crop plants: fertiliser Flashcards
5.3
what do fertilisers increase?
the amount of key nutrients in the soil for crop plants, meaning they can grow larger and are more healthy- increasing the yield
what do pesticides do?
kill off unwanted insects and weed species- meaning there is less damage done to crop plants by insects and reducing competition from other plant species- increasing yield
what do fertilisers provide?
elements needed by plants to grow such as nitrates for proteins and magnesium for the production of chlorophyll
what do fertilisers replace?
mineral ions
what can fertilisers do for crops?
make crops grow bigger and faster so that yields are increased
what 2 forms can fertilisers be in?
organic
inorganic (chemical)
what are organic fertilisers commonly used by farmers?
farmyard manure
compost
what is organic fertiliser made from?
the faeces of a range of animals- sometimes mixed with straw
compost from legumes such as clover
what is chemical fertiliser?
inorganic compounds carefully formulated to yield a specific concentration of a particular ion when applied according to the manufacturer’s instructions
how are chemical fertilisers applied to the soil?
in dry granules or sprayed on in liquid form
what 3 ions do fertilisers usually provide crops with?
nitrogen
phosphorous
potassium
what is nitrogen absorbed in the form of?
nitrates
what is nitrogen needed to make?
amino acids- the building bocks of proteins
what does a lack of nitrogen cause?
weak growth and yellowing of the leaves of plants
what is phosphorous absorbed in the form of?
phosphates
what is phosphorous needed to make?
DNA and cell membranes
what can a lack of phosphorous create?
poor root growth and discoloured leaves
what is potassium absorbed in?
various compounds of potassium
what does potassium allow?
allows enzyme reactions to take place to produce ATP in respiration as well as being needed for the enzymes in photosynthesis
what can a lack of potassium cause?
poor growth of fruit and flowers as well as brown spots on leaves
advantages of organic fertiliser?
improves soil structure
greater range of minerals
less cost to farmer- already available on the farm
disadvantages of organic fertiliser?
slow acting- has to be decomposed first
bulkier- more difficult to apply than inorganic fertilisers
may contain pests
what are the advantages of inorganic fertilisers?
mineral ions release immediately so fast acting
contents known
easy to appy
what are the disadvantages of chemical/inorganic fertilisers?
can lead to eutrophication as fertiliser is soluble
requires regular reapplication