To amend or not to amend soil

Is it nessessary to know my soil content before I add compost, etc to it or is it ok to just go ahead and add organic matter? I have soil that was added as fill when the house was built in the 1980s. Its a little clayie and also medium dark. I want to add the contents of my compost pile to it and till it in. I also plan to mulch up a lot of leaves this fall and add them either in the fall of wait till spring. They will not be composted but just shredded well.

You'll hear different things but I wouldn't hesitate to add finished compost to your soil right now. It is theoretically possible to have too much organic matter in soil, but if you haven't been amending that seems unlikely to be a problem for you.

You might want to be thoughtful about how you add the leaves. As you probably know, the decomposition of leaves (like that of woodchips etc.) ties up nitrogen for a while. There are different ways to mitigate this. Depending on your climate, adding the leaves late in the season may be enough, as they can then break down over the winter. This is my main method. Another possibility is to add nitrogen in the form of golden tea (9:1 water:urine) or something else to prevent a lack during the period of breakdown.

Testing is often recommended but to be honest we still have never done it and our garden plots produce just fine (after adding a lot of organic matter, manure, planting green manures, and so on). I'd go ahead and give it a try right now and see what happens. If you have trouble or just want to do better, you can always get a test later.

I myself would say it is not necessary to get a soil analysis or know a soils mineral content *to add compost*. Adding quality compost and organic matter is generally always a good idea. You mention you want to add your compost and till it in. This is ok to do, but, if for example the compost is still high in carbon materials and isn't a fully finished compost, when it gets tilled in the microbes in the soil will start to break down the remaining carbon and use a lot of the nitrogen in the soil to do so. Then with the nitrogen being used by microbes, plant growth will suffer. If you want to till in the compost, this is a great opportunity to also add some amendments that may be needed. Phosphorous is a great example. Only a soil test will tell you if you lack phosphorous. Using soft rock phosphate to raise phosphorous levels really requires working it into the soil to gain the most benefit. Sprinkling it on the surface will not gain much benefit.

I imagine you want to add compost to improve your soil so plants grow better. This is true, and it will help, but if there are mineral deficiencies in the soil, compost is likely not going to raise the levels of those deficient minerals. I guarantee you there is at least one mineral deficiency in the soil, as naturally occurring well balanced soils are for the most part long gone, and only occurred in a few regions across the globe. It may behoove you to get a $25 soil analysis so you have the data and you can make calculated mineral amendments, and add those when you add the compost, and then till all that in. That would really help your soil and reap the best rewards if you plan to grow food crops in this soil.

Edit: I didn't mean to repeat what Chip wrote, I believe we were typing at the same time

This new garden is in a yard that was poorly maintained grass. I am preparing it now for planting NEXT SPRING. So I am assuming that any shredded leaves or other organics will be broken down by springtime.

Then there is no harm in adding that organic matter. While you will probably want a soil test to make sure your mineral levels are sufficient, compost mulch and other organic matter additions serve the biology as well as the chemistry. Even if you're deficient in certain elements, a healthy soil biota can ensure that what elements are present are available to your plants.

I believe Elaine Ingham has gone so far as to claim that no soil needs mineral amendments if there is sufficient soil life present. Personally I take that to mean 'it's hard to overstate the value healthy soil life has in the flourishing of plants".

I would echo the others sentiments about feeling free to add compost now.  My 2 cents on soil tests are that, if you are a numbersy type of person or very scientifically minded you may enjoy getting a soil test and crafting a specific amendment blend to your soil and it might make gardening more fun for you. If, however, you are not numbersy then I would recommend against it because the test will just be a very technical piece of paper that might make you second guess yourself and feel anxiety about not amending right. Grow your garden, observe the growth of various plants and try to consider what they tell you about what's in the soil. Then do your best to improve the soil next fall and observe again. Soil tests are great for certain people and for commercial production but I think often overwhelm less technical gardeners.

Me personally, I find it hard to know where to test,I have too many beds.
I used to  "till" amendment into the soil, now I just add it on top.
This is supposed to minimize how much nitrogen is tied up by unfinished compost.
I might till the plot just before first frost and then top dress. I think most of what you till in at that point will be nitrogen heavy or balanced.

Dar Helwig wrote:Is it nessessary to know my soil content before I add compost, etc to it or is it ok to just go ahead and add organic matter? I have soil that was added as fill when the house was built in the 1980s. Its a little clayie and also medium dark. I want to add the contents of my compost pile to it and till it in. I also plan to mulch up a lot of leaves this fall and add them either in the fall of wait till spring. They will not be composted but just shredded well.

It isn't necessary to have a soil test in hand to start making improvements to soils.
Compost is great and it can be turned into the soil or left on top as a mulch.
Shredded leaves are another story, if the plants these leaves came from had any sort of disease or insect damage then you could re-infect by using non-composted leaves.
If the leaves were nice and clean, then no worries, but if you can pile them up and wait, then you will also get to add the microbiota that wake up and grow during that piled up waiting period, along with some fungi that will grow from any spores present on the leaf matter.

Either way, the only harm could come from re-infection through using disease carrying leaves.

If your trees and plants are growing well, then I would not worry much and simply start making nice additions.
If you start seeing yellowing leaves or other anomalies, then let me know and I'll go through the sampling procedure for you, that would be when it would be a good thing to do.

Redhawk

Echoing what others have said, adding compost to your soil is generally always a good idea. It helps improve the majority of soils in texture and nutrients.

There are some ways for new gardeners to get better acquainted with the soil they are working with such as doing a jar soil test. This will allow you to generally understand the different textures of your soil (Sand/Clay/Silt). I'd then recommend to look up other people's experiences growing in your soil type and climate.

Just start planting.  I couldn't know about my soils and how to build my compost until I started growing stuff.

If a person doesn't know about their soil a soil test might help.

Folks cant go wrong adding organic matter like compost, compost tea ...

Bryant said, It isn't necessary to have a soil test in hand to start making improvements to soils.

Compost is great and it can be turned into the soil or left on top as a mulch.

Its hard to imagine how adding any compost will possibly cause harm to the soil.


I have a thought for some optimal results though.  

If you are making/amending beds now, I suggest making a compost pile on top of one (or more) of the beds.  The reason:  as the compost pile breaks down, water and gravity will inevitably drag all that good material--and much more importantly the microbes--right into the soil beneath.  I have seen places that have had compost piles on top of them in previous seasons and those spots are amazingly fertile.  In fact, I have made unintentional (and very poor quality) compost piles.  The poor quality made no difference as the soil beneath was magically fertile for years afterwards.  A huge portion of this fertility lay not in the chemistry that soaks down but all the microbes that wash in.  It is truly amazing.  And it is too bad that most compost piles sit in unused spots behind a shed!


Eric