Enhance your understanding of agronomy concepts with this easy quiz tailored to the ICAR AIEEA PG Agronomy exam. Test your grasp of crop management, environmental factors, and sustainable agriculture practices essential for postgraduate agricultural studies.
Which of the following substances is primarily responsible for the reduction of ozone concentration in the atmosphere?
Explanation: Chlorofluorocarbons (CFCs) and chlorine (Cl2) release chlorine atoms that directly contribute to the destruction of ozone molecules in the stratosphere. Carbon dioxide (CO2) and oxygen (O2) do not destroy ozone, though CO2 is a greenhouse gas. Hydrogen sulfide (H2S) and methane (CH4) are also not linked with ozone depletion, and nitrogen (N2) and nitrous oxide (N2O) have a minimal effect on the ozone layer compared to CFCs.
Why is crop rotation considered a sustainable practice in agronomy?
Explanation: Crop rotation helps break the life cycle of pests and diseases by changing the type of crop grown each season. This method does not increase pesticide use; instead, it reduces dependency on chemicals. Crop rotation improves, rather than reduces, soil fertility, and it usually lessens the risk of soil erosion due to varied root structures.
What is the main role of nitrogen in plant growth, for example, in cereal crops?
Explanation: Nitrogen is a central component of chlorophyll, the molecule responsible for photosynthesis and the green color of plants. While nitrogen does support some root growth, other nutrients like phosphorus are more directly linked to root development. Increased pest resistance and decreased water needs are not direct results of nitrogen application.
What is the primary advantage of drip irrigation for crops compared to flood irrigation?
Explanation: Drip irrigation delivers water directly to the plant root zone, minimizing losses due to evaporation or runoff and increasing irrigation efficiency. Unlike flood irrigation, it limits water wastage. Drip systems do not typically cause more soil salinity or decrease yields; rather, they often improve productivity. The opposite, increasing water wastage, is not a benefit.
Which agricultural benefit is most commonly associated with the symbiotic relationship between leguminous plants and Rhizobium bacteria?
Explanation: Rhizobium bacteria live in the root nodules of leguminous plants and help convert atmospheric nitrogen into forms usable by plants, enriching soil nitrogen content. This relationship does not reduce sunlight absorption or cause excessive water loss. Soil compaction is unrelated; in fact, legume cultivation can improve soil structure.