The first rule for producing healthy vegetable plants is to feed the soil. Read any organic or naturally grown manual on raising veg and this golden rule will be right there at the beginning. The soil needs to be amended just as the body needs replenishing of organic matter. For all the micro nutrients, organisms, and structure of the soil to remain strong, some inputs by the grower is unavoidable. In the fall most growers, at some point or another, add limestone to raise pH and calcium levels. This need be done only every 3 years in most circumstances. Having never added anything but organic matter to my soil, the pH is significantly lower than I would like. Horse manure will grow the soil's body and nitrogen content but to raise the pH it'll need calcitic lime or something similar. I chose aragonite which I have been told is roughly 3 times stronger than the lime and helps to add even more calcium. Like anything in growing it's to a certain degree an experiment. The reaction time of lime or aragonite is supposed to be around 6 months. I'll see in the spring if my veg grows better and my soil structure seems improved.