Compacted soil remedy?

Hi All,

I have started looking after a family member’s garden as I opened my mouth, stating the garden was screaming out “ I need a good feed”. The plants were showing the usual signs of yellowing leaves etc.

Now to the compacted soil. On closer inspection of the soil, I tried to push a fork into the ground and found that it went in an inch and no further. I would have liked to at least open the soil to allow air and water in but it was not possible it was that hard.

I have spread a good mineral mix, organic fertiliser, organic compost and a 3 inches layer of wood chips. Gave it a thorough watering and finished off with a dose of kelp and fish emulsion.  

Question – Is there anything else that can be done to get this soil back to some sort of normality?

My mission is to get the soil healthy.

Cheers
Anthony

My experience and what I've read is that a thick layer of mulch, such as leaves, spoiled hay, straw, sticks or even wood chips can soften up the soil a lot in a single season. My experience is that I had to (or did, anyway) fertilise with various things, mostly my kitchen dishwater, and sometimes used coffee grounds or "liquid gold" but then I never had to dig the soil up, it just got softer and softer by itself under there. Kinda like how you warm up under the blankets in winter, and by late night get all relaxed and warm. Well, no, of course it has to do with the soil organisms doing their thing.

Rebecca has great advice on how to improve that soil. Also, calcium is good for loosening the soil structure, and a great way to add this calcium is by applying gypsum to the soil. The rain will wash it into the soil and then soil chemistry and microbes will do the rest!

Hi Anthony.

I would suggest a comprehensive soil test. I know a lot of people consider that a hassle when what they really want is to get their hands dirty, but making an informed decision is infinitely better than just doing something.

If your soil has a clayey compaction going on, I think James might be right about the need for calcium. Gypsum is great because it is pH neutral and breaks down slowly, so it's harder to overdo. Of course, if you had a soil test done, you wouldn't have to guess.

What grows in the garden already? Could you list some of the weed species? Oftentimes you can tell what the soil needs from what's growing there because the weeds that volunteer first and thrive are showing up to take advantage of a bad soil situation, to which they're well adapted, and that they often end up remedying.

Take the example of dandelions and other tap-rooted weed species that show up on hardpan. Their taproots punch down through the hardpan and compaction, and even if you don't pull them up, taking the root systems and physically loosening the soil, the organic matter will rot in the ground, providing a corridor of compost in the compaction for something else to come in, something that doesn't like compaction, say, but loves unimproved soil, and happens to be a nitrogen-fixing bacterial host or a hyperaccumulator, whose life cycle will fix that particular problem.

Also, you might want to think about a one-time plowing, or at least a broad-forking (I prefer the latter, because in clayey soil conditions, the action of the plow can smoothe and seal the soil layer immediately under it, causing drainage issues). Broad-forking I think is much better, because it aerates the soil without inverting its structure, but even plowing can be done once to get all those amendments into the top layers of soil, to accelerate the healing process (keeping in mind the sealing caveat).

After that, I would plant daikon radishes or mangelwurtzel beets to further combat the compaction. If you don't eat daikon, you can feed them to livestock or just leave them to fertilize the next crop.

I think you might benefit greatly from some of Bryant Redhawk's soil threads, specifically the ones where he discusses the making and use of compost extracts. If you can increase the fungal and bacterial counts in your soil, the rest of the "ground crew" will show up and not only decompact everything for you, but keep it that way, and look after nutrient and mineral redistribution for you.

But keep us posted. Let us know how you decide to proceed, and good luck.

-CK

What Rebecca said: mulch.

I don't know if you get a freeze/thaw cycle in Australia, as that is a common way that nature decompacts soil.  But even that isn't as simple and straightforward.  You need adequate moisture throughout the soil profile in order for a freeze to decompact heavy soil.  

Are you working with clay soil?  Clay tends to be the worse, but, again, the answer is mulch.  A heavy layer of wood chips or other organic biomass will do a couple of things.  First, it will create an environment for biota to inhabit the soil.  Worms, beetles, and micro-biota all form a critical component of the soil food web.  Fungi will begin to work through the soil profile and the exudates from the fungal strands help build soil aggregates.  Water infiltration increases with soil aggregation.

Any sort of root that punctures through the soil profile will break up compaction.  Common weeds like dandilions and mallow send a strong tap-root down through the compacted soil.  If weeds can grow in a crack on the sidewalk, they do pretty well in compacted soil.

So haul in the mulch, spread it around thick, plant a cover crop of soil penetrating plants, and leave it alone.  Within 2 years you'll see tremendous improvement.