ON LANDSCAPING, SOILS, SOIL AMENDMENTS AND PROPER SEED ESTABLISHMENT (BOTH GRASS LAWNS AND MEADOWS).

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Brittney Ross
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Chibirka USDA-NRCS Resource Soil Scientist 1238 County Welfare Road,

1 ON LANDSCAPING, SOILS, SOIL AMENDMENTS AND PROPER SEED ESTABLISHMENT (BOTH GRASS LAWNS AND MEADOWS). John D. Chibirka USDA-NRCS Resource Soil Scientist 1238 County Welfare Road, Suite 220 Leesport, PA (610) x112 (610) fax

2 Topics Topsoil properties & why vegetation needs topsoil for permanent growth The importance of Soil Health Post-development soil properties Soil restoration and the BMP manual

3 Topsoil properties & why vegetation needs topsoil for permanent growth

4 Topsoil is: The mineral surface layer of soil that exhibit obliteration of all or much of the original rock structure and must show the following:

$fraction and not dominated by properties characteristic of subsurface$

5 (1) an accumulation of humified organic matter closely mixed with the mineral fraction and not dominated by properties characteristic of subsurface horizons;

6 (2) has reasonable tilth (biological, chemical and physical properties) to support plant growth

8 Relative Proportion of components for well-drained soil. Organic 1-5% Mineral 45% Air 20-30% Water 20-30%

9 Master Horizons O horizon A horizon E horizon B horizon C horizon R horizon O A E B C R

10 O horizon Predominantly organic matter (litter and humus)

11 A horizon Zone of organic matter accumulation

12 B horizon Zone of accumulation (clay, Fe, Al, CaC0 3, salts ). Forms below O, A, or E horizon

13 C horizon Little or no pedogenic alteration. Unconsolidated parent material, soft bedrock.

14 R horizon hard, continuous bedrock

15 Back to Topsoil and have two or more of the following: 1. A bulk density of less than 1.5g/cc installed 2. Less than 15 percent by weight coarse fragments greater than 2mm 3. Identifiable USDA structure, soil clods called peds, no massive structure 4. No contamination (i.e. Toxic weeds, chemicals, heavy metals, construction debris) that inhibit desired plant growth or human activity.

16 Soil Resource Min Requirements Oxygen in soil atmosphere (for root survival) 3% 21% Air pore space (for root growth) 12% 60% Soil bulk density of the surface 24 - Penetration resistance (moist) 50 lbs/in 2 Max 93.6 lbs/ft 3 (clays) lbs/ft 3 (sands) 275 lbs/in 2 (clays) 300 lbs/in 2 (sands) Water content 12% 40% Temperature limits for roots and soil biology 40 F/4 C 94 F/34 C Soil ph Soil Cation Exchange Capacity (CEC) of the surface 6 8 meq/100g >8 meq/100g Soil organic matter content of surface 6 only 3% 8% Soil organic matter content of subsoil - <1% Soil coarse fragment content of the surface 6 (rocks etc. >75mm) - <20% Table 2 Properties for Optimal Plant Growth Source: developed from Coder, 2000; Craul and Craul, 2006 see Soil texture table from Urban Soil Quality, USDA-NRCS for greater detail

17 Soil Texture Ideal Bulk Densities Bulk Densities at which may affect root elongation Bulk Densities that restrict root elongation Pore Space Range g/cm 3 g/cm 3 g/cm 3 % Sands, loamy sands < % Sandy loams < % Sandy clay loams, loams, clay loams < % Silt, light silt loams < % Heavy silt loams, silty clay loams Sandy clays, sitly clays, clay loams (35-45% clay) < % < % Clays (>45% clay) < % Table 3 Typical Soil Density and Porosity Properties for Soil Textures Source: Modified from Protecting Urban Soil Quality, USDA-NRCS

18 THE IMPORTANCE OF MYCORRHIZAE- GO TO USDA NRCS SOIL HEALTH PAGE

19 SOIL HEALTH INCREASING SOIL ORGANIC MATTER TYPICALLY IMPROVES SOIL HEALTH SINCE ORGANIC MATTER AFFECTS SEVERAL CRITICAL SOIL FUNCTIONS. HEALTHY SOILS ARE ALSO POROUS, WHICH ALLOWS AIR AND WATER TO MOVE FREELY THROUGH THEM. THIS BALANCE ENSURES A SUITABLE HABITAT FOR THE MYRIAD OF SOIL ORGANISMS THAT SUPPORT GROWING PLANTS. IT S NOT DIFFICULT TO IMPROVE SOIL HEALTH. HERE S HOW: TILL THE SOIL AS LITTLE AS POSSIBLE; GROW AS MANY DIFFERENT SPECIES OF PLANTS AS POSSIBLE THROUGH ROTATIONS AND A DIVERSE MIXTURE OF COVER CROPS; KEEP LIVING PLANTS IN THE SOIL AS LONG AS POSSIBLE WITH CROPS AND COVER CROPS; AND KEEP THE SOIL SURFACE COVERED WITH RESIDUE YEAR ROUND. *this is geared more towards agriculture, not urban soil amendments.

