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Gary350
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What Nitrogen Fertilizer are you using on CORN ?

I'm glad I can't buy Ammonium Nitrate anymore it is too easy to over dose plants. Urea is slow release, it works good on other plants but corn is so nitrogen hungry corn plants are starving. I have not tried, ammonium sulfate, sodium nitrate, potassium nitrate yet. I don't know of any other fertilizers by name? I put 30 lbs of Urea on 250 corn plants last year & plants were still small.

My cousin farms 2000 acres of corn every year he applies anhydrous ammonia at the same time he plants seeds so nitrogen is already in the soil before seeds germinate. I can't do ammonia unless I buy 10 gallons of laundry ammonia but I can do a different fertilizer. Ammonium sulfate will lower soil ph, my soil was 7ph last year, I hope soil tests 6ph this year. I should have tested soil ph last week before it turned into a swamp it has rained for 4 days.

What nitrogen fertilizer do you use for corn?
Last edited by Gary350 on Thu Dec 17, 2020 5:21 pm, edited 1 time in total.

PaulF
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This is a little tricky without a soil test. Sweet corn, or field corn for that matter does need nitrogen for best results. If you think your soil is relatively fertile, I would add nitrogen only fertilizer. Since corn is a grass any fertilizer for grasses will work fine. I have used 24-0-0. Follow directions so not to over fertilize. This can be applied in the fall or early spring. A side dressing sprinkled at the base of the plants after they are 6-10 inches tall will also help.

Corn likes the pH to be in the 6.0 range so ammonium sulphate would be OK if you higher than the 6.0 pH. If you are unsure of the soil fertility using a garden style 10-10-10 fertilizer will add the nitrogen necessary and help build up general soil health.

There are organic nitrogen heavy fertilizers but I am not afraid of chemical fertilizers and can't speak about organics. Composts of all kinds only would help and I do apply organics on a regular basis, but corn needs an additional boost. No matter the form it is a good idea to apply nitrogen pre-plant and then again once or twice as a side dressing during the growing season.

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Gary350
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I have found a lot of good information about corn today. Farmers preferred corn fertilizer is ammonia. Fertilize corn at the time of planting when soil is 55°, fertilize again when corn in knee high, fertilize again first sign of silks on ears.

I also found this, 1 lb of Urea for every 30 ft of corn, 3 times during growing season.

I tested my soil today it is 6ph in all 16 places that I tested. This is good.

I need to test my 15-15-15 fertilizer, I need to know if it contains Ammonium Nitrate. If I mix room temperature water with room temperature 15-15-15 then if temperature suddenly drops 20° colder in 30 seconds it contains Ammonium nitrate & not Urea or some other nitrogen fertilizer.

Farmers Co-op don't have Ammonium Sulfate in stock. My soil tests good so I don't need anything that contains sulfur. I bought 50 lbs of 0-20-20 fertilizer $13 for, potatoes, tomatoes, onions, garlic.

I learned nitrogen fixing legumes does not work well without fertilizer. Fertilizer can make nitrogen fixing work many times better. Some beans & peas nitrogen fix much better than others. Beans are very poor nitrogen fixers. Cowpeas & soybeans are high on the list of good nitrogen fixers. Plant nitrogen fixed cowpeas with corn to give corn nitrogen. Nitrogen fixed cowpeas can add up to 250 lbs of nitrogen per acre.

PaulF, I am not afraid of chemical fertilizers either. Ammonia NH3 is still NH3 in all manure fertilizers. There can be as much as 1% to 10% NH3 in organic fertilizer while factory is also NH3 and several times more concentrated.

imafan26
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I use sulfate of ammonia. Urea's analysis is 46-0-0. It is too concentrated for me to use. Sulfate of ammonia is half that at 21-0-0. Corn requirement is about 37 ppm. I give about 1/2 cup per 100 square ft (1/2 of the total requirement) after the true leaves come out, ( 4 Tbls) 1/4 about a month later. The last will be given around 2-3 weeks after that at around 60 days from germination. Corn is a heavy feeder, but my soil is actually rich in nitrogen so after I plant corn, I plant cabbages as a scavenger crop to scavenge leftover nutrients. I test my soil and I have to add very little nitrogen. I know this formula works for me because if I plant a second crop of corn without adding any more nitrogen, I will get short corn again, so I am using the nitrogen I have added efficiently. My soil is red clay, but it is heavily amended with organic matter to hold on to nutrients.

