Virginia Tech Crop and Soil Environmental Sciences. Managing Animal Manure Nutrients for Optimum Yields and Water Quality. Rory Maguire Virginia Tech

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1 Managing Animal Manure Nutrients for Optimum Yields and Water Quality Rory Maguire Virginia Tech

2 Manure Management Options 1. Nutrient management, but Imbalance of N and P in manures Uneven distribution of manure 2. Phosphorus Index 3. Diet and feed modification with phytase and reduced P feeds Decrease P in manure, improve N:P ratio 4. Manure injection 5. Pyrolyzing manure into biochar

3 Spatial Distribution of Manure P Surplus: (Manure P Crop Removal) Maguire et al, 2007

4 Manure Injection

5 Why Inject or Incorporate Manure? 1. Reduce odors 2. Agronomic - Improve N use efficiency by decreasing ammonia volatilization 3. Environmental - Decrease N and P losses in runoff A BMP that is cost effective?

6 Types of tool available SIDE VIEW AFTER APPLICATION a) Sleighfoot or traveling shoe b) Disk or chisel injector 75 cm 15 cm c) Aerator (with or without banding) 15 cm Injection d) Chisel and sweep 15 cm 15 cm

7 Dairy Manure Plant Available Nitrogen (lbs/1000 gal) Total N NH 4 = Org N Surface Injected Organic (35%) (35%) Ammonia (25%) (95%) Total PAN ~6 12

8 Drawbacks to manure Injection 1. Slower, therefore takes more time 2. Equipment costs more to buy and maintain, can the increased nitrogen use efficiency cover the cost? Retro fit an existing tanker with toolbar, hydraulic shredder, distributor with hoses, 6 x Yetter Avenger Injection units = $17,134 Use nurse trucks NRCS cost share available

9 Pyrolyzing manure into biochar

10 Why Pyrolyze Manure? 1. Reduce manure mass making transport more cost effective 2. Create a value added product Beneficial soil amendment Carbon sequestration A BMP that is cost effective?

11 Pyrolysis is the thermal decomposition of organic matter in an oxygen depleted environment and biochar is the resulting solid phase Biochar is essentially charcoal which is intended as a soil amendment. Pyrolyzed Rose Photo by SeaChar

12 Biochar Formation (Lehmann & Joseph, 2009)

13 Photo from the IBI website: - international. org/biochar/s oils Native Soil Terra Preta

14 Fluidized bed reactor for fast pyrolysis

15 ph phs of the Three Biochars Poultry Litter Char Field Trials Poultry Litter Char Greenhouse Type of Char Hardwood Char

16 Percent Percent Carbon, Nitrogen, and Ash for Three Different Biochars % Carbon % Nitrogen % Ash Poultry Litter Field Trials 27.7 Poultry Litter Greenhouse Trials Hardwood 30.5 Type of Char

17 Phosphorous Concentration g/kg Phosphorous Distribution In Three Different Biochars Total P Water Soluble P Poultry Litter Field Trials Poultry Litter Green House Trials Type of Biochar 0.15 Hardwood 0.007

18 Germination Study Biochar was mixed with two different soils in the following percentages by weight: 0, 0.2, 0.5, 1, 2.5, 5, 10, 15, 20, 25, 30, 40, 60, 80, and lettuce seeds were planted in each tray and germination was monitored for 10 days.

19 Germination Percentage Germination Percentages for Two Soils from 0 to 100% Poultry Litter Biochar 80 Silt Loam Bojac Sandy Loam 20 Highest yearly application in Field Trials 0 % PL Biochar by Weight

20 Souble Salts in ppm Soluble Salts (SS) in the Germination Soils and Washed PL Biochar Salt toxicity starts Silt Loam Sandy Loam 100% Poultry Litter Biochar PL Biochar Washed with DI Water % Biochar made from Poultry Litter (w/w)

21 Part 3: Field Study Methods Contol (no biochar or compost) 2 tons/acre PL Biochar 2 tons/acre PL Biochar + Compost 4 tons/acre PL Biochar 4 tons/acre PL Biochar + Compost 4 tons/acre Hardwood Biochar + Compost

22 ph ph for Field Sites AF RM Control PLC2 PLC2+C PLC4 PLC4+C WC4+C Treatment

23 Soluble Salts (ppm) Soluble Salts for Field Sites AF RM Control PLC2 PLC2+C PLC4 PLC4+C WC4+C Treatment

24 CEC cmolc/kg soil Cation Exchange Capacity (CEC) for AF and RM Field Sites AF CEC RM CEC Poultry Litter Biochar CEC = 17.5cmolc/kg Control PL2 PL2+C PL4 Treatment PL4+C WC4+C Hard Wood Biochar CEC = 11.2cmolc/kg

25 Conclusions Both wood and litter biochar were ~1/4 carbon Litter biochar added substantial nutrients (not N), wood biochar did not Poultry litter biochar can have toxic effects on plants if over applied due to salts Poultry litter biochar raises soil ph, wood biochar does not

26 Conclusions Both wood and litter biochar increased water holding capacity and cation exchange capacity Salts can be leached so further application is possible, but soil test P and SS should be monitored Litter Biochar needs to be exported from areas with manure and high soil test P, possibly mix with wood biochar