+ Nitrogen release and disease suppressive activity of four compost amendments on three vegetable farms Lori Hoagland Dept. of Horticulture and Landscape Architecture Purdue University Presented by Liz Maynard, 219-531-4200 x4206; emaynard@purdue.edu
+ Outline Relationships between soil health and pest severity Our on-farm trials investigating fertility amendments, soil health and pest severity How you can apply this information
+ Pest outbreaks on your farm Susceptible host The perfect storm Favorable environment Unwanted pest
+ Soil health http://www.lawrieco.com.au/about-us/?id=7 Foundation for sustainable crop production
+ Soil physical properties Compaction affects: - water infiltration & drainage - soil biological activity - seed germination & root growth
+ Soil chemical properties Salinity: salt content - soil tilth & plant health - challenge in high tunnels Nutrient availability: - over & under fertilization ph: acidity/alkalinity of soil - nutrient availability - pathogen severity Excess nitrogen
+ Soil biological properties The soil s livestock Regulate key soil processes: - influence soil structure - detoxify pollutants - regulate nutrient cycling - mediate pathogen and insect pressure It s Alive!
+ Disease suppressive soil Pathogen fails to cause infection despite susceptible host & favorable environment Biologically mediated: - competition for resources - parasitism - antibiosis - induced systemic resistance (stimulation of a plants immune system) Can be induced by management Antibiosis
+ Organic fertility amendments Animal manures, compost, vermicompost, specially formulated products Supply nutrients Provide soil organic matter Have suppressed pests: - soil-borne pathogens - foliar pathogens - insects http://www.compostforsoils.com/index.php?id=38
+ Challenge: Amendments must mineralize before nutrients are available for plant uptake Mineralization rate depends on: - amendment composition - environmental conditions - management practices - soil health http://www.rothamsted.ac.uk/aen/smbweb1/paradox.html
+ Challenge: Not all composts are pest suppressive Suppressive activity depends on: - feedstocks - processing conditions - pest Still no perfect recipe or reliable tests to predict suppressive activity Suppressive activity well documented in container based systems, but results variable in field trials
Our study (2013-2015) Purdue: Lori Hoagland, Elizabeth Maynard, Natasha Cerruti, Dan Egel Growers: Jeff Evard, Ben Nava, Steve Spencer +
+ On-farm research trials LIFE Farm, Martinsville, IN Feel Good Farm, Sheridan, IN EcOhio Farm, Mason, OH
+ Methods 3 year vegetable crop rotation Winter cover crop (rye & vetch) Repeated applications of 4 fertility amendments Soil, pest and plant measurements 2013 Red Cabbage cv. Red Express 2014 Acorn squash cv. Sweet Reba 2015 Paste tomato cv. TBD
+ Amendment application rate Focus on N (tends to be most limiting nutrient) Rate depends on the needs of the crop Assume 50% release rate Product (N, P, K) Rate Applied 2013 (lb/a) Rate Applied 2014 (lb/a) Chicken litter (3-4-3) 8000 6000 Animal byproducts (8-5-5) 3000 2250 Plant & animal byproducts (7-5-10) 3430 2570 Vermicompost (1.2-2-1) + Chicken litter (3-4-3) 10000 +4000 7500 +3000
+ 2013: Soil N availability varies by amendment and farm Soil N availability across amendments Soil N availability across farms 250.00 250 200.00 200 150.00 150 lbs N/ac 100.00 lbs N/ac 100 50.00 50 0.00 At planting Midseason At harvest Fall 0 At planting Midseason At harvest Fall Chicken litter Plant & animal byproducts Animal byproducts Vermicompost + chicken litter LIFE Feel Good Farm EcOhio
+ 2013: Amendments influence black rot severity & cabbage yield (Xanthomonas campestris) 70 Foliar Black Rot Symptoms (%) 60 50 a 40 30 20 10 Chicken FT VD Plant & animal Animal byproducts NS VM Vermicompost A AB BC C 0 6/25 6/30 7/5 7/10 7/15 7/20 Date
+ 2014: Amendments influence squash N uptake 41.5 Squash leaf chlorophyll (SPAD) across farms 41 40.5 40 39.5 Additive effect? 39 38.5 38 37.5 37
+2014: Amendments influence susceptibility to silverleaf whitefly (Bemisia argentifolia) 3.5 Silverleaf whitefly severity rating 3 2.5 2 1.5 1 0.5 0
+ 2014: Amendments influence soil health & susceptibility to damping off by Rhizoctonia solani 16 Life 2014 3 14 12 2.5 average lenght cm 10 8 6 4 2 2 1.5 1 0.5 root rating 0 baseline animal byproducts chicken litter plant/animal worm castings treatments 0 shoot length root length root rating
+ Conclusions Nutrient release varies by amendment and farm - potential nutrient additive effect with some amendments Amendments influence pest severity - in some cases effects were consistent across farms - in some cases pest severity was correlated with nitrogen availability - in some cases pest severity was correlated with soil quality
+ How can you apply this information?
+ On-farm research Best way to determine what will work best on your farm Resources: - Local extension educators - Sustainable Agriculture Research and Extension (SARE) www.sare.org - On-farm research guide - Grant opportunities
+ Soil quality testing Monitor your soil over time On-farm soil quality tests: - NRCS Soil Quality Test Kit - Soil quality scorecards - Solvita test Laboratory tests: - Cornell Soil Health Lab - Comprehensive assessment http://soilhealth.cals.cornell.edu
+ Nutrient management Avoid over and under fertilization OSU organic fertilizer calculator: http://smallfarms.oregonstate.edu/calculator Soil and plant tissue tests: - basic soil nutrient tests - pre sidedress soil nitrate tests (pre sidedress) - plant tissue tests (more expensive but more accurate) Petiole sap tests (N & K) - Midwest Veg Prod Guide
+ Disease suppressive composts Stable, mature and of consistent quality General recommendations (Hoitink et al., 1997) 1) cure at least 4 months or more 2) incorporate several months before planting 3) maintain high moisture (40-50%) during curing and inoculate with beneficials May be more suppressive - Higher C:N ratio - Hardwood bark compost - Vermicompost
+ Questions? Liz Maynard 219-531-4200 ext 4206 emaynard@purdue.edu