I've had similar results with alfalfa as it isn't the greatest fertilizer but good for use in the middle of summer when you don't necessarily want a lot of growth out of cool season grasses. It has a lot of nutrients that provide for even feeding throughout the year but if you want to see greening results out of a grain then you can't beat soybean (unless you have money or cheap access to CGM). Try that and see how it works for you in 3 weeks (I've had great results). Otherwise don't think you've just wasted time with the alfalfa, you've still given the soil some good nutrients!

I've never been a big fan of the weeds as indicators concept. I think part of the reason is that I spilled some 21-0-0 fertilizer (years ago, when I was using it) and it killed the grass in that area. The first thing that popped up there was black medic, supposedly a sign of nitrogen deficiency. I'm now convinced that clover (or black medic) popping up is a sign that you had seeds there ready to germinate.

What do you mean when you say your soil is slightly sweet? I think I've heard of soils being described as sweet or sour, but I don't really know what it means.

I'm not a big fan of spreading sulfur over a lawn. My soil is alkaline, but spreading the sulfur on the surface never seemed to help. I've targeted specific plants by drilling holes around the drip line with a bulb auger, pouring sulfur in the holes, then filling back up with soil. If it's spread on the surface, too much of it goes into the atmosphere.

For a large surface area like a lawn, you'll probably have better results just trying to increase the organic content of the soil.

Sweet=Alkaline, Sour=Acidic (think lemons).

I thought turfgrass liked a slightly high to neutral pH. So does slightly sweet mean it's above neutral pH or that the pH is slightly too high for your grass?

Yes my soil is alkaline according to my soil test (pH is 7.5, test says grass likes 6.5 to 7.0). I've decided to forgo the sulfur as this will save some $$ and as we are naturally alkaline I'd have to keep doing it. Seems silly. Having it more in the range recommended makes your lawn take up the nutrients more easily but I think I may be better to invest the $$ in more alfalfa or CGM which will also increase organic matter.

Sharon

Old timey farmers, my grandfather included, claimed they could judge the pH of their soil by taste, hence "sweet" and "sour" soils. I'll confess I've tried it but maybe my dirt palate isn't as refined as it needs to be. I can't tell any difference at all.