NS 435 Unit 5:Effect of Soil Composition on Nutrition & Health “The soil is the great connector of our lives, the source and destination of all.” Wendell Berry Nanna Cross, PhD, RD, LDN

Reminders  Unit 3 Project Questions  Unit 6 Project  Unit 9 Project  Tour of USDA website

What are the Four Main Components of Soil?  Minerals 45%  Air 25%  Water 25%  Organic Matter2 – 5%

WHAT ARE FIVE FUNCTIONS OF SOIL?

What Soil Does  Regulates water  Soil helps control where rain, snowmelt, and irrigation water goes.  Water and dissolved solutes flow over the land or into and through the soil. Source: Soil Quality Concepts. USDA. Natural Resources Conservation Service.

What Soil Does  Sustains plant and animal life  The diversity and productivity of living things depends on soil. Source: Soil Quality Concepts. USDA. Natural Resources Conservation Service.

What Soil Does  Filters potential pollutants  Minerals & microbes in soil are responsible for filtering, buffering, degrading, immobilizing, & detoxifying organic & inorganic materials, including industrial & municipal by-products & atmospheric deposits. Source: Soil Quality Concepts. USDA. Natural Resources Conservation Service.

What Soil Does  Cycles nutrients  Carbon, nitrogen, phosphorus, and many other nutrients are stored, transformed, and cycled through soil. Source: Soil Quality Concepts. USDA. Natural Resources Conservation Service.

What Soil Does  Supports structures  Buildings need stable soil for support.  Archeological treasures associated with human habitation are protected in soils. Source: Soil Quality Concepts. USDA. Natural Resources Conservation Service.

What are the Characteristics of Good Soil?  Drains well  Soaks up heavy rain with little runoff  Stores moisture for periods of drought

What are the Characteristics of Good Soil?  Resists erosion & nutrient loss  Supports soil organisms  Produces healthy, high quality crops

Soil Fertility: A Delicate Balance is Essential  pH “best” pH for fruits/veggies = 6.0 to 7.0  Soil nutrients nitrogen calcium magnesium phosphorus potassium sulfur boron, iron, zinc

What are the Resources for Soil Testing in Your Community?  Soil testing to keep soil “healthy” &/or fertile  Soil testing for toxins (lead)

Managing Soil Organic Matter Source: Soil Organic Matter. USDA. Natural Resources Conservation Service.

Explain These Terms Related to Soil Management Agricultural production  Cover crops  Reduced tillage  Prescribed grazing  Manure management  High biomass rotation Landscaping  Xeriscaping

Sustainable Agriculture

Do these Practices Sustain Soil?  Tillage speeds up decomposition  Excess nitrogen (fertilizer/manure) speeds up decomposition  Insufficient nitrogen (fertilizer) slows down decomposition & starves plants

Management of Water Runoff

What’s Your Soil Problem? Impact of climate change on soil drought flooding Wind/water erosion with loss of water top soil nutrients Leaching- r/t quality & type of soil

Soil Erosion

Dust Bowl Days

Soil Erosion

How Does Soil Affect Human Health? Industrial pollution Lead, arsenic Dioxin, PCBs Agricultural pollution Animal waste (manure) Pesticides Fertilizers Herbicides

How Does Soil Affect Human Health? Soil pollution can adversely affect human health Infectious diseases: parasites Toxins/pollutants Nutrient quality of soil impacts absence/presence of disease states protein calorie malnutrition

How Does Soil Affect Human Nutrition? Affects nutritional status via: Deficiencies/toxicities may be related to nutrient quality of the soil  nitrogen depleted soil  nitrogen leakage more likely in sandy soil

How Does Soil Affect Human Nutrition? Affects nutritional status via: Soil provides nutrients  minerals  nitrogen Different types of soil have varied nutrients  clay holds more nutrients than sand

The Living Soil  Earthworms  Bacteria  Arthropods  Fungi  Actinomycetes  Nematodes  Algae

Weights of Soil Organisms in Top 7 Inches of Fertile Soil OrganismPounds of Live Weight/Acre Bacteria1000 Actinomycetes1000 Molds2000 Algae 100 Protozoa 200 Nematodes 50 Insects 100 Worms1000 Plant Roots2000

What can I do to be a Steward of the Soil?  Compositing  Xeriscaping  Mulching  Collecting rain (rain barrel)  Choose native plants  Choose pest resistant plants

References  Photos courtesy of USDA, NACD, and Ron Francis  NRCS/USDA. (n.d.) Soil quality/soil health concepts. Retrieved from pts.html  Sullivan, P. (2004) Sustainable Soils Management. Soils Systems Guide. Pgs Retrieved from: *no longer free access * pub/PDF/soilmgmt.pdf * pub/PDF/soilmgmt.pdf

Tour of USDA Website  usdahome usdahome  Food and Nutrition Search for Food Assistance Programs  Agriculture  Natural Resources and Environment Search for Soil Search for Recycling & Waste Management  Disaster and Drought Assistance