Summary: Abiotic Stress

Read the summary and the most important questions on abiotic stress

• 1 Intro and Impact

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• What are the different impacts of abiotic stress on high input and low input agriculture?

  - High input agriculture is affected by decreased yields, economic repercussions, and limited availability of essential resources like water and nutrients. It utilizes buffers such as storage and financing to mitigate these effects.
  - Low input agriculture, often tied to subsistence farming, struggles with scarce resources, prioritizes survival, and lacks buffers to counteract adverse conditions, making stability crucial for ensuring at least a harvest.

• What inputs are required to maintain high crop yields and what are the consequences of not providing these inputs?

  - Arable land, specifically designated for food production, is pivotal for high yields.
  - Essential resources include:
  - Water for irrigation and sustenance of crops.
  - Key nutrients, specifically Nitrogen (N), Phosphorus (P), and Potassium (K).
  - Fossil energy for various agricultural processes.
  - Insufficient input can lead to suboptimal growth conditions and consequent yield loss.

• What are the annual worldwide additions of nitrogenous fertilizers to the soil and what change has occurred in the consumption of synthetic nitrogen according to the slide?

  - Annually, between 85-90 million metric tons of nitrogenous fertilizers are added to soils globally.
  - There has been a dramatic escalation in the consumption of synthetic nitrogen, as mentioned without specifying exact figures.

• What are the environmental and availability concerns regarding nutrients, particularly nitrogen (N) and phosphorus (P), for fertilization in agriculture?

  - Nitrogen used for fertilization demands significant energy, chiefly relying on the energy-intensive Haber-Bosch process.
  - Nitrogen is often not fully utilized by crops, leading to environmental issues such as leaching and pollution.
  - Restrictions on nitrogen usage are anticipated due to increased environmental and cost concerns.
  - Phosphorus is a crucial but non-renewable resource for crop growth.
  - The scarcity of phosphorus is predicted as reserves are depleted, posing a risk for agriculture which is dependent on P for high yield levels.

• What are the threats to global food security as noted on the presentation slide?

  - Availability of arable land is not increasing and may be diminishing.
  - Inputs for agriculture are below optimal levels.
  - Crops are often grown in suboptimal conditions due to these limitations.
  - There is a goal to produce "2x more with 2x less," implying improving efficiency in agriculture.

• What are the effects and requirements for addressing climate change according to the provided information?

  - Climate change leads to less predictable weather conditions.
  - It disproportionately affects poorer or low resource regions around the globe.
  - To cope with climate change, adaptation to the evolving environmental conditions is necessary.
  - Agricultural practices must also evolve, necessitating both management and adaptation of crops.

• What strategies can be implemented to meet future agricultural challenges according to the provided content?

  - Optimization of food, feed, and fuel production systems involves minimizing input while maximizing output.
  - Improvement of agricultural management is advised.
  - Efficient utilization of nutrients and resources should be optimized.
  - Selection of the correct crops for cultivation is recommended.
  - Enhancement of crops through the optimization of growth conditions.
  - Genetic enhancement through breeding to improve crops' inherent properties.

• What are the goals in breeding plants for abiotic stress

  - Enhance tolerance to drought/water limitations, flooding, heat, cold, and frost.
  - Improve nutrient use efficiency and resistance to diseases and insects, especially under changing environmental conditions.
  - Achieve optimal utilization of crops that inherently require low input.
  - Develop or explore new crops that are more tolerant to low input conditions, such as quinoa, which is mentioned as having high saline and drought tolerance, and also an ability to grow with economic yield in typically non-food production areas.

• What are the challenges faced in breeding crops for abiotic stress tolerance?

  - Environmental factors often conceal the genetic components of abiotic stress tolerance.
  - Crops generally achieve only a portion of their genetic potential due to limiting growth conditions.
  - The trait is complex, involving multiple interacting processes and genes.
  - Tolerance to stress is due to the presence of a combination of traits and genetic factors.
  - The abiotic stresses that affect crops can change annually, with conditions like drought, flooding, and salinity presenting varied challenges.
  - The unpredictability of these stress factors has been on the rise in recent years.

• What is the end observation or goal in phenotyping for stress tolerance in crops and what strategies are proposed to achieve this goal?

  - The ultimate objective in phenotyping for stress tolerance is to increase crop yield.
  - Increase in yield is achieved through the interaction of multiple processes at various developmental stages.
  - Multiple genes influence yield, making it suboptimal for selection.
  - To address this, it is suggested to dissect drought tolerance into well-defined traits such as stomatal conductance, root properties, and osmotic adjustment.
  - Uncovering quantitative trait loci (QTLs) or genes that govern these traits.
  - The strategy intends to combine favorable QTLs to enhance crop improvement.