If you have fields on your farm that you're not currently using, you should not let them grow too wild but should instead have someone who provides lawn mowing services trim them every now and again. Read on to learn why.
It could deter pests
Having someone drive or push a lawnmower across your unused fields every few weeks could help to deter pests who might otherwise set up camp in these areas. Many pests can be attracted to an overgrown field due to the fact that they can use the plentiful grass to build their nests (in the case of mice or rats) and because the tall weeds and grass blades could help them to hide from predators. If a group of pests move into your fields, they may then be more likely to visit nearby fields that you're using to grow crops or that your farm animals graze in. This could result in some of these crops being eaten and your livestock getting ill as a result of coming into contact with, for example, rodent excretions. Furthermore, when you eventually clear the fields, you might have to take extra precautions to avoid being bitten by the resident pests (for example, you might have to wear protective overalls and perhaps apply toxic pest control substances).
If, however, you use a lawn-mowing service that stops the grass from ever growing too tall and which trims back weeds, you can make these fields less attractive to nearby pests which should, in turn, protect you, your farm animals and your crops.
To ensure the field is ready for use at a moment's notice
Having someone trim your fields with a lawn mower will also ensure that these fields are ready for use at short notice. This could be incredibly useful if, for example, you spot some livestock on sale for a particularly low price and want to purchase them before anyone else does, as you'll have a field set up and ready for them to graze on then and there. If your fields were completely overgrown, you would not be able to take advantage of this opportunity to expand your agricultural business.
Similarly, if another field in which you've just planted some crops gets damaged by a fire or the spillage of some weedkiller, you could quickly plant a fresh batch of these crops in these other fields, provided they are trimmed back. If these fields were not maintained, however, you would probably not be able to plant and finish growing your crops in them fast enough to sell the crops at the time of year you had expected to.