Fertilizer is a material that is added to soil to improve its fertility and promote plant growth. The crossword solutions for the term FERTILIZER include GUANO (5 letters), COMPOST (7 letters), MARL (4 letters), MANURE (6 letters), POTASH (6 letters), NITRATE (7 letters), PLANTFOOD (9 letters) and SPERMCELL (9 letters). GUANO is a type of fertilizer made from bird droppings, while COMPOST is a mixture of decaying organic matter used as a soil amendment. MARL is a type of soil composed of clay and calcium carbonate, while MANURE is a type of organic fertilizer made from animal waste. POTASH is a type of potassium-rich fertilizer, while NITRATE is a type of nitrogen-rich fertilizer. Plantfood is a type of fertilizer specifically designed for plants, while spermcell is a type of fertilizer made from fish eggs.