Steadyhand
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Nitrogen depleted

Hi, my wife and I have begun some gardening this year. It is our first time ever. We recently acquired some property and now have the freedom to do this. We built several raised bed gardens. One we filled with all miracle gro garden soil so naturally all soil tests are showing good.

However we have another raised bed we made out of an old circle tub and it has all our pepper plants. We had already put in the peppers when I decided to test the soil in that container. Results were:

PH: 6.5
Nitrogen: Depleted
Potash: K4 Surplus
Phosphorus: P4 Surplus

The soil mix in the pepper tub was 1/3 potting soil, 1/3 garden soil, and 1/3 compost.

I expected it would have some nitrogen in it but the test results are saying it has none. What would you recommend?

imafan26
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If you have surplus and your pH is 6.5 your soil test would recommend urea 46-0-0. PH 6.5 is a good range for peppers, so you do not need to add any lime, but if you added something like sulfate of ammonia 21-0-0 you would be adding sulfur. You would probably only need a couple of tablespoons worked into the soil to start with and side dress after the the plants have bloomed and again when the fruit forms and monthly thereafter.

Most gardens are nitrogen depleted because nitrogen just does not last. It is a normal part of the nitrogen cycle. Even if it was not depleted you would have to add some. Compost by the way, if it is not fully decomposed will compete with plants for nitrogen.

In a pot it is harder to do organic because you just do not have the soil community in number and nutrients are not going to be readily available to plants because they have to be broken down or mineralized to a form the plants can use. Blood meal is the highest source of organic nitrogen at 13-0-0 and is relatively fast. But it still takes soil organisms to break it down. Peppers, tomatoes are not light feeders. You would have to supplement with fish emulsion weekly.

If you planted legumes first it would help since if they are inoculated to provide the microrrhizzae then the bacteria will fix nitrogen from the air and if you till in the beans around flowering time, you will have slow release nitrogen for the next crop and seeded your pot with the good bacteria. It would take about 6 weeks for the cowpeas to get to that stage. BTW it still helps to have some nitrogen in the pot even with legumes because the micorhizzae are fixing nitrogen for themselves and not really for the plant. The plant just benefits because the micorhizzae need to colonize their roots so it is a reward to the plant. To release the nitrogen you have to till to kill the plant and bacteria to get them to decompose and release the sequestered nitrogen. If you toss all of the residues in the compost pile, it benefits the compost, but not the pot. If you wait until the beans have pods and you eat them, you are taking energy out of the system.

In a balanced system inputs = outputs. Nitrogen fixing bacteria fix nitrogen some of it feeds the bacteria, some the plants, and some of it are scavenged by detryfing bacteria that turns it back into a gas and returns it to the air. Everytime you harvest you take nutrients out of the system. Every plant that goes into the compost heap helps the compost heap, but you have to add organic matter and fertilizer back into the soil from which it came in exchange for what was consumed or taken out. Even in the compost pile, the nitrogen in the greens is consumed by the organisms in the pile during the decomposition process that is why compost is not really fertilizer. In the end most of it is decayed matter and mostly carbon and why you still need to add fertilizer even if you add compost to the soil especially on new gardens. Older gardens (like several years old) may have enough of a soil community built up and depending on how it is managed, may have surplus nutrients, but usually organic is nitrogen deficient and manure, blood meal , fish meal, feather meal, cottonseed, fish emulsion, or some other nitrogen source must be continuously added. It takes years because most of this source material can take months or years to release. It is why organic produce is usually smaller because of nitrogen limiting growth than conventionally grown produce which can be nitrogen in a form readily available to plants at the time the plants need it to sustain growth.

Mr green
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Mulch with grassclippings or other green plant parts (be carefull with weeds with seeds or so called root spreading weeds).
Nettletea is also very good, high enough in nitrogen, you can do this with many other plants as well, but the nettles are good since has alot of different minierals as well.
Comfrey and Dandelions are other good plants to make such a brew.

The process is easy all you need is a bucket with a lid, fill 3/4 or so (packed down a bit) with the plant material, add water, you might wanna shake it every now and then. Leave it in the shadows for a couple of weeks and you have amazing fertilizer that is quick to benefit your plants as well. Dilute it something like 1/10.
Best with this is that it is free.

In the end you don't want to overdo nitrogen in that bed, it may give you big plants with lots of green growth but less fruit.
So far I havnt added any to my beds, and has worked fine since I started them in the heavy clay, theres bacteria that binds nitrogen from the air these bacteria are hyper sensetive to syntetic fertilizers and pesticides and stuff, so those things are a no no for a cost effective low labour garden.

imafan26
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Comfrey is high in calcium. You could also use fish emulsion weekly for nitrogen. Green plants and green manure actually use up nitrogen while they are decomposing. As mulch they do not, but they lose most of their nitrogen to the air.

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rainbowgardener
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Nitrogen gets readily depleted. It is the most transient of the nutrients. So part of gardening is that you have to be regularly replacing the Nitrogen (and to a lesser extent other nutrients) that get washed out of the soil as you water, taken up by the plants, etc. You do that with regular additions of compost, keeping your soil well mulched, and use of supplements that have been mentioned such as fish emulsion, compost tea, blood meal, feather meal, drowned weeds, etc.

drainey0
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how did you get your soil tested?



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