Finally, the cost of turning horse manure into organic fertilizer is essential. In general, from composting to packaging, a complete horse manure powder fertilizer making line needs an investment of $30,000-$100,000. While you need to prepare $ 100,000-$550,000 for a whole set of horse manure pellet making line machines. In addition, the smaller the capacity and the less the equipment, the lower the cost. The larger the scale and the more the equipment, the higher the investment.