Intercropping Winter Greens between Blackberry Rows for Year-round High Tunnel Production

Abstract

<jats:p>A decrease in available farmland worldwide has prompted interest in polyculture systems such as intercropping where two or more crops are grown simultaneously on the same land to increase the yield per farm area. In Alcalde, NM, a year-round intercropping system was designed to evaluate organically produced blackberry cultivars (<jats:italic>Rubus</jats:italic>, subgenus <jats:italic>Rubus</jats:italic>) and winter greens in a high tunnel over a 2-year period. Two floricane fruiting blackberry cultivars, Chester Thornless and Triple Crown, were grown intercropped with ‘Red Russian’ kale (<jats:italic>Brassica napus</jats:italic>) and ‘Bloomsdale’ spinach (<jats:italic>Spinacia oleracea</jats:italic>) in a high tunnel. In an adjacent field, the planting of blackberry was repeated with no winter intercrop and no high tunnel. Both cultivars of blackberry were harvested July to September, and fresh weights were measured to determine suitability to the intercropping system in the high tunnel. Both species of winter greens were harvested January to April, and fresh yield weights were measured to discern fitness as possible intercrops in this system. Row covers were used for kale and spinach, and air temperatures were monitored November to April inside the high tunnel. High tunnel temperatures were within acceptable ranges for the production of greens with the use of rowcovers. Yield data from this study indicates that ‘Triple Crown’ blackberry outperformed ‘Chester Thornless’ blackberry in both the high tunnel and field trials with significant difference in the second season. Additionally, blackberry yields from both cultivars were observed to be higher in the field than in the high tunnel for both years. High temperature damage to high tunnel berry canes was noticed for both cultivars, with observed yield decreases in the second year in the high tunnel. Overall, this study indicates that the phenology and climate needs of the two winter greens and blackberry cultivars were not compatible for sustaining year-round organic high tunnel production.</jats:p>

Effect of Harvest Schedule on Organic Kale Grown during the Winter in High Tunnels

“…Compared with 'Bloomsdale Longstanding' spinach (Spinacia oleracea) grown in the same soils and in the same structures before this study, fresh weight yields were greater and were distributed over a harvest season that both began earlier and ended later (Heyduck et al, 2019). In another winter study at Alcalde, 'Red Russian' kale out-yielded 'Bloomsdale Longstanding' spinach 442 to 201 g/ft 2 when grown together in the same high tunnel (Cormier et al, 2020).…”