A petiole is the stalk that connects a leaf blade to the stem of a plant.
It is standard practice in Western Australia for the pH of acidic soil, with pH below 6, to be measured in a weak calcium chloride solution (1 part soil to 5 parts 0.01 molar calcium chloride). In alkaline soil with a pH above 8, the standard practice is to measure pH in the extract of 1 part soil to 5 parts water. Soil pH measured in calcium chloride is designated pHCa and gives a lower value than pH measured in water (pHW).
Refers to plants that require specific light duration to trigger flowering.
Plant available water (PAW) is the portion of available water in a soil within the root zone that can be absorbed by plant roots.
A plinthic layer resembles a clayey horizon and is often found below ironstone gravels. A plinthic layer exhibits prominent iron mottling in a net-like (reticulate) pattern, resulting in red, yellow, and grey colours. It generally has an initial texture of gritty sandy loam to sandy clay loam, which increases to a clay loam or clayey texture group as texturing time increases.
Soil reengineering is a process that involves the redesign of soil profiles to improve the conditions for crop growth. This can include adding organic and inorganic soil improvers, adjusting soil pH, and improving soil structure to enhance water retention and nutrient availability. The goal is to create a more favourable environment for plant roots to access water and nutrients. Soil reengineering has been shown to potentially double grain yield and water use efficiency, especially in favourable seasons. However, the long-term sustainability and economic returns of these improvements are still key questions being investigated by researchers.
Relative yield is a way of expressing how well a crop treatment performs compared to a reference or maximum yield, rather than as an absolute number. It is usually shown as a percentage.
Soil water repellence occurs when individual soil particles—particularly sand grains—are coated in water-repelling (hydrophobic) substances. These waxy organic coatings are primarily derived from plant residues and the by-products of biodegradation.
Rhizobacteria are root-associated bacteria that form symbiotic relationships with many plants. Plant growth-promoting rhizobacteria are a group of free-living rhizobacteria that benefit plant growth. Bacteria of diverse genera have been identified as plant growth-promoting rhizobacteria, with Bacillus and Pseudomonas species being the predominant ones.
Rhizobia are a group of diazotrophic bacteria found in the soil, or applied as an inoculant to seed. After infecting plant legume (Fabaceae or Leguminosae) roots, they produce nodules where they fix nitrogen gas (N2) from the atmosphere turning it into a more readily useful form of nitrogen.