Give a scientific explanation for any four of the following: (a) The growing of first early potato crops in specific regions of Ireland - Leaving Cert Agricultural Science - Question 9 - 2009

Farm animals reared outdoors during winter experience a greater demand for energy primarily due to the necessity of maintaining body heat in colder conditions. As ambient temperatures drop, animals utilize more energy for thermoregulation through respiration. The colder environment also necessitates increased physical activity for foraging and seeking shelter, further elevating their energy requirements.

Cereal seeds may fail to germinate for several reasons. A lack of adequate moisture can lead to waterlogging or insufficient water availability, which hinders crucial metabolic processes. Additionally, if the soil is too cold, it can slow down enzymatic reactions necessary for germination. Diseases, such as damping off, and soil compaction can also affect seed viability by depriving seeds of oxygen or by creating unfavorable growth conditions.

The formation of an iron pan typically occurs due to higher rainfall and subsequent leaching processes, which wash away essential nutrients from the A horizon of the soil. Over time, iron oxides accumulate in the B horizon, solidifying to create a hard, impermeable layer known as an iron pan. This impedes water drainage and root growth, negatively affecting soil fertility and crop yield.

Using plastic in maize cultivation offers several advantages. Plastics can help raise soil temperature, which is crucial for maize as it thrives in higher temperatures (typically around 17°C). This results in a longer growing season and potentially higher yields. Furthermore, biodegradable plastics can enhance moisture conservation in the soil, minimize weed control efforts, and reduce the need for watering, leading to improved crop health.