Organic materials as fertilizers and soil amendments. Andy Bary WSU Puyallup

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1 Organic materials as fertilizers and soil amendments Andy Bary WSU Puyallup

2 Nitrogen Cycle Organic N Ammonium NH 4 + Nitrate NO 3 - Soil organic matter, Plant residues, Manure Plants, Microbes N fixation Leaching Gases (N 2, N 2 O) Atmosphere

3 Organic materials Management depends on: C:N ratio degree of decomposition

4 Carbon:Nitrogen ratio Ranges from <5:1 to >500:1 in organic materials Low C:N supplies N to plants High C:N ties up N by biological immobilization

5 Predicting Nitrogen Availability from Organic Amendments

6 Jubilee sweet corn 8-11 materials/site/yr Control & 4 urea rates N recovery from crop and soil Field research in Puyallup, WA and Aurora, OR

7 Materials Primary Amendments Broiler litter, raw & composted Dairy manure solids, raw & composted Yard trimmings, raw & composted Rabbit manure, raw & composted Specialty Products Fish fertilizer, pelleted Canola meal Feather meal, etc.

8 8 Organic amendment nitrogen data Nitrogen (% dry matter) Organic N % NH4-N % NO3-N % 0 Broiler litter (all) Dairy solids Dairy solids compost Other composts Specialty products

9 Amendment decomposition in soil Fresh 80 Decomposition (%) Broiler litter Decomposition (%) Dairy solids Composted dairy solids Decomposition (%) Specialty products Other composts Days Days Days

10 Plant Available N Fresh Compost 80 Broiler litter Specialty products PAN (%) C:N = 9 PAN (%) Dairy solids C:N = 20 C:N = 27 PAN (%) C:N = 7 C:N = Other composts Days Days Days

11 Lab vs. full-season field PAN (4-site yr.) Field full season PAN (%) :1 Broiler litter Dairy solids Rabbit manure Yard trimmings Specialty products Composts Laboratory 70-d PAN (%)

12 Amendment C:N vs. plant-available N (field) Full-Season PAN (% of amendment N) Broiler litter Dairy solids Rabbit manure Yard trimmings Specialty products Composts Amendment C:N Gale et al., Journal of Environmental Quality 35:2321

13 ORGANIC FERTILIZER CALCULATOR Sample calculations How much of this fertilizer should I apply? How do these two fertilizers compare? What s the cheapest source of available N, P, K, etc.? Does this program match my fertilizer recommendation?

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16 Organic Fertilizer Calculator" estimates of plant-available N (PAN) Fresh Amendment total N Example Fresh Amendment C:N PAN 28 days PAN full season % dry wt. Approx. % of total N % of total N 1 Solid manure w/bedding 35 < Dairy solids Yard Debris Compost 6+ Specialty products less than

17 Soil Quality in Intensive Organic Management Systems Craig Cogger, Doug Collins, Andy Bary, Ann-Marie Fortuna, and Ann Kennedy

18 Three Cover Crop Treatments Relay planted Legume (RLY) Post-Harvest Cereal & legume (PH) Short-term Grass-legume Pasture (LEY)

19 Two tillage treatments are included in the experiment CONV = Conventional tillage (plow, disc, rototill) SPD = Modified tillage (low-speed rotating spader)

20 Soil amendments include High-C compost and Low-C broiler litter. Chicken (Broiler) litter: (CKN) Low C application ( dt/ac) Mixed on-farm compost: (OFC) High C application (8-17 dt/acre)

21 REP 2 REP 1 REP 4 REP 3

22 Soil quality measurements include physical, chemical, and biological indicators Bulk Density Infiltration Compaction Particulate OM Enzyme activity Nematodes Collembola Microbial biomass Nitrogen cycling Microbial community structure Nutrients and carbon

23 . Bulk density is an indicator of porosity, and organic matter.

24 Bulk density is lower with high-c compost additions. 1.3 Chicken manure compost On-farm compost 1.2 Bulk density, g/ml a a a b a b a a a b a a b b Amendment without ley

25 Measuring water infiltration using a simple field method.

26 Infiltration is usually faster in plots treated with high-c compost. Infiltration, ml/min a b a b a b Chicken manure compost On-farm compost a b 4 Amendment, without Ley

27 The penetrometer measures compaction to a depth of 16 inches

28 Amendment had no effect on compaction in the soil profile. surface 60 Jul 2005 Aug 2010 Soil depth, cm High C Low C High C Low C Pene sys sum 2feb12.jnb Penetrometer resistance, kpa 5.5 x 7.5 image

29 Spader-tilled soils had a less compact profile than conventional tillage Soil depth, cm surface ns b a Spader tillage Conventional Jul 2005 ns pene sys feb12 Aug 2010 Spader tillage Conventional Penetrometer resistance, kpa b b a a ns

30 Compost & Manure Use/Management and Words of Wisdom

31 Manure and Pathogens Fresh manure can contain Salmonella, E. coli O157:H7, etc. We must use manure properly to avoid spreading diseases Kevin Sorenson, Snow College

32 Types of Organic Amendments Hot stuff C:N <10:1 Cool stuff C:N 15:1 to 25:1 Woody stuff C:N > 30:1

33 Hot Stuff C:N < 10:1 Rapid N availability Use as a fertilizer Over application leads to excess nutrient levels in soil -- potentially harming crop and water quality.

34 Hot Stuff Poultry manure Seed meals Fish and feather meals Fresh grass clippings Fresh rabbit manure Dewatered or dried biosolids

35 Cool Stuff, C:N 15:1 to 25:1 Slow N availability Can add large amounts without risk of overfertilization Use as a soil amendment N immobilization (tie-up) likely with fresh materials in first few weeks after app. Compost organic matter lasts a long time in soil

36 Cool Stuff Compost (yard debris, most manures, biosolids) Fresh materials: o Yard debris o Cover crop residues o Dairy manure solids o Coffee grounds

37 Woody Stuff, C:N > 30:1 N immobilization Need to add N along with organic amendment Use as mulch or bulking agent for compost

38 Woody Stuff Straw Sawdust Paper waste Horse manure rich in bedding

39 Feed the microbes and let them do the work for you! Organic nutrient management Compost usage Research updates Manure Management Field day announcements

40 Thank you Questions