Food Production flowering plants Flashcards
(38 cards)
how do polythene tunnels and glasshouses increase yield (what do they provide)
an enclosed environment in which farmers can, to some extent, control the climate inside
what conditions are manipulated to increase photosynthesis in glasshouses (4)
- artificial heating
- artificial lighting
- (increasing) CO₂ content
- regular watering
why is heating controlled in glasshouses
enzymes controlling photosynthesis work faster at higher temperatures
why is lighting controlled in glasshouses
allows plants to photosynthesize longer
what might there be in a glasshouse in a tropical country, and not in a cold one
ventilation
why is CO₂ content increased in glasshouses
because its a raw material of photosynthesis, so the more there is, the quicker the photosynthesis
what do farmers need to balance in glasshouses
the increased cost with the increased income
what are polythene tunnels
large plastic tunnels which cover crops
what do fertilisers do
increase the amount of key nutrients in the soil for crop plants, meaning they grow healthier and larger, increasing yield
what do polythene tunnels do
protect crops grown outside from the effects of weather
fertilisers come in 2 forms
organic and chemical
does anything change in a polythene tunnel (2)
yes but its naturally:
- temperature rises a little
- it prevents the entry of pests
if temperature becomes too high,
enzymes denature and photosynthesis can no longer occur
what are pesticides and what do they do
chemicals which kill of unwanted insects and weed species, meaning less damage is done to crop plants by insects & reduced competition from other plant species which increases crop yield
organic fertilisers
used by farmers and include manure and compost
how do fertilisers increase crop yield (process)
- plants require a range of mineral ions to grow well
- as crops take up these mineral ions from the soil, they need to be replaced if crops are repeatedly grown there
- fertilisers replace these mineral ions
they make crops grow faster and bigger, increasing yields
chemical fertilisers
usually applied to soil as dry granules or can be sprayed in liquid for
what do fertilisers mainly provide (3)
phosphorous
nitrogen
potassium
how is nitrogen absorbed
form of nitrates
what is nitrogen for
for the building of amino acids, (healthy growth)
phosphorous needed to
make DNA and cell membranes
lack of nitrogen means
chlorosis and stunted growth
phosphorous is absorbed in the form
phosphates
lack of phosphorous
poor root growth and chlorosis
