Tomatoes and potatoes for instance, can’t cope with too much manure. Well, it’s us that can’t cope because we want the bits of the plant that they grow for reproduction (tomato fruits or potato tubers), but when they have a lot of Nitrogen they don’t feel the need to make babies; they just grow and grow and grow. All leaf and no good bits. Carrots and beetroot can be like that too. They all like a fertile ground, but not too fertile. Got to keep them thinking the end is almost nigh so they make plans for continuing their line. That’s where seaweed is ideal, it gives them what they need but no more.
Brassicas on the other hand can’t get enough and benefit from a good dollop of both seaweed (for the micro-nutrients, because they’re awfully sensitive to deprivation) and poo (for big green leafy plants). They can be in the ground for a long time too and need long-term slow release foods. Seaweed and manure are excellent for this. As they rot down they release their nutrients into the soil over a period of months and years, adding organic matter to the soil at the same time.
To complicate things, not all poo is created equal. Here at Turriefield we have 6 different animal manures, (soon to become 7 when our own horse arrives) and I’d really love some good old cow muck too, but I think that’s a project for another day. Chicken manure is the king of the poo pile with at least 5 times more nutrient content than cow muck, but as such needs to be treated with respect; well-rotted and used sparingly. Horse manure is high in organic matter and often comes combined with straw which makes for some lovely soil conditioning material. Sheep poo as all crofters know, is probably the least exciting manure, but if it’s all you’ve got, mix it with plenty of seaweed and it’s better than nothing.