Environmental Factors Affecting Crop Production

These flashcards cover critical concepts from the lectures on environmental factors affecting crop production.

What is the formula for phenotype in relation to genotype and environment?

Phenotype = Genotype (G) + Environment (E) + (G x E)

What does 'G' represent in the formula for phenotype?

G represents the genotype or variety.

What type of environmental factors affect crop production?

Abiotic and biotic factors.

What are abiotic factors?

Non-living environmental factors such as climatic and edaphic (soil) factors.

Name three types of abiotic stresses affecting crops.

Drought, salinity, and acidity.

What are biotic factors?

Living environmental factors such as pests and beneficial organisms.

Define climate.

Long-term weather patterns including temperature, precipitation, and wind.

Define weather.

Atmospheric conditions in any area at a given time, including sun, cloud, temperature, wind, and rain.

What is the difference between climate and weather?

Climate is what you expect (long-term), while weather is what you get (short-term).

What is solar radiation's role in agriculture?

It is the most important climatic factor influencing agricultural productivity.

What does 'albedo' refer to in environmental science?

The fraction of solar energy reflected from the Earth back into space.

What is photoperiodism?

Plant response to the length of day and night as conditioned by daylength.

What is the significance of temperature in plant processes?

Affects chemical, physiological, and biochemical processes, including growth and development.

Name classifications of crops based on temperature requirements.

Cool season, warm season, tropical, and sub-tropical.

What are Growing Degree Days (GDD)?

A measurement of the departure of daily mean temperature above the minimum threshold for growth.

What is the role of water in plant growth?

It acts as a reactant in biological processes, a medium for nutrient transport, and a temperature regulator.

What two factors influence precipitation distribution?

Air circulation and topography.

How does soil texture affect infiltration rates?

Coarse textured soils have greater infiltration rates than fine textured soils.

Define cation-exchange capacity (CEC).

A measure of the quantity of cations that can be adsorbed and held by a soil.

What is the effect of soil pH on nutrient availability?

Affects the availability of toxic metals and essential nutrients.

What are the main types of decomposers?

Bacteria, fungi, and actinomycetes.

What is allelopathy?

Chemical inhibition of one species by another through the release of allelopathic chemicals.

What is the impact of allelopathic plants on crop growth?

They can inhibit growth and nutrient uptake of neighboring plants.

Define global warming.

Gradual increase in Earth's average temperature due to rising greenhouse gas concentrations.

What gases are considered greenhouse gases?

Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O).

What is the carbon cycle?

The process of movement of carbon between the atmosphere, land, and oceans.

How does temperature affect photosynthesis?

High temperatures can lead to protein denaturation and reduced photosynthetic efficiency.

What are the impacts of wind on crops?

Lodging, grain shattering, and alterations in pollination.

Describe the role of pollinators.

Biotic agents that transfer pollen to facilitate fertilization in flowering plants.

What are natural pest enemies?

Organisms that control pest populations without human intervention.

What factors classify a plant as a xerophyte?

Plants adapted to survive in dry conditions, such as deserts.

What is the difference between short day and long day plants?

Short day plants flower when nights are longer than a certain length, while long day plants flower when nights are shorter.

What is one characteristic of cool season crops?

They thrive in cooler temperatures and are generally planted in early spring or late summer.

Define nutrient cycling.

The movement and exchange of nutrients in different forms through the environment.

What is genetic engineering in crops?

The manipulation and transfer of genetic material to produce desirable traits.

What are the main environmental components that influence crop production?

Climate, soil properties, and biotic interactions.

Explain the process of traditional plant breeding.

It involves selecting and crossing plants to enhance desirable traits in subsequent generations.

What is the significance of genetic resources?

Essential for ensuring food security and biodiversity in crops.

What is ex situ conservation?

Conservation of genetic resources outside their natural habitat, such as seed banks.

What effect does soil organic matter have on soil properties?

It improves soil structure, enhances water retention, and provides nutrients.

Describe the term 'phenotype.'

The observable characteristics of an organism determined by genotype and environment.

What are the impacts of high relative humidity on plants?

Can lead to disease incidence and complications in postharvest handling.

What is soil salinity and its implication for agriculture?

Salt accumulation in soil which can restrict plant growth and productivity.

What is the effect of soil depth on plant growth?

Affects the availability of nutrients and water for plant support.

How can climatic stresses like drought affect crop yield?

Drought leads to insufficient moisture, which can cause reduced yield or crop failure.

What does the term 'photosynthetically active radiation' (PAR) refer to?

The portion of sunlight that plants use for photosynthesis.

Define the 'biological window' of light.

The range of light wavelengths that have biological effects on organisms.

What role do decomposers play in the ecosystem?

They break down dead organic matter, returning nutrients to the soil.

How does temperature influence the rate of crop maturation?

Higher temperatures can accelerate growth rates but extreme heat can hinder maturation.

What biotic factors include pests?

Insects, pathogens, weeds, and vertebrate pests.

