This could be a stupid question.

The two worst sections of my garden are the two areas rotovated. The best area is the section where I just hand weeded and then put down a thick layer of Organic Farmyard Manure.

 

You could apply a 50mm layer of compost (any well decayed organic matter) and plant plants directly into it. Have a look at Charles Dowdings website HOME
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Sounds like you have heavy sticky clay which tends to be very fine. I had some very heavy sticky clay delivered to me a couple of years ago, about 1500 ton. When dried and put through a 10mm screen there is hardly any waste, hardly any stone what so ever. The area you have rotovated was there any stone? going by your post I doubt there was and the area has just binded back to what it was prior to rotovating.
My advice to anymore who is going to rotovate heavy sticky clay, add some organic matter and horticultural grit ideally about 3/8mm before rotovating, if you don't you are just wasting your time and you will be back to square one.

 

Or make flowerpots and bricks.

 

Plenty of big stones but very few small stones

 

This will create a nightmare for watering, at least for a while until the worms do their thing and drag it under.

Clay has incredible water holding capacity due to the immense surface area of the tiny clay particles. That also gives clay it's ability to literally suck water out of anything with larger particles, such as compost. It's basic physics. Surface tension on water makes it stick to surfaces. The larger surface area of clay means there's more surface for water to bond to, so the combination of gravity and surface tension means any moisture in compost on top of clay will quickly transfer to the clay, leaving the compost very dry unless it's watered very regularly.

When you incorporate organic matter into clay, you slow down the clay's ability to lock onto water, effectively by holding particles of clay apart from eachother, so while the clay will still do its thing and suck water out of the compost, the much more fragmented clay will reach saturation much more quickly, and thus suck less moisture from anything on the surface.

This much is just basic physics, but to see it in action in a horticultural or agricultural sense, you only need to look at the current crisis in Ukraine, formerly known as the breadbasket of Europe, where their incredibly productivity is attributed to the rich soil that's naturally occurring there, where it's so rich in organic matter it's almost black.

 

You disregard the water table. The importance in not cultivating is to maintain the structure of soils, which enable the movement of groundwater by capillery action. Naturally the groundwater varies in its position of saturation according to the pattern of rainfall/percolation. If the soil structure is good, it will adjust moisture within itself, keeping adequate within the root range of established plants. Only necessary to water initially to establish plant root contact with soil structure. Regular light watering will support plants but at the cost of discouraging them to go deep enough to survive.If the plant is planted firmly into moist structured soil, that is all it normally requires. In the way that plants require sufficient light, they also need not to compete with , for example, established oak trees that will take all available moisture to meet their own requirements.

 

With respect, no I don't. The water table could be at any depth, depending where you are and what the weather's been doing.

Unless you're in a particularly wet area, it's likely to be anything from a few feet to many metres down. You can test this simply by digging a hole. If you find the water table, the bottom of the hole will fill with water. In my front garden, I reckon I'd find bedrock before finding water.

There's an easy way to test what I'm trying to explain. I learned this the hard way, losing several healthy plants before realising what was going on. Try this in poor clay soil. Take a healthy plant in a pot. Dig a hole in the clay just big enough to plant the plant in, and plant it in. Pack it in nice, water it in, and watch it struggle over the next few days. I've pulled dead plants out that just come back out, their original compost still pot shaped, compost bone dry even after recent watering. My personal record for killing a plant in such clay soil is just over 24 hours. I put some courgettes in. At that time I was doing an experiment testing straw as a mulch. I mulched some, and left others in exposed soil. The first plant was dead in a little over a day, with the rest following within a week, despite being watered daily. In every case, they'd just dried out.

 

I have lost three shrubs in exactly these circumstances.

 

I am flabbergasted. Never in more than 50 years of growing, on Wealden clay within sight of the Warnham brickyards, on London clay in the depths of Crookham, and on London clay here on the Hampshire coast have I suffered such occurance as you describe. I've lost boots in the depths of winter, been guilty of insufficient preparation of ground, even since converting to no dig, some crops fail,suffered predations by birds, deer,voles,pigs, caterpillers and slugs ad norseum, even drought but never in 24 hours!! Where is this quatermass that consumes all?

 

I've always dug in organic material when possible, I also use green manure over winter.
The only reason I didn't dig part of the allotment this year was because my knees hurt.

Spreading organic material on the surface is ok, but you are wanting the worms and weather to incorporate it for you rather than digging it in.

Its not until that happens that the clay becomes friable and stops setting like concrete when it dries out and becomes an airless mass when wet.

 

You must be right then.

 

This is the worst section of my garden. Today I broke up the top few inches and started putting manure as a top dressing. Just a couple of bags so far but fairly thick. You can just make it out at the back. I will need a few tons to finish the job!

 

It looks like the soil in my front garden. It's a bit of a nightmare in hot dry weather. I'm sure you'll sort it though. I foolishly put potatoes of all things in mine this year. That's probably why we're having a heatwave and drought. If I'd filled it with Mediterranean herbs we'd have got a washout of a summer.