Farm Table says:
What is the problem?
Permanent raised bed (PRB) farming systems combine several elements of conservation agriculture
- reduced tillage
- controlled traffic
- stubble retention.
PRB systems have recently been introduced into irrigated areas but there is a lack of information on the agronomic and irrigation performance of these systems under these conditions
What did the research involve?
Three years of field research into the performance of irrigated PRBs was conducted in south east Queensland, Australia and north west Pakistan.
These studies benchmarked the irrigation performance of variously sized PRB systems and explored the impact of bed renovation method (no tillage (NT), shallow cultivation (SC) and blade ploughing (BP)) on soil hydro-physical properties (bulk density, soil moisture storage, infiltration), irrigation performance, crop yield and input water productivity (WP).
Irrigation management strategies to improve lateral infiltration and irrigation performance were also investigated
The initial benchmarking study was conducted on two farms with clayey Vertisol (Australia) and three farms with sandy clay loam, Alfisol, (Pakistan) soils
What were the key findings?
This research has shown that the existing irrigation performance of PRBs is often low and highly variable.
A key constraint is the potential for poor lateral infiltration into the beds and inadequate wetting to the centre of wide beds. However, this work has also highlighted that the adoption of appropriate bed renovation methods (particularly BP) and irrigation management practices (e.g. Q and Tco) can substantially improve irrigation performance and input WP.
Although the applicability of the specific decision support tools developed is restricted to the soil types and field conditions encountered, the general understanding and insight into the basic principles of performance optimisation and for agronomic and irrigation interactions is expected to be beneficial in refining understanding and the promotion of sustainable crop production under a wider range of environmental conditions.