Husson O.,UPR 115 AIDA and AfricaRice Center |
Husson B.,IDEEAQUACULTURE |
Brunet A.,CIRAD - Agricultural Research for Development |
Babre D.,CIRAD - Agricultural Research for Development |
And 6 more authors.
Analytica Chimica Acta | Year: 2016
The soil redox potential (Eh) can provide essential information to characterise soil conditions. In practice, however, numerous problems may arise regarding: (i) Eh determination in soils, especially aerobic soils, e.g. variations in the instrumentation and methodology for Eh measurement, high spatial and temporal Eh variability in soils, irreversibility of the redox reaction at the surface electrode, chemical disequilibrium; and (ii) measurement interpretation.This study aimed at developing a standardised method for redox potential measurement in soils, in order to use Eh as a soil quality indicator.This paper presents practical improvements in soil Eh measurement, especially regarding the control of electromagnetic perturbations, electrode choice and preparation, soil sample preparation (drying procedure) and soil:water extraction rate. The repeatability and reproducibility of the measurement method developed are highlighted. The use of Eh corrected at pH7, pe+pH or rH2, which are equivalent notions, is proposed to facilitate interpretation of the results. The application of this Eh measurement method allows characterisation of soil conditions with sufficient repeatability, reproducibility and accuracy to demonstrate that conservation agriculture systems positively alter the protonic and electronic balance of soil as compared to conventional systems. © 2015 Elsevier B.V.
Husson O.,CIRAD - Agricultural Research for Development |
Tran Quoc H.,CIRAD |
Boulakia S.,CIRAD - Agricultural Research for Development |
Chabanne A.,CIRAD - Agricultural Research for Development |
And 14 more authors.
Renewable Agriculture and Food Systems | Year: 2015
Rapid changes in agricultural systems call for profound changes in agricultural research and extension practices. The Diagnosis, Design, Assessment, Training and Extension (DATE) approach was developed and applied to co-design Conservation Agriculture-based cropping systems in contrasted situations. DATE is a multi-scale, multi-stakeholder participatory approach that integrates scientific and local knowledge. It emerged in response to questions raised by and issues encountered in the design of innovative systems. A key feature of this approach is the high input of innovative systems which are often although not exclusively based on conservation agricultural practices. Prototyping of innovative cropping systems (ICSs) largely relies on a conceptual model of soil–plant–macrofauna–microorganism system functioning. By comparing the implementation of the DATE approach and conservation agriculture-based cropping systems in Madagascar, Lao PDR, and Cambodia, we show that: (i) the DATE approach is flexible enough to be adapted to local conditions; (ii) market conditions need to be taken into account in designing agricultural development scenarios; and (iii) the learning process during the transition to conservation agriculture requires time. The DATE approach not only enables the co-design of ICSs with farmers, but also incorporates training and extension dimensions. It feeds back practitioners’ questions to researchers, and provides a renewed and extended source of innovation to farmers. Copyright © Cambridge University Press 2015