Ecology, Environment and Climate Change in Agriculture MCQs 2026
50 questions with detailed answers · 0 from past papers · 5 quiz batches available
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- Q1 medium
The farming system formed by crops, livestock, soil organisms and their physical environment is best called
💡 Explanation:An agroecosystem is an ecosystem deliberately managed for agricultural production and includes biotic and abiotic components.
- Q2 medium
The ecological rule stating that only a small fraction of energy passes to the next trophic level is the
💡 Explanation:In food chains, roughly 10 percent of energy is transferred to the next trophic level while most is lost as heat and metabolism.
- Q3 medium
The nutrient most commonly limiting crop productivity in many intensively cultivated agroecosystems is
💡 Explanation:Nitrogen is required in large amounts for proteins and chlorophyll, and it is often depleted quickly by crop removal and leaching.
- Q4 medium
Using predators, parasitoids or pathogens to suppress an agricultural pest is known as
💡 Explanation:Biological control uses natural enemies of pests and is a core component of ecologically based pest management.
- Q5 medium
Storing atmospheric carbon in soil organic matter and plant biomass is termed
💡 Explanation:Carbon sequestration removes carbon dioxide from the atmosphere and stores it in relatively stable soil or biomass pools.
- Q6 medium
Flooded rice fields mainly emit which greenhouse gas because of anaerobic decomposition
💡 Explanation:Under flooded anaerobic conditions, methanogenic microbes produce methane from organic matter in rice soils.
- Q7 medium
The soil component that improves aggregation, cation exchange capacity and water holding is
💡 Explanation:Soil organic matter binds particles into aggregates and increases nutrient and water retention.
- Q8 medium
Nutrient enrichment of water bodies that causes algal blooms is called
💡 Explanation:Excess nitrogen and phosphorus in runoff stimulate algal blooms and oxygen depletion, the process called eutrophication.
- Q9 medium
Combining cultural, biological, mechanical and chemical tactics based on pest thresholds is called
💡 Explanation:Integrated pest management uses compatible measures and applies pesticides only when pest populations justify control.
- Q10 medium
A row of trees planted to reduce wind speed and wind erosion around fields is known as
💡 Explanation:Shelterbelts reduce wind velocity, protect crops, and lower the risk of wind erosion and moisture loss.
- Q11 medium
Chlorofluorocarbons are most closely associated with which environmental problem
💡 Explanation:CFCs release chlorine radicals in the stratosphere, which catalytically destroy ozone molecules.
- Q12 medium
The 2015 international agreement aimed at limiting global temperature rise is the
💡 Explanation:The Paris Agreement under the UNFCCC seeks to limit warming well below 2 Celsius and pursue 1.5 Celsius efforts.
- Q13 medium
Growing a crop such as sesbania or mungbean and incorporating it into soil to add organic matter is
💡 Explanation:Green manure crops are incorporated while green to supply organic matter and often nitrogen to the soil.
- Q14 medium
Changing crops in a planned sequence on the same field mainly helps break pest cycles and maintain soil fertility; this practice is
💡 Explanation:Crop rotation interrupts host-specific pests and diseases and balances nutrient demand better than continuous monoculture.
- Q15 medium
The method used to evaluate environmental impacts of a product from inputs through disposal is
💡 Explanation:Life cycle assessment estimates impacts across stages such as production, transport, use and end-of-life disposal.
- Q16 medium
The tillage approach that leaves residues on the soil surface and minimizes soil disturbance is
💡 Explanation:No-till and conservation tillage reduce erosion, protect soil structure and can improve soil carbon retention.
- Q17 medium
The combined loss of water from soil evaporation and plant transpiration is
💡 Explanation:Evapotranspiration is the total water vapor flux from soil surfaces plus plant transpiration.
- Q18 medium
Conserving crop landraces in their natural farming areas is an example of
💡 Explanation:In-situ conservation preserves genetic resources in the habitat or farming system where they evolved and are maintained.
- Q19 medium
The gradual replacement of one plant community by another over time is called
💡 Explanation:Ecological succession is a directional change in community composition after disturbance or during habitat development.
- Q20 medium
The warming effect caused when atmospheric gases absorb outgoing longwave radiation is the
💡 Explanation:Greenhouse gases absorb infrared radiation emitted by Earth, raising the lower atmosphere temperature.
- Q21 medium
Tillage and planting across a slope along lines of equal elevation is called
💡 Explanation:Contour farming slows runoff by aligning field operations along contours rather than up and down the slope.
- Q22 medium
The microbial conversion of nitrate into nitrogen gases under anaerobic soil conditions is
💡 Explanation:Denitrifying bacteria reduce nitrate to gases such as N2O and N2 when oxygen is limited.
- Q23 medium
The variety of genes, species and ecosystems in a region is called
💡 Explanation:Biodiversity includes genetic diversity, species diversity and ecosystem diversity.
- Q24 medium
The United Nations body that assesses scientific knowledge on climate change is
💡 Explanation:The IPCC reviews and assesses climate science, impacts, adaptation and mitigation for policymakers.
