A scientist recommended that 75 kg of N and 6 kg of P should be applied to a hectare sorghum. NPK (23-10-5+6S+1Zn) and Urea (46% N) are the only fertilisers available at a local market?

To calculate the amount of NPK and Urea needed to apply 75 kg of N and 6 kg of P to a hectare of sorghum, we can use the following formulas:

1. For NPK:
- N content in NPK = 23%
- P content in NPK = 10%
- Total weight of NPK needed = (75 kg / 0.23) = 326.09 kg
- Weight of P in NPK = (326.09 kg * 0.10) = 32.61 kg

2. For Urea:
- N content in Urea = 46%
- Total weight of Urea needed = (75 kg / 0.46) = 163.04 kg

Therefore, you would need to apply approximately 326.09 kg of NPK and 163.04 kg of Urea to meet the recommended amounts of N and P for a hectare of sorghum.