The current cost of fertilizer, corn, and land has many livestock owners wondering how to stay profitable. Unfortunately there are not quick solutions. This article on nutrient cycling in pastures should help. I have condensed it for quicker reading.
Appropriate pasture management can enhance the nutrient cycle, increase productivity, and reduce costs. Two practical indicators of soil health are the number of earthworms and the percentage of organic matter in the soil.
Paddock design and stocking density can also affect the efficiency of nutrient cycling in a pasture system. Supplementation of natural fertility, based on soil tests, balances the soil's mineral composition, resulting in better plant and animal growth and increased soil health.
When nutrients cycle efficiently in a pasture system, they move through various soil organisms and pasture plants, then through the grazing animals, and back to the soil again as manure and urine.
With good management, nutrients can cycle quickly with minimal losses to air and water. Less fertilizer will be required, and this means increased profitability for the entire farm.
Good-quality soils produce good-quality pastures. Good-quality soils don't erode, since water flows quickly into the ground and is stored there. Good-quality pastures are springy underfoot, with deep green forage that covers the soil and a moderate amount of dead residue under the canopy. They produce nutritious forage with balanced mineral levels. Livestock find these forages palatable and thrive on them.
Producers create this kind of soil through good management. Using smart grazing strategies, testing soils regularly and applying fertilizers, lime, and organic amendments as needed.
Organic matter is critical for storing water and nutrients in the soil. It holds nutrients in plant-available forms that don't easily wash away. It creates an open soil structure into which water, dissolved minerals, and oxygen can move, ready for plants to use. It provides further nutrient storage in the soil and can disable certain plant toxins.
Trees, many broadleaf weeds, and forages such as alfalfa have taproots that go deep into the soil horizon where some grass roots cannot reach. The nutrients from these deeper soil levels are used by the plant, but become available at the soil surface once the tree leaves fall or the weeds die, decompose, and release their nutrients.
The roots constitute at least half the weight of a grass plant. Many native warm-season perennial grasses have root systems that reach six feet or more into the soil horizon. They occupy a huge underground area and form a network that holds the soil in place. Every year 20-50% of this mass, as well as all of the top growth in temperate climates, dies and becomes organic matter.
Grazing Livestock Affect Pasture Nutrient Cycles
Livestock feeding on pasture use a small proportion of the minerals they ingest in forages to build bones, meat, and hide. The rest is excreted in dung and urine. In general, urine contains most of the nitrogen (N) and potassium (K) wastes, and dung contains most of the phosphorus (P) the animals don't use.
Value Of NPK In Manure And Urine
|One 1000-pound cow produces 50-60 lbs. of manure and urine per day, which contains:
| 0.35 lb. N @ 38¢/lb.
|| = 13¢ N
| 0.23 lb. P @ 50¢/lb.
|| = 11¢ P
| 0.28 lb. K @ 28¢/lb.
|| = 10&c