Poor agricultural practices such as burning of land and over cultivation or monoculture cause soil to be deficient in some mineral nutrient leading to loss of soil fertility
other human activities such as quarrying and construction of roads interfere with soil structure leading to sail degeneration
soil erosion interfere with soil structure leading to loss of top fertile soil
excessive drought leads to accumulation of salts in the topsoil making it saline
leaching due to heavy rainfall can lead to percolation of soil nutrients to the lower horizons leading to deficiency of nutrients to the topsoil
Excessive or wrong application of fertilizers may affect the soil PH making it acidic interfering with soil microorganisms.