SEMINAR: Soil and Water Seminar (SEE):

Dr Mark Farrell from CSIRO will give a Soil and Water seminar next week, PLEASE NOTE the different time/day of 11am on Tues Oct 19th. All welcome!

TITLE: "Soil organic matter interactions in soils: From dissolved organic nitrogen to biochar"

ABSTRACT:This talk aims to cover two areas of my research, namely dissolved organic nitrogen (DON) cycling in soils, and composting and addition of organic ‘wastes’ such as biochars and compost to soils. Despite common assumptions that nutrients taken up by plants and microbes in an inorganic form, dissolved organic nutrients also constitute a significant direct and indirect resource in many terrestrial and marine ecosystems. They also represent one of the major nutrient loss pathways, although rarely are they included in ecosystem models. One area of great uncertainty surrounds the cycling of dissolved organic N (DON) at the root-soil interface. We understand comparatively little about the processes involved in this cycling and the competition between microbes and plants for its resource. During the talk I will provide a background of the work carried out within the research group at Bangor University, then progress with findings from my own work there, and their potential implications. I will primarily focus my talk on low molecular species of organic nitrogen, primarily amino acids and peptides, and their potential for N-nutrition.

I will then move on to the other main theme of my work – the addition of organic wastes to land and in particular, composts and biochar. Composting wastes is known to both increase their overall stability, and whilst concentrating total metal concentrations, the process generally facilitates a reduction in the availability of heavy metals contained as contaminants. Composted wastes are a versatile soil improver material, and in the second half of this presentation I hope to highlight some of the areas of work regarding composts that I have covered. Finally, I will discuss the ongoing work at CSIRO on biochars, and their use in agriculture.

ABOUT THE SPEAKER: Mark Farrell is a Research Scientist at CSIRO based at the Waite Campus in Adelaide. He arrived in Australia four months ago after two years of postdoctoral work at Bangor and Lancaster Universities in the UK investigating the role of dissolved organic nitrogen in temperate grassland ecosystems. Prior to this, he completed his PhD on waste management and land remediation at Bangor University. His current research focus at CSIRO is on the application of biochars to land and their interactions with the soil.