* High Nitrogen Content: Horse urine is extremely concentrated in nitrogen. While nitrogen is a vital nutrient for grass, too much of it can overwhelm the plant's system.
* High pH: Horse urine is also alkaline, meaning it has a high pH. This high pH can burn the grass, causing yellowing, browning, and even wilting.
* Salt Concentration: Horse urine contains significant amounts of salts. These salts can build up in the soil, making it difficult for grass to absorb water and nutrients.
* Urine Spots: Horses tend to urinate in the same spots, creating concentrated areas of high nitrogen, high pH, and salt buildup. This intensifies the damage to the grass.
What can be done?
* Spread the "wealth": Moving horses frequently can help spread out the urine and reduce the concentration in specific areas.
* Water and dilute: Watering the affected areas can help dilute the urine and wash away some of the excess nitrogen and salts.
* Soil amendments: Adding organic matter to the soil can help buffer the pH and improve the soil's ability to absorb nutrients.
* Selective grazing: Rotating pastures and giving horses access to different areas can help prevent excessive damage to any one section.
It's important to note that some grasses are more tolerant of horse urine than others. However, even the most tolerant varieties will suffer if exposed to excessive urine over time.