Soil-biodegradable mulch is an alternative to non-biodegradable plastic mulches in a strawberry-lettuce double-cropping system

Abstract

Double-cropping strawberry (Fragaria × ananassa Duch.) and lettuce (Lactuca sativa L.) could be a sustainable alternative practice for diversified specialty crop growers. Plastic mulch is beneficial for strawberry and lettuce production with soil-biodegradable mulch (BDM) providing opportunities to reduce plastic waste generation and costs of mulch disposal. The objective of this study was to compare non-biodegradable plastic mulches and BDM to bare ground cultivation in a strawberry–lettuce double-cropping system in a Mediterranean climate. A split-plot randomized complete block design experiment with mulch treatment [non-biodegradable polyethylene (PE) film, “weedmat” (woven, PE-based), BDM, and bare ground control] as the main factor and double-cropping rotation scheme (rotation 1 or 2) as the split-plot factor was conducted between 2020 and 2021. Strawberry yield was overall greatest when mulched with BDM, PE, and weedmat compared to the bare ground control. Total soluble solids (TSS), pH, and total titratable acidity (TA) of strawberry differed due to harvest date, but only pH differed due to mulch treatment. For lettuce canopy cover, rotation 2 had greater canopy cover (86%) compared with rotation 1 (66%) 30 days after transplanting. Average head weight (0.4 kg) and head length and diameter (both 20 cm) did not differ due to mulch or rotation. Average soil temperatures under PE and BDM were ~1.5°C higher than under weedmat and 2.5°C higher than the bare ground control. Soil under weedmat had the highest moisture content, whereas the PE, BDM, and bare ground treatments had similar levels. PE, BDM, and weedmat provided equivalent weed suppression, whereas the bare ground control had the most weeds. BDM deterioration estimated as percent soil exposure (PSE) was greatest (59% PSE) by the end of the experiment, whereas PE had 18% PSE and weedmat had no deterioration. Results show that despite high levels of deterioration, BDM performs similarly to PE in terms of soil temperature and moisture modification, weed suppression, and promotion of crop growth and yield in a double-cropped system. Double-cropping strawberry and lettuce is a promising alternative for growers to diversify their crop type and with potential economic benefits by increasing mulch lifespan.

Hydromulches suppress weeds and maintain fruit production in organically managed strawberry systems

“…Strawberry plant canopy percentage was at peak in PE mulch, followed by 6%PH, 2PH, 6%GG, 2%GG, and NP hydromulch. These results align with the prior study by Wang et al (2022), which indicated that PE mulch provided optimal strawberry crop canopy percentage compared to biodegradable plastic mulch and paper mulch. One might anticipate a similar pattern for strawberry crop canopy and leaf dry biomass across mulch treatments, but the present study revealed different outcomes from expectations.…”

Physical characteristics of soil-biodegradable and nonbiodegradable plastic mulches impact conidial splash dispersal of Botrytis cinerea

“…New, unweathered PE, weedmat, and embossed BDM mulches included in this study ( Table 1 ) were the same products that had been used in a previous mulch experiment [ 41 ]. Surface microtopographic features of mulch samples were assessed using a digital microscope (Keyence VHX-7000) in the Composite Materials and Engineering Center at Washington State University (WSU) in Pullman, Washington, USA.…”