Fertilizers are the synthetic or naturally occurring chemical compounds applied to soil to supply plant nutrients for growth. The nutrients in fertilizers are present in higher concentration and in forms which can be readily applied by the plants directly or after rapid transformation.
Being concentrated in nutrient elements the fertilizers have the advantage of smaller bulk but their dose can be adjusted to suit the requirements as determined by soil fertility evaluation nature and commercial mode of supply fertilizers are classified as straight, complex and mixed.
Fertilizers form a wide group of agro- chemicals based on nutrient content i.e. Single or more on the basis of chemical nature and commercial mode of supply fertilizers are classified as straight, complex and mixed. When a fertilizer contains and used for supplying a single nutrient, it is called straight fertilizers e.g. – Nitrogenous fertilizers.
When a fertilizer contains and used for supplying a single nutrient, it is called straight fertilizers e.g. – Nitrogenous fertilizers. When a fertilizer contains two more nutrients in one compound, it is compound fertilizer where as mixed fertilizers are mixture of two or more straight fertilizers.