Dr. Sara Via, svia@umd.edu 6/7/20 The Climate Problem - Warming from unprecedented increases in atmospheric CO 2 already causing serious impacts Regenerative landscaping: How to make suburban landscapes part of the climate solution Dr. Sara Via June 1, 2020, Professor & Climate CO 2 = 418 ppm Extension Specialist - For the best future, we must reduce emissions & UMD College Park remove carbon from the atmosphere svia@umd.edu 1 2 Source: Modern Farmer Source: Modern Farmer 1 2 The Soil Problem The Water Problem - Soil & habitat seriously degraded by - Streams & coastal waters polluted by conventional agricultural practices chemicals, pathogens & sediment - Tillage & erosion has removed organic - Nutrient runoff (fertilizer, manure) matter, damaged soil structure increases pollution è “dead zones” bigag.com - Ability of soil to soak up, hold & purify Nitrogen runoff from Midwest has water reduced è water problem cost Gulf fishermen up to 2.8 billion/year for 30 years! - More heavy rains è more flooding, erosion & runoff - Soil microbial communities degraded, reducing nutrient cycling, increased - More summer heat, hotter Kansas Dept of Agriculture fertilizer & chemical use cropwatch.unl.edu streams, more drought - Habitat for natural enemies & - How to reduce water pollinators lost, increasing pests pollution & control stormwater? è biodiversity problem 3 4 cropwatch.unl.edu Source: Modern Farmer Union of Concerned Scientists 3 4 1
Dr. Sara Via, svia@umd.edu 6/7/20 The Biodiversity Problem Rethink our suburban landscapes to increase soil health - Dramatic loss of habitat & biodiversity from development, climate change & agricultural practices Reduce emissions, Rebuild bird & insect sequester carbon populations - In landscaping, reliance on Increase infiltration, mowed turfgrass causes bigag.co reduce flooding, habitat loss & reduces boost water holding & biodiversity improve purification mcveymowing.com - Loss of birds and insects threatens ecosystem function, Climate Biodiversity allows pests to increase & reduces pollination Water Solutions?? Two strategies: Lawn Mimics & Pollinator Gardens Kansas Dept of Agriculture 5 6 Source: Modern Farmer 5 6 Lawn is the default landscape The environmental cost of lawn “Ideal home” includes expanse of manicured lawn - 42 million acres of lawn in US, (1.3 million acres in Maryland) - Long history of lawn as symbol of wealth & - uses 30-50% municipal water home ownership - yard tools è 5% US emissions - Requires little thought to - 17 million gallons fuel spilled/yr choose & install - Upkeep is familiar, many - Lawns often over-fertilized suburban residents NO 3 runs off and N 2 O emitted grew up with lawn care - 10x more nitrogen & chemical Ryanhomes.com - Can be easily hired out runoff from lawns/acre than from agricultural fields - Most common municipal & commercial landscape - monoculture of introduced species -- poor habitat The dark side of lawn-- environmental & economic impacts 7 7 8 2
Dr. Sara Via, svia@umd.edu 6/7/20 The economic cost of residential lawn The cost of mowed open space Mow lawn yourself Use lawn service Howard Co, MD ~ 4000 acres mowed turfgrass, excluding parks Columbia, MD - 1600 acres mowed turfgrass - mowed every 1-2 weeks during the summer, - emissions from thousands of gallons of diesel - requires tons of fertilizer and chemicals Plus: fertilizer, herbicides, Plus: fertilizer, core aeration - ballpark cost: $2000/acre annually ($8m for HoCo?) insecticides, fungicides, herbicides, insecticides, Open space can be part of the gas, time (70-100hrs/yr) fungicides climate solution instead of part of the problem https://www.yourgreenpal.com/blog/mow-the-lawn-or-pay-a-service 9 10 Why lawn needs so much maintenance Approaches to reducing lawn impact - Reduce lawn - OK for experienced gardeners but * * * can be threatening overall - Hard to find alternatives for large scale landscapes Lawn - Accept imperfection 0- - Stop using fertilizer &chemicals - Let lawn go dormant in summer 5’- - Mow high with mulching mower Credit: Ingrid Blanton) - Don’t mow unless it needs it * * * * * 10’ - - Find a substitute that fills the niche but is climate-friendly - The lawn mimic 15’- 11 12 What can we do to minimize costs of lawn? Conservation Res. Inst. 1995 11 12 3
