Building Healthy Soils. Mary Hagedorn

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1 Building Healthy Soils Mary Hagedorn

2 Please Silence Cell Phone Thank you!

5 Our Vision: A healthier world through environmental stewardship. Our Mission: To support the University of Maryland Extension mission by educating residents about safe, effective & sustainable horticultural practices that build healthy gardens, landscapes, & communities.

6 Topics Soil Basics (origin, texture, profile) Learning what kind of soil you have Soil amendment Strategies for soil problems Changing environment and soil

7 Soil Basics: Formation Parent materials: Weathered rock Climate: Rain, freeze/thaw cycles, humidity, growing season length Living organisms: Worms, bacteria, fungi Topography: Erosion Time: Geological time; about 500 years for 1 of topsoil

8 Soil Basics: Composition

9 Soil Basics: Composition Minerals in soil (about 45%) include silt, sand, and clay in varying proportions. Pores space for air and water essential for root growth transmission of air, water, and nutrients Organic matter: includes decayed leaves and plants, manure, organisms, etc. Fact sheet FS 640: Basic Principles of Soil Fertility II: Soil Properties

10 Soil Basics: Particle sizes

11 Soil Basics: Soil texture

12 Soil is a living system Organic matter does the lion s share of the work of soil. Organisms -- bacteria and fungi. Decomposers consume carbons and break down plant litter, pesticides, pollutants. Mutualists form partnerships with plants. Other bacteria and fungi are pathogens. Healthy soil will usually have lots of earthworms.

13 Soil Basics: Horizons/ Soil Profile O: Organic 0 to 2 from surface A: Topsoil 3 to 10 from surface B: Subsoil 11 to 30 from surface C: Substratum 30 to 48 from surface US Department of Agriculture:

14 Impacts on Soil Profile Many of us live in housing developments. Construction involves moving earth. Layers are overturned and mixed. Heavy equipment causes compaction.

15 Soil Basics: Soil tilth Soil suitability to support plant life, particularly, root growth. Aggregates (crumbs) of sand/silt/clay/organic matter; pore spaces for water and air; adequate nutrients. We often focus on fertility and pests; many plant problems result from soil tilth issues.

16 Soil ph Soil ph is a measure of hydrogen ion concentration. 7.0 is neutral Below 7.0 is acidic ( sour soil ) Above 7.0 is alkaline ( sweet soil ) Soil nutrients are most available to plant roots and microbial activity is greatest when soil ph is in the 5.5 to 7.0 range. Plants may show symptoms of nutrient deficiency or toxicity at very high or low soil ph.

17 Soil ph & nutrient availability

18 Your soil? There are 40 types of soil in Montgomery County. What kind of soil do you have? How do you find out? Why is it important?

19 Montgomery County Soils

20 Why it s important to know Soil texture determines activity in the soil. Sandy soils: Large air space, low water holding, high leaching, low nutrient retention, low erosion. Loams: Good air space, moderate in water holding/ leaching/nutrient retention, but high in erosion. Clay: High water retention impedes drainage, small air spaces, high nutrient retention, but poor nutrient exchange.

21 Why it s important to know Soil drainage is affected by texture and compaction and is a factor in oxygen availability. Good drainage prevents rotting of roots and bulbs. Soil ph is related to the availability of nutrients and plant needs. Healthy soil holds carbon: organic matter in soil holds onto carbon and helps to reduce the amount of CO2 in the atmosphere.

22 Finding out what you ve got Soil test by laboratory Organic matter Ph (acidity/alkalinity) Nutrients Soil texture Other tests, e.g., lead Choose lab time, cost, tests included Soil sampling Take samples from various locations in your yard Send to lab in container they provide Receive report in a few days to a couple of weeks Fact Sheets HG 11, HG 110, HG 110a on soil testing and laboratories

23 Finding out what you ve got Soil Test Report: A&L Eastern Laboratories

24 Finding out what you ve got Soil Test Report: A&L Eastern Laboratories Consider Maryland laws/guidelines in fertilizing.

25 Finding out what you ve got Do-it-yourself (not a substitute for lab test) Home test kit Ph test or meter Jar test of soil texture Ribbon test

26 The Jar Test Take sample, remove roots, insects, rocks. Allow to dry, crush soil. Place in jar, add 1 tsp dishwasher detergent, add water. Shake vigorously several minutes. Measure layers.

27 The Jar Test

28 The Ribbon Test Make a ball of soil in hand; press into a log shape. Hold in closed hand. Use thumb to push out a ribbon. Won t form a ball? Sand. Weak ribbon less than 1? Loam. Ribbon of 1 to 2? Clay loam. Ribbon of 2 or more? Clay.

29 Drainage (perc) test Dig a hole a foot deep. Fill with water and allow water to drain. Fill again and measure depth. Check how long it takes to drain. Less than 1 per hour is poor drainage. 1 to 6 per hour is desirable. More than 6 per hour is excessive drainage.