20 POST-DEVELOPMENT SOIL PROPERTIES

21 UNDER POST DEVELOPMENT PROPERTIES, IF A SOIL HAS BEEN SCRAPED, POUNDED INTO SUBMISSION, THE HSG SHOULD BE A CLASS LESS WHEN MAKING THE CALCULATIONS. I HAVE RUN KSAT AT PRINCETON ON SOILS THAT HAVE HAD COMPACTION ISSUES EITHER THROUGH CONSTRUCTION (MOST COMMON) TO VIBRATION FROM ADJACENT STREETS WHERE THE KSAT IN THE UPPER 40 INCHES IN VARIOUS LAYERS ARE LESS THAN 0.06 IN/HR. I HAD ONE THAT WAS IN/HR WITH A BD OF 2.11G/CC DRY. MOST OF THE BD WERE AROUND 1.75 TO 1.9 IN MEDIUM TEXTURED SOILS, PLANT ROOTS CANNOT GO THROUGH THAT. EVEN THOUGH THESE SOILS HAD PORE SPACE, THE PORES WERE NOT CONNECTED. THE COMPACTION HAD SQUEEZED THE MACROPORES CLOSED AND THE SMALLER PORES THAT HAD WATER IN THEM DID NOT COMPACT DUE TO THE INCOMPRESSIBILITY OF WATER. CRAUL, 2013

23 SOIL RESTORATION

24 PENNSYLVANIA STORMWATER BEST MANAGEMENT PRACTICES MANUAL CHAPTER 6 BMP 6.7.3: SOIL AMENDMENT & RESTORATION SOIL AMENDMENT AND RESTORATION IS THE PROCESS OF IMPROVING DISTURBED SOILS AND LOW ORGANIC SOILS BY RESTORING SOIL POROSITY AND/OR ADDING A SOIL AMENDMENT, SUCH AS COMPOST, FOR THE PURPOSE OF REESTABLISHING THE SOIL S LONG-TERM CAPACITY FOR INFILTRATION AND POLLUTION REMOVAL.

25 THE ENTIRE STORMWATER MANUAL IS BEING REVISED BASED MORE ON SCIENTIFIC REASONING THAN IN THE PREVIOUS MANUAL. THE COMMITTEE THAT IS WORKING ON THIS IS ABOUT 140 SCIENTISTS, ENGINEERS, LANDSCAPE ARCHITECTS, DEP MEMBERS, COUNTY, LOCAL AND CITY PLANNERS TO MENTION A FEW. THE MANUAL WILL BE BASED ON PRACTICAL AND PROVEN METHODS TO REDUCE STORMWATER RUNOFF.

26 FOR SOIL AMENDMENTS, THERE IS A HOST OF THINGS, THE MOST IMPORTANT IS THE COMPOST. IT HAS TO BE GOOD COMPOST, WELL CURED AND BIOLOGICALLY ACTIVE. THE RATE I USUALLY MIX IN WITH DEGRADED TOPSOIL IS 3.1 CY/1000SQFT (1 INCH OF COMPOST INCORPORATED) OR FOR SUBSOIL OR SOIL WILL VERY LOW OM CONTENT (BELOW 1%) I USE 6.3 CY/1000SQFT (OR ABOUT 2 INCHES OF COMPOST INCORPORATED INTO THE UPPER 4-6 INCHES) [CRAUL AND CRAUL, 2006])

27 I GUESS THE BOTTOM LINE IS THAT EVERY SITE IS DIFFERENT AND THE PROCEDURES AND SOIL AMENDMENTS MUST BE TAILORED TO THE SOIL PROPERTIES ON SITE AND CANNOT BE GUESSED AT. THIS IS WHY SOIL RESTORATION ATTEMPTS ARE NOT AS SUCCESSFUL WITH A ONE-SIZE FITS ALL SPECIFICATION DOCUMENT

28 Summary Topsoil properties & why vegetation needs topsoil for permanent growth The importance of Soil health Post-development soil properties Soil restoration BMP Manual

29 QUESTIONS?

Specifying Soils for Plant Growth

Specifying Soils for Plant Growth Which by coincidence reduces runoff Timothy A. Craul, CPSSc President, Craul Land Scientists The soil must be plant friendly. The soil is a natural system. All soils are