Dr. Sara Via, svia@umd.edu 6/7/20 Lawn Mimics Lawn mimics maintain the look Lawn mimic: a mix of low & slow growing grasses (fine Howard County Innovation Grant 2020 fescues) plus optional microclover (or white clover) for N - collaboration w/ Howard Co. and CA for field trials Lawn mimics look like regular lawn, but.. - testing four lawn mimic mixes (2 with a native grass) - bare ground: two trials of each in sun and shade ) - No fertilizer or chemicals - 20% as much mowing - 80% less CO 2 emissions - Some carbon sequestration 13 14 Increase use of native perennials Lawn mimics in landscape plots Howard County Innovation Grant 2020 - Increase pollinators & biodiversity - Overseeding: Can we convert current turfgrass stands - Increase pollinators & biodiversity to lawn mimics by overseeding? - Deep rooted plants sequester carbon - Deep rooted plants sequester carbon - This could transform mowed open space while - Plants absorb CO 2 during - Plants absorb CO 2 during keeping the open look photosynthesis, make sugar photosynthesis, make sugar - Up to 40% of the sugar goes to roots Benefits - Up to 40% of the sugar goes to roots to feed soil bacteria and fungi, they - No fertilizer or chemicals to feed soil bacteria and fungi, they - 70-80% less mowing store atmospheric carbon store atmospheric carbon - Cost to County reduced from - Carbon sequestration in soil a - Carbon sequestration in soil a $2000/acre to $400-600/acre “ natural climate solution” “ natural climate solution” Compass plant for a savings up to $5.6 million/yr Big Bluestem, Indiangrass National Geographic 2015 15 16 4
Dr. Sara Via, svia@umd.edu 6/7/20 Go Native: Deeper roots, more carbon storage Weed-free perennial beds Need for hand weeding a deterrent to establishing native plant beds * * * Howard County Innovation Grant 2020 - Field trials of weed reduction strategies -- interseed plugs with red clover or violets -- plant plugs through brown kraft paper 0- -- in fall, overseed with pollinator mix 5’- plugs planted plugs in bare soil through paper * * * * * 10’ - interseeded with interseeded with violets red clover Conservation Res. Inst. 1995 15’- Deep dense roots also build soil health & control erosion 17 17 18 Combined climate and watershed benefits Using deep-rooted perennial grasses to of pollinator gardens stabilize streambanks Use deep-rooted native plants in swales, raingardens - Mowing right up to bank & median strips to control flooding, boost pollinators causes rapid erosion and sequester carbon - Stop mowing 4-6’ out - Plant deep-rooted grasses, i.e. Virginia wild rye - OK in shade, gebl.org attractive in winter 19 20 NRCS ncsu.edu, Options for Backyard Stream Repair northcreeknurseries.com 19 20 5
Dr. Sara Via, svia@umd.edu 6/7/20 Reducing turfgrass in Maryland communities: Progressively reducing meadows, contained native beds, groundcovers turfgrass in community Typical layout Small area of lawn around the house Contiguous trees & Native grass and pollinator meadows sequester the most carbon, 21 plantings benefit wildlife and soil 22 Shallower rooted plants less sequestration, but reduce emissions credit: Charlie Bailey 21 22 We can use our suburban landscapes to reduce emissions, store carbon & increase biodiversity… all while saving time Credit: Ingrid Blanton & money! email me anytime-- svia@umd.edu 23 23 6
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