general knowldge Flashcards
1
Q
what does BOD stand for
A
biological oxygen demand
2
Q
what is biological oxygen demand
A
the amount of oxygen needed by microorganisms to take pollutants out of the water
3
Q
what depth is a standard soil sample on arable land
A
15cm
4
Q
what depth is a standard soil sample for grassland
A
7.5cm
5
Q
what are the two main loss pathways of nitrogen
A
ammonia volatisation and nitrate leeching
6
Q
5 principles of regenerative farming
A
reduce soil movement, maintain living roots, grow a range of crops, keep soil covered, integrate livestock
7
Q
what temperature does nitrification begin to take place
A
over 4 degrees Celsius
8
Q
what can be used to replace some potash requirements
A
sodium
9
Q
if crops remain a pale green despite nitrogen application the what may they be deficient in
A
sulphur
