How and for what purpose is hummus used in the garden?
Think of humus as being a big sponge that can hold up to 90% of it’s weight in water. This water holding capacity of humus is why humus rich soil will remain moist for weeks longer than soil without humus.
Humus is left after organic matter decomposes. Each time you add organic matter to the soil, it will increase the amount of humus in the soil. It is a slow process but if organic matter is added each year, the amount of humus will continue to increase.