Photo AI
Give a scientific explanation for four of the following: (a) The improvement of a soil by the addition of lime - Leaving Cert Agricultural Science - Question 9 - 2008
Question 9
Give a scientific explanation for four of the following: (a) The improvement of a soil by the addition of lime. (b) The appearance of yellow leaves in crop plants. ... show full transcript
Worked Solution & Example Answer:Give a scientific explanation for four of the following: (a) The improvement of a soil by the addition of lime - Leaving Cert Agricultural Science - Question 9 - 2008
Step 1
The improvement of a soil by the addition of lime.
Answer
Lime contains calcium salts that increase the pH of the soil, making it less acidic. This improves flocculation and drainage, leading to better water retention and aeration. Additionally, the presence of lime can enhance bacterial activity which increases the availability of essential nutrients. An improved soil structure also benefits earthworm populations and overall cation exchange.
Step 2
The appearance of yellow leaves in crop plants.
Answer
Yellow leaves can indicate a deficiency in nitrogen (N) or magnesium (Mg), both crucial for chlorophyll synthesis. Other factors like overwatering, which leaches nutrients away, or viral infections may also contribute. Environmental stressors such as drought or pests can further hinder nutrient uptake, leading to chlorosis in plants.
Step 3
The pruning of a field hedge.
Answer
Pruning involves removing apical buds or meristem, which stimulates lateral growth and thickening of the hedge. This method enhances the bushy appearance and helps to keep the hedge healthy and aesthetically pleasing. Additionally, it promotes greater shelter for wildlife and can improve road safety by maintaining visibility.
Step 4
The greening of potatoes.
Answer
When potatoes are exposed to light, they undergo photosynthesis, causing chlorophyll production. This greening indicates the formation of toxic compounds known as solanine, which can occur in unprotected tubers. The lack of adequate earthing-up increases the risk of exposure to sunlight, thus resulting in a more pronounced green color.
Step 5
The production of gases in a slurry tank.
Answer
The decomposition of organic materials within the slurry tank occurs through anaerobic processes. Microorganisms such as bacteria break down the organic matter, leading to the production of gases including carbon dioxide, methane, ammonia, and hydrogen sulfide. This anaerobic digestion is crucial for managing waste and can produce biogas as a renewable energy source.