The correct answer is: d) All of the above.
Soil fertility is the ability of a soil to sustain plant growth. It is influenced by a number of factors, including parent material, climate, vegetation, and management practices.
Parent material is the material from which the soil was formed. It can be rock, sediment, or organic matter. The type of parent material affects the soil’s texture, structure, and nutrient content.
Climate affects the soil through temperature and precipitation. Temperature affects the rate of decomposition of organic matter and the availability of nutrients. Precipitation affects the amount of water in the soil and the leaching of nutrients.
Vegetation affects the soil through root growth, litterfall, and nutrient cycling. Root growth helps to aerate the soil and improve drainage. Litterfall adds organic matter to the soil and provides nutrients for soil organisms. Nutrient cycling helps to keep nutrients in the soil and available for plant growth.
Management practices, such as tillage, irrigation, and fertilization, can also affect soil fertility. Tillage can improve drainage and aeration, but it can also compact the soil and reduce organic matter content. Irrigation can provide water for plant growth, but it can also leach nutrients from the soil. Fertilization can add nutrients to the soil, but it can also pollute groundwater if not done properly.
In conclusion, soil fertility is influenced by a number of factors, including parent material, climate, vegetation, and management practices. These factors interact in complex ways to determine the productivity of a soil.