Compost Utilization Quality Guidelines in Tomato Production Monica Ozores-Hampton, Ph.D University of Florida/IFAS/SWFREC
What is Composting? It s a biological decomposition process where microorganisms convert raw organic materials into relatively stable humus-like materials
Composting serves as both a waste management method and a product manufacturer: you can generate revenue in both end (tipping fees) and the back end (product sales) Compost Facts The horticultural industry is the primary consumer of compost
Florida Waste and Composting In 1988, the Florida Legislature approved the comprehensive Solid Waste Management Act to minimize landfills space by increasing number of composting facilities. However, the number of permitted composting facilities increased only from 11 to 34 as 2015. 7% 8% 9% Compost Type 5% 1% YW MSW On farm Institution 70% BS Florida recycling rate mandate goal by 2020 is the 75%, but the average now is only 56%. Others
LOCATION OF FLORIDA COMPOSTING FACILITIES
Compost and Tomato Production 1. Growers can use compost as a soil conditioner. 2. As nutrient source to supplement the fertility program. Nutrients such as nitrogen, phosphorous, and potassium may be low. 3. In high compost application rates to lower the environmental impact compost should be applied to match the nutrient crop requirements of P. https://www.ndsu.edu/soilhealth/wp-content/uploads/2013/03/screen-shot-2013-03-23-at-1.13.49-pm.png
Copyright 2014 by Monica Ozores-Hampton. All rights reserved
Compost Guidelines 1. Compost quality use guidelines for assessing compost quality for use in tomato production are limited. USCC have a general for vegetable production and some compost Lab. 2. The lack of compost use guidelines is due to the diversity and variability of a number of factor such as feedstocks, composting methods, application methods, application alone or combined with other organic or inorganic nutrient sources, etc.
Objectives Present compost quality guidelines to help growers to determine high quality compost to be use in tomato production
Compost Use Quality Guidelines
( F) 158 140 122 104 86 68 50 32 USEPA Regulation 40 CFR Part 503 Thermophilic Mesophilic Time Windrow methods average 131 o F for first 15 days and turned pile 5 times Curing & Maturation ( C) 70 60 50 40 30 20 10 0 Temperature
Thermophilic Stage Usually 130-150 o F Heat should be controlled
Compost Facility Documentation Before compost is delivered to the tomato producer, the supplier should provide the following documentation: The compost meets Federal, State and County or City health and safety regulations The composting process has met time, temperature and turning requirements (503 regulation) Laboratory analysis that is less than 4 months old from a composite sample and analyze every 20,000 tons of compost produced or every 3 months, whichever comes first by a certified laboratory following Test Methods for the Examination of Composting and Compost (TMECC).
Compost Guidelines Physical Properties Parameter (Unit) Optimal range Bulk density (lb/yard 3 wet basis) 740 980 Moisture (%) 30 (dry) - 60 (wet) Organic matter (%) 40-60 Particle size 98% pass through 3/4-inch screen or smaller than 1 inch Physical contaminants (%) <2 %
Bulk density: calculated as weight divided by volume 740 980 lb/yard 3 wet basis http://www.engineeringintro.com/wp-content/uploads/2012/07/bulk-density.jpg
Moisture: Dry compost will be light and dusty and wet compost will be heavy and clumpy. 30 60 % http://www2.luresext.edu/photos/h2o.jpg
Organic matter (OM): Lower OM content indicates the presence of an inorganic component such as sand, clay, silt or man-made materials such as plastics and metals. Optimal 40 to 60 % http://www.quartoknows.com/blog/quartohomes/wp-content/uploads/sites/2/2015/04/organic-matter-525.jpg
Particle size: is determined by passing the compost through a series of sieves. Large particle size will indicate poor quality or immature compost. Physical contaminants (inert materials): Man-made materials that are aesthetically offensive and decrease the value of the finished compost. Less than 2%
