Asparagus is becoming denser
The new plantings are carried out with densities of between 30,000 and 32,000 for large-calibre crown varieties and between 22,000 and 25,000 for the most common ones. Density increases as distances between rows widen. This trend is directly related to the reduction in pickers’ movement. In an asparagus plantation with 2-metre inter-rows, the distance travelled by a picker is 5km per ha. When rows are distanced at 3.30m, pickers cover only 3.3km per ha. After 50 days of harvest, the travel gain is 85km/ha. The picker will have walked 250km in the first plot and 165km in the second.
More soil volume for roots
But if the planting distance widens, the density must increase to keep the same number of plants per hectare. At distances of 2.50m, 5 crowns can be planted per linear metre compared to 7 crowns for an inter-row of 3.30m. Some plantations now have 4m gaps between rows. This increase requires a new arrangement of the crowns on the row. From one planting line, we move to two planting lines 20cm apart and a staggered crown layout to provide more useful space in which the claw can grow. It will therefore be necessary to open a wider planting trench. Observations made on these new asparagus designs show that they generate a 10% increase in yield compared to the smaller spread. They also extend the lifespan of asparagus plantations by 3-5 years thanks to the associated reduction in health risks. Moreover, they allow for better quality and better calibre spears thanks in particular to the large volume of earth available between rows. The widening of the inter-rows also facilitates ridging-up with a larger volume of surface soil available between the rows. It leads to better aeration of vegetation and a reduction in foliage health problems (e.g. rust and stemphylium). Working between rows is also facilitated and work times reduced (shorter rows to be covered and maintained). It reduces investment in equipment in linear metres (drip feed ducts, plastic covers, etc.). Finally, this mode of implantation allows the cultivation of green manure in the inter-rows and offers the possibility of replanting in soil that is (almost) free of asparagus.
Read also: Establishing an asparagus plantation