200 likes | 429 Views
Biosolids, Manure, and Micronutrients. Robert Mullen & Nick Basta Nutrient Management/Soil Fertility Specialist Ohio State University February 21, 2008. Overview. Essential micronutrients Deficiency/toxicity Biosolids/manure micronutrient content Micronutrient soil availability.
E N D
Biosolids, Manure, and Micronutrients Robert Mullen & Nick Basta Nutrient Management/Soil Fertility Specialist Ohio State University February 21, 2008
Overview • Essential micronutrients • Deficiency/toxicity • Biosolids/manure micronutrient content • Micronutrient soil availability MWEA 2008
Essential Nutrients • Thirteen essential nutrients • Nitrogen, phosphorus, potassium, calcium, magnesium, sulfur (macros) • Iron, manganese, boron, molybdenum, copper, zinc, and chlorine (micros) • Nickel has recently been added • Micros are needed in much lower concentrations to ensure adequate supply MWEA 2008
Essential Nutrients • Necessary micronutrient concentrations for plant growth MWEA 2008
Essential Nutrients • Micronutrients can be toxic when supplied at levels higher than plant nutrient need University of Hawaii MWEA 2008
Biosolids/Manures • It stands to reason that human and animal waste contain the macro-/micronutrients needed for higher plant nutrition • Everything we consume is plant based • Thus, logically any animal waste material likely contains some level of micronutrient nutrition MWEA 2008
Biosolids/Manures • Typical biosolid micronutrient content Sommers (1997) – Journal of Environmental Quality 6:225-232. MWEA 2008
Biosolids/Manures • Average animal manure micronutrient content of different animal sources Micronutrient Status of Manure, University of Wisconsin, 2001 MWEA 2008
Biosolids/Manures • Biosolids/manures can be good sources of plant essential micronutrients • Let’s calculate just how much we add based upon a single application rate MWEA 2008
Biosolids/Manures • Suppose we are applying 3 tons of biosolids per acre (dry basis), how much iron, manganese, boron, zinc, copper, and molybdenum have we supplied? MWEA 2008
Biosolids/Manure • Do not assume that application will necessarily result in higher plant uptakes • We have ample evidence that shows levels will increase if the nutrient was deficient • But non-deficient sites will not necessarily show increases in crop uptake MWEA 2008
Biosolids/Manure • Remember, biosolids/manure do not supply a salt form analogous to commercial forms • Availability may not necessarily be comparable to commercial forms (at least short-term) • Predicated on biosolid/manure application rate MWEA 2008
Biosolids/Manure • Application rates and availability • Long-term application of biosolids (13 years) on micronutrient availability (DTPA extractable) • Study conducted at Oklahoma State University • Biosolids application rate ranged from 3,500 – 10,000 lbs/acre (depending upon nitrogen analysis of material) MWEA 2008
Biosolids/Manure • Total micronutrient analysis of soil Schroeder et al. (2008) Soil Science Society of America Journal 72:73-82. MWEA 2008
Micronutrient Soil Availability • Even though we may be supplementing micronutrient nutrition through biosolid/manure application their availability is dictated by soil pH • More of a concern as it relates to toxicity from long-term application of biosolids/manures MWEA 2008
Micronutrient Availability MWEA 2008
Micronutrient Availability • More acid soils have better (?) micronutrient availability (this goes for most of the heavy metals) • Exception being molybdenum • More acid soils also have greater risk of micronutrient toxicity (especially if the soil has a history of biosolids/manure applications) MWEA 2008
Micronutrient Availability • To minimize risk of toxicity maintain soil pH in optimum range for crop production (6.0-7.0) • Soils that have high soil pH levels are more likely to exhibit micronutrient deficiencies, thus application of biosolids/manure on these soils can be very beneficial MWEA 2008
Summary • Biosolids/manure can be excellent sources of micronutrient nutrition for higher plants • Soils with application histories can show higher micronutrient availability levels than those receiving commercial fertilization • Maintaining adequate soil pH for crop production should ensure good micronutrient availability MWEA 2008
Questions?? • Thanks! • http://agcrops.osu.edu/fertility/ • Robert W. Mullen • Mullen.91@osu.edu MWEA 2008