I used to add the first increment of nitrogen with my starter fertilizer, but if I add too much, germination suffers, and the seeds don't need it to germinate. It works better for me to wait until the true leaves come out and band the fertilizer. When the corn is knee high and when the tassels first appear is about right for the last increments.

I need to redo my soil test, but it is harder to get a sample to the UH now with the COVID restrictions.

Legumes benefit the next crop, not the current crop. It is true they do need to have some nitrogen while they are growing. Beans and legumes make more nitrogen fixing nodules when they are inoculated first. To benefit the next crop, the cover crop should be tilled under just as they begin to flower, so the decaying matter and dying nitrogen fixing bacteria can release their stored nitrogen.If you planting beans to eat and eating the pods, then there will be a net nitrogen loss as after flowering, the beans will start to transfer nutrients to the pods. Organic nitrogen is one of the hardest nutrients to get to "deliver on a schedule". You have to have an older organic garden that has had time to build up its fertility in order to get enough nitrogen to get a good corn crop. When I tried to grow corn on organic fertilizer, I got 5ft tall corn with an average of less than 1 short ear per plants (5 inch ear). The same variety of corn grown with ammonium nitrate as the main nitrogen source gets me an 8 ft plant with 1or 2 of 3 ears that are fully pollinated. My yield averaged 67 ears from 40 plants or about 1.5 ears per plant. I could have gotten more by bagging tassels since I only have a very small garden space and I am planting corn 8 inches apart. This still essentially takes up all of the available main garden space or 90 days.

Even when I have trench composted which takes 5 months to mature, I still added sulfate of ammonia. I would get an excellent crop, but it was not sustainable for repeat cropping. I would have to do another trench compost. I don't have the space to allow an entire section to go fallow for half a year. I don't have a winter where I can't grow anything anyway. I need to keep my garden actively planted and productive as long as possible. I only let the garden go fallow June-August because very little grows well in the heat. I will use that time to solarize and add more organic matter.

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Gary350
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imafan26 wrote:
Thu Dec 17, 2020 7:03 pm
Urea's analysis is 46-0-0. It is too concentrated for me to use.
Online says, Urea is slow release fertilizer, it has to come in contact with calcium & soil moisture in soil to convert to ammonia. It also says, soil that is low in calcium urea will be very slow and not a useful fertilizer. I always mix wood ash with Urea to make sure it has enough calcium to convert Urea to ammonia.

I mixed, Urea & calcium in 1 gallon of water, in a 5 gallon bucket with a lid. 1 day later it has a very slight ammonia smell, 2 days larger ammonia smell is a little stronger, 3 days larger ammonia is stronger. When I fertilized corn this summer there was never any big noticeable increase in plant growth & green color like I use to see with ammoniums nitrate. Even when I doubled & tripled Urea corn seemed like it could use more.

I gave beans & peppers Urea with no noticeable difference in growth or color. Then I doubled the amount of urea then 2 weeks later I gave plants 3 times more urea, it never overdosed the plants, (ammonium nitrate would have killed the plants). There was a big improve in beans but not peppers. Peppers do better with 15-15-15 fertilizer. And peppers do several times better with 15-15-30, plants get so heavy with peppers limbs break off if I don't tie them up.

I like Urea, I have not been able to over dose an kill any plants even when I try. Urea is such a slow release it is like no fertilizer at all if you don't use enough. Online information says, Urea slow release depends on how much calcium & moisture is in the soil. If soil calcium is too low Urea will convert to ammonia too slow to have much fertilizer value.

PaulF
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Urea would be good for my high calcium, 8.0pH soil.

imafan26
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Urea is twice as concentrated as Sulfate of Ammonia. it has its advantages. It is cheaper per pound since you have twice the nitrogen and less filler per pound. Sulfate of ammonia is a storage issue since it can be explosive, urea is more stable. Sulfate of ammonia is more acidifying so you would also have to watch the soil pH more carefully and adjust pH to keep other things in balance. When urea reacts with water it initially form ammonium which is alkaline, but also produces CO2 as a byproduct canceling out each other so urea ultimately has a neutral effect on pH.

Both forms of nitrogen are readily available. Urea does have to be converted by soil bacteria into a form that plants can use by converting urea to its nitrate form. Luckily, this is still a fast process and happens in hours if temperatures are higher than 50 degrees F. So, it is actually not a slow nitrogen.

