Potassium sulphate, commonly referred to as Sulphate of Potash (SOP), has the chemical formula K2SO4. It is a widely used inorganic fertilizer that provides plants with both essential potassium and sulphur. Unlike potassium chloride (KCl), it is preferred for crops that are sensitive to chloride ions, such as tobacco, potatoes, and certain fruits, as it provides nutrients without the potential toxicity associated with high chloride levels.

Bentonite is a clay mineral known for its swelling capacity and thixotropic properties. In drilling operations, it is used to create a filter cake on the borehole walls, which prevents fluid loss, lubricates the drill bit, and cools the equipment. Its ability to form a stable, impermeable wall is essential for maintaining borehole integrity during the drilling process.

Pedology is the branch of soil science that studies soil in its natural environment. It views soil as a dynamic, natural body that evolves over time through the interaction of climate, organisms, relief, and parent material. Unlike the edaphological approach, which focuses primarily on soil as a medium for plant growth, pedology emphasizes the formation, classification, and mapping of soil as a distinct entity within the Earth's critical zone.

Calcite (calcium carbonate) is a non-silicate mineral because it does not contain the silicon-oxygen tetrahedron structure characteristic of silicate minerals. Non-silicate minerals are categorized into groups such as carbonates, oxides, and sulfates based on their chemical composition. In contrast, minerals like kaolinite, amphibole, and vermiculite are all silicates, which are the most abundant minerals in the Earth's crust and play a major role in soil mineralogy.

A habitat is the specific physical and biological environment that provides the necessary conditions—such as food, water, shelter, and climate—for an organism to survive and reproduce. It encompasses the surroundings where a species naturally occurs. Understanding the habitat is fundamental to ecology and agricultural science, as it dictates the distribution, behavior, and management requirements of various plant and animal species within an ecosystem.

When soil nutrient levels fall below the critical threshold, crops are expected to show a positive response to fertilizer application. The critical level is the concentration below which yield increases significantly upon nutrient addition. This threshold varies by crop and nutrient, marking the transition point between deficiency and sufficiency in plant nutrition.

Nitrogen (N), Phosphorus (P), and Potassium (K) are the primary macronutrients required by plants in large quantities. Nitrogen is vital for amino acid and chlorophyll synthesis. Phosphorus is a structural component of nucleic acids (DNA/RNA) and energy transfer molecules like ATP. Potassium acts as an enzyme activator and regulates turgor pressure and stomatal function. These three elements are essential for biomass production and overall plant health.

DTPA (Diethylenetriaminepentaacetic acid) is the most widely accepted chelating agent used for the extraction and estimation of plant-available micronutrients like iron, zinc, copper, and manganese. Developed by Lindsay and Norvell, the DTPA test is effective because it mimics the ability of plant roots to extract these metals from the soil solution and solid phase, providing a reliable index of potential nutrient deficiency.

Conservation is a multifaceted approach that includes the protection, sustainable management, and efficient utilization of natural resources. It aims to prevent the depletion of biodiversity and essential environmental functions, such as nutrient cycling. By ensuring that resources are used wisely and protected from degradation, conservation efforts guarantee that ecosystems remain functional and resilient, providing necessary services for both current and future generations of all living organisms.

The greenhouse effect is primarily driven by the accumulation of greenhouse gases, such as carbon dioxide (CO2), methane, and nitrous oxide, in the atmosphere. These gases trap outgoing long-wave infrared radiation emitted from the Earth's surface, preventing it from escaping into space. The significant rise in atmospheric CO2 concentrations, largely due to human activities, is the leading cause of global warming and enhanced greenhouse effects.