What is the primary purpose of flowers?

To attract pollinators for reproductive success.

What are key traits of warm season crops?

They require warmth and are typically planted in late spring to summer.

What climatic phenomenon is associated with increased storm severity?

Climate change due to rising greenhouse gas levels.

How can precipitation patterns be altered by climate change?

Changes in rainfall can lead to droughts or flooding in different regions.

What is the importance of genetic diversity in crops?

Enhances resilience to pests, diseases, and changing environmental conditions.

What factors affect the optimal growing conditions in crops?

Temperature, soil properties, water availability, and light conditions.

What methods are used for in situ conservation?

Conservation of species in their natural habitats.

What physical properties influence soil quality?

Texture, structure, depth, and topography.

What is the impact of excessive cultivation on soil structure?

Can lead to decreased aggregate stability and loss of organic matter.

What are the physiological effects of excess soil moisture?

Can harm root respiration and promote disease.

Define plant genetic resources.

Plants of present or potential value, vital for biodiversity and crop improvement.

What types of environmental factors can be classified under abiotic?

Climatic, soil, and physical factors.

What is the process of migration in the context of plant breeding?

The transfer of genetic material between populations or species.

What determines soil permeability?

The size, shape, and continuity of soil pores.

What kind of environmental changes may result from increased greenhouse gases?

Changes in precipitation patterns and temperature extremes.

What is the function of moisture in plant physiology?

Essential for photosynthesis, nutrient transport, and temperature regulation.

Describe the 'soil food web.'

The complex network of organisms interacting in the soil ecosystem.

What is the significance of the greenhouse effect?

It keeps the Earth warm by trapping heat in the atmosphere.

What are the effects of an acidic soil pH on plant growth?

Increased availability of toxic metals and reduced nutrient availability.

What is the definition of cultivar?

A distinct variant of a plant species selected for specific traits.

What do abiotic stresses include?

Factors such as drought, salinity, and extreme temperatures.

What is the significance of soil microorganisms?

They are crucial for nutrient cycling and maintaining soil health.

What is the concept of heat units?

A cumulative measure of temperature above a specified base temperature for crops.

What are the potential effects of climate change on agriculture?

Altered growing conditions, increased pest pressures, and shifting agricultural zones.

What practices help maintain good soil structure?

Crop rotation, addition of organic matter, and careful tillage.

How can genetic engineering contribute to crop improvement?

By introducing specific traits from one organism to another without traditional breeding limitations.

What is 'thermal radiation' in environmental science?

The emission of infrared radiation from Earth's surface.

How does soil structure affect crop yields?

Good soil structure enhances water and air movement to roots, promoting growth.

What can excessive nitrogen fertilization lead to in crops?

Can lead to nutrient imbalances and excessive vegetative growth.

What is the relationship between altitude and temperature in a given location?

Temperature typically decreases with increased altitude.

What role do certain fungi play in the soil environment?

They assist in decomposing organic materials and enhancing nutrient availability.

What is meant by the term 'phenotypic plasticity?'

The ability of a genotype to alter its phenotype in response to environmental conditions.

How does soil depth influence crop selection?

Different crops have varying root depth requirements that correlate with soil depth.

What effect did the eruption of Mount Pinatubo have on the local environment?

It caused lahars, affecting soil and water resources in surrounding areas.

What is the significance of plant breeding selection?

To enhance crop productivity by selecting the best plants for propagation.

What is the role of social and economic factors in crop selection?

They influence market demand and agricultural practices for sustainable farming.

Define soil organic matter.

Decomposed plant and animal residues that improve soil fertility and structure.

What are two types of plant breeding?

Traditional breeding and genetic engineering.

How is carbon dioxide absorbed by plants?

Primarily through stomata during photosynthesis.

What environmental factor is measured by soil salinity tests?

The concentration of soluble salts in soil solution.

What is the difference between horizontal and vertical root growth?

Horizontal roots spread for laterally accessing water, while vertical roots grow deeper for moisture and nutrients.

What is the impact of decomposers on nutrient cycling?

They recycle nutrients back into the soil, making them available for plant uptake.

How do light intensity and quality affect plant growth?

Different wavelengths of light can influence photosynthesis and flowering in plants.

What role do atmospheric conditions play in weather phenomena?

They determine daily variations in temperature, precipitation, and other weather events.

Define the term 'microbial biomass.'

The total mass of all microorganisms living in a given volume of soil.

What is the relationship between soil texture and water retention?

Finer textured soils (clays) retain more water than coarser soils (sands).

Name two greenhouse gases and their impact on climate change.

Carbon dioxide: contributed to global warming; methane: potent greenhouse gas that traps heat.

What factors influence the distribution of plant species?

Climate, soil properties, and biotic interactions.

What is the impact of urbanization on agricultural land?

Reduces available land for agriculture and increases soil sealing.

What role does temperature play in seed germination?

Optimal temperatures are required for seeds to activate growth processes.