Crop Plants: Fertiliser (Edexcel IGCSE Science)

Crop Plants: Fertilisers

Spec point — 5.3 · understand how the use of fertiliser can increase crop yield

• Modern technology has increased food supply substantially
• One of the key ways this has been achieved is with the use of fertilisers
• Fertilisers increase the amount of key nutrients in the soil for crop plants, meaning that they can grow larger and are more healthy, which increases yields

Using fertilisers to increase crop yields

• Plants require a range of mineral ions in order to grow well
• As crop plants take up these mineral ions from the soil, the mineral ions need to be replaced if crops are grown repeatedly in the same field (i.e. year after year)
• Fertilisers are used to replace these mineral ions
• They can make crops grow faster and bigger so that yields are increased
• Fertilisers can be in the form of organic fertiliser or chemical fertiliser
• Organic fertilisers commonly used by farmers include farmyard manure and compost
• Chemical fertilisers are often applied to the soil as dry granules or can be sprayed on in liquid form
• Two mineral ions plants require for growth are magnesium ions and nitrate ions

• There are other mineral ions that plants require:

Exam Hint The specification only requires you to know that magnesium ions are needed for chlorophyll and nitrate ions are needed for amino acids, so be sure to learn the functions of these two ions.

It's important to spell 'nitrate' correctly in the exam! Plants require nitrate ions, NOT nitrites or nitrogen.