Fertiliser

Fertiliser also feeds the soil and comes in a nice handy box or bottle that's cheap and easy to use. So why not just use fertiliser instead of mulching, or as well as? I liken the use of fertiliser to our own diets as humans. You might read about how good for you apples are, for example. But if you then decide to eat a hundred apples, you are very likely to get a stomach ache (at best!) and the health benefits wouldn't last long. A few days later you'd be lacking in Vitamin C again if you hadn't eaten any other type of fruit or vegetable since. This is much like fertiliser, especially the liquid forms. It floods the soil with food. Much of it is washed away but what remains creates chaos amongst the ecosystem. The microorganisms at the bottom of the food chain go on a huge binge and a short while later all the food is gone. Then those microorganisms die, leaving a brief binge opportunity followed by a period of starvation for the next layer of the soil food chain and the knock-on-effect ripples throughout the system. Plants also get to have a good binge on the intense supply of nutrients, often creating a burst of luscious growth that gives the impression of a health impact. However because it is so brief, the plants often then become weak and vulnerable. 

Fertiliser that comes in a box is usually in pellets and more recently "slow release" versions are being made available and are marketed as being better for the environment. This is because there is less leaching of nutrients and they break down more slowly in the soil. This is a much better option than liquid fertiliser but still falls short of how compost, merely laid on top of the soil, provides the right nutrients and fibrous material that plants, microorganisms and fungi are naturally adapted to working with. The result is a more robust soil ecosystem and more robust plants.