Alternative cropping practices for sustainable soil management and yield optimisation in asparagus.

Asparagus (Asparagus officinalis L.) is a high value perennial crop with long economic production period ranging between 10-20 years. Field operations associated with conventional UK asparagus production such as re-ridging and intensive foot and vehicular trafficking of the wheelings however run a danger of causing a range of negative environmental impacts and pose a risk to long-term asparagus productivity. Nonetheless, majority of British growers continues to cultivate asparagus in the conventional way due to a lack of alternatives to the conventional practice. The aim of this research is to critically evaluate the long-term efficacy of a set of potential best management practices (BMPs) targeted at preventing or remediating soil compaction in asparagus interrows, promoting root growth and increasing profitability of asparagus production. The research further aimed to quantify the impacts of annual re-ridging associated with the conventional production on soil compaction, root development, yields and on soil bio-chemical characteristics. The experimental field trial located in Herefordshire tested a range of potential BMPs inducing (i) companion cropping with either rye (Secale cereale L.) or mustard (Sinapis alba L.) which were re-ridged or non-ridged, (ii) interrow surface mulching with either straw mulch or compost which were re- ridged or non-ridged and (iii) a combination of tillage practices (ridging and shallow soil disturbance) applied to bare soil interrows. Treatments were applied annually from 2018-2020. This research showed that the field management practice currently adopted by the of British asparagus industry is unsustainable and poses high risks to both the soil environment and asparagus productivity. Key findings show that soil compaction, root growth, asparagus profitability and soil bio-chemistry in asparagus cropping systems can be effectively modified and managed by BMPs. Consequently, this research identified a set of BMPs to be considered for practical application.