I look at a lot of soil reports these days, and the sodium adsorption ratio (SAR) is one number that is very informative to me.

Simply put, SAR of a soil extract takes into account how much the adverse effect of sodium (Na⁺) is moderated by the other cations calcium (Ca²⁺) and magnesium (Mg²⁺). As you all know, calcium and magnesium can replace sodium on soil particles, subsequently permitting this toxin to be washed away from the plant roots.   So the more free calcium and magnesium we have around in the soil, the better odds we have of mitigating sodium.

SAR levels below 6 are OK, levels which run above 10 mean trouble.

Although most soil reports will give you a calculated value for SAR, you can calculate SAR yourself.   It's simple: SAR = Na⁺/((1/2(Ca²⁺ + Mg²⁺))^1/2 ), where Na⁺, Ca²⁺ and Mg²⁺ are all measured in meq/L (milliequivalents per liter).

Nifty article from the Economist regarding indoor farming:

http://www.economist.com/news/science-and-technology/21602194-indoor-farming-may-be-taking-root-light-fantastic?fsrc=scn/tw/te/pe/thelightfantastic

Key takeaways:

Lots of advantages of being able to to grow 24/7 365 days a year cutting growing cycles in half right next to lucrative markets, recycling of irrigation water, and use of sensing technology to monitor nutrient levels.  LED lighting uses a lot less energy, and is significantly cooler than traditional lighting, cutting air conditioning costs as well as offering the ability to precisely adjust light wavelength to that exactly needed for optimal plant growth.

Nifty.

Just a quick note and pictures to add to our growing catalogue of physiological damage to strawberries and caneberries.

Depicted below are several instances of sunburn and/or heat damage to strawberry.  The top two pictures were of a strawberry plant up next to a wall getting full sun during the entire hot spell we had last week, so it is without a doubt it is heat and sun which caused the damage depicted in the pictures below. 

These are good features to recognize for the diagnostician in the field.

UC Cooperative Extension Farm Advisors Shimat Joseph, Surendra Dara and Mark Bolda are holding a mite meeting in Spanish and English at the ALBA training facility at 1700 Old Stage Road in Salinas.  All aspects of mite management will be covered, from proper identification of predatory, twospotted spider and Lewis mites, treatment thresholds, use of botanical and botanical controls, and aspects of chemical, cultural and biological control.

Meeting starts at 9 and will wrap up by 11 am.  This promises to be a very good meeting.