There are a number of factors that will determine how much horse, or any other manure or any other nutrient source you can use, but the only way to know that is with a good, reliable soil test. What is the humus level in your soil? How is the balance of Phosphorus, Potassium, Magnesium, Calcium, Zinc, Iron, Manganese, Molybdenum, Sulfur, Boron, and Copper?

What I have been doing is loosening up the soil close around the plants. Sometimes about an inch deep, and maybe 2 "deep a little further back, then putting on the manure, and mixing it in. But I dont think you would have to do that. I would think the rains would wash the nutrients down around the roots. I did it because my soil is so bad, and I am trying to loosen up the packed clay. I seen a huge difference in my plants in just a few weeks. Tammy

"(ii) Incorporated into the soil not less than 120 days prior to the harvest of a product whose edible portion has direct contact with the soil surface or soil particles; or" for root crops which is, I think what I wrote. "(iii) Incorporated into the soil not less than 90 days prior to the harvest of a product whose edible portion does not have direct contact with the soil surface or soil particles;" For above ground crops, which is, I think, what I wrote. The news is filled, almost weekly, with stories of people being poisoned, in the USA, by E-Coli, Salmonaela, Listeria, etc. from animal manure contaminated foods. The Center for Disease Control believes this is much more common because most cases of this food poisoing do not get reported becasue too many people think they have the 24 or 48 hour "flu", actually gastroenteritis and not influenza.

When I did, in my ignorance, add animal manures to the garden beds without first composting those manures, I did see an increase in "weeds" and it made no difference if it was manure from dairy cows, horses, pigs, goats, sheep, llamas or alpacas, unless it was dehydrated manure. It seems the heat used to dry that manure was enough to kill any "weed" seeds. Since the easiest method to keep these "weed" seeds out of the garden is to compost the manure first it simply makes sense to do that, along with all the other very good reasons to compost manure before applying it to your garden soil.