30 Amending Soil The surest way to improve plant growth is the regular incorporation of organic matter such as composted yard waste. Organic matter improves soil structure, slowly releases nutrients, and increases beneficial microbial activity. Fact Sheet HG 42: Soil Amendments and Fertilizers

31 Amending Soil Most garden and landscape plants perform best in soils high in organic matter. Well amended soil is loose, easy to work, has large number of earthworms. Organic matter improves water hold capacity.

32 Amending Soil: Moisture Management Our changing environment affects moisture in our soil. Increasing average temperatures lead to evaporation Longer periods without rain dry out soils Dryer soils more subject to wind erosion More intense weather events lead to water erosion Soil amended with organic matter holds moisture, has better drainage, and is more resistant to erosion.

33 Amending Soil: Buy or Make Your Own Compost: Commercial or home-grown Humus: End product of composting process Peat moss: Mined from prehistoric nonrenewable bogs LeafGro: Composted leaves and yard debris Manure: Available from some local farms Coconut coir: Renewable and does not repel water like peat moss Fact Sheet HG 42: Soil Amendments and Fertilizers

34 Amending Soil Mushroom compost: Used or spent compost from mushroom farming Pine bark fines: Finely shredded pine bark Sand: Coarse builder s sand (not play sand) Sawdust: Must be well-decayed Fireplace ash: Highly alkaline Charcoal ashes: may contain harmful chemicals (except bio-char) Fact Sheet HG 42: Soil Amendments and Fertilizers

35 Amending Soil Topsoil No state or federal standards Quality will vary Inspect topsoil, ask for references Ask about source and any testing Avoid very sticky, grayish, mottled, soils that smell bad Blended topsoil & compost mixes 70% topsoil and 30% leaf compost Excellent for an instant raised bed garden Can be purchased by the cubic yard Fact Sheet HG 42: Soil Amendments and Fertilizers

36 Amending Soil: Changing ph Lowering ph: Acidifiers Iron sulfate Sulfur (elemental sulfur) Miracid temporary effect Holly Tone plant food containing sulfur Aluminum sulfate: not recommended (possible toxic aluminum build-up) Fact Sheet HG 42: Soil Amendments and Fertilizers

37 Amending Soil: Changing ph Raising ph: Lime Aragonite Agricultural limestone Hydrated lime Burnt lime ( quick lime ) Dolomitic Pelletized lime Wood Ash Fact Sheet HG 42: Soil Amendments and Fertilizers

38 Ongoing amendment Top dressing Spot amendment Between existing plants When adding new plants When dividing or moving perennials Dig in lightly: no till

39 Timing is important! Amend soil when it is neither too wet nor too dry. Under both conditions, may affect soil structure. Working soil that is too wet can increase the compaction of the soil. Working soil that is very dry can contribute to wind erosion. And it s just plain harder! In general, spring and fall are the best times.

40 Raised beds Soil level higher than surrounding soil Benefits: Better soil condition Root room Easier to work Higher yields of vegetables Pest control

41 Raised beds Double-dug and raised soil No soil addition, no structure

42 Raised beds: Structures Wood: Not pressure treated lumber or railroad ties. Cinder blocks: They get hot. New ones can be alkaline.

43 Raised beds: Structures Photos: Gardener s Supply Company

44 Cover your soil Bare soil is subject to Moisture loss through evaporation Higher average temperatures Less frequent rain Erosion Wind erosion when soil is dry Water erosion, especially with more active weather events Compaction (rain)

45 Cover your soil Mulch Helps to retain moisture, provides a rain break, helps to prevent erosion Organic: shredded bark, shredded leaves, grass clippings, compost Inorganic: gravel, marble chips (alkaline), sand Films: plastic, wet newspaper

46 Cover your soil Groundcover plants Look for native and/or noninvasive plants Avoid invasive plants HG 120: Native Plants of Maryland

47 Plant diversity & soil health Plants convert carbon dioxide to carbohydrates Carbohydrates are given to soil microbes in exchange for nutrients Different microbes require different types of carbohydrates Plant diversity helps to support soil microbe populations

48 Summary: Building healthy soil Learn what you have. Amend, amend, amend. Use strategies to overcome problem areas. Double digging Raised beds Cover your soil to protect it Manage moisture: A healthy soil can better handle both droughts and downpours

49 Resources Home and Garden Information Center (HGIC) Publications United States Department of Agriculture: National Resources Conservation Service Land Stewardship Project (2017), Soil Health, Water & Climate Change.

50 This program was brought to you by the Master Gardener Program of Montgomery County, University of Maryland Extension.

Making the Most of the Soil You ve Got. Mary Hagedorn

Making the Most of the Soil You ve Got Mary Hagedorn College of Agriculture and Natural Resources 2 Topics Soils of Maryland & Montgomery County Soil Basics (origin, texture, profile) Learning what kind