Sulfate of ammonia is also rapidly converted by soil bacteria by the nitrification process. First ammonia readily dissolves. It is acidic so it does lower pH. If left on the surface, nitrogen will volatilize and be lost back to the environment so it should be incorporated in the soil and dissolved in water. Besides the downside of it being more expensive and it could be a problem if your soils are already very acidic. You would have to lime to correct it. That is where lime or wood ashes would come in. However, you need to be careful not to alter the pH in either direction too extremely because it is ultimately bad for soil health.

Organic nitrogen is dependent on being mineralized to a nitrate form that plants can use. It is more dependent then the synthetic fertilizers, since this process is relatively slow and only part of the nitrogen is relatively fast to convert with the majority of the organic nitrogen being made available slowly up to a two year period. Unfortunately, you will need to plan well ahead on the type of organic fertilizer you use. Plants demand the most nitrogen in the early stages of growth. Organic nitrogen has low concentration. If the nitrogen is not available in sufficient quantities, then it becomes a limiting factor of growth.

Remember too, all of these processes still involve having a healthy soil web with sufficient numbers and remember that the soil organisms are not trying to give the plants any nitrogen at all. The plants are the accidental beneficiaries in nature's grand plan. The soil bacteria do all this work because they want the nitrogen to sustain themselves and the plants get what is left.

Excess is not any better than having too little nitrogen. Excess nitrogen on the surface evaporates back into the environment, is bound to the soil and unavailable, is denitrified by denitrifying bacteria, or leached from the soil through water and can end up polluting rivers and oceans downstream by causing overgrowth that upsets the balance nature intended. The same is true for when too much phosphorus is applied and leaches into the environment polluting waterways and making other other vital elements less available.

I agree with the organic principles that a steady diet of modern farming practices which include intensive mono cropping, heavy use of pesticides, and a steady diet of synthetic fertilizers achieves today's increased production by slowly ruining the soil for the future. This has happened throughout the history of civilization. Thriving Mayan and Sumerian cities were abandoned by the pollution and destruction left by an overpopulated human race that were not good stewards of the land. They did not know better, we should.

On the other hand, prior to the advent of modern fertilizer, it took a whole lot of land and a huge number of people to just provide food for the nation. The urbanization movement and the fact that more crops are able to be produced on less land and with less people engaged in agriculture is not necessarily a bad thing. It allowed people to do other things and make advances in other areas.

I am for balance. I know you are doing what worked for you. However, I have tried urea and I did have a problem. I don't add wood ashes and I only lime when my soil test indicates it. I have limed one plot pH 6.0 once in 8 years. My other plots have a pH 7.8 so, they need more acidity, not lime. When I added urea, I did not weigh it and I should have, my bad. I did apply too much and nothing grew. I had to till it a few times to leach is out and then I could replant. This was also before I realized I should divide my annual nitrogen into two or three side dressings for the crops that took more than 40 days to mature.

A steady diet of synthetic fertilizers would be bad for the soil web, so I try to incorporate organic matter in the form of compost every time I plant a new crop. Soil organisms need carbon as well as nitrogen to be healthy. I have tried to use minimum till. It has helped with keeping weeds under control, but I find that while it works for shallow short term crops, it does not work as well for crops with deep roots. Nutrition does not trickle down. The compost does help to make the soil behave more neutrally even when it is not. Compost added to my acidic garden is alkaline so it helps to temper the pH since I do use sulfate of ammonia which is not the best choice for it. I do follow soil test recommendations. However, compost does have a lot of phosphorus I don't need, but the advantages outweigh the disadvantages. I only apply a very small amount of nitrogen. I measure it now and divide the nitrogen for long term crops into 2-3 parts. Used in the right way in the right amounts, I can avoid burning plants and get large productive plants that are not all leaves. I only add complete fertilizers to potted plants and for that I use a low NPK and slow N product with micro nutrients that has worked well for me.

https://www.nofa.org/soil/html/nitrogen.php
https://www.extension.purdue.edu/extmed ... y-204.html
https://www.physicalgeography.net/fundamentals/9s.html

Nyan
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One nifty little trick I do with heavy feeders (like corn), is to let some of my 15-15-15 fertilizer sit in an open container when the humidity is high for a few days. Then just before planting, I throw a handful of agricultural lime in and mix it well.

