SQWIB
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Compost Analysis

Can someone take a look at this analysis and let me know if its good or bad for vegetable gardening, I'm a bit overwhelmed trying to understand it.

https://www.phila.gov/ParksandRecreation ... Report.pdf



I have been getting compost from The Fairmount Park Organic Recycling center, here in Philly.

https://www.phila.gov/ParksandRecreation ... enter.aspx




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imafan26
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The compost analysis is actually pretty good.

A finished compost pH is 7.9 and is typical. Composts usually start off acidic but become more alkaline at the end as the bacteria and fungi consume the nitrogen that is in the feedstocks. The type of feed stock will determine how acidic your compost starts out. Alkaline pH is typical of aerobic composting. Acidic composts like peat moss are acidic because they are created anaerobically.

The only numbers that are slightly low are the ammonium NH4 of 1009 mgkg or less than 0.0002 percent. There is very little fast release nitrogen in the compost that is readily available to plants. It is also why compost is not fertilizer.

Total Carbon is less than 29.1 % by weight and it contributes to the low C:N ratio of 17.4 but the C:N ratio is still in average range. This just means that a lot of the carbon in the compost was consumed in the process which is not a bad thing because it means that the compost was cooking.

Nitrogen and Carbon are closely related. A C:N ratio in the range of 15-20 will mineralize the organic nitrogen slow release nitrogen to an inorganic amoniacal form over time (a period of up to two years) to make Nitrogen available to plants. So the while the compost does not have a lot of fast nitrogen for plants now, it has stored Nitrogen which will be released slowly over the next couple of years.

This is why it takes an organic garden about 3 years to get to peak production and become sustainable as long as compost is continuously added every year. It is also why it is best if you are going to start an organic garden that you start early like 6 months before you plant to get the bed ready for planting. It is also why you have to supplement young plants and heavy feeders. In a new organic garden it is best to plant legumes like bean, peas, and peanuts that can with inoculation improve soil nitrogen rather than start with a heavy feeder like tomatoes.

It looks like you have a very good compost with average amounts of stored nitrogen and some trace minerals. You have very little fast nitrogen in the form of ammonia so you will have to add fertilizer to provide additional N for plants immediate needs.
Unless your soil is very alkaline, the pH of the compost will not be indicative of the pH of the soil. For that you would have to do a soil test about 6 weeks after you have incorporated the compost, fertilizer and soil together. The compost will improve soil tilth and water holding capacity and it will also buffer pH and hold on to nutrients better as well as feed the microbes in the soil.

Usually I do not add more than 4 inches, or about 20% compost to my garden. The alkaline compost does not hurt my acidic plot (pH 6.0) , but I have two alkaline plots (pH7.8). For those plots, my the available alkaline compost (it tests at pH 8.13) would make it worse so I added peat moss and sulfur, this year instead.

SQWIB
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Thank you for the quick response.

I usually top off with Black Kow in the fall and spring but my last batch of Black Kow looked like sand. I was hoping for good feedback with the "Philly" compost.

Most of my beds are early stage Hugel beds, 2nd season and 1st season.
I have added Lime with calcium and add 10-10-10 to the beds and some Blood Meal, I will add 10-10-10 and the bloodmeal one more time this growing season, probably in 4 weeks or so, I have also added some ash. I have yet to add my own compost as this is my first year getting back into composting. I should have some decent compost in the spring to side dress the plants.
I underplanted some Crimson Clover and will be planting some Oats in late August.
I was hoping that after 3 or 4 years of establishing the beds that no fertz would be needed and my own compost and cover crops would be adequate for the plants.


On a side note, I inadvertently purchased some Milorganite that I wont use on the veggies but have been using on my flowers tree and shrubs.

Everything is doing OK but not as good as my established 25 year beds (non hugelkultur)

toxcrusadr
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Not sure if you have clay or not, but if so, be especially careful with the triple 10. P and K are not as mobile as N and will tend to build up, more so with silt than sand, and even more with clay. Compost has P and K so over many years you may end up with excessive P and K. I had to cut back after a couple decades, and I never really used much fertilizer, it was almost all from compost. Just keep an eye on your soil by testing every few years. Excess of certain nutrients can interfere with the uptake of others.

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applestar
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Well, that's a good information. Thanks toxcrusadr. Maybe that means it will be OK that I didn't get around to prepping my (acidic clay subsoil) garden beds with rock phosphate, greensand, and soaked alfalfa pellets this spring, which is what I usually do. Mostly just dolomitic lime and compost and minimum dose application of one of the -tones.

I read about someone using SuperBloom every 2 weeks on his tomato garden -- his tomatoes were giant dark -almost blue-green- towers. loaded with fruits. I looked it up and analysis is 12-55-6 with 0.10% chelated iron. :o ---- I felt so bad for my underfed garden (two applications of citrus, plant, and/or tomato or garden-tone since spring) that I went out and side dressed with kelp meal. :lol:

SQWIB
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Thanks for all the input.
I did find out I was washing away most of my nutrients, Last week I was in my neighbors yard looking for one of the escaped turtles and saw water pouring from the bottom of the Hugel beds.
I checked my timer on the drip irrigation and realized it was set to 25 minutes 4x a day... :oops: ! I readjusted accordingly.

His yard is now doing real well :shock:



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