You didn't mention the soil type. First of all, if sandy, nutrients can be leeching. Secondly, this is the classic large scale non-organic gardening method. This depletes the soil and destroys the soil food web. If you are using more organic methods including using compost and mulching in addition to the manure you will build a soil food web that will require much less fertilizer and artificial N sources. This the big problem with commercial farming in that as the soil degrades, more and more synthetic ferts are required. Try feeding the soil instead of the plant. I use synthetic ferts in pots, but rarely in soil.

It sounds like you are using (literally) tons of fertilizer. It is not surprising that you have great yields, but it may be possible to achieve similar or acceptable yields while consuming much less fertilizer - the idea of gardening is to produce from the sun and soil, right? If you are interested, calculate the amount of fossil fuel consumed and energy and resources required for each 50 pound bag of fertilizer.

As far as soil prep, compost, manure, and mulch will help to build a healthy soil, but it may take a while to learn and transition to different (and possibly less costly) methods.

If N2 is supposed to be kept to the levels that most on the internet say it is, Why did my grandfathers tomatoes grow so well and why do mine grow so well at these high levels of Nitrogen exposure? I experimented last year growing tomatoes the way they are supposed to be grown in a control plot, and they yielded less than half the fruit per plant than the ones I grew my traditional way.
I am a bit confused on this.

Much of the confusion comes from trying to compare 2 very different approaches to gardening - healthy soil feeding the plants vs. the gardener with depleted soil feeding the plants.

Both may work but they aren't interchangeable nor can they be compared based on a 1 season trial. They have totally different needs and the gardener has to decide which route he/she wants to go. With depleted, heavily supplement-dependent soil such as you describe it would take some time and work to return it to healthy, sustainable levels but it sure is possible if you decide you are interested.

Dave

Agree with Dave. Restoring a depleted soil takes more then one season. I create new beds in my sandy soil which is very nutrient poor, and it takes about three years before my maximum production is reached and the worms move in. I put alot of organic matter in that time, but once the soil is alive, it takes much less input and mulching is usually enough to maintain it's fertility as the worms and bugs break it down over the season. I think this why farmers are hesitant to switch, as the first couple of years takes alot of input building the soil and may have reduced yields until the soil matures.

All bring up some interesting things to consider. This soil was Ga. Clay.
This soil grew cotton from the mid 1800's until the bowl weavel wiped cotton out in the early 1900's. From then until I put it in tomatoes, it grew sorghum, watermellons, and corn. For about the last 12 or so years it has had tomatoes. It no longer even resembles red clay. It is now black and slightly sandy. It has literally had tons of hay, pine needles, ashes, and marble dust dumped into it over this time.

Have you had a recent professional soil test done on it? The country ag extension service provides them in most states for a nominal fee.

They can tell you the pH (vital), organic content %, N-P-K and micro-nutrient levels, mineral needs if any, etc. and what is needed to bring it back. That is the best place to start. Given all the heavy feeder crops it has grown over the years it could be quite depleted. But a soil test is the only way to know for sure.

From what you have listed it would be all the marble dust that would concern me. That and the ashes can easily skew the soil pH so far out of whack that it would take an awful lots of nitrogen to make the plants productive while a healthy soil could produce half-again as much with a 1/3 of the added nitrogen.

Just some points to consider.

Dave

I have had the soil tested a couple of times. I always collected the sample about 2 months prior to planting. Everything in the soil is within the parameters the University recommend for Tomatoes except Nitrogen. It was low both times. I am sure if I tested after I fertilized the N2 would be well above recommended levels. I am not having any problems with my plants, I am just wondering if there is a better way of growing than the method I am using. I think just for curiosity, I am going to test the Nitrogen level in about a month to see what it is.

If your soil is low in N, you can grow legumes as a cover crop, add more green organic matter, manure or compost. You mentioned that your soil has a sandy appearance. If so, that might be part of why N is low, although all the crops the soil has supported use a lot of N. Most of the organic amendments you mention are not high in nitrogen. If you increase organic nitrogen, you can probably reduce your use of nitrogen salts. One thing to keep in mind though, organic sources of N are slower releasing. May need to put it down earlier and give the bugs a bit of time to break it down.

By the way, I applaud your effort to farm in a more sustainable manner. Change is not easy, but you may be able to sell your products at a premium if you can go all the way with it. If you depend on these crops for a living, you may be able to gradually move into it, either by setting aside a portion of your land to improve at a time (while you are also still learning), or increase organic components and reduce salts slowly until you eliminate them completely. One thing though, with the price of oil getting high, fertilizers will not be getting cheaper either.

I admit, I am not a farmer, but an avid gardener. But one advantage I've had is that I do not depend on my personal crops for a living, and can experiment without consequence other then not having fresh vegetables on the table. But aside from the economics, I have had to deal with depleted sandy soil. The land I live on was formerly commercial agricultural soil that got depleted and eroded to the point that it was no longer feasible for farming (with traditional methods) and was abandoned. Even grass wouldn't grow on my land until I planted clover with the grass to supply nitrogen. I've had to bring back soil from the dead, and can vouch for being able to restore soil to a vibrant healthy soil web, that takes less inputs as time goes on. I hope that you can find a way to make this happen too, although I realize it's a lot tougher when it is your bread and butter. But if you do make the transition, hopefully your neighbors will start doing the same. Good luck!

Thanks for the advice.
I am not a commercial farmer, but I do grow a lot of tomatoes and sell them just for extra income, but I do not rely on them for a living. I did learn to grow them from a commercial farmer, and the old practices are hard to break.

Understood. Sounds like you are in a similar situation that I was when I first bought my property. Might want to check into Permaculture, which has many good practices in it for restoring/reclaiming damaged soil. A big part of it is using legumes to restore soil and add nitrogen. It works. It's what gave me the idea for mixing clover with my grass to get it to grow, as well as the practices I've learned to eliminate using fertilizers and pesticides on my substantial vegetable gardens. I still use ferts in my containers, but that is something different since I am not trying to maintain a soil in containers, and runoff is minimal.

I will have to research permaculture. It sounds like it could be the answer. I was thinking today when I had to go pay big bucks for water souluable nitrogen that this is getting expensive now that fertilizer prices have gone up so much.

One thing about permaculture, is that you can take it as far or as little as you want. I haven't really gotten into the low maintenance edible landscape (yet), and all the layers it entails, but the practices used to restore soil, recycle nutrients, conserve water and reduce inputs are very valid for all gardeners. If you saw my property before and after, you wouldn't believe the difference in the lushness.