1. What’s New with Mulches ? David Granatstein Center for Sustaining Agriculture and Natural Resources, Wenatchee, WA Alfalfa mulch in apple

2. Credits Funding support from WA Tree Fruit Research Commission and Small Planet Foods, Inc. Co-operators: Kent Mullinix, Gene Hogue, Leo Garcia, Tom Auvil Technical Support: Laura VanWechel and Elizabeth Kirby Thanks to Keyes Fibre Inc. for supplying spray-on paper pulp and to Simplot Soilbuilders for use of the Enviroscan system.

3. Fall-planted Dwarf white clover

4. Late summer 2000 Early spring 2002 Rodents – the weak link for clover.

5. Lessons Learned So Far Weeds Winners – shredded paper, wood chip, clover Chopped alfalfa acts like potting soil

6. Shredded paper mulch

7. Wood chip mulch

8. WVC Mulch Trial Weed Control by Mulches – 6/1/00

9. Lessons Learned So Far Weeds Winners – shredded paper, wood chip, clover Chopped alfalfa acts like potting soil Water 25% water savings possible Clover living mulch has minimal competition

10. Mulched 10-day interval Unmulched 6-day interval Soil moisture conservation with a wood chip mulch – Gala/M26 6 th leaf

12. Lessons Learned So Far Nitrogen Alfalfa N boosts tree growth, fruit yield, but can be excessive – caused alternate bearing Clover able to supply adequate N for trees; need to work on timing

13. Nitrogen release over 3 weeks from orchard soil (6 th leaf Red Delicious/M26 – Wenatchee, WA) A – control plot; tube + cover; no clover B – control plot; tube + cover + clover clips C – clover plot; tube + cover + clover clips D - clover plot; tube – cover + clover clips E – control plot; no tube F – clover plot, no tube 0-6” depth

14. Lessons Learned So Far Nitrogen Alfalfa N boosts tree growth, fruit yield, but can be excessive – caused alternate bearing Clover able to supply adequate N for trees; need to work on timing Tree Growth and Yield N effect from alfalfa, clover led to most growth Wood chip, shredded paper also boosted growth over the Control

15. New Directions Spray-on paper mulch ‘Grow Your Own Mulch’ Cover crop gone wild !

16. Spray-on Paper Mulch Applied August 2001 August 2002 Cost and longevity are key issues.

17. ‘Grow Your Own Mulch’ Trial Control (companion grass) Forage grass Alfalfa Alfalfa / grass mix

18. June 2002 Grass hay Control Grass hay Sept 2002 ‘Grow Your Own Mulch’ Trial

19. Trefoil insectary mix planted in alleys June 1996. August 1999 August 2002

20. Thank you !

21. Release of N from composts, alfalfa hay and fish meal organic fertilizer in 2002 DairyAlfalfa (T. Forge, PARC)

22. Recommended (tentative) application rates (in tons/acre) to release 100 lbs mineral N/acre in first year Poultry compost Dairy compostOgogrowAlfalfa hay Fishmeal fert. % N (start)4.81.01.53.79.2 % N lost4729314782 Tons/acre to yield 100 lbs N/acre2.217112.90.7 lbs N/acre if add 25 t/acre1136147227862n.a. (T. Forge, PARC)

23. TCSA (cm 2 ) 4-Yr % Increase TCSACum. Yield 3-Yr (kg/tree) Alfalfa(D)90 a66 Clover(GH)75 b61 Wood chip (B)74 b48 Paper (C)72 b52 Mustard70 b55 Rye60 c53 Control (A)59 c50 Tree Growth and Yield Red Delicious/M26 Wenatchee, WA

24. Effect of mulch on soil moisture 10 cm depth 30 cm depth A = control; B = wood chip; G = clover; more negative centibars = drier