I have read through all of the info you have on lawn care and I am trying to convince my husband not to use herbicides and pesticides on our 2-3 acre lawn in the country. Can you tell me what we can safely use as a pre-emergent? How can we get rid of bahaia grass and what is appropriately aged manure. We have 2 horses and save the manure, but don't want to add too much nitrogen to the lawn or possible seed from the processed grain.
When using aged (not composted) manure, the following practices will reduce the potential for contamination: Manure is considered "aged" when it has sat for a year. Never apply manure to growing food Crops. Apply manure in the fall after harvest, and mix it in. Fall application allows the longest period from application to harvest. Do not leave manure on the soil surface where it can have direct contact with the crop. Always mix it into the soil. Wait 120 days from manure application to crop harvest. This can be safely reduced to 90 days if the edible portion is protected by a husk, pod or shell.
The Tacoma Permaculture Project www.tacoma.freeforums.org
My philosophies on this are really different than most folks. So you might wanna take this with a grain of salt ...
I (me, myself) would avoid the use of a pre-emergent ... or anything ... a lawn is a decorative and it turns out just great if you just mow it right and water it right.
In fact, by mowing it tall (3 to 4 inches) it beats out almost all the weeds. And the turf becomes really thick.
So using a pre-emergent would make almost no difference. That just extra money and effort with almost no payback.
As for the manures ... well, that dips into another area of ag philosophy I have that is contrary to what most folks do: I wouldn't want to keep an animal any place long enough to accumulate enough poop to make shoveling it worthwhile. Long before that happened, I would move the animals to a new paddock and drag the shelter to the new paddock too.
So that makes aging the manure, and all of that manure handling stuff moot.