PLANT PRODUCTION Flashcards
What role does standardisation play in experimental design ?
Ensures that factors other than the variable under investigation do not affect the results.
What statistical measures provides information about the spread of the data collected ?
Standard deviation
What features of soil cannot be changed by land management practices ?
Texture
A soil has returned a pH reading of 5.0 What actions would be the most effective in making the soil more productive ?
Spread lime onto the soil and incorporate it into the soil
Microorganisms in soils play various roles, what are 3 of these roles ?
Return nutrients to mineral form, break down organic matter, fix nitrogen
Which nutrient is associated with the nodules on the roots of legumes ?
Nitrogen
The prime purpose of regulating access to water on farms is to …
Balance the needs of farmers and environmental flows
Which combination of farming practices is most likely to lead a decrease in water quality in waterways ?
fertiliser usage, cultivation, stock access
What best describes an effect that the use of fertilisers can have on water quality ?
decreases water quality as fertilisers contribute to algae blooms
What is the most effective way of managing riparian zones in order to improve water quality ?
fencing to exclude livestock
What is the benefit of crop rotation for the farmer ?
it eliminates parasites which have selective hosts
What is the main cause of reduced soil fertility ?
imbalanced use of fertilisers
Describe how organic matter affects the physical characteristics of soil ? (2 marks)
Organic matter binds the sand, silt and clay particles together to form aggregates, which gives the soil structure.
Explain how soil texture can influence the water holding capacity of soil ? (2 marks)
Clay soils have a greater water-holding capacity than sandy soil because of the greater total volume of pore spaces between the particles. The smaller pores in clay soils also hold water more strongly against the force of gravity.
What is the purpose of whole farm planning ?
To classify land and match it to intended usage
How do Australian land capability assessment systems encourage more sustainable farming ?
They regulate what farmers can and cannot do on their land
What is NOT a common reason for the use of soil classification maps ?
They determine the land drainage capabilities of an area
Explain how conservation tillage assists in maintaining soil fertility ?
conservation tillage assists in maintaining soil fertility by decreasing the destruction of soil aggregates that occur when soils are cultivated repeatedly. It also assists in maintaining soil organic matter levels, thus assisting in the development of soil structure and improving the nutrient and water holding capacity of the soil.
Which combination of factors affects the rate of photosynthesis in a plant?
Carbon dioxide and light intensity
After germination, what is the correct order of the phases of growth for a plant?
Emergence, vegetative, reproductive
Under what conditions is the net assimilation rate of plants likely to be highest?
Warm days and cool nights
Net assimilation rate (NAR) is an important measure of the rate of plant growth. It is determined by calculating the balance between …
Photosynthesis and respiration
Explain how land capability assessment can be used to improve the long-term sustainability of Australian farms? (6 marks)
Land capability assessment involves using a classification system to gain knowledge regarding the suitability of a piece of land for particular agricultural activities and to identify land that is not suitable for farming. The five-class system that has been developed by the NSW DPI evaluates the physical, social and historical factors that pertain to the land under investigation. The resulting land class placed on the land (from 1-5) indicates the range of agricultural practices that can safely be carried out on that land. For example, only land classified as class 1 or 2 can be cultivated regularly. Cultivation of land classified 3 or more is likely to lead to erosion problems. Hence land classification systems enhance sustainability by ensuring that land use is closely matched to the capacity of the land to withstand detrimental effects associated with farming.
Explain how one land use practice has led to a named soil degradation problem? (3 marks)
The land management practice of clearing trees for pasture production or cropping on farms has led to the soil degradation issue of dryland salinity. Deep-rooted trees and plants will take up groundwater, keeping the water table at a lower level. Clearing of this vegetation results in the rise of the water table, which brings dissolved salts closer to the surface of the earth. This causes an accumulation of salts at the plant root zone, known as dryland salinity.
