Effects of different paper mulches on soil temperature and yield of cucumber (Cucumis sativus L.) in the temperate zone

The effect of different paper mulches and two different biodegradable plastic mulches on the yield of field-grown cucumber (Cucumis sativus L.) was examined. The studies were conducted during two climatically different growing seasons 2011 and 2012 in Southern Finland. All the mulches increased the yield as compared to bare ground. In 2011, cucumbers on all the mulches with a dark upper surface produced higher yields than those on kraft paper alone. In 2012, when the average temperatures were lower than in 2011, there were no differences in yield between different types of mulches. Soil temperatures of the experimental plots were monitored throughout the growing seasons. The mulches with a dark-colored upper surface increased the soil temperature more than the ones with a light-colored upper surface. The soil warming effect of the mulches was greater during early season and diminished when the plants grew larger and their leaves covered most of the mulch surface. There was no need for weed control except in uncovered plots. In conclusion, during both years dark-colored paper mulch was comparable to biodegradable film in yield production and could replace it as a mulch material in cucumber production.