New Directions for Reduced Tillage Organic Agriculture Unlock the Secrets to Soil Health ~ Aurora, OR ~ 6 April, 2017

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1 YOUTH & AGRICULTURE FAMILIES HEALTH ECONOMY ENVIRONMENT ENERGY COMMUNITIES New Directions for Reduced Tillage Organic Agriculture Unlock the Secrets to Soil Health ~ Aurora, OR ~ 6 April, 2017 Project Directors: Doug Collins, Chris Benedict, Andy Bary, Craig Cogger (retired) Graduate Students: Sandra Wayman (completed) David Sullivan Bethany Wolters (completed) Ryan Tarbell Becky Collier (completed) Farmer Collaborators: Colin Barricklow-Kirsop Farm Adam McCurdy-Oxbow Farm Steve Hallstrom-LetUs Farm, Judy Feldman - Organic Farm School

2 Organic producers must implement tillage and cultivation practices that maintain or improve the physical, chemical, and biological condition of soil. Cover crop varieties NOP Rule, Adoption Soil health & weeds Cover crop termination Ground preparation

3 Presentation outline. 1. Selecting and terminating cover crops 2. Reduced tillage systems experiment: New directions for reduced tillage organic agriculture research a) Precision Cover Cropping b) Aggressive Strip Tillage c) Continuous Reduced Tillage

4 What does tillage do? Manage residue Manage weeds Prepare seed bed Aeration Modify moisture Modify temperature

5 Management practices to encourage beneficial soil functions Use plant diversity to increase the diversity in the soil biota Keep a living root growing throughout the year Keep the soil covered as much as possible Manage more by disturbing less

6 In selecting winter cover crops for reduced tillage we look for large biomass and early development in spring

7 Cover crops are terminated with a flail mower or roller/crimper. Mowed cover crop Rolled cover crop

8 Zadoks Stages of grain development Early = Late anthesis 69 Zadoks et al., 1974 Late = Early milk 73

9 Mischler vetch development Early = 60% flowering Mischler et al., 2009 Late = 100% flowering

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11 Long-term experiment includes 5 treatments & 3 crops (squash, broccoli, beans) Squa Broc Bns Broc Squa Bns Broc Bns SquaSqua Broc Bns Squa Broc Bns flailing + no-till flailing + strip till flailing + complete till roll/crimp + strip till roll/crimp + no-till. Grain Beans Vetch Broccoli Grain Squash cover crop cash crop cover crop cash crop cover crop cash crop

12 No Till Strip Till

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15 Water infiltration

16 Penetrometer to measure compaction

17 August 12 Bulk density; an indication of compaction.

18 Microbial biomass, soil respiration, nutrient availability.

19 Earthworms can be coaxed from the soil with a skin irritant, or physically removed.

20 Infiltration A Infiltration 8 6 B B B 4 B 2 0 Flail ST Flail PA Full Till Roll ST Roll PA Flail ST Flail PA Full Till Roll ST Roll PA

21 Soils were more compact at the surface in reduced tillage

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26 Squash yields were larger in the fully tilled treatment in 2 out of 3 years.

27 Among reduced tillage treatments, flail mowed treatments yielded more squash 2 out of 3 years.

28 Broccoli yields have been similar in reduced tillage and fully tilled treatments.

29 Reduced tillage did not succeeded at Let Us Farm with a silt loam soil

30 Reduced tillage has been promising at Kirsop Farm with broccoli and kale planted into flailed vetch in a loamy sand Broccoli Kirsop Farm Kale Plant Biomass, lb/plant Kirsop Farm, Flail Strip Till Full Tillage Flail Strip Till Full Tillage

31 Flail mowed mulch at Kirsop

32 New Directions for Cover Crop and Weed Management in Reduced Tillage Organic Agriculture a) Precision Cover Cropping b) Aggressive Strip Tillage c) Continuous Reduced Tillage

33 High-residue cultivation to control between-row weeds

34 Mechanical Transplanter with No-Till attachment.

35 Strip-tillage into heavy residue can be problematic

36 High Residue in conventional strip tillage production

37 Off-the-shelf products are designed with the assumption that herbicides are used.

38 When it comes to strip tilling into residue, could less be more? Rolled rye cover crop Flailed vetch cover crop less biomass degrades quickly adds nitrogen

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44 An experiment currently planted will examine transition to reduced-tillage and precision cover crop planting. 2 years of summer cultivation 1 years of summer cultivation

45 More aggressive strip tillage to: 1) handle high cover crop residue, 2) increase cultivation options, 3) warm soils, and 4) improve rooting conditions in a narrow zone. Power-driven walk-behind tiller, modified to produce a 9 strip (used in 2015)

46 Early results from 2015 where we used a walk-behind power roto-tiller for secondary strip tillage: Soil Temperature by Tillage Type

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52 From we only examined rotational reduced tillage. Continuous conservation tillage treatment introduced in 2015

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54 Continuous conservation tillage approach

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56 Minimum-Till Planted Vetch Full-Till Planted Vetch

57 No-till rye cover crop planting Tilled rye cover crop planting February 5, 2015

58 On-farm reduced tillage trial planted at Organic Farm School, Whidbey Island, Oct 3, 2016

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61 Earthworm analysis Full Till Plot (before spring tillage) Reduced Tillage Plot

62 Earthworm biomass in three tillage systems; a minimum of 7 months after tillage

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64 P value=0.07

65 P value=0.12

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68 Conclusions and direction forward. With Reduced Tillage. Earthworm populations Soil CO 2 emissions Annual weeds suppressed Soil temperature Soil moisture Bulk density and compaction

69 Some equipment is highly specialized and models designed for conventional RT may require modification for high-residue organic.

70 Adoption of RT organic ag will likely depend on efficient weed control. Manage for the transition to reduce initial weed pressure.

71 . Two possible paths to successful weed control.

72 Our research is supported by Federal and State Grants and inkind donations Primary support from Western Region Sustainable Agriculture and Education Early support by WSU Center for Sustaining Ag and Nat Resources BIOAg Cover crop seed: ProGene Plant Research, Othello, WA Doug Collins WSU Small Farms Program Resources: Wayman, S. & Collins, D.P., For the life of the soil: Farmer perspectives and experiences adopting reduced tillage organic agriculture. Tilth Producers Quarterly, 23(4), pp.1,4 5 Wayman, et. al The influence of cover crop variety, termination timing, and termination method on mulch, weed cover, and soil nitrate in organic reduced-tillage. Renewable Agriculture and Food Systems. FirstView: 1-11.