Unit 02- Requirements For Crop Growth Flashcards
(T/F) Soil structure describes the proportion of sand, silt and clay particles present in the soil while soil texture refers to the arrangement of these soil particles into aggregates
False
Top soil is the most productive soil layer because…
It is where most organic matter is found
The process by which organisms can take nitrogen from the atmosphere and convert it to soil nitrogen is..
Biological Nitrogen Fixation
The macronutrient that is difficult to manage because it is very strongly held by most soils is:
Phosphorous
In conservation tillage operations at least _____ of the soil surface is covered with plant residues.
30%
We generally do NOT find nutrient deficiencies associated with the following soil condition:
Soils with high organic matter contents
The Haber-Bosch process is the industrial process used to produce:
Nitrogen fertilizers
The first trophic level of a soil food web consists of:
Plants
Which of the following statements about soil organic matter is NOT true:
a) Soil organic matter is biologically derived
b) Soil organic matter usually constitutes between 1 and 5% of a mineral soil
c) Soil organic matter is a very homogeneous mixture of materials
d) Soil organic matter constitutes approximately 30% of an organic soil
e) Soil organic matter is very important for soil structural stability
C
Nitrification describes the process whereby:
Ammonium is converted into nitrate (the more plant available form of nitrogen)
The following is a broad spectrum herbicide used to kill broad-leaf weeds and grasses
Glyphosate
The following is the commonly used insecticide linked to Honey Bee Colony Collapse Disorder
Neonicotinoids
(T/F) System pesticides are pesticides that kill as a result of direct contact
False
The environmentally sensitive approach to pest control that uses pesticides judiciously is called:
IPM
(T/F) A soil with greater than 30% organic matter is considered to be an organic soil.
True
Moldboard ploughs are generally associated with conservation tillage operations
False
An important benefit of conservation tillage is decreased weeds
False
No-till operations are particularly suitable for cereal crops
True
Broadcasting is better than side-dressing because it involves the localized placement of fertilizers
False
Draining soils can lead to increased fungal diseases in the soil
False
Irrigated agriculture is the largest consumer of freshwater in the world
True
In order to improve the water use efficiency of irrigation the following can be used:
a) Furrow irrigation
b) Sprinkler irrigation
c) Mulches
d) Drip irrigation
e) None of the above
D) Drip irrigation
The amount of open space between soil particles
Porosity
This soil particle size is very important because it has a very large surface area
Clay
The proportion of sand, silt and clay sized particles in a soil
Soil Texture
The arrangement of san, silt and clay into soil aggregates
Soil Structure
When approximately half of all soil pores are filled with water
Field Capacity
Well decomposed soil organic material
Humus
The mechanism by which CO2 is taken up by plants
Photosynthesis
The mechanism by which CO2 is released by organisms
Respiration
A soil with at leas 30% organic matter
Organic Soil
A low oxygen environment
Anaerobic