Compost Guidelines Chemical Properties Parameter (Unit) Optimal range ph 5.0-8.0 Electrical conductivity (mmho/cm) < 6 Stability (Carbon dioxide (CO 2 ) evolution rate or oxygen consumption) CO 2 -C/unit volatile solid (VS)/day as < 2 = very stable; 2-8 = stable and > 8 = unstable. Oxygen (O 2 ) uptake O 2 /VS/h < 0.5 as very stable; 0.5-1.5 = no stable and > 1.5 = no stable C/N (Carbon:nitrogen) 10-25 Nitrogen (%) 0.5-6.0 Phosphorous (%) 0.2-3.0 Potassium (%) 0.10-3.5 Heavy metals Meet or exceed USEPA Class A standard, 40 CFR 503.13 or DEP 62-709 Arsenic (As) (ppm) < 41 Cadmium (Cd) (ppm) < 15 (DEP) Copper (Cu) (ppm) < 450 (DEP) Lead (Lb) (ppm) < 300 Mercury (Hg) (ppm) < 17 Molybdenum (Mo) (ppm) < 75 Nickel (Ni) (ppm) < 50 (DEP) Selenium (Se) (ppm) < 100 Zinc (Zn) (ppm) < 900 (DEP)
ph: a measure of the acidity or alkalinity of the compost. Most composts have the ph values between 5 to 8, with a preferred ranged of 6 to 7.5. Electrical conductivity [(EC) (soluble salts]: Some specific salts (sodium and chloride) may be detrimental to vegetable crops. However, a higher EC in most compost is due to higher nutrient content, and at recommended field application rates do not contain sufficient levels of these salts to cause phytotoxicity. Less than 6 (mmho/cm).
Stability: Can be defined as the point at which easily degradable carbon decrease so that its decomposition rate is no longer control the overall rate of the decomposition of the feedstocks. CO 2 -C/unit volatile solid (VS)/day < 2 = very stable; 2-8 = stable and > 8 = unstable. Oxygen (O 2 ) uptake O 2 /VS/h < 0.5 very stable; 0.5-1.5 = no stable and > 1.5 = no stable.
C:N ratio: this is the balance of the two elements for optimal performance of the compost once it is incorporated into the soil as optimal 10:1 to 25:1. N-P-K: this is normally as a percentage of dry or wet weight. Compost N-P-K content is low compare with commercial fertilizer; however, when compost is applied at higher rates it can cause a soil nutrient buildup. Heavy metals: trace elements whose concentration must meet national, state, and/or local safety standards to be marketable, due to the potential for toxicity to humans, animals, and plants.
Compost Guidelines Biological Properties Parameter (Unit) Maturity (Seed emergence and seedling vigor) Weed-free Pathogen Fecal coliform (MPN/g TS) < 1,000 Salmonella (MPN/4 g) < 3 MPN = most probably number: TS = total solids. Optimal range >80% relative to positive control No or very low weed seeds [Meet or exceed US EPA Class A standard, 40 CFR 503.32(a)]
Maturity (growth screening): Is the degree to which the compost is free of phytotoxic substances (acetic, propionic and butyric acid) that limit seed germination and plant growth and is determined empirically using bioassay. More than 80% of the control.
Weeds-free: Compost should not add weed seed or tubers into the soil. Human pathogen: The public health needs to be protected from potential pathogen content, such as fecal coliform and Salmonella. Therefore, all compost that contains regulated feedstocks must meet national, state and/or local safety standards to be marketable. Fecal coliform (MPN/g TS) < 1000 and Salmonella (MPN/4 g) < 3
Composting Facilities should be Participating in the Seal of Testing Assurance (STA) US Composting Council (USCC) https://compostingcouncil.org/ Rules: Practice On-going Testing, Disclosure of test data, end use instructions Uniform compost testing and sampling protocols (TMECC). Participants in the program will gain market advantage by using STA Seal (Logo). Testing by Certified Laboratory using (TMECC)
Conclusion Compost quality guidelines for tomato production are still limited and non-comprehensive in addressing all the potential positive and negative effects of compost. However, compost physical, chemical, and biological properties presented here will promote positive effects of compost and minimize negative impact in tomato production.
General Compost Quality Guidelines Ozores-Hampton, M. 2016. Guidelines for assessing compost quality for safe and effective utilization in vegetable production. HortTechnology 27:162-165. Ozores-Hampton, M. 2012. Developing a vegetable fertility program using organic amendments and inorganic fertilizers. HortTechnology 22:743-750.
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