Lots of issues with non-green yards around here may be years of watering with high SAR (sodium adsorption ratio) water, especially in the swelling clays and gumbo around here with little or no percolation.
http://en.wikipedia.org/wiki/Sodium_adsorption_ratioAccording to WIKI: If irrigation water with a high SAR is applied to a soil for years, the sodium in the water can displace the calcium and magnesium in the soil. This will cause a decrease in the ability of the soil to form stable aggregates and a loss of soil structure and tilth. This will also lead to a decrease in infiltration and permeability of the soil to water leading to problems with crop production.
I know I have run SAR tests on water and spoken with a lot of ag experts on my hay crops and have learned this from the results (40+ SAR values) of the tests and the advice they have given. Basically, We have enough rain during average seasons that, coupled with higher permeable soils, will offset the effects of watering with the local high sar stuff. BUT, if it is not permeable soil and we are in a drought, some damage will occur. Once the permeability has been severely effected, it requires some mechanical intervention to deal with it, to the best of my understanding.
[This message has been edited by Yuccadoo (edited 3/19/2014 1:33p).]