Charged Cation Exchange Sites Isomorphous substitution: substitution within the crystalline lattice of divalent for trivalent cations, creating a net negative charge for that structure. Broken edges of clay plates Organic matter functional groups
Tetrahedral Octehedral
1:1 and 2:1 layer structures
Typical Soil Properties CEC 11-50 cmol/kg CEC 1-10 cmol/kg high clay higher nutrient holding high sand capacity more leaching greater potential to potential aggregate lower water holding higher water holding capacity capacity lower lime requirement for given more lime required for ph given ph
Typical Charge Characteristics of Clay Minerals and Humus Mineral CEC (cmol/kg) Montmorillonite 100 1 Vermiculite 140 0 Kaolinite 4 3 Gibbsite 5 5 Goethite 4 4 Allophane 51 17 Humus 200 --- AEC (cmol/kg) *1 cmol/kg = 1 meq/100g
Anion Exchange Capacity (AEC): amount of (+) charge on soil colloids Anions are held on (+) sites in soils. AEC important in soils with iron and aluminum oxides - highly weathered soils (eg. ultisols, oxisols) NO 3 - Cl - SO 4-2 + + + +
Sources of positive charge for anion adsorption sites alumina octehedral sheets iron and aluminum oxides in highly weathered soils.
ph scale Soil ph: Indicator of soil acidity 9 8 7 6 5 4 strong medium slight neutral slight moderate strong very strong basicity acidity
Nutrient Cycling: Scale Considerations Global Farm Local ecological system
Human Consumption Nitrogen Cycle??
Global Nutrient Flows Assnmt. 1.3, Part 2: How do nutrients travel around the globe? Name one distinctly different example of nutrient forms that globally travel, cite examples of geographical points of origin and destination. Cite a different example than the global N flow described in this lecture. How does this impact the ability to cycle nutrients in place?