This causes the urea in the fertilizer to start breaking down into ammonia at a rapid pace, so you need to put it under the ground (preferably slightly moist soil) immediately. I usually put that in about two inches to the side and four inches deep along the corn rows. This is supposed to be the best band to put in starter fertilizer for corn planted two inches deep, and I use about 4 pounds of the triple 15 with lime to do four 16ft rows.

I still broadcast triple 15, chicken manure and compost over the whole thing to fertilize later, but the ammonia from the starter band seems to do a lot toward getting the corn growing fast.

You will know you have enough moisture in the fertilizer when you add the lime and wave your hand over the container. You should be able to smell a Very Strong ammonia odor from several feet away.

Side note...

Long ago I worked at a fertilizer plant, and one day one of the guys saw a small pile of really hard old fertilizer in one of the back bins. It was too hard to break with our fertilizer loading buckets, so he went to the shop and grabbed some of the blasting compound to break it up.

Long story short, it was ammonium nitrate, and when the charge went off it blew a two ft. thick concrete wall out of the back of the building... Heh, we were ducking and running that day...

imafan26
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Urea is obtainable in 50 lb bags here from the agricultural suppliers, but sulfate of ammonia is available everywhere. You just can't buy a lot of bags of it without a permit. I actually sent away to get potassium nitrate instead because my main garden does not need sulfur, but it did need potassium.

I have not used wood ashes before, so I don't know how that would work out and the wood it came from might matter. Hardwoods are not that easy to find here and most tropical woods are not high in potassium The only other way to increase potassium in my soil it so trench compost banana and potato peels. My orchid club promotes the use of lime to neutralize acidity, but they do it so unscientifically basically by sprinkling a bit of lime when they plant. Considering that orchid media really is designed to leach and be free draining, I don't know how much of that actually is absorbed by the plant.

Adding wood ash to urea or sulfate of ammonia is not recommended. They do counter each other the sulfate of ammonia is acidic while the wood ash would be strongly alkaline. Putting the two together does cause a chemical reaction accelerating the conversion of urea to ammonia. Ammonia is volatile but if it is buried or dissolved in water it can be quickly converted to its nitrate form. Ammonia gas would be a health hazard and would make the compound much more dangerous to be around.

I don't understand why you would have to add Urea so often. If I added sulfate of ammonia in such short intervals. Yes, the plants that survived would probably burn and too much nitrogen can cause stunting as well as rank growth. Urea should have worked if it was applied properly the first time. It is very sensitive to volitization if it is left on the surface of the soil instead of being tilled or watered in almost immediately.

https://blogs.ifas.ufl.edu/bakerco/2017/10/04/use-wood-ashes-garden-wisely/
https://www.google.com/search?client=fi ... mmonia+gas

https://extension.psu.edu/nitrogen-appl ... ry-weather

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Gary350
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A lot of information tells people to side dress plants with fertilizer but does not say any thing else. If you work fertilizer into the soil by hand that is a lot of work and could damage plant roots. You can also side dress plants with fertilizer then water the fertilizer to make it soak into the soil. I find it to be a lot less work to disolve 5 lb of urea into 5 gallons of water then add calcium to the water. Then I fill 10 empty milk jugs with urea water then pour 1 gallon on every 20 ft of corn. When our rain stops first week of June soil soaks up water quick.

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I side dress by banding fertilizer. Corn is the only crop I grow in rows and the only one I actually band. The band is placed in a shallow trench about 4 inches from the corn row. I grow most things in French intensive style. Seeds of different crops that are about the same size and are compatible are mixed and broad cast or randomly planted from starts. To side dress the main garden, I scratch between the plants and then mix the nitrogen with compost and top dress with that. I admit I do get lazy to do that and sometimes I do a similar thing as you do. I scratch the surface and broadcast the fertilizer and water it in immediately. If I am really lazy and when it is something that is hard to fertilize, like the orchids, I use miracle grow. Orchids and plants and plants that are hard to get to are easier to fertilize with Miracle Grow or Peter's than by trying to fertilize each individual pot. The orchid special fertilizer is actually a water soluble 13-2-13 and is used in conjunction with the slow release nutracote (13-13-13, type270). Some orchids are just mounted or are not planted in any media and the water soluble fertilizer or organic tea is the only practical way to feed them.

Since you are only using one gallon for 20 ft of corn, you are not using much so it is why your plants don't burn.



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