Sunday, February 9, 2014

Just not ready to go there...

Have you tested your soil lately? These are the results from my latest test.


Three years ago the test results were very different. I lost the hard copy to a trade shower last spring so i don't have it to post as a comparison. The pH started out around 5.3-very acidic. Calcium, magnesium and phosphorus were also very low. Potassium, interestingly enough, was sitting right about where it is now. I added lime, dolomite, gypsum and bone meal as directed in the 'fertilizer recommendations' section of the test when i completed the initial bed preparation.  I have continued to add horse/rabbit/poultry manure and fish scraps during replanting. It's not a good idea to randomly add inputs without knowing what your baseline levels are but that's exactly what i did after the initial amendment, using azomite to add micro nutrients and/or a variant of Steve Solomon's complete organic fertilizer to replace outputs from time to time. I plan to do more extensive soil testing next year and hope that i haven't mucked things up too badly.

The big test surprise for me is the very high phosphorus result. It could mean that i went a little crazy with the bone meal, but it might also mean that a lot of phosphorus was bound up with aluminum at the lower pH. When the soil was limed, calcium replaced the aluminum creating calcium phosphates which are more water soluble and readily available.  (I love that soil science is mostly chemistry but it does make my head spin a little.)  So what to do about it? Many of my garden favorites are heavy phosphorus users so i expect the levels to correct themselves over time as long as i don't keep adding more. My main input this year will be nitrogen in the form of expensive blood and feather meal. There is a readily available and free source of nitrogen available to each of us but i'm just not ready to go there.  Yet.

An option to be aware of, just in case.
If you are in Hawaii and are curious about how your soil stacks up, basic soil testing is available through the College of Tropical Agriculture and Human Resources (CTAHR) for around $12.

4 comments:

Barry said...

I was away with relatives at the last reasonably decent weather for soil testing - but I think you have a real bargain with CTAHR's $12 charge for testing! We are looking at $38 or so, not counting postage for each 2-cup samples With almost 10 acres, it would be lolo to do a bunch of samples to see if the pasture is different from the corrals, or the blackberry jungle, or the garden beds-to-be [sigh]. I'll settle for maybe two samples, taken from the east half and the west half, amd hope they look pretty much alike.
You are doing a terrific job on the soil! The high P is likely the bone meal and the alkalinizing reactions. K - potassium - moves more slowly, so it shows that you are fertilizing pretty consistently. We have a tendency for acidic soil here, so folks toss lime everywhere. I hope to get some sampling done between storms, so I can adjust things a bit more intelligently.

Julie said...

Cool, I feel good about getting such a good deal now ;) Seems like I remember the price being much higher ten or fifteen years ago. I don't know what changed but I'm glad it did!

You should get some little goats to help you out with the blackberry jungle; )

A Kihei Garden Cuisine said...

That's fascinating and so affordable. It seems like high phosphorus might be a good thing for some veggies especially tomatoes, eggplant and peppers.

Julie said...

Jane i am busy reading Steve Solomon's latest book, 'The Intelligent Gardener'. He makes the case that nutritious food grows in properly mineralized soils. I may be doing some more intensive soil testing next year!