Soils, Fertilizers and Composting

Transcription

1 Soils, Fertilizers and Composting Bill Hlubik Professor, Agricultural and Resource Management Agent RCE, Middlesex County EARTH Center Mt. Washington 5 1

2 Causes of poor growth Compaction, inadequate soil aeration moisture, adverse climate, improper ph, nutrient toxicity, deficiencies, Disease, insects 7 8 Root Shock Transplants / Construction Transplants need to re-establish root damage for normal growth Plants disturbed by construction within the past 5 to 10 years may be in shock and produce limited new foliage What is soil? a natural body on the surface of the earth in which plants grow; comprised of mineral and organic materials and living organisms Minerals - Sand, Silt, Clay in varying proportions Physical Characteristics - Texture Texture Fineness or coarseness of the soil Based on the amounts of the three different sized particles that make up the mineral component Sand Silt Clay Soil Micro and Macro Organisms 2

3 Relative Size of Soil Separates Sand University of Nebraska-Lincoln, Plant and Soil Sciences elibrary, Textural Classes of Soil Based on percentage of sand, silt and clay Feel Method Using Feel Method to Determine Texture Soil Profile Soil Profile Layers in the soil are called horizons Topsoil Subsoil Parent Material The upper layer is called topsoil The middle layer is called the subsoil The parent material or bedrock is found below these layers 3

4 Physical Characteristics Soils are comprised of: Solids Mineral component Organic component Liquids water Gases ex. O 2, CO 2 Physical Characteristics Water Movement in Soil Infiltration Movement of water into the soil surface Physical Characteristics - Tilth Tilth or structure is affected by several factors, including: Physical Characteristics - Tilth Organic matter, limestone, biological activity All increase aggregation or flocculation of particles Sodium Decreases aggregation or dispersion of particles Tilth is primarily a by-product of biological activity Feel Method Falls apart = sand Stays together, extend far beyond fingers = clay Some form but crumbles = silt Compaction Rough = sand Slick, greasy when wet = clay Smooth when dry = silt Ribbon Method 4

5 Physical Characteristics - Drainage Drainage affects Soil drying or moisture holding Air flow or gas exchange Selection of turf grass species Physical Characteristics - Drainage Do a mini perc test or percolation test to determine the internal drainage 1. Dig a 12 inch deep hole 2. Fill hole with water 3. Let all of water drain out of hole 4. Fill hole again and measure time for water to drain out Physical Characteristics - Drainage Evaluate the results. If all of the water drains out of the hole in: minutes or less = well drained soil minutes = moderately drained soil Greater than 45 minutes = poorly drained soil Physical Characteristics - Drainage Based on internal and surface drainage, do the following: Choose plant materials appropriate for the site Improve water drainage and percolation Irrigate when necessary Use mulches to conserve moisture Physical Characteristics Compaction Compaction Physical pressure due to weight on soil squeezes out the air space, making the soil more dense Bulk Density The weight of dry soil per unit volume including air space Physical Characteristics Compaction Reducing Compaction Mechanical aeration Tillage Organic matter Chemically Prevention 5

6 Physical Characteristics Compaction Physical Characteristics Compaction Images from Turf North, Nov 2005 Drainage and Puddling 33 Soils Map of New Jersey This map shows the major soil series of NJ Note the strong association between the bedrock geology and the soil formed Soils differ across geographical regions due to many other factors, not just geology Local Soils Maps Soils types can vary within a small area due to many factors Natural differences, erosion, replacement, building Web-based copies may be found at: usda.gov/app/ 6

7 Biological Characteristics - Organic Matter Benefits: Enhances biological activity Improves tilth and structure Increases porosity and infiltration Reduces crusting and erosion Increases water holding capacity Improves nutrient holding and release Cation exchange capacity Clay and organic matter involved in cation exchange Biological Characteristics Nutrient Availability, Transformation N transformation impacted by many factors including: Soil temperatures Soil moisture C:N ratio of amendments Microbial populations Soil Biological Characteristics Soil Biological Indicators Soil microorganisms (fungi and bacteria) and other fauna (e.g., earthworms, insects, arthropods) influence the availability of nutrients for crop growth by decomposing soil organic matter and releasing or immobilizing plant nutrients. 42 7

