摘要

Grow tubes are well established in forestry and are gaining attention in establishing some woody perennial crops. To date, microclimate descriptions have addressed the aboveground environment, hula mulched raised bed system with organic mulch-incorporated soil requires both the above- and belowground microclimate to be quantified. We measured the microclimate of commercially used, non-ventilated translucent and non-ventilated opaque grow tubes in a model crop of blueberry (Vaccinium corymzbosum L.) grown on sawdust-mulch-covered raised beds formed from sawdust-incorporated tilled soil. The differences in air temperature between tubes and ambient were consistent with those reported in the literature. Air temperature in translucent tubes was up to 19.7 degrees C higher than ambient. Differences in vapor pressure deficit were largely a function of differences in air temperature between tubes and ambient rather than actual vapor pressure. Stem temperatures were highest outside of the tubes as a result of radiation load. The surface temperature of ambient sawdust mulch (maximum 53 degrees C) was up to 14 degrees C above that in the translucent tube and 20 degrees C above that in the opaque tube. The largest gradients in the bed system were between the loose dry mulch and the soil mulch interface. The presence of a grow tube did not influence soil temperature or its daily amplitude at 15 cm below the surface the native tilled soil. Temperatures associated with the opaque tubes were between ambient and those in the translucent tubes. The temperature data indicate that both opaque and translucent unventilated grow tubes should influence shoot and crown growth but may have little influence on root growth in this shallow-rooted plant.

  • 出版日期2013-11