Soil amendments are made by adding fertilizer to the soil but there are different types of fertilizers. There is bulky organic fertilizer, such as cow manure, bat guano, bone meal, organic compost and green manure crops. And then there is also chemical fertilizer which is also referred to as inorganic fertilizer and is made up with different formulations to suit a variety of specified uses. Though many governments and agricultural departments go to great lengths to increase the supply of organic fertilizers, such as bulky organic manures and composting materials, there is just not enough of these fertilizers available to meet the existing and future fertilizer needs. Compared to organic compost, chemical or inorganic fertilizers also have the added advantage of being less bulky. Being less bulky makes chemical fertilizer easier to transport, both overland and from the soil into the plants itself, because they get to be available to the plant relatively quickly when incorporated as part of the plant-food constituents. Chemical fertilizer usually comes in either granular or powder form in bags and boxes, or in liquid formulations in bottles. The different types of chemical fertilizers are usually classified according to the three principal elements, namely Nitrogen (N), Phosphorous (P) and Potassium (K), and may, therefore, be included in more than one group.