Nitrogen, irrigation, and alley management affects raspberry crop response and soil nitrogen and root‐lesion nematode dynamics

Abstract

AbstractThere is a need to improve raspberry crop nitrogen (N) management practices, particularly when grown over aquifers vulnerable to nitrate (NO3) leaching. This study quantified the effects of N, irrigation and alley management strategies on berry yield, indices of crop vigor and N status, growing season soil N dynamics, and root‐lesion nematode (RLN) population dynamics under red raspberry production in British Columbia, Canada. Conventional management (100 kg N ha−1 surface broadcast on the row, clean cultivation of alleys, and drip irrigation for a fixed duration regardless of evapotranspiration [ET]) was compared with different mineral fertilizer N rates, application of N as manure, seeding the alley to either a perennial forage grass (perennial ryegrass [Lolium perenne L.] and ‘Bridgeport II’ chewings fescue [Festuca rubra subsp. commutate]) or an autumn‐seeded spring barley crop, or ET‐scheduled irrigation. In addition, the combination of ET‐scheduled irrigation plus fertigation of a reduced rate of N was compared with conventional practices at a reduced N rate. There was little or no crop response to N source and rate, a finding attributed primarily to high nonmanaged N inputs, and possibly also to RLNs present at population densities (grand mean = 4 per cm3 soil) expected to suppress raspberry growth. ET‐scheduled irrigation reduced water use ∼50% compared with fixed‐duration irrigation without compromising crop performance. The perennial forage grass in the alley reduced soil mineral N but not yield. Taken together, these findings demonstrate that more environmentally sustainable raspberry production can be achieved through integrated management systems even in soils vulnerable to NO3 leaching.