Slurry and farmyard manure are two sources of nutrients for crops - Leaving Cert Agricultural Science - Question a - 2018

1. Correct Application Rate: Farmers should carefully regulate the amount of slurry applied to avoid over-application, especially during wet weather.
2. Storage in Leak-Proof Tanks: Farmers should store slurry in leak-proof tanks to prevent it from contaminating water supplies.

The principal elements provided by 18-6-12 fertiliser are:

1. Nitrogen (N)
2. Phosphorus (P)
3. Potassium (K)

Advantage: Artificial fertilisers are specially formulated for various crops, allowing farmers to precisely meet the nutrient requirements of their crops.

Disadvantage: They may lead to pollution if applied improperly, potentially washing away into water bodies.

Nitrogen: It is essential for the synthesis of chlorophyll, which is crucial for photosynthesis and gives plants their green color.

1. Weighing the Sample: First, weigh a clean and dry beaker (B1). Take a soil sample (fresh) and add it to the beaker, then weigh again (B2) to get the total mass.

2. Drying Process: Place the beaker with soil in an oven at 100°C for 24 hours to remove moisture.

3. Final Weighing: After drying, weigh the beaker with the dry soil again (B3).

4. Calculation of Water Content: Calculate the mass of water lost:

   $ext{Mass of water} = (B2 - B3)$

5. Percentage Water Calculation: Finally, compute the percentage of water in the soil sample using the formula:

   ext{Percentage of water} = rac{ ext{Mass of water}}{ ext{Mass of fresh soil}} imes 100