How About a +/- Stat for Veggies?

[Meadowlark]

The +/- (plus-minus) statistic is a measure widely used in sports, particularly in hockey and basketball. It's designed to show the impact a player has on the game when they are on the court or ice.

I’m thinking about a +/- stat for veggie plants to quantify how much soil nutrients measured in ppm. they use to make a crop. For example, say the starting level for Nitrogen is 40 ppm and the post harvest level for nitrogen is 10 ppm that would equal a +/- for that plant for nitrogen of -30.

I have made meager start at this with onions and potatoes:

Element	Onion +/-	potato +/-
pH	0.3​	0.2​
Total Nitrogen (N)	-27​	-36​
Nitrate (NO3-N)	-22​	-29​
Ammonium (NH4-N)	-5​	-7​
Phosphorus (P)	47​	13​
Potassium (K)	-61​	-107​
Sulfur (S)	-4​	-0.1​
Calcium (Ca)	544​	378​
Magnesium (Mg)	3​	-15​
Sodium (Na)	7​	2​
Iron (Fe)	0.3​	-0.2​
Manganese (Mn)	7​	0.8​
Zinc (Zn)	0.3​	0.4​
Copper (Cu)	0.1​	0​
Boron (B)	0​	0​

This seems like it could be a useful informative statistic for gardeners contemplating planting a certain variety. There are some unexplained anomalies in the above data, e.g. calcium, but for now I'm just looking for critic on the concept.

Anyone know if this or a similar statistic is being applied to plants? Any comments? ...any interest?

 

[Chuck]

It appears to me that it would require 2 soil tests, otherwise how would one know his soil had 40 ppm at planting and 10 ppm at harvest. Most home gardeners do not bother with a soil test at all, much less two. And all they have to do is look at their plants to see if everything is growing OK. If not, most either fertilize or ask their questions here. And the next season they just fertilize again for the upcoming season. Once in awhile one actually has a soil test done. Also, does not a certain plant use different levels of nutrients depending on the climate and soil? This would mean that the statics on Jack Sprats tomatoes grown in California would be different than Joe Blows tomatoes grown in Maine. I have heard of doing this but all I have actually seen are in university research endeavors. I am sure there are a few gardeners who would be interested in this for their own personal knowledge but as a general reference I don't think it would work. And as a new forum I doubt many would be interested. But, I have been wrong before.

 

[Meadowlark]

It appears to me that it would require 2 soil tests, otherwise how would one know his soil had 40 ppm at planting and 10 ppm at harvest.

Of course, a minimum of two tests required.

I think the statistic would actually need about five years of two tests a year data to be considered reliable. The +/- then would be an average over 5 years. Now that would be a powerful statistic IMO.

Most home gardeners do not bother with a soil test at all, much less two. And all they have to do is look at their plants to see if everything is growing OK. If not, most either fertilize or ask their questions here. And the next season they just fertilize again for the upcoming season.

This statistic would actually aid those home gardeners who do not "bother" with a soil test. Knowing the nutrients each plant consumes in a typical growing season would be valuable info...with or without a soil test.

Also, does not a certain plant use different levels of nutrients depending on the climate and soil? This would mean that the statics on Jack Sprats tomatoes grown in California would be different than Joe Blows tomatoes grown in Maine. I have heard of doing this but all I have actually seen are in university research endeavors.

That is why I stated above that five years of data could make this a powerful statistic...one year, not so much, but interesting nonetheless to me.

... I have heard of doing this but all I have actually seen are in university research endeavors.

I'm looking to propose this as a research project to Texas A&M.
Nothing ventured, nothing gained.

But, I have been wrong before.

So have I obviously ...and science is all about learning from failures and pushing the knowledge envelop forward.

Thanks for your comments.

 

[Meadowlark]

Maybe a clarification...this stat isn't something I'm thinking a home gardener should or would ever determine.

