Here is what I found....
Chloramines make the water acidic which over time can change soil pH. This may result in nutrient tie-up and create yellowing (chlorosis) problems in many plants. Chloramines prevent the absorption of other nutrients which also may lead to yellowing.
The action of chlorine and chloramines kill bacteria both good and bad. Many good bacteria that live in the soil control fungal diseases. When we lose these good bacteria there is no natural control and turf grass diseases like "Brown Patch, Take All and St. Augustine Decline" become rampant. In other words the more one waters, the greater the chance that one will experience disease problems in their grass and other plants.
Chlorine and chloramines kill the nitrifying bacteria that fix nitrogen from the air into the soil. Hence additional nitrogen must be supplied to the plants to replace the loss of free nitrogen from nature.
Container plants (hanging baskets, pots, etc.) are more susceptible to damage from chloramines as they tend to require more watering.
Studies have shown that chloramines hurt the germination of seeds from many species of plants.
Chloramine is neutralized in the soil by reactions with organic matter, destroying it in the process. Organic matter in the form of humus can hold 15 times its weight in water, hence the soil loses some of its ability to hold and store water.
Chloramine hurts the production of compost tea as it kills off some of the microbial species that one is trying to grow to high densities. Note: One teaspoon of humic acid (liquid form of humate) can neutralize the chloramines in 100 gallons of water depending on the exact concentration of chloramines.
Using high humus products like compost, native mulches (that have been composted) and humate in ones landscape is the easiest way to minimize the damage from chloramines and chlorine. This ensures that even if some of the organic matter is destroyed and some of the beneficial microbes are killed, the soil life can quickly regenerate and prevent problems.
