After almost 7 hrs of un forecast overnight frost & me not putting an old sheet over the dwarf apple trees I too lost all the apples .........shame as the trees were full of blossom & breaking buds . Still I've got the first crop of plumbs off my six year old trees to harvest in a few weeks if ther is no early frosts .
Potatoes .
Make sure that the horse muck you use is not mixed with the dropped hay from the feed nets as you'll end up growing zillions of weeds.
The best well rotted animal manure is cattle muck with straw bedding , poultry muck with straw beddings , pig muck with straw bedding.
These animals & other species have a different digestion system to the horse and as a result few if any weed seeds pass through their digestive system and survive .
You can also bulk out the dungs by adding a good 50 to 70 % more of clean unused straw , turn it in the heap , wetting it as you go & then cover it with a plastic sheet and weigh it down . It's not long 3 days or so before the beneficial bacteria get working , raising the temperature of the pile and feeding natural moulds that break the straw fibres etc down .
Every three to four days for the next 15 days rebuild the heap , putting the outside edges into the middle of the new heap . Re wetting a bit to keep every thing nice and moist/ wet , which is good for rotting it down .
Make as much of this sort of composted straw & dungs as you can afford or have the strength to make , as it is just about the best thing you can put into clay soil at the rate of two standard barrow loads each" double " dug square yards .
A heavy manuring like this is good for seven or more years , but wise veg growers keep adding a barrow per square yard as a top dressing off this sort of home made new compost every autumn or when the ground is free of crops . It's called building the soil .. it stays moist in the wet & any droughts and can reach down to abouta four foot depth in eight or so years withe help of the worms .
However do not use if for the proposed root crop growing area which has to be free of any manure based compost for at least year or you'll end up with root crops like cows udders .
Note.... Too much steer or bull dung & straw bedding or neat slury out the miling parlour can lead to the soil becoming too acidic , that's why we use other animal & the bird beddings & dungs as well .
Ideally up to 70 % by weight of straw will work well in clay in about three years of cultivation once it is well mixed , wetted & composted properly . a few bags of gypsum based plaster powder sprinkled over the area and rotated in also helps to crumb the clay soil , providing it is gypsum it does not greatly affect the acidity or alkalinity of the soils unlike if you use gardening lime to crumb the clay .
This enrichment of the clays using this compost allows not only water drain down to the lowest point , it feds the worms who eat the compost which in turn gives you a fantastic addition by way of their dung aka. worm casts . It also allows air to get to the fine hair roots so they can then live off the tiny microscopic globules of humus produced by further aerobic action on the bits of compost in the soil.
A well compost supplied clay soil also provides easier food for all manner of pests ,so they tend to stay off your crops. Using the new nematode slug control method also works very well in a high fibre soil & tends to stay active for five to six week providing the soil damp & the temp is above 10 oC