8 Trichoderma species 43 Trichoderma species Biological Characteristics - Disease Prevention Trichoderma harzianum Rhizoctonia solani Higher levels of biological activity and diversity often lead to higher levels of suppression through various mechanisms Pythium and Phytophthora Mycorrhizal fungi Springtails and mites Fertile, properly managed soils are the foundation for healthy plants. 8

9 Proper management of soils can help reduce plant stress and disease problems while protecting the local environment. Liebig s concept of the limiting factor Plant production is constrained by the essential element* (or Increasing level of a non-limiting factor will not improve production *Other factors that can be limiting are ph, light, water, temperature, etc. other factor) that is most limiting Brady & Weil, 1999 Soil ph affects the availability of some nutrients, availability/toxicity of aluminum, and the activity of microorganisms. Selection of Liming Material Dolomitic lime (high Mg) Use when soil test Mg level is low relative to Ca Calcitic lime (high Ca) Use when soil test Ca level is low relative to Mg Gypsum (calcium sulfate) Use when soil ph is high but Ca is needed Brady & Weil, Limestone Rate Based on Soil ph and Soil Texture Pounds of Limestone/1000 ft 2 to Raise ph to Desired Level Change in Soil ph (initial -> desired) 4.0 > > > > > 6.5 Soil Texture Sand Loam Clay Loam Chemical Characteristics - ph To increase acidity Sulfur (S) Elemental sulfur Iron sulfate Aluminum sulfate Acidic organic materials Pine needles, peat moss 9

10 Sulfur Needed to Increase Soil Acidity to ph 6.5 Pounds of Sulfur/1000 ft 2 to Lower ph to Desired Level Change in Soil ph (initial -> desired) 8.5 > > > > 6.5 Soil Texture Sand Loam Clay Loam Relative nutrient level Deficient plant not achieving genetic capacity deficiency symptoms, or hidden hunger Management strategy: build up soil test level to increase growth Adequate level - at 100% growth potential not limiting growth Management strategy: maintain soil test level Excess level - imbalance or toxicity growth decreased Mangement strategy: draw down soil test level to reduce excess Improper management of soils can lead to: Poor Yields Decreased Profits -$$$$$$ Increase in Diseases and Pests Soil Erosion Environmental Problems Soil Testing 6-8 Take multiple, randomly selected sub-samples from the area to be tested Parameter Soil ph Lime req. index (LRI) Buffer ph Ca Mg N P K Micronutrients (Mn, Cu, Zn, B, Fe) Soil Test Interpretation/Recommendation Need for lime or sulfur and rate Balance indicates type of lime Not based on soil test Based on soil test level Based on soil test level Based on soil test level and soil ph Soil Sample Results will provide information on: soil texture soil ph soil nutrient levels fertilizer and limestone/sulfur recommendations Use it, don t lose it! 10

11 Soil sample depth depends on crop and management Dividing by Plant Type and Landscape Management Area 1a Area 3 Area 2 Area 1b Area 4 1 =lawn 2= vegetable garden 3= rose bed 4= acid-loving species bed Random subsampling within an area Area 1b 1 =lawn 2= vegetable garden 3= rose bed 4= acid-loving species bed Final Sample to Lab Break up cores and mix thoroug hly in clean bucket Submit two cups of soil for testing Soil Testing Indicate whether a new seeding/planting or established planting Send the soil sample and questionnaire to the laboratory Results are usually returned in 1-2 weeks Soil Testing Best results are obtained from properly collected sample Remove any stones, roots and other materials Air dry the sample before sending it to the laboratory 11

12 Evaluate and Implement Review and interpret the soil test results Existing ph level Numerical value Verbal description Existing nutrient levels and corresponding fertility category Very low, low or medium = Below optimum High = Optimum Very high = Above optimum SAMPLE Determines amount of lime Selection of liming materials Need for phosphorus and potassium fertilizer Need for micronutrient fertilizer Soil ph: Degree of Acidity [H+] or Alkalinity Alkaline (example) ph 9, [H+] = 10-9 = Neutral ph 7, [H+] = 10-7 = Acid (example) ph 5, [H+] = 10-5 = Why isn t N analysis included in standard fertility tests? Nitrogen exists in many rapidly interchangeable forms in soil; Some forms are subject to loss from the soil; Therefore Amount in soil may have changed by the time the analysis is completed Recommendations are based on seasonal needs (short-term) 12

