Authors: Lars Elsgaard
Publish Date: 2010/08/07
Volume: 46, Issue: 8, Pages: 883-889
Abstract
Steaming of narrow soil bands prior to sowing is a new technique that reduces the need for intrarow weeding in herbicidefree row crops However the steam treatment may eliminate both weed seeds and nontarget soil organisms thereby affecting the nutrient cycling in the soil This study tested the effect of bandsteaming on N and C dynamics in a sandy loam soil that was steamed in situ to maximal temperatures of 70–90°C using a prototype bandsteamer Soil samples 0–5 cm depth were collected during 90 days from bandsteamed soil undisturbed control soil and control soil treated just mechanically with the bandsteamer In the steamed soil ammonium concentrations increased from 11 to 203 μg NH 4 + N g−1 dry weight during 28 days This coincided with an immediate and persistent inhibition of potential nitrification 33–61 inhibition during 90 days Assays of the temperature response of potential nitrification confirmed the temperature sensitivity and showed an optimum temperature of 271°C and a temperature coefficient Q 10 of 19 The effects of bandsteaming on concentrations of nitrate and watersoluble carbon were divergent and stimulatory respectively but generally not statistically significant Mechanical effects of bandsteaming were negligible The observed ammonium surplus could be of agronomic benefit and should be evaluated in integrated studies of the effects of bandsteaming on crop growth and plant N uptakeAddendum in proof Further studies on the effects of soil steaming on waterextractable organic carbon in laboratory incubations were recently published by D RouxMichollet Y Dudal L JocteurMonrozier and S Czarnes in Biol Fertil Soils 2010 46607616I thank JK Kristensen and EF Kristensen for assistance in the field K Kristensen for statistical advice and KK Brandt J Larsen P Sørensen and B Melander for helpful suggestions Also comments to the final manuscript by Søren O Petersen and the laboratory assistance of K Dyrberg and D Thomassen are highly appreciated The study was supported by a research grant from Fonden for Økologisk Landbrug
Keywords: