Struvite: a slow-release fertiliser for sustainable phosphorus management?

Background And Aim: Recycled sources of phosphorus (P), such as struvite extracted from wastewater, have potential to substitute for more soluble manufactured fertilisers and help reduce the long-term threat to food security from dwindling finite reserves of phosphate rock (PR). This study aimed to determine whether struvite could be a component of a sustainable P fertiliser management strategy for arable crops.

Methods: A combination of laboratory experiments, pot trials and mathematical modelling of the root system examined the P release properties of commercial fertiliser-grade struvite and patterns of P uptake from a low-P sandy soil by two different crop types, in comparison to more soluble inorganic P fertilisers (di-ammonium phosphate (DAP) and triple super phosphate (TSP)).

Phosphate depletion modulates auxin transport in Triticum aestivum leading to altered root branching.

Understanding the mechanisms by which nutritional signals impact upon root system architecture is a key facet in the drive for greater nutrient application efficiency in agricultural systems. Cereal plants reduce their rate of lateral root emergence under inorganic phosphate (Pi) shortage; this study uses molecular and pharmacological techniques to dissect this Pi response in Triticum aestivum. Plants were grown in coarse sand washed in high- or low-Pi nutrient solution before being assessed for their root branching density and expression of AUX/IAA and PIN genes.

Feed the crop not the soil: rethinking phosphorus management in the food chain.

Society relies heavily on inorganic phosphorus (P) compounds throughout its food chain. This dependency is not only very inefficient and increasingly costly but is depleting finite global reserves of rock phosphate. It has also left a legacy of P accumulation in soils, sediments and wastes that is leaking into our surface waters and contributing to widespread eutrophication.

Auxin secretion by Bacillus amyloliquefaciens FZB42 both stimulates root exudation and limits phosphorus uptake in Triticum aestivium.

Background: The use of auxin-producing rhizosphere bacteria as agricultural products promises increased root production and therefore greater phosphate (Pi) uptake. Whilst such bacteria promote root production in vitro, the nature of the bacteria-plant interaction in live soil, particularly concerning any effects on nutrient uptake, are not known. This study uses Bacillus amyloliquefaciens FZB42, an auxin-producing rhizobacterium, as a dressing on Triticum aestivium seeds.

ABA signalling modulates the detection of the LM6 arabinan cell wall epitope at the surface of Arabidopsis thaliana seedling root apices.

• The hormonal and physiological regulations underpinning the cell contexts of structural features of the heterogeneous cell wall pectic polysaccharide rhamnogalacturonan-I are far from being understood. • The effect of the modulation of abscisic acid (ABA) concentrations and sensitivity on the detection of the LM6 1,5-arabinan epitope at the surface of Arabidopsis thaliana seedling root apices was assessed by means of fluorescence imaging. • Treatment with 50 nM ABA resulted in an increase in the detection of the LM6 epitope at the root surface in the region of the meristem.