Irrigation Flashcards
(25 cards)
What is irrigation?
A process of taking water from a nearby source and using it to water the land where crops have been planted
What affects water quality?
Hard water has lots of calcium which raises the pH, water from boreholes near the sea can have high levels of salt, water from rivers can have high levels of algae, bacterial and fungal pollution
What are the issues of automatic irrigation systems?
Can break down, watering can be missed, need resetting when conditions change, need frequent changes
What are the methods of field irrigation?
Surface, sprinkler, drip/trickle and sub surface
What is surface irrigation?
Uses gravity to draw water from a higher area of land to the fields. The slopes need to be steep enough to allow the water to flow, but not to steep as to flood the field
Advantages of surface irrigation?
It requires no advanced technology to work
Disadvantages of surface irrigation
Can be difficult to regulate the flow of the water meaning fields could be covered with excess water for periods of time
What is sprinkler irrigation?
It uses a series of pipes and specially designed spray heads but the water must be pumped through the pipes to gain the right pressure
Advantages of sprinkler irrigation
Can be used on any soil type and any degree of slope, easy to use, reliable and low maintenance and can use various different nozzles
Disadvantages of sprinkler irrigation
Can be expensive option and it can consume a lot of energy, inefficient as 75 to 80% of water from a sprinkler is wasted and nozzles can be blockes
What is sub surface irrigation?
Uses a series of pipes to water the crops under the surface of the soil
Advantages of sub surface irrigation
More effective hydration of the plant roots, once installed it only takes a small amount of maintenance, highly efficient as the water doesn’t evaporate like other forms of irrigation
Disadvantages of sub surface irrigation
Cost of installing is high, small pipes in the soil can be damaged by farm machinery or get clogged by plant roots
What is drip irrigation?
Works in a similar way to sub surface but the pipes are located at the surface of the soil and are only designed to water the plants immediately near them
Advantages of drip irrigation
Ideal for any soil type and any degree of slope and well suited to rows of crops
Disadvantages of drip irrigation
Cost of fitting this is high, needs a skilled person to manage the water being used, filters and regular cleaning of the pipes is needed to prevent blockages
What are the advantages of porous pipes?
Deliver slowly to soil leaving foliage dry and reduces water loss as water spreads below the surface
What are the methods of applying water to container grown plants?
Hoses, overhead sprinklers, ebb and flow, capillary benches, drip irrigation and watering cans
What is ebb and flow?
For plant pots in compost, shallow tray or bench is filled with a few cm’s of water, pots take it up and then excess is drained off which creates high humidity around plants
What are capillary benches?
Pots stand on a level 50mm bed of sand kept saturated at base by automatic water supply. Water lost by evaporation and from plant is replaced by capillary rise
What is drip/micro irrigation?
Usually to individual pots via Spaghetti tubing
Advantages of drip irrigation?
Precise and efficient, minimised water loss, reduce disease
Disadvantages of drip irrigation
Roots can be restricted to the wet area and needs periodic maintenance
