Alternatives to polyethylene mulch film — a field assessment of transported materials in capsicum (Capsicum annuum L.)

Abstract

Materials used as mulches may be either transported to the farm then laid on the soil surface or grown in situ. To assess biodegradable alternatives to non-degradable polyethylene film, the response of capsicum (Capsicum annuum L. cv. Target) grown in soil beds covered with hessian (burlap), hardwood sawdust, sugarcane (Saccharum spp.) trash, paper film, black biodegradable polymer film, white polyethylene film, or left uncovered was investigated in a field trial during the autumn–winter growing season in subtropical Australia. Use of a split-plot design (mulch whole plots with weeded or unweeded subplots) permitted both weed growth and the effect of weed competition on fruit yield to be measured. The presence of substances within the materials that were possibly detrimental to plant growth was assessed in a separate experiment. The weight of marketable fruit was highest for capsicum plants grown in the weeded subplots of biodegradable polymer and polyethylene, although the yields from these subplots were not different from those for plants grown in the weeded subplots of the paper and sawdust or the unweeded subplots of the biodegradable polymer and paper. The reduction in weight of marketable capsicum fruit from weed competition was ranked for the various mulch treatments as follows: paper < biodegradable polymer < cane trash < polyethylene < hessian < sawdust < bare soil. More hours at optimum soil temperature for root growth (18.9–30˚C) before canopy closure probably accounted for the variation in marketable yield of the capsicum crop. Results from the mulch toxicity experiment indicated that the mulch materials were unlikely to contain phytotoxic substances. Provided the practical difficulties of laying paper film can be overcome and the high cost of biodegradable polymer is reduced, these materials appear to be the best of the biodegradable alternatives tested to polyethylene film.

Assessing the potential for spunbond, nonwoven biodegradable fabric as mulches for tomato and bell pepper crops

“…Increased soil temperature beneath bioplastic films relative to bare soil has been demonstrated in previous studies (Larsson and Båth, 1996;Olsen and Gounder, 2001). However, less is known about the effect of biofabrics on soil temperature.…”

“…Wheat straw and chopped newspaper waste can suppress weeds when applied in a thick layer (>7.6 cm), but this benefit is accompanied by substantially cooler soil temperatures early in the growing season (Monks et al, 1997;Larsson and Båth, 1996;Warnick et al, 2006). Unfortunately, reduced soil temperature beneath organic mulches can lead to reductions in crop yield (Olsen and Gounder, 2001). In addition to these agronomic drawbacks, organic mulches can be difficult and costly to apply on a commercial scale.…”

“…In addition to these agronomic drawbacks, organic mulches can be difficult and costly to apply on a commercial scale. Paper-based mulches are a commercially available alternative to PE and are popular because of their low cost (Olsen and Gounder, 2001) and potential status as an approved input in USDA certified organic crop production. There is also some evidence that vegetable crop yields in paper-based mulch systems can be competitive with those in PE mulch (Jenni et al, 2004;Cirujeda et al, 2012).…”

“…As a result, bioplastic films often deteriorate faster than PE during the growing season and are more susceptible to rips, tears, and holes, which threaten its capacity for season-long weed suppression (Martin-Closas et al, 2008;Moreno and Moreno, 2008;Ngouajio et al, 2008;Waterer, 2010;Miles et al, 2012). Even in cropping situations where the agronomic performance of bioplastic films is comparable to PE, the significantly higher cost of these products continues to limit on-farm adoption (Olsen and Gounder, 2001).…”

Effect of Simulated Weathering on Physicochemical Properties and Inherent Biodegradation of PLA/PHA Nonwoven Mulches

“…Recent studies have demonstrated the loss of mechanical strength and partial conversion into CO 2 for BDMs when buried in soil or placed at the water-air surface [1,3,[13][14][15][16][17][18]. But, BDMs also have undesirable attributes, including high price (2.5 9 conventional polyethylene mulches) [19], an uncontrollable and unpredictable onset and rate of biodegradation [20], and low biobased content (e.g., PBAT and PBS are mainly derived from fossil fuel feedstocks) [2,12,21]. Due to the inclusion of fossil fuel-based components, BDMs have been labelled as ''synthetics'' and therefore are not allowed for use in US certifiable organic agriculture [8,22].…”