Clay and biochar amendments decreased inorganic but not dissolved organic nitrogen leaching in soil

Published source details Dempster D.N., Jones D.L. & Murphy D.V. (2012) Clay and biochar amendments decreased inorganic but not dissolved organic nitrogen leaching in soil. Soil Research, 50, 216-216.
Share Tweet Email

This study is summarised as evidence for the following.

	Action	Category
	Amend the soil with non-chemical minerals and mineral wastes Action Link

Amend the soil with non-chemical minerals and mineral wastes

A replicated, controlled experiment in 2011 using sandy clay in Meckering, Western Australia (Dempster et al. 2012) found that adding clay or biochar to soil reduced nitrate and ammonium loss from soil, by 25% and 20% respectively, compared to the control. Adding biochar saved more nitrate (12.9 mg nitrate remaining in pot) than adding clay (12.1 mg nitrate/pot). Soil was collected from a crop-pasture rotation including wheat Triticum aestivum or cape weed Arctotheca calendula with annual ryegrass Lolium rigidum and clover Trifolium subterraneum. Biochar and clay were either added at 25 t/ha as a layer at 10 cm depth with soil on top, or evenly incorporated into the top 10 cm of soil. Biochar was produced using jarrah Eucalyptus marginata wood and clay was taken from a clay pit close to the soil collection site. Nitrogen fertilizer was added at 40 kg N/ha. Amended soils were watered with the equivalent of 30 mm rainfall daily for 10 days, then on days 13, 15, 17 and 20.