February 2020 past exam questions R2102 Flashcards
name some types of organic matter that can be used as garden mulch
well rotted fym composted leaf mould well rotted garden compost composted bark spent mushroom compost
describe three ways in which om can benefit the soil
om feeds soil organisms-allowing populations to thrive.
soil organi. incorporate om into the soil and recycle nutrients for plant growth
soil organisms create tunnels within soil as they incorporate the om-these allow for greater porosity-also creates more space for gaseous and water exchange
improves soil structure-organisms produce humus that helps hold the soil crumbs together-this helps break up solid clay soils
om can make sandy soil more fertile and improve its water holding capacity
why should om be well rotted before use?
plants can be scorched by high levels of nitrogen/ammonia if om not well rotted
nitrogen can be robbed from soil as the decomposition process continues
risk of passing on diseases to existing plants
describe the process of composting for : choice of material
anything organic:
eg: carbon material (browns) and nitrogen (greens)
what should you never compost?
cooked food, meat, perennial weeds, diseased plant material
what are carbon materials for composting?
cardboard, non-glossy paper, shredded newspaper, straw, shredded woody prunings
what are nitrogen materials for composting?
grass clippings, annual weeds, kitchen waste, green prunings
why is aeration important for composting?
to encourage aerobic respiration-which encourages soil organisms to break down the materials.
A lack of air leads to anaerobic respiration which slows down the rate at which materials are broken down
how do you increase aeration when composting?
turn the pile regularly-once a month.
It helps prevent the pile from compacting too.
why is moisture content important when composting?
Soil organisms need moisture to survive.
If material too dry, process slows down so add water.
if the compost becomes too wet and slimy what should be done to remedy it?
add more carbon material eg: straw, shredded woody prunings and turn the compost to add air.
what can slow the composting process down?
lack of air, not enough moisture or too much moisture.
what are accelerators when composting?
grass clippings, seaweed ( anything that provides nitrogen)
why would you need and accelerator for composting?
to make the process as efficient as possible-you need the correct Carbon:Nitrogen ratio
why is temperature important for composting?
soil organisms are most active when the ideal temp is reached (60-80 degrees c)
what increases the composting process and how is this maintained?
temperature, turn the compost and cover with a lid or cover-to keep heat in/wet out.
what are four situations where excess water can occur in a domestic garden
leaking pipes
poor soil structure- compaction of soil surface pan so water doesn’t drain quickly
poor soil texture-high clay content so water doesn’t drain quickly
a high water table
sloping site-wet at bottom
runoff from hard landscaping eg: patios
how do you deal with excess water in domestic garden situations?
compaction: double dig to break up compacted area and add bulky om to improve soil structure and improve aeration
add coarse sand/grit and bulky om to a clay soil.
build a raised bed to keep root zone out of wet soil (make sure soil well structure so it can drain well)
install drains: soakaway or french drain
