How does making hay or silage affect the soil fertility and pasture regrowth in a paddock?

Answer 1

Any sort of anthropological activity that involves removal of vegetation so that no organic matter can go back into the soil is going to decrease soil fertility. This does not count with livestock grazing. Unless the field is fertilized regularly (like once or twice a year), plant growth will decrease to the point of desertification. Of course this will only occur over several years and not when the second or third cutting needs to be taken off.

Fertilization of hay or silage fields can be done in four different ways: spreading manure (solid or liquid) from corrals or lagoons, spreading boughten pelleted or liquid fertilizer that is in higher forms of concentration than manure, or grazing cattle on the fields (crop-residue grazing on silage fields and/or bale grazing in winter on hay fields). The latter has shown, scientifically, to be more sustainable and efficient than the first two methods which involve running machinery and using diesel fuel and, for the second method, buying the fertilizer.

Plant regrowth will always be slow for the first week before it begins to grow exponentially to the point where it may need cutting again. This would not be so with annuals that are being cut for silage, since once the plants are removed, little growth will occur to replace those plants. The plants that do come up after a field has been taken off for silage are slow to regrow in comparison to those perennials that are used for hay. Most annuals do not come back after the first cutting.