The maximum rate for glyphosate for a burndown is 44 oz. per acre. Use 48 oz. ammonium sulfate and 16 oz. crop oil per acre in your mix for best results. Put the ammonium sulfate in the tank first.
Yes, AMS can make gly more effective.
For the OP:
Depending on your water source, water can have minerals or dirt particles in it. When you add gly to the water, these particles bind with some of the gly making it less effective. You fill your tank with water first, then add the AMS and agitate. The minerals bind with the AMS. You then add the gly. Since the minerals are tied up with the AMS, they can't bind with the gly.
One more note. Weed management is not quite so straight forward over time. No matter what broad spectrum herbicide we use, some plants will have a natural resistance to it. When we use it repeatedly, we remove less resistant weeds and allow the more resistant weeds to propagate. Over time, we favor specific weeds. In areas with heavy farming, gly has been used for many, many years repeatedly. In these areas, many weeds have developed a resistance to gly. Some weeds have always had a natural resistance even in non-farming areas. Marestail is an example of this. Back when we used gly regularly, Marestail began to dominate the field.
One more thing to think about is this: "What is a weed?". The best definition I've seen is "A plant growing where you don't want it to". For a farmer, anything he doesn't plant is a weed. It is taking resources away from his crop and reducing his yield. To a deer manager, that is not true. Many of the plants farmers call "weeds" are as good or better deer food than the crops we plant for deer. Granted, some are not, especially most non-native grasses. Weeds can be managed as deer food. See this thread for more information:
Weed Management Thread
This doesn't mean we should not use gly or burn-down and plant food plots. I like to do a good burn-down (typically chemical) and no-till plant a plot. After that, I become weed-tolerant in the plot. So, for example let's use clover. I always plant perennial clover in the fall with a winter rye nurse crop. The following spring I'll mow the WR each time it begins to shade out the clover to slowly release it. After that, I only mow once a year right before hunting season. During the subsequent summers we see more and more summer weeds in the plot to the point where you don't even know there is clover in there without looking for it. But after fall mowing and the cool evenings favor clover, it bounces back and dominates the plot for many years. Eventually, the plot needs to be rotated. This is just an example of weed-tolerance.
The final long-term thing to think about is rotating weed management techniques. Gly is a great tool, but should not be the only tool we uses. I like to rotate between using fire, gly, and liberty herbicides for weed control.
There is probably too much information to absorb all at once. I'm just trying to stimulate thought as you progress with your food plotting.
Best of luck!