13 Other tests Natural Acidifying Processes in Soil CO 2 from respiration + water H 2 CO 3 Organic acids produced by roots, microbes Soil textural analysis Soil organic matter Soil respiration And others: soluble salts gravel content nitrogen tests etc. H+ released by roots Leaching of basic cations Ca++, K+, Mg++ Especially in humid (high-rainfall) climate Oxidation of ammonium & other compounds In NJ climate, tendency is for soils to become more acidic. Chemical Characteristics Fertilizers and Nutrients Macronutrients: Nitrogen (N) Phosphorus (P) Potassium (K) Calcium (Ca) Magnesium (Mg) Sulfur (S) Micronutrients Iron (Fe) Copper (Cu) Boron (B) Chlorine (Cl) Manganese (Mn) Zinc (Zn) Molybdenum (Mo) Fertilization is not a cure all Fertilization may be helpful, but only after you correct other issues that may be impacting the plant Quick release water soluble Slow release Fertilizers Organic or Natural 77 13

14 Chemical Characteristics - Plant Nutrients Element Symbol Function in Plant Sources Magnesium Mg Aids photosynthesis. Key element for chlorophyll. Epsom salts, dolomitic limestone Sulfur S Helps to build proteins. Sulfur, superphosphate Calcium Ca Part of cell walls. Part of enzymes. Limestone, gypsum Chemical Characteristics - Plant Nutrients Element Symbol Function in Plant Sources Nitrogen N Gives dark green color to plant. Increases growth of leaf and stem. Phosphorus P Formation and growth of roots, seed formation. Potassium K Increases vigor and disease resistance. Stimulates production of sugar, starches, oils. Manure, blood meal, fish emulsion Superphosphate, rock phosphate, bone meal Sulfate of potash, greensand, wood ashes, seaweed Chemical Characteristics - Plant Nutrients Element Symbol Function in Plant Sources Zinc Zn Aids in cell division. In enzymes and auxins. Iron Fe A catalyst. In the enzyme system. Zinc sulfate Iron sulfate, chelated iron Manganese Mn In enzyme system. Manganese sulfate Copper Cu Enzyme activator. Copper sulfate Molybdenum Mo Helps in the use of N. Sodium molybdate Boron B Affects absorption of other elements. Affects germination of pollen tube. Borax N = Nitrogen: critical component of proteins, chlorophyll molecules green up too much and improperly timed N causes excessive top growth What s in the bag? P = Phosphorus used in fall for root growth component of DNA, RNA, photosynthesis K= Potassium used all year involved in heat/cold tolerance, disease resistance & other stresses 82 Complete Fertilizers Contain N-P-K 2:1:1, 3:1:1, 4:1:2, etc Fertilizer Ratios Fertilizers come in Multiple Ratios Balanced Fertilizer 1:1:1 Ratio or a Product Incomplete Fertilizer One or more nutrient is not present High Analysis Fertilizer One Nutrient is present in excess of 30% 83 Nitrogen (N) Major component of organic compounds (amino acids, nucleic acids, chlorophyll) Deprived plants - pale green or yellow--a condition known as chlorosis --due to a lack of chlorophyll. Older leaves affected first then younger leaves act as nutrient sinks draw nutrients at the expense of older structures

15 Nitrogen Deficient Phosphorus (P) New leaves draw from older leaves ATP and other nucleotides; phosphorylation of sugars Deficiency - stunted growth and sometimes purple blotches, but not chlorotic. Older leaves are the first to be affected, P def is fairly uncommon deficiency.) Potassium (K) Numerous metabolic pathways Regulate stomatal opening and closing via moving Cl - and K + ions, Deficiency - yellowing (followed by browning) of the leaf margins, which can sometimes be mistaken for wind burn. Protein deficiency, K-starved plants susceptible to environmental stresses such as frost or pathogens N 89 15

