Permanent bed planting in irrigated Mediterranean conditions: Short-term effects on soil quality, crop yield and water use efficiency

In the Mediterranean region, conservation agriculture principles like minimum soil disturbance or retaining residues on soil surface are rarely applied in irrigated annual cropping systems. This paper compares a conservation agriculture practice, permanent bed planting (PB), with a conventional system in which the ridges are reformed annually (CB). Comparisons were made throughout a crop sequence of cotton (Gossypium hirsutum L)–maize (Zea mays L.) – cotton in which PB was introduced before the maize cropping. Traffic was controlled during the study. Both maize and cotton crops produced higher leaf area index and biomass under PB than CB and 8 and 24% higher yield respectively though the yield benefit for maize was not significant. The PB system did not improve Water-use Efficiency but delayed water use until the later growth stages. Soil organic matter (SOM) was significantly higher in PB compared to CB one year after the introduction of the system, and this difference was due to higher SOM in the 0–0.05 m layer, particularly in the furrows. The lack of negative effects of PB on yield and the positive effects on SOM, coupled with increased water infiltration and reduced erosion shown in previous studies, point to the beneficial adoption of PB in the region assuming the patterns are confirmed in the longer term.

► We compared permanent (PB) and conventional (CB) bed plantings in southern Spain. ► Soil compaction is reduced by combining the systems with controlled traffic. ► PB improves growth and yield of irrigated maize and low input cotton. ► Water use was delayed in PB compared to CB but did not have an effect in WUE. ► Soil organic carbon accumulates fast in irrigated PB maize-based systems.