- Q25 medium
The land-use system that deliberately combines trees with crops or livestock is
💡 Explanation:Agroforestry integrates woody perennials into agricultural fields or farms for ecological and economic benefits.
- Q26 medium
The accumulation of soluble salts in the root zone due to poor irrigation and drainage is
💡 Explanation:Salinization occurs when evaporation leaves salts behind and drainage is insufficient to leach them.
- Q27 medium
The symbiotic association between plant roots and fungi that improves phosphorus uptake is
💡 Explanation:Mycorrhizal fungi extend the effective root absorbing area and commonly improve phosphorus acquisition.
- Q28 medium
The measure of biologically productive area needed to supply resources and absorb wastes for a population is
💡 Explanation:An ecological footprint expresses human demand on productive land and water area in comparable units.
- Q29 medium
The most abundant long-lived anthropogenic greenhouse gas emitted globally by human activities is
💡 Explanation:Carbon dioxide is emitted in the largest quantity globally from fossil fuel combustion, land-use change and industry.
- Q30 medium
The conservation agriculture principle set includes minimum soil disturbance, permanent soil cover and
💡 Explanation:Conservation agriculture rests on minimum disturbance, soil cover and diversification through rotations or associations.
- Q31 medium
The charcoal-like product of heating biomass under limited oxygen that can improve soil carbon storage is
💡 Explanation:Biochar is produced by pyrolysis and can persist in soil while improving some soil physical and chemical properties.
- Q32 medium
A species whose presence or absence signals a particular environmental condition is an
💡 Explanation:Indicator species are sensitive to environmental conditions and therefore reflect habitat quality or pollution status.
- Q33 medium
Rainfall made more acidic mainly by sulfur and nitrogen oxides is known as
💡 Explanation:Sulfur dioxide and nitrogen oxides form acids in the atmosphere, lowering rainwater pH.
- Q34 medium
The pest density at which control action should begin to prevent economic loss is the
💡 Explanation:The economic threshold is lower than the economic injury level and signals when control should be started.
- Q35 medium
The microbial oxidation of ammonium first to nitrite and then nitrate is called
💡 Explanation:Nitrification is an aerobic process that converts NH4+ to NO2- and then NO3-.
- Q36 medium
The index comparing the heat-trapping ability of a gas with carbon dioxide over a set time is
💡 Explanation:Global warming potential expresses the relative warming effect of a greenhouse gas compared with CO2.
- Q37 medium
The irrigation method usually most efficient for delivering water directly to the crop root zone is
💡 Explanation:Drip irrigation applies small amounts near roots, reducing conveyance, runoff and evaporation losses.
- Q38 medium
Breaking a large continuous habitat into smaller isolated patches is termed
💡 Explanation:Habitat fragmentation reduces continuous habitat area and can isolate populations, affecting biodiversity.
- Q39 medium
In water footprint terminology, surface water and groundwater consumed in production are called
💡 Explanation:Blue water refers to irrigation or other use of surface and groundwater resources.
- Q40 medium
A major agricultural consequence of declining bees and other pollinators is reduced
💡 Explanation:Many fruits, oilseeds and vegetables depend on animal pollination, so pollinator decline lowers fruit and seed formation.
- Q41 medium
Growing one crop species over a large area or repeatedly on the same land is called
💡 Explanation:Monoculture simplifies management but often increases vulnerability to pests, diseases and market or climate shocks.
- Q42 medium
The increase in concentration of persistent toxins at higher trophic levels is
💡 Explanation:Persistent chemicals can accumulate in organisms and become more concentrated through food chains.
- Q43 medium
A prolonged period of abnormally low rainfall causing crop moisture stress is
💡 Explanation:Drought is a sustained moisture deficit that reduces crop growth, yield and water availability.
- Q44 medium
The approach that aims to increase productivity, strengthen adaptation and reduce emissions where possible is
💡 Explanation:Climate-smart agriculture has three linked aims: productivity, adaptation or resilience, and mitigation where feasible.
- Q45 medium
Agriculture that meets present food needs while conserving resources for future generations is
💡 Explanation:Sustainable agriculture balances productivity, profitability, environmental quality and social responsibility over time.
- Q46 medium
The fraction of incoming solar radiation reflected by a surface is called
💡 Explanation:Albedo is surface reflectivity; lighter surfaces generally reflect more radiation than darker surfaces.
- Q47 medium
Preserving seeds or plant genetic material in a gene bank is an example of
💡 Explanation:Ex-situ conservation maintains genetic resources outside their natural habitat, such as in seed banks or field gene banks.
- Q48 medium
Leaving crop residues as a soil cover mainly reduces evaporation and
💡 Explanation:Residue mulch absorbs raindrop impact, slows runoff and shields the soil surface from evaporation and erosion.
- Q49 medium
The capacity of an agroecosystem to absorb disturbance and recover function is called
💡 Explanation:Resilience is the ability of a system to withstand shocks such as drought, pest outbreaks or floods and regain function.
- Q50 medium
The greenhouse gas with high warming potential commonly emitted from nitrogen fertilizers and manure is
💡 Explanation:Nitrous oxide is released during nitrification and denitrification of reactive nitrogen in soils and manure systems.