Fertilisers Flashcards
what do fertilisers do?
increase crop yield
how do plants absorb minerals?
through their roots
Describe fertilisers
chemicals that provide plantswith essential chemical elements
what are nitrogen, phosphorus and potassium?
three essential elements needed for plant growth
Understand that the use of fertilisers can be beneficial and also cause problems
increasing food supply
e.g. death of aquatic organisms (eutrophication)
Identify the apparatus needed to prepare a fertiliser
by the neutralisation of an acid with an alkali:
- burette and measuring cylinder
* filter funnel
Identify arguments for and against the use of
fertilisers:
- world population is rising so need to produce
more food - eutrophication and pollution of water supplies can
result from excessive use of fertilisers
Explain how the use of fertilisers increases crop yield:
• replaces essential elements used by a previous
crop or provides extra essential elements
• more nitrogen gets incorporated into plant protein
so increased growth.
Explain the process of eutrophication
- run-off of fertiliser
- increase of nitrate or phosphate in river water
- algal bloom
- blocks off sunlight to other plants which die
- aerobic bacteria use up oxygen
- most living organisms die
Describe the preparation of a named synthetic
fertiliser by the reaction of an acid and an alkali
- names of reactants
- experimental method
- how a neutral solution is obtained
- how solid fertiliser is obtained
Explain why fertilisers must be dissolved in water
before they can be absorbed by plants
plants can only take up these chemical elements through their roots if the fertiliser is dissolved in water
How to make fertiliser?
- Measure alkali
- Add acid. Test the solution’s pH using indicator paper
- Evaporate the solution
- Filter to separate the crystals