16 - P -K Recycling Nutrients 16

17 Material Nitrogen Sources Analysis (% dry wt) Rate of Nutrient Release Bat guano Medium-rapid Compost Slow Cow manure Slow Dried blood Medium-rapid Fish meal Slow Grass clippings Medium Soybean meal Slow-medium Alfalfa meal Medium Material Phosphorus and Potassium Sources Analysis (% dry wt) Rock phosphate Slow Bone meal 15 0 Medium Wood ash 2 6 Rapid Potassium sulfate 0 50 Rapid Rate of Nutrient Release Greensand Very to extremely slow Potential N Fixation of Selected Legumes Crop Estimated Production (lb N/A/year) Alfalfa Nutrient Sources Manures Alsike clover Ladino clover Sweet clover Crown vetch Hairy vetch Fertilizers Nutrient Sources Nutrient Sources Compost Legumes Mulches Grass Clippings 17

18 Recycle Grass Clippings Provides 30% or more of Nitrogen needs of grass. Great slow release source of Nitrogen. Lawns green-up earlier and stay green longer in the fall. Can help to reduce stress as well as pest and weed problems. Micro Clovers Establishing Clover 2 to 8 oz per 1000 sq. ft use Dutch white clover and not the larger, forage types such as Ladino white, or Alsike or Red White Clover. (Trifolium repens) Composts are not all created equal Manure Manures % Nitrogen % Phosphate % Potash Bat Beef (fresh) Beef (dry) Chicken (fresh) Chicken (dry) Hog (fresh) Hog (dry) Horse (fresh) Rabbit (fresh) Turkey (fresh) Bio-Solids Not permitted in organic production systems Concern for heavy metals, pathogens and other contaminants in the waste stream 107 Blood Meal dry powder made from blood & used as a high nitrogen fertilizer N = 13.25%, P = 1.0%, K = 0.6%. one of the highest non-synthetic sources of nitrogen. A by- product from catlle slaugnterhousese

19 Seaweeed / Kelp Products 12,000+ var seaweed minimal bulk but alginate binds soil Nutrients - 0.3% N, - 0.1%P, - 1.0% K, trace elements & amino acids & growth regulators Salt content, clean source Seaweed / Kelp J Plant Growth Regul (2009) 28: Fertilizing Trees Nutrient Sources Nitrogen often comes from fertilizer application and from the air (legumes N from atmosphere) Phosphorus often comes from fertilizer, bone meal, and superphosphate. Potassium is supplied to plants by soil minerals, organic materials, and fertilizer

20 Nutrient Sources Sources of calcium are calcitic and dolomitic limestone, gypsum, and superphosphate. Magnesian and dolomitic limestones, soil minerals, organic material, and fertilizers are sources of magnesium for plants. Sulfur may be supplied to the soil from rainwater. It is also added in some fertilizers as an impurity, especially the lower grade fertilizers. The use of gypsum also increases soil sulfur levels. Organic Matter Organic Matter Leaf Compost Add 3 to 4 inches on bare ground Economical Some weeds and other contaminants Mix in top 6 to 12 inches of soil Physical Characteristics - Tilth Physical Characteristics - Tilth Tilth or structure is affected by several factors, including: Organic matter, limestone, biological activity All increase aggregation or flocculation of particles Sodium Decreases aggregation or dispersion of particles Tilth is primarily a by-product of biological activity 20

21 Physical Characteristics - Tilth BACKYARD COMPOSTING Bill Hlubik Professor - Agricultural and Resource Management Agent for Rutgers Cooperative Extension of Middlesex County WHY COMPOST YARD AND KITCHEN WASTE National Composting Council estimates the average U.S. household generates 650 lb of compostables every year. Limited landfill space should be reserved for materials that cannot be recycled or composted Garbage handling is the 4 th largest expense for many cities. Composting can reduce those costs WHY COMPOST Saves money and time Reduces fertilizer and water use Reduces need for soil and plant amendments Improves soil structure Increases aeration and water holding capacity Stimulates healthy root development Reduces chemical inputs Conserves natural resources 2007 Municipal Solid Waste Production in the U.S. Paper products 32.7% (54) Metals 8.2% Glass 5.3% Plastic 12.1% Food 12.5% (2.6) Other 16.4% Yard 12.8% (64) Total = 254 million tons/yr (4.6 lb/person/day) Percent of category that was recycled The overall recycling rate was 33% in 2007 Backyard composting can increase recycling of yard and food wastes. Composting Size of bin Carbon to Nitrogen ratios Watering Aerating Adding Soil 21

