Many of the materials for lawn fertilization are cheap: you already have them in the garden (plant and animal waste), or in the house (waste that can be turned into compost).
How to make natural fertilizers
Maceration of plant debris
Maceration of plant debris is a natural process by which plants are allowed to decompose over time, with or without the aid of water. Some plants contain large amounts of nutrients and are widely used in the production of some of the best fertilizer for grass.
Biohumus is one of the most powerful fertilizers. It has a neutral pH, it improves soil aeration, and it retains the necessary moisture. Moreover, it contains all the necessary substances for the soil and allows for ideal drainage.
Compost is obtained by breaking down plant debris (grass, leaves, kitchen waste) and is used to improve the functions and the physical and chemical properties of the substrate. The compost turns into humus over time, which helps to revitalize infertile soils.
Mulch is a layer of organic matter (plant debris, straw, leaves) that covers the soil to protect it from the sun and drying. It also protects plants from some diseases and pests. When mulch decomposes, it will release the necessary nutrients into the soil.