Fertilisers & Crop Yields Flashcards
What do fertilisers do?
Fertilisers increase crop yield
How do plants absorb minerals?
Plants absorb minerals through their roots.
Describe fertilisers
Chemicals that provide plants with essential chemical elements
Recall three essential elements needed for plant growth.
Nitrogen, phosphorus and potassium. NPK
What are the essential elements in (NH4)3PO4
Nitrogen, Phosphorus
How can the use of fertilisers can be beneficial?
They increasing food supply
How can the use of fertilisers cause problems?
Death of aquatic organisms (eutrophication)
Identify the apparatus needed to prepare a fertiliser by neutralisation.
Burette, measuring cylinder, filter funnel, conical flask
Recall the names of two nitrogenous fertilisers manufactured from ammonia
Ammonium nitrate, ammonium phosphate, ammonium sulphate, urea.
Explain why fertilisers are dissolved in water so they can be absorbed by plants.
Plants absorb minerals through their roots as solutions
Identify arguments for and against the use of fertilisers.
World population is rising so we 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:
a. Replaces essential elements used by a previous crop or gives essential elements
b. More nitrogen gets incorporated into plant protein so increased growth.
Explain the process of eutrophication:
- run-off of fertiliser
- more nitrate or phosphate in river
- algal bloom
- blocks off sunlight, other plants die
- aerobic bacteria use up oxygen
- most living organisms die.
Predict the name of the acid and the alkali needed to make ammonium nitrate
Ammonia solution and nitric acid
Describe the preparation of ammonium nitrate in the lab.
25cm3 of ammonia is neutralised by hydrochloric acid using a burette and indicator. The same volumes of acid and ammonia are then mixed without the indicator. The fertiliser is made by evaporation and crystallisation
