The nitrogen in urea releases promptly with a high “burn up opportunity”. Tackle and use with care. Must combine into soil to stop conversion to ammonia and subsequent escape into the air. Sulfur-coated urea is a sluggish-release formulation. Bone meal: Floor-up bones (commonly from cattle) have some nitrogen and calcium, https://mopfertilizerexporteruaet59123.anchor-blog.com/18102003/considerations-to-know-about-agricultural-grade-dap-fertilizer