Soil Science and Fertilizers

Bacteria and fungi carry out the decomposition of plant residues, breaking them down and holding the nutrients in their bodies, this prevents the nutrients leaching out into the soil. They hold the nutrients until the nutrients are consumed- by protozoa, nematodes and then release the remaining nutrients in plant available form.

Lime (calcium carbonate or calcium hydroxide) is an alkaline substance used to raise the pH of acidic soils, neutralizing the acidity. Gypsum, on the other hand, is typically used to treat alkaline or sodic soils.

Soil pH, nutrient levels, and day length are physical and chemical components of an environment that do not derive from living organisms, classifying them as abiotic factors.

Fertile soil is rich in nutrients and highly capable of supporting abundant plant growth. Early agricultural civilizations settled near river valleys because the flooding left behind fertile soil ideal for farming.

Decomposers, such as fungi and bacteria, are responsible for breaking down dead organic material and returning essential nutrients to the soil.

In a mycorrhizal association, the fungus provides the plant with minerals and water, while the plant provides the fungus with carbohydrates and other organic compounds.

Soil provides the necessary nutrients, water retention, and physical support required for plants to grow. Water alone is used in hydroponics, but soil is the standard medium for general plant growth.

Unlike the carbon, nitrogen, and water cycles, the phosphorus cycle does not include a significant gaseous phase. Phosphorus primarily cycles through soil, water, and living organisms.

Decomposers are organisms that break down dead organic matter, thereby recycling nutrients back into the ecosystem. Bacteria and fungi are classic examples of this role.

Citrus rinds are generally avoided in home compost piles because they are acidic and can contain oils that inhibit the beneficial bacteria and worms needed for composting.

Inorganic fertilizers from Midwestern farms wash down the Mississippi River, carrying nitrogen and phosphorus into the Gulf of Mexico. This causes algal blooms that deplete oxygen, creating a 'dead zone' (hypoxia) where marine life cannot survive. Note: option D has a typo ('Gulf' misspelled as 'Guld').

Inorganic fertilizers are water-soluble and can be quickly leached from soil by rain or irrigation before plants absorb them. This wastes money, pollutes waterways, and requires frequent reapplication. Organic fertilizers release nutrients more slowly. Note: option B has a typo ('easy' misspelled as 'esay').

Soil erosion is the process by which the top layer of soil is removed by wind or water. Since soil formation is a very slow process, preventing erosion is critical for maintaining soil health.

Humus is the organic component of soil, formed by the decomposition of leaves and other plant material. It is rich in nutrients, making it excellent for growing plants.

Humus is formed from decayed organic matter. As it decomposes, it releases essential nutrients like nitrogen, phosphorus, and potassium back into the soil, which plants absorb.