22 YES Leaves Vegetable and Fruit scraps Paper products Composting Meat scraps Bones NO Oils and Soaps Composting Composting is the transformation of organic material (plant matter) through decomposition into a soil-like material called compost. Invertebrates (insects and earthworms), and microorganisms (bacteria and fungi) help in this transformation. Composting - Speeding up the natural decay process What do you need to make compost? A compost pile or bin allows you to control Air (oxygen) Water Food, and Temperature By managing these factors you can speed up the otherwise slow natural decay process Decomposers Your composting work crew. These are the microbes (mainly bacteria and fungi) that do all the work for you. Food for the decomposers The organic materials to be composted The right amount of air, water, and warmth to keep the work crew happy Where do the decomposers come from? If you build it, they will come Composting Soil Leaves, Chopped twigs, paper Food scraps Manure, and Finished compost Each of these will add microorganisms to the compost pile 22

23 One teaspoon of good garden soil to which compost has been added contains 100 million bacteria 800 feet of fungal threads Numerous additives and starters are available but are not needed for good or rapid composting What is the best food for your decomposers? All organic materials will compost, but not all should be added to a backyard compost pile Organic wastes that should be composted include: Garden trimmings Kitchen scraps Grass clippings Leaves Also Used potting soil Manure Sawdust Hair Materials to avoid Avoid organic materials that could cause problems during or after composting Oil, fat, grease, meat, fish or dairy products, unwashed egg shells (tend to attract pests, vermin, limit activity of beneficial microbes) Hard to kill weeds (bindweed, quackgrass) and weeds that have gone to seed (could infest garden area when compost is used). 23

24 Materials to avoid Is shredding necessary? Cat or dog waste (attracts pests, could spread disease) Diseased or insect ridden plants (could infect or attack garden plants when compost is used) Smaller particles decompose faster Have greater surface area per unit volume Allows microbes to get at more of the food Chipping or shredding coarse materials (twigs, stems) will speed up the rate at which they decompose Decomposition Your compost workers will thrive if you give them a balanced diet. Composting will be most rapid if the decomposers are fed a mix of carbon rich and nitrogen rich materials. Carbon rich organic wastes are known as browns Nitrogen rich organic wastes are known as greens High carbon materials such as Leaves (30-80:1) Straw (40-100:1) Paper ( :1) Sawdust ( :1) Animal bedding mixed with manure (30-80:1) High nitrogen materials such as Vegetable scraps (12-20:1) Coffee grounds (20:1) Grass clippings (12-25:1) Manure Cow (20:1) Horse (25:1) Poultry (10:1), with litter (13-18:1) Hog (5-7:1) Browns Decay very slowly Coarse browns can keep pile aerated Tend to accumulate in the fall Tie up nitrogen in soil if not fully composted May need to stockpile until can mix with greens Decay rapidly Greens Poor aeration may have foul odors if composted alone Tend to accumulate in spring and summer Supply nitrogen for composting Best composting if mixed with browns 24

25 Aerobic composting Aerobic composting and temperature Composting with decomposers that need air (oxygen) The fastest way to make high quality compost Produces no foul odors Aerobic decomposers produce heat Active composting occurs in the temperature range of 55 o F to 155 o F Pile temperature may increase above 140 o F but this is too hot 155 for most bacteria and decomposition will slow until temperature decreases again. A thermometer is a nice tool but is not essential for good composting Does my compost pile have to get hot? Good compost can be made in a pile that never gets hot, but Decay will be slower and it will take longer to make compost Not enough air, to little or too much water, or too many browns in the mix could all keep a pile from heating. High pile temperature provides the benefits of The most rapid composting Killing pathogenic (disease causing) organisms Killing weed seeds Warm air rising through the pile draws fresh air in from bottom and sides Wind can stimulate aeration Getting air to your decomposers O 2 O 2 rich Hot air low O 2 cool air Pile aeration Depends upon adequate porosity Pile aeration Getting air to your work force Porosity is the air filled space between particles Browns help to maintain good porosity in the pile A compacted pile has lost porosity, can be increased by turning Aeration can be increased by inserting sticks, cornstalks, or perforated pipes into or under the pile Turning the pile mixes fresh air into the pile Turning tools can make the job easier 25

