SOIL HEALTH: Finding A Way In Karen Lowell, Ph.D., CCA Area Agronomist, NRCS Salinas, CA CARCD Annual Meeting and Conference Ventura, CA November 14, 2014 1. Keep the soil covered as much as possible 2. Disturb the soil as little as possible 3. Keep plants growing throughout the year to feed the soil 4. Diversify as much as possible using crop rotation and cover crops WHAT MATTERS TO YOU? Increased Water Holding Capacity Carbon Sequestration Nutrient Cycling Pest & Disease Suppression Reduced Crusting & Sealing Increased Available Water Improved Infiltration & Drainage Improved Buffering Capacity WHAT DO YOU NEED? WHAT ARE YOU MANAGING? WHAT CAN YOU DO? WHAT CAN YOU DO? Time to dive into the details “You might want to make yourself comfortable. I may be down there for a while.” Tillage Radish Bagrada Bug, Cole Crop Pest Percent damping off Cover Crop Fallow + Debris Un-amended Days after Cover Crop Incorporation ? Cover crop is vetch oats mix Fallow + debris is cover crop not incorporated From: Van Bruggen and Semenov, 2000. Applied Soil Ecology, 15:13-24. What About Water? • Often need water to establish, ~ 6 acre inches common • Water use isn’t simple math • Residue on the surface may reduce evaporation by > 25% • Cover crops may draw water (nutrients too!) from depth (> 6’ some cases) • May increase infiltration & available water holding capacity • Changes in cash crop rooting patterns may have benefits • Where possible to combine cover crops with reduced tillage benefits may be multiplied • May increase stored water by soil structure benefits that improve infiltration and by avoiding moving moist soil to surface where moisture lost to evaporation Hatfield et al., 2001. Managing soils for greater water use efficiency: A Review. Agron. J. 93:271-280. https://www.agronomy.org/publications/aj/pdfs/93/2/271 Tantalizing Tidbit…. When cover crops depleted surface water in vineyard, the vine roots modified their growth pattern to explore soil in narrower band to greater depth. QUESTION: How can we use this information? BUT You also have to be smart enough to know when you are stepping into CRAZY! Resources to Guide Use of Cover Crops Resources to Guide Use of Cover Crops Available free as a PDF download Comprehensive Guide: Includes “big picture” planning questions and detailed “how to” Find it here: http://www.sare.org/LearningCenter/Books/Managing-CoverCrops-Profitably-3rd-Edition More realistically: Google Title! Resources to Guide Use of Cover Crops Karen Lowell, Ph.D., CCA Area Agronomist USDA-NRCS Salinas, CA [email protected] 831.424.1036 x119 I welcome your calls and emails to find creative ways to support Soil Health! How to measure • • • • • • Infiltration Structure Microbial activity Haney Test Solvita test Farmers recognize it in tilth, “mellowness”, workability, structure (compaction), etc.