Ag 101 Week 29

C.E.C – The Rest of the Story

Last week I brought up points why I think clay is the misunderstood underdog of soil fertility. Ironically, later that week I saw someone post on social media how they have to rip out an entire bed dedicated to growing cut flowers and what they said was “…amend the soil within an inch of its life.” I’ll be honest; I wasn’t sure what they meant. So being the person I am, I reached out to them and offered some suggestions that would be cost-effective and hopefully spare anyone and any soil from coming within an inch of its life. As I was emailing back and forth with the grower, some things dawned on me.

First, I am not calling them out in any way shape or form to be malicious, mean-spirited or insult them in any way. They are not the first grower I’ve talked to that does not entirely understand soil fertility. For that, I look at the industry and wish so-called experts would do a better job at giving people the facts about soil fertility and not warm fuzzies to get them to buy or believe the stuff they don’t need or isn’t always accurate.

Second, most people think amending soil is as easy as adding organic matter, and all your issues are solved. Kind of like those little foam things you buy at the dollar store that when soaked in water explodes into a dinosaur. Or popping a pill and you are magically cured forever. Or paying someone a lot of money and being photo shopped to be a tall blond and you’re a 4’11’’ brunette.  Nothing about soil is instant, cured forever, or making it something it’s not. It is a constant endeavor called farming.

Soil fertility is starting with inherent baseline characteristics, determining the crop best suited to it and you, and the constant tinkering to get you, the soil, and the plants all working together.

This is where C.E.C otherwise known as cation exchange capacity comes in. CEC is the soils ability to hold onto cations which are positively charged ions.  You often hear it referred to as the storehouse or reservoir where nutrients are being kept for a plant to access for use. I like to think of it as the pantry where soil microbes go to get the nutrients the plants need. On a weighted base, organic matter is a more dominant player than clay. However, it is the two that give rise to CEC.

You use CEC in conjunction with pH to tinker with cations and anions -ions with a negative charge- to create a soil environment the crop you want to grow with be sustainable, productive, and healthy. Do you add organic matter sometimes? Yes or no, depending on how much is already there and what your goals are.

The primary nutrients that are involved are calcium-Ca++, magnesium-Mg++, potassium-K+, sodium-Na+, and hydrogen-H+. There are others that need to be taken into consideration, but for the sake of not making this any more confusing, I’m not discussing them now.

As a side note, on a regular basis, my dad points out the fact water is a universal solvent. It’s chemistry -pH mainly- must always be taken into consideration. It brings either hydrogen -H+- or hydroxyl -OH¯- ions making a soil or the water in the soil acidic or alkaline.  Acidic soil is having more hydrogen and alkaline having more hydroxyl ions.

Notice earlier, I listed the nutrients in order of strength.  You can use more prominent nutrients, like calcium which has a double positive charge, to adjust the chemistry of the soil to achieve specific physical conditions. For more about soils' physical characteristics refer to Week 8

The picture below is an excellent example of this. All though it may be hard to see it in the photo, the upper part of the field was harder for the farmer to work. It didn’t plow well. Nothing was growing well in it, and it was overall harder for the farmer to work. It lacked tilth. The lower part of the field was a different story. It was easier to work with, things grew relatively well and overall was better ground to grow in.

20160413_122001 (1).jpg

When I looked at the soil test before going to the farm one field was lower in calcium than the other, both had the same level of organic matter and were the same soil type. The lower part had been fertilized differently for several years and was showing an imbalance of nutrients. All the upper portion needed to be was the appropriate calcium source and the following year started showing signs of becoming more productive and easier to work.  We tinkered until we got the soil, the crop, and the farmer working together again. However, it is a constant work in progress. It doesn’t happen instantly, there is no magic pill, and you can’t make it something it’s not.