It would be a "look-up" that would be provided to prospective gardeners. Because of the volume of data/cost needed to build a reliable stat, it would require something like a well-endowed University aka TAMU. AI would be terrific at compiling the data and responding to questions.

Like..."how much nitrogen will potatoes consume in a typical growing season."

Seems it would be beneficial for a newbie to look up on their phone the nutrient requirements for a given plant.

Maybe a crazy idea...but it would make one Heck of a research project. There have been many far worse ones.

 

[Oliver Buckle]

Interesting to a degree, but I already know , for example, potatoes use a fair bit of nitrogen at first and then more potassium later on, so I'll dig in manure in the Autumn to prepare for them. What I don't know is how much nitrogen is in that lot of manure, or how accessible it is. I'm certainly not doing tests to find out, the general rule is quite sufficient for me. Test the soil, test the manure, test the wood ash I put in when I earth up, no thanks, it would be cheaper to nip down the shop and buy a bag. I'll stick with 'adding plenty'.

 

[redback]

I'll stick with 'adding plenty'

Me too.
The life in the soil is the main fertility element and is not recorded in testing.

 

[Oliver Buckle]

The life in the soil is the main fertility element and is not recorded in testing.

Good point. Appropriate moisture content for various plants might be more useful, water is something we add much more frequently, at least during the growing season. Mind you I have found HK helps no end with that, I even wonder if the constancy of moisture content might be a large part of the variable output between HK containers and ground grown plants.

 

[Meadowlark]

This stat would be for the younger, less experienced gardener. They will probably never get a soil test let alone try to build nutrient dense soils.

 

[Meadowlark]

Me too.
The life in the soil is the main fertility element and is not recorded in testing.

Ahh but it is, at least a huge indicator of it is.

My lab determines a nutrient density probability score...an indicator of the probability that the soil will produce highly nutrient dense veggies. I have found that invaluable.

Those who use synthetic fertilizers should really compare that soil to one that is based on natural organic matter. My soil routinely tests out at 95%...synthetic fertilized soils will never see anywhere near those levels, even half.

I have asked them, the testing lab, how they compute the nutrient density probability...but they will only say it is proprietary...and that my soil is as good as it gets.

I love having it and knowing my soil is almost certain to produce nutrient rich veggies.

Sometime I'm going to test out a synthetically fertilized soil just to show how terrible the nutrient density score is...but would have to find some of it first.

 

[Oliver Buckle]

I sometimes wonder. You know what you are doing, you are doing it right and have been for ages, why do you bother with soil tests? It's not like they are going to suddenly come back to you one year and say, "You need more of everything". Seems like a bit of a waste of money to me.

 

[Meadowlark]

I'm a scientist by training, profession, and intellect. I can't help but think that way.

I wonder why things happen the way they do and what variable causes which reaction in what amounts.

It's a curse yes, and money has zero relevance when it comes to knowledge to me. It's all about knowledge.

 

[YumYum]

Really it sounds like a good ideal but the data you collect will be all over the place because plant available nutrients can move out of the soil and therefore look like the plant has consumed it. For instance nitrates will flow with water and end up in your well water and ammonium can evaporate into thin air. Nutrients can also move into the soil by city or well water which mainly add calcium and magnesium which is going to vary from person to person and looks like you're seeing that in your data already. Another variable is acid rain which dissolves calcium and magnesium in the soil into plant available form.

 

[Meadowlark]

Excellent points @YumYum as expected!

My assumption was that over time, and I thought a 5-year average, but that might not be enough, those variables would normalize out. Maybe not.

I'm going to the university, and they may laugh me out.

 

[YumYum]

I know you don't do this or me either, but someone who runs hydroponics would come closest to figuring out this kind of information in great accuracy. They would have to keep a record of what and how much fertilizer was added up until harvest and then send a water sample to a lab to see what minerals are left in the solution. An EC meter wouldn't differentiate between leftover minerals so a lab test would be required.

 

[Meadowlark]

That would eliminate some of the variables and also sounds like a viable research project to me. I'll bet someone is doing that in a lab somewhere.