Hmm never had rust and sounds like I hope I never have to put up with it! How big is the lawn? I would stay on schedule with giving the grass plant what it needs in an infrequent deep heavy watering when you see the plant stress. It might be OK to go ahead with the soybean meal as it is a pretty effective growth stimulant. It seems rust likes conditions when they favor a slowdown in grass growth. Otherwise the only thing I could recommend would be an additional monthly dose of corn meal/cracked corn of 20lbs/1000sqft to combat that fungus. You shouldn't have to worry about over fertilizing since it is kind of a weak protein base. If you are real ambitious I would hit it with a good blast of compost tea as a foliar soak to increase microbial diversity and hopefully balance out the conditions and impede further rust spread. I have a powdery mildew issue I never fully got rid of since I put the sod down (3 years). In my second year of organics, I'm starting to give the shady area (powdery mildew infected section) of the lawn big doses of cracked corn as fast as it can decompose. I figure I'll have an infestation of beneficial trichoderma all over my soil and hopefully it squeezes out the bad fungus. Good luck.

According to the people who write in here, corn meal does nothing against rust or red thread. However, research from Brazil indicates that milk is effective against those two diseases. I supposed it would not hurt anything to use it at any strength. The dilution used in the research was 3 ounces of milk per gallon to cover 1,000 square feet.

Here is a link that might be useful: Link to Abstract of Brazil Study on Powdery Mildew

Thanks dchall! Always nice to find out new (and possibly effective) means of combating diseases. Time to dump some milk in my sprayer and start experimenting. I just wish it weren't 3 bucks a gallon!

If you are having habitual problems with rust then you should consider applying more nitrogen. It is one of the very few diseases that indicates too little nitrogen. Milk and cornmeal apps are great but its easier not to have the issue in the first place.