Transcript 5.0 Soils
Mrs. Schratwieser Horticulture I Growing Media Peat Moss Vermiculite Perlite Organic Matter Compost Bark Sphagnum moss Peat Moss Organic (natural) Partially decomposed material mined from swamps Good moisture holding properties Vermiculite Inorganic Mica mineral matter Commonly used to start seeds & cuttings Holds moisture Neutral pH Perlite Inorganic Natural volcanic ash Aids with aeration & water holding capacity Organic Matter Dead plant or animal tissue Contains carbon Compost Decaying organic matter Soil conditioner Fertilizer Bark Organic Larger matter added to some media to promote drainage Adds weight to soilless mixtures Widely used in tree and shrub production Spagnum Moss Organic Dehydrated remains of acid bog plants Hold moisture Very acidic Commonly used to line wire hanging baskets Advantages of Soilless Media Sterile pH is neutral Disease & weed free Good form starting disease sensitive seeds (tomato) Easy to control the nutrient content of soil Improves crop uniformity Easy to create soil for particular needs Disadvantages of Horticulture Soils Expensive Light weight Additional Materials Used Sawdust Wood shavings Sawdust & Wood Shavings High carbon to Nitrogen ratio N is unavailable for plant use Soil Profile Soil layers – Horizons O Horizon A Horizon B Horizon C Horizon R Horizon O Horizon Rich in organic matter Various stages of decomposition Dark in color Most fertile layer in the soil profile A Horizon Topsoil Just below the O horizon Earthworms and soil organisms Brown in color due to organic matter B Horizon Subsoil Clayey soil high in mineral content Usually brown or reddish (clay) C Horizon Parent material Mainly clumps of un-weathered rocks R Horizon Bed rock Cannot be dug by hand Very few roots can penetrate bedrock Soil Structure “how the soil particles fit together” Sandy soils – looses structure Silty/loam have a granular structure Clayey soils have a blocky/platy soil Granular soil structure is the best Soil Texture Sand – largest particles (low moisture & nutrient holding capacity) Silt – medium size particles (good moisture & nutrient holding capacity) Clay – smallest particle size (high water & nutrient holding capacity) Loam – almost equal parts of all three textures (ideal texture for most outside/non container plants) Soil pH Measure of acidity or alkalinity of the soil 0-14 (range) 0-6.9 (low pH - Acid) 7 (neutral) 7.1-14 (high pH – alkaline) Lime raises pH Calcium or Sulfur lowers pH Ideal pH for vegetable garden soils 5.5-7.0 pH Physical Properties of Soil Permeability – rate at which water moves through Water holding capacity – ability to hold water Porosity – amount of air space between particles Ideal Soil Makeup 50 % - pore space 50% - soil Pore Space: 25% water, 25 % air Soil: 45% mineral matter, 5% organic matter Soil Sample Testing for accurate fertilizer recommendations Growing plant Should be done 1 growing seasons before planting Soil Sample Procedures Create a visual grid of area to be planted (5-10 subsamples from the site) Use a stainless steel soil-sampling probe 4” for lawns, 6-8” crops Mix soil samples together Remove any grass, rocks, other materials than soil Avoid unusually spots, separate box Place in soil sample box (Extension office), fill our sample information sheet Mail box and information to Agronomic Division Soil Test Lab in Raleigh (free)