Composts Flashcards
Total porosity (TP)
refers to the fraction of the total soil volume that is taken up by the pore space
Bulk density (BD)
Bulk density is an indicator of soil compaction. It is calculated as the dry weight of soil divided by its volume.
Water infiltration rate (WIR)
Infiltration rates are a measure of how fast water enters the soil and are typically expressed in inches per hour. For initial in-field assessments, however, it is more practical to express infiltration time in the number of minutes it takes soil to absorb each inch of water applied to the soil surface.
Saturated hydraulic conductivity (SHC)
is the ease with which pores of a saturated soil transmit water.
Where do soil borne diseases develop predominately?
Highly mineralised soils deficient in SOM (readily biodegradable OM). Low in microflora
Actinomycetes (G+ bacteria) are important for the nutrient cycling of…?
Chitin and cellulose.
Pseudonomads (bacteria) are important for nutrient cycling of…..?
Plant available P, and biological control of plant pathogens.
Beneficial micro-organisms are higher in organic production systems, apposed to …
Conventional fertiliser systems.
Yard waste?
Waste from the backyard of households, collected by contract gardeners; chipped tree branches, grass clippings, leaves, roots ect.
MSW compost
Compost attained from kerbside green bins, plant material, food scraps, pet poo, leaves, grass clippings, branches, wood and paper.
Compost nitrogen mineralization occurs in phases. Phase 1:
Significant release of inorganic N in the first weeks upon application.
Decay series
Phrase used to describe the slow decay of composts and slow release of nutrients.
What percentage of nitrogen in compost is in a organic form.
90% is in an organic form. Therefore application timing is not so important in comparison with raw manures.
In acidic soils P availability are predominately controlled by…
Iron and aluminium
As soil Ph increases, the potential for P to precipitate….
Increases.
