WIB Demonstration Projects

1. WIB Demonstration Projects • categories (including but not limited to): • School and Community Gardens • Permaculture/Biointensive Gardening • Traditional Dryland Farming • Food Preservation • Food Justice • The Business of Food • awards will be presented at 2014 Conversations • tell us about your idea!

2. Stop the BS!

3. Or, more kindly… Thanks for coming to our workshop on soil health.

4. Desert Difficulties • alkalinity • high pH reduces availability of some nutrients • salinity and sodicity • salt levels affect nutrient and water uptake • poor drainage • affects plant growth and makes leaching of salts impossible

5. DessertDifficulties • pH of rainwater ~ slightly acidic • desert soils tend towards alkalinity • ocean now desert • salt in water  salt in soil  salt on soil • clay compounds the problems • gardening methods also contribute • amendments • irrigation techniques

6. Sodic Soils • definition: high level exchangeable NA, low total level salts • characteristics: high pH, poor drainage, crusted when dry, brown film on top of soil • effects on plant growth: reduced nutrient uptake, sodium toxicity

7. Sodic Soils • miracle cure for sodic soil: gypsum • time and correct treatments can help soil recover structure • BUT adding gypsum to saline soil will only increase salinity…

8. Saline Soils • definition: high level of salts dissolved in soil and water • characteristics: salty crust often visible on soil as low rainfall and clay prevent salts from being flushed out • effect on plant growth: reduced water uptake • Salt-affected soils may inhibit seed germination, retard plant growth, and cause irrigation difficulties. • Saline soils cannot be reclaimed by chemical amendments, conditioners or fertilizers. • Saline soils are often reclaimed by leaching salts from the plant root zone. • Soils high in salt and/or sodium may limit crop yields. Periodic soil testing and treatment, combined with proper management procedures, can improve the conditions in salt-affected soils that contribute to poor plant growth.

9. Factors Contributing to Salt Problems • Drainage • A common sign of salt problems is the accumulation of salts at the soil surface due to limited percolation in compacted and/or clayey soils.  Soluble salts move with the soil water.  Deep percolation of water down through the soil profile moves salt out of the rooting zone.  Surface evaporation concentrates the salts at the soil surface.  Salt deposits may or may not be seen as a white crust on the soil surface.  • In some areas, salt naturally accumulates, due to limited rainfall to leach the salt out. Here, corrective measures are limited to improvements in soil drainage. Legumes. • Soil Amendments • Manure, biosolids, and compost made with manure or biosolids may be high in salt.  When using manure or compost made with manure, routinely monitor salt levels.  • Excessive or Unnecessary Fertilizer Applications • Unwarranted application of fertilizers (such as phosphate or potash) increases the salt level.  On soils marginally high in salts, potash fertilizers should be avoided unless a potassium deficiency is identified by soil tests. • Pet Urine • Damage by pet urine is also a salt problem.  Water moves by osmotic pressure from the roots to the high salt concentration in the soil, dehydrating and killing roots. • http://www.ext.colostate.edu/pubs/crops/00503.html • http://aces.nmsu.edu/pubs/_circulars/CR656.pdf

10. Saline Soil Management • Residue Management • Crop residue at the soil surface reduces evaporative water losses, thereby limiting the upward movement of salt (from shallow, saline groundwater) into the root zone. Evaporation and thus, salt accumulation, tends to be greater in bare soils. Fields need to have 30 percent to 50 percent residue cover to significantly reduce evaporation. Under crop residue, soils remain wetter, allowing fall or winter precipitation to be more effective in leaching salts, particularly from the surface soil layers where damage to crop seedlings is most likely to occur. • Plastic mulches used with drip irrigation effectivly reduce salt concentration from evaporation. Sub-surface drip irrigation pushes salts to the edge of the soil wetting front, reducing harmful effects on seedlings and plant roots. • Irrigation Frequency Management • Salts are most efficiently leached from the soil profile under higher frequency irrigation (shorter irrigation intervals). Keeping soil moisture levels higher between irrigation events effectively dilutes salt concentrations in the root zone, thereby reducing the salinity hazard. • Most surface irrigation systems (flood or furrow systems) cannot be controlled to apply less than 3 or 4 inches of water per application and are not generally suited to this method of salinity control. Sprinkler systems, particularly center-pivot and linear-move systems configured with low energy precision application (LEPA) nozzle packages or properly spaced drop nozzles, and drip irrigation systems provide the best control to allow this type of salinity management. • Don’t use city water, very salty

11. Stop the BS, err Manure! • manure and compost made from manure contain salts vs.

12. Working with Saline Soils • salt tolerance of different crops • irrigation techniques • garden and bed design

13. Salt Tolerance of Different Crops High {} Medium {} Low High {} Medium {} Low

14. Irrigation Techniques • consider pH and salt content of irrigation water • hint: rainwater is best! • sub-surface drip is best choice considering efficiency and salt management

15. Garden and Bed Design

16. Garden and Bed Design • wisdom of ancestors: waffle gardens

17. Desert Difficulties:The Long View • miracle cure for sodicity = gypsum • but no miracle cure for salinity  • if we can’t fix it, let’s not make it worse • manure? no! or at least test and monitor your salinity levels, and apply in moderation • Organic Matter we love you! • compost! • cover crops!

18. Your Ideas! • Sid: soil swapping and garden tours, worms, garden wide compost, cover tarp, sand from mcgaffey exit, acidic peat moss

19. Bo-whatty? Bokashi! • What You Need • Bucket with leachate valve (or no valve…more labor in end) • 2 buckets that stack inside each other (fairly tight fit) • Valve/Spigot, Rubber Washers, Nut • Buying everything new about $20 (ACE) • Microbe-innoculated bran • recipe: 12 lb. bran + 3 oz. molasses + 3 oz. mother + 1 gal water • $34 + $2 + $2 = $38 = enough bran for several months • the method • scraps* + bran + time • *even animal products! • anaerobic decomposition in 2-4 weeks

20. And Bokashi for All • scale up for big gardens and institutions • remember, NO sorting of scraps (perfect for kids) • try it out and spread the bran, I mean, word!

21. Cover the World with Cover Crops • aka ‘Gone Legumin’ • primary benefit (for desert gardens): increase OM content of soil • water infiltration and retention • nutrient cycling • soil microecology • etcetcetc

22. The Goodie Bag • Summer Alfalfa • annual (not very winter hardy) • makes loads of biomass • taproot breaks up hard soil • Sweet Clover • needs only 16 inches precip/year • great forage for bees and other pollinators • mines nutrients and brings to surface

23. Let’s Go Legumin’ • plant your alfalfa and sweet clover in April or May (depending on how warm it is) • work up ground, broadcast, and rake over (recommendation is to plant ¼” deep) • you may have to irrigate to get cover crop established, but remember… • the goals is to improve the soil so that it can retain water in the future