Compost can help improve horse pasture soil quality. | Photos.comQ: My horse pastures have not been as healthy as Id like, and I must feed my horse more hay than most people living in my area to be sure hes getting enough forage. I know soil health is the first step to cultivating healthier horse pastures. How can I be sure my pasture soil is healthy and can support the grasses I want growing?A: Healthy soil in horse pastures can allow grasses to function to their highest potential with minimal support, says Brad McIntyre, a farmer in Southwestern Idaho with productive organic pastures and an interest in soil health.Soil is part of a natural system, created way before us, says McIntyre. Animals are part of that natural ecosystem (too), he adds, noting that their manure and urine help build a healthy pasture environment.Here are McIntyres Top 4 tips for creating healthy horse pastures.1.Grazing HeightKeep pasture grass at least 4 inches tall; dont let horses graze them any shorter. Grasses shed rootsthe roots change color from bright white to gray, then brown, and eventually black as the plant tissues dieand their roots are typically as long as the plant stand. If horses overgraze plants every day, the grass constantly sheds its roots, making it shorter. When horses overgraze a pasture, they often wipe out the desirable grass species, leaving room for undesirable species to take over. 2. CompostCompost provides a rich source of nutrients and beneficial microbes. Composting involves encouraging microbes to break down organic material into a soil amendment that acts as a long-term, slow-release fertilizer. On horse farms this typically includes animal manure, stall waste, and dead plant material. Compost manure and other organic matter on your farm and reapply it to your pastures to encourage beneficial plant growth.3. WaterWater and sun can go a long way in improving horse pasture soil health. If you live in a hot and dry environment, you might need to irrigate your pastures to improve growth. But, if you add too much water, you might essentially drown the desirable grasses in your pasture. Plants prefer a heavy amount of water, then a period of rest to regrow. Typically, McIntyre irrigates for 24 hours every seven to 10 days.4. Rest PasturesLet your pasture rest and your grasses seed out after grazing periods. Then turn your animals back out to graze; as they move and eat, theyll press the seed heads into the soil. In effect, you get a free reseeding. McIntyre aims to do this every few years.Take-Home MessageHealthy soil drives better horse pasture growth. To protect it, make sure your grass stays a few inches tall. Work with whats free. Its a natural system, says McIntyre. Healthy soil leads to healthy pastures and, in turn, healthy horses and a healthier planet, he adds.