Question
First question: Is Roundup really any worse than using 5% vinegar?
Please be very detailed in your answer so I can explain to my customer base the true answer.

Second question: Fertilizing Rye grass: Do the benefits of corn gluten meal out weigh the benefits of a herbicide treated cottonseed meal(previously treated to kill the cotton for harvest)
I have always used cottonseed meal for my gardening with great results.
In Texas, corn gluten cost about twice as much.
I'm only interested in the fertilizing aspect in CGM.
I'll be applying CGM or CSM to rye grass in late November in North Central Texas Black clay 7.5 PH soil.

Answer
1.  Roundup is a chemical pesticide, toxic to plant life.  Vinegar is an organic method of killing weeds by just making the soil acidic so nothing will grow there until the soil is rebalanced.  If you want to kill weeds use mulch!  Four inches will not only prevent weeds, it will add nutrients to your soil.

2.  Cottonseed meal is heavily polluted with pesticides and herbicides. It will add residues to your soil and anything that you eat from your garden.  Corn gluten meal will just help to prevent germination, it does not add much in the way of nutrients.  You can buy organic cottonseed meal which is a high source of nitrogen.

We all should be trying to make our soils sustainable over time, and chemical pesticides just ruin the soil, water tables, and eventually make the soil unable to grow much of anything organic.

If you are trying to increase the fertility of your soil, I would suggest using alfalfa hay ground up with sheep manure or some other cold or composted manure.  If you apply it to your garden as a mulch about four inches thick and turn it into the soil in the spring and fall, and then re-apply four inches of mulch to keep weeds from sprouting and to keep the soil moist and the plant roots cool, add nitrogen to your soil, and you will create a very rich soil that will invite earthworms who will do the fertilizing for you over time.

For more information on soil building, please visit our website:  www.avant-gardening.com