Soils, Crops and Fertilizer Use: Chapter 9: Using chemical fertilizers: What are chemical fertilizers?

Soils, Crops and Fertilizer Use

Chapter 9: Using chemical fertilizers

		What are chemical fertilizers?
		Are chemical fertilizers appropriate for limited-resource farmers?
		An introduction to chemical fertilizers
		Common chemical fertilizers and their characteristics
		The effect of fertilizers on soil pH
		Fertilizer salt index and "burn" potential
		Basic application principles for N, P, and K
		Fertilizer application methods explained and compared
		Troubleshooting faulty fertilizer practices
		Getting the most out of fertilizer use: crop management as an integrated system
		Understanding fertilizer math

What are chemical fertilizers?

As opposed to organic fertilizers which originate from plants and animals (compost, manure, etc.) or are unprocessed minerals like raw rock phosphate, chemical fertilizers are derived from a chemical manufacturing or synthesizing process. Some examples are urea fertilizer (45-46 percent N) made from carbon dioxide and ammonia, or single superphosphate 18-21 percent P₂O₅) made from combining rock phosphate and sulfuric acid.