26 Water Rapid decomposition requires optimum water content If too dry, bacterial activity will slow or cease If too wet, loss of air in the pile will lead to anaerobic conditions Pile water content should be at 40-60% As wet as a squeezed out sponge If too dry, add water as you turn the pile If too wet, add browns and/or turn the pile Making compost the fast way Turn the pile every 5 to 7 days, move outer material to the pile center add water if needed During the first few weeks temp should reach 140 o F After about 4 weeks less heat will be produced and compost will maintain lower temp (100 o F) Making compost the fast way (cont.) After about 4 more weeks the pile will no longer heat after turning and volume will be about one third of original. Allow the pile to cure (stand without turning) for 4 more weeks before using the compost When is compost finished? Compost is mature when The color is dark brown It is crumbly, loose, and humus-like It has an earthy smell It contains no readily recognizable feedstock The pile has shrunk to about 1/3 of its original volume Where should I put my compost pile? Shaded area will help prevent drying out in summer Avoid areas that will interfere with lawn and garden activities Adequate work area around the pile Area for storage Water available Considerations for locating the compost pile Good drainage Away from any wells Near where finished compost will be used Be a good neighbor Make your composting area attractive, or Keep it out of your neighbors view 26

27 Bin/pile construction Ideal size is approximately a 3 foot cube Promotes sufficient aeration Retains sufficient heat to maintain warm temps Piles larger than 5 x 5 x 5 feet are difficult to turn and tend to become anaerobic in the center Manufactured bins The Earth Machine Bin Soil Saver Bin Compost Troubleshooting Odors Odors are one of the most frequent but easily avoidable composting problems. Rotten odor Putrid smell or rotten egg smell Usually results from anaerobic conditions Excess moisture, compaction Turn pile, add dry porous material (browns), cover kitchen scraps Ammonia odor Too much nitrogen (greens) Add high carbon material (browns), turn pile Compost Troubleshooting Temperature Low pile temperature Pile too small, cold weather, too dry, poor aeration, or lacks nitrogen Make pile bigger or insulate sides, add water, turn the pile, add greens or manure High pile temperature Pile too large, insufficient ventilation Reduce pile size, turn 27

28 Compost Troubleshooting Pests: raccoons, rats, insects Presence of meat scraps or fatty food waste, rotten odors Remove meats and fatty foods, cover with sawdust or leaves, turn the pile Compost in an animal-proof bin Covered bin, trash can bin, cone bin, or barrel bin Wire mesh sides and floor (1/4 1/2 in openings) Use worm composting (vermicomposting) for food scraps Compost is not a fertilizer, but does contain plant nutrients Nitrogen and phosphorus are mostly in organic forms Released slowly to plants Not readily leached from the topsoil Compost contains many trace nutrients that are essential for plant growth Benefits of compost Plant nutrients Using finished compost Soil amendment Be sure that compost is mature, has an earthy smell (no ammonia or rotten smell), looks dark and crumbly with no recognizable feedstock Compost improves soil health when mixed in the top 4 to 6 inches (work in no more than a 2 layer of compost) Will improve water and nutrient retention of sandy soils Will loosen compacted clay soils and make them more friable Ecolawn self propelled applicator copyright 2002, Hlubik, Rutgers, The 166 Using finished compost Surface mulch in the garden/landscape Maximum 3 depth Start 3-4 from trunk Extend out to dripline Mulch provides Protection from temp extremes Slows moisture loss from soil Provides some slow release nutrients 28

29 Using finished compost Lawn topdressing Be sure compost is very mature to avoid harming the lawn Use fine (screened) compost, ¼ depth raked over lawn Best if lawn is cored before applying compost Retains moisture, supplies slow release nutrients, prevents soil compaction Potting mix Compost must be very mature to avoid injury to plants Use fine textured compost Mix no more than 1/3 compost by volume Resources Educational demonstrations at the EARTH center at Davidsons Mill Pond Park in South Brunswick, NJ Master Gardener Program 29