Diversifying Dryland Grain Cropping Systems for Organic Production

1. Diversifying Dryland Grain Cropping Systems for Organic Production Kristy Ott Borrelli Ph.D. Candidate Department of Crop and Soil Sciences

2. Outline • Background of Region and Organic Wheat Production • Dryland Organic Grain Production from Transition to Certification • Intercropping winter pea and wheat for optimal soil nitrogen and moisture • Dryland organic grain management considerations

3. The Palouse Prairie

4. Sub humid Region • 500 mm annual precipitation (21 inches) • 60% precipitation November through March • Rain-fed annual cropping systems • Soft White Winter Wheat • 2 to 3 year rotations • Winter Wheat – Spring Legume – Spring Wheat • Winter Wheat – Spring Legume – Winter Wheat • Winter Wheat – Winter Wheat – Winter Wheat Papendick, 1996; Cook, 1986; McCool et al., 2001

5. WA Organic Grain Production Which of the following are your main reasons for NOT having any certified organic acres? Jones et al., 2006

6. Within the last five years, 2001 – 2005, have you considered transitioning any of your acreage to certified organic? Joneset al., 2006

7. Dryland Organic Grain Production from Transition to Certification(AKA The Boyd Farm Project)

8. Dryland organic cropping systems • Identify strategies to minimize economic and • management risks for organic grain growers • To evaluate different transition cropping • systems • Do not rely on inversion tillage • Supply N using legume crops (grain, • green manure and forage)

9. Objectives • To identify how cropping systems in transition phase impacted grain yield and protein during the certified organic phase. • To develop a soil fertility management plan for organic grain producers. • Construct a nitrogen budget

10. Materials and Methods

11. Experimental Design

12. Rotation Systems

13. General Agronomics • 2x Seeding Density • Cereal Crops • BioGro 7-7-2 NPK • Foliar Fish Emulsion 12-0.25-1 NPK • Gypsum

14. Rotary Harrow • Pre-plant weed control and soil prep. • 1-2 passes

15. Rotary Hoe • In-crop weed management • 3-5 passes

16. Sub Sampling • Crops and Weeds • Separated and biomass yield was determined • Total N • Grain N measured separately • Soil Samples • 1.5 m depth • Inorganic N

17. Harvest • Green Manure Crops were Flail Mowed • Residue retained on soil • Forage cut 1-2x season • Baled as hay • Grain Harvested • Gallagher, R.S., D. Pittmann, A.M. Snyder, R.T. Koenig, E.P. Fuerst, I.C. Burke, & L. Hoagland, 2010. Alternative strategies for transitioning to organic production in direct-seeded grain systems in Eastern Washington I: Crop agronomy. Journal of Sustainable Agriculture 34:483-503.

18. Nitrogen Balance • Net N input = (Fertilizer N + Plant N + Post-harvest Soil N) – Pre-plant Soil N • Fertilizer N = organic N when applied to cereal crops • Plant N = crop N + weed N • Pre-plant soil N = post-harvest soil N from the previous year • Net N Balance = Net N input – N removal (crop) • Net N input = equation above • Crop N removal = grain or forage crop N only

19. Transition Phase Results

20. Net System Nitrogen Balance (by year) ns = not significant 2003; ab for 2004; xyz for 2005 Cash cereal/grain x GRM last year x x 3yr GRM x x x xy Forage b b b b b b b a b ns† yz z

21. Soil Inorganic Nitrogen (by year) ns b b b b a b b b b ns† Cash cereal/grain GRM last year 3 yr GRM Forage • † ns = not significant (2003 and 2005); ab for 2004

22. Certified Organic Phase Results

23. 2006 Spring Wheat Yield (bars) and Protein (dots) 3 yr GRM Cash cereal/grain GRM last year Forage x x x x x x y y 3293 kg ha-1 y cde de bcd de abc bcd ab a e

24. 2007 Winter Wheat Yield (bars) and Protein (dots) 5052 kg ha-1 3 yr GRM Cash cereal/grain GRM last year Forage x x x x x y y y y bcd abc abcd d cd a ab a a

25. Soil Inorganic N in Certified Organic Phase †ns a bc ab bc cd de e wx w yz wxy z wx wx w xyz e e †ns (not significant) for Sp 2006; abc for Fa 2006; wxy for Fa 2007

26. Summary • Certified organic grain had some of the highest yields and protein levels following Forage systems in the 1st year • decreased 2nd year • Green manure in 3rd year of transition resulted in some of the highest grain yields 2nd year • High protein levels both years

27. Intercropping winter pea and wheat for optimal soil nitrogen and moisture

28. Intercropping • The simultaneous cultivation of more than one crop species on the same piece of land with part of the crop life-cycles overlapping. (Hauggaard-Nielsen et al., 2008; Walker et al., 2011; Pridham and Entz, 2008).

29. Benefits of Intercropping • Source of plant N to cereal crops • Suppress weeds • Reduce disease • Stabilize erodible soils • Increase SOM • Provide crop rotation options • Management tool in organic or low-input systems • Reduce time spent growing a green manure (Walker and Ogindo, 2003; Blackshaw et al., 2010; Hauggaard-Nielsen et al., 2008; Walker et al., 2011; Liebman and Dyck, 1993; Thiessen Martens et al., 2005; Lithourgidis et al., 2011; Hartl 1989; Reynolds et al., 1994)

30. Objective • Determine the optimal time to mechanically remove winter pea intercropped with winter wheat • Improve N input • Reduce soil moisture stress

31. Materials and Methods

32. Experimental Design

33. Seeded Mid-October • Winter Wheat • (Triticumaestivum L. cv. ‘Brundage 96’) • Winter Pea • (Pisumsativum L. cv. ‘Granger’) • “Direct seeded” 2.2 m wide Fabro® no-till drill • Wheat 135 lbs. acre-1; 15” row spacing (152 kg ha-1; 38 cm row spacing) • Pea 200 lbs. acre-1; 15” row spacing (225 kg ha-1; 38 cm row spacing)

36. Treatments 25% Cover Early May 50% Cover Mid May

37. 75% Cover Early June 100% Cover Late June

38. Intercrop No Removal No Intercrop Control

39. Soil Samples • Pre and Post season 1.5 m • 0 to 30 cm • Repeated each sampling date • Gravimetric water content • Inorganic nitrogen

40. Plant Biomass • 0.3 m2 collected on each sampling date • Repeated each sampling date • Dried and weighed Grain Yield • Late August

41. Inter-row Cultivator

43. Results

44. % Soil Moisture (0-30 cm) Over Time 2010 2011 Sampling Date

45. Soil Moisture (0 – 1.5 m) Pre and Post Season 2010 2011 ns a b ab ab b b b Treatment

46. Soil Inorganic Nitrogen (0-30 cm) Over Time 2010 2011 Sampling Date

47. Soil Inorganic N (0 – 1.5 m) Pre and Post Season 2010 2011 a b b b ab ab b a b b b b b b Treatment

48. Wheat Biomass Variation with Intercrop Removal Time a x a x Sampling Date

49. Wheat Grain Yield after Pea Removal for Different Crop Growth Phases 2010 2011 ns ns ns 5666 kg ha-1 Mean = 5560 kg ha-1 Mean = 3527 kg ha-1 Treatment

50. Summary • No differences in soil moisture • No difference in soil nitrogen • No difference in grain yield or protein • No difference among plant N levels or biomass yield