If compost is less than 40 percent organic matter and is not dark brown in color, then it will make soil less fertile and will worsen soil drainage. In the best garden compost, the organic matter is completely decomposed. Compost that is 80 percent organic matter has probably not decomposed sufficiently. Compost that is dark brown in color and emits a strong ammonia smell is not good garden compost.
Any good garden compost may appropriately be used for soil drainage and fertility. The best compost is 40 to 60 percent organic matter and is dark brown in color. However, compost that emits a strong ammonia smell should not be used for drainage and fertility, for that smell means that the organic matter has not sufficiently decomposed.
Which one of the following is most strongly supported by the information above?