Question

You are provided with a compound fertilizer, 40-15-10. Calculate the quantity of fertilizer to add to a one hectare field to supply a. Nitrogen at 120 kg/ha (2 marks) b. Nitrogen at 90 kg/ha (2 marks) c. Phosphorus (P 2 O 5 ) at rate of 60 kg/ha (2 marks) d. Potassium (K 2 O) at rate of 60 kg/ha

Answer 1

Answer:

The correct answer is a) 300 Kg b) 225 Kg c) 400 Kg and d) 600 Kg.

Explanation:

Based on the given value, that is. 40-15-10 shows the compositions of nitrogen, phosphorus, and potassium found in the compound fertilizer in the form of percentage.  

41 percent nitrogen is equal to 40/100 = 0.4, 15 percent phosphorus is equal to 15/100 = 0.15, and 10 percent potassium is equal to 10/100 = 0.1.  

To find the amount of fertilizer, which is needed per hectare to supply the different nutrients per hectare, there is a need to divide the quantity to be supplied by the percentage composition, now the values comes out as:  

a) At 120 Kg per ha, the required nitrogen will be 120/0.4 = 300 Kilogram of fertilizer.  

b) At 90 kg per ha, the required nitrogen will be 90/0.4 = 225 Kilograms of fertilizer.  

c) At 60 kg per ha, the required phosphorus will be 60/0.15 = 400 Kilograms of fertilizer.  

d) At 60 Kg per ha, the required potassium will be 60/0.1 = 600 Kilograms of fertilizer.