Deterioration of Potentially Biodegradable Alternatives to Black Plastic Mulch in Three Tomato Production Regions

Abstract

<jats:p>Four potentially biodegradable mulch products (BioAgri, BioTelo, WeedGuardPlus, and SB-PLA-10) were evaluated during 2010 in three contrasting regions of the United States (Knoxville, TN; Lubbock, TX; and Mount Vernon, WA) and compared with black plastic mulch and a no-mulch control for durability, weed control, and impact on tomato yield in high tunnel and open field production systems. WeedGuardPlus, BioTelo, and BioAgri had the greatest number of rips, tears, and holes (RTH) and percent visually observed deterioration (PVD) at all three sites (<jats:italic>P</jats:italic> ≤ 0.05), and values were greater in the open field than high tunnels, likely as a result of high winds and greater solar radiation and rainfall. SB-PLA-10 showed essentially no deterioration at all three sites and was equivalent to black plastic in both high tunnels and the open field. Weed growth at the sites did not differ in high tunnels as compared with the open field (<jats:italic>P</jats:italic> &gt; 0.05). Weed growth at Knoxville and Mount Vernon was greatest under SB-PLA-10 (<jats:italic>P</jats:italic> ≤ 0.02), likely as a result of the white, translucent nature of this test product. Tomato yield was greater in the high tunnels than open field at all three sites (<jats:italic>P</jats:italic> ≤ 0.03), except for total fruit weight at Knoxville (<jats:italic>P</jats:italic> ≤ 0.53). Total number of tomato fruit and total fruit weight were lowest for bare ground at both Knoxville (150 × 10<jats:sup>4</jats:sup> fruit/ha and 29 t·ha<jats:sup>−1</jats:sup>; <jats:italic>P</jats:italic> ≤ 0.04) and Mount Vernon (44 × 10<jats:sup>4</jats:sup> fruit/ha and 11 t·ha<jats:sup>−1</jats:sup>; <jats:italic>P</jats:italic> ≤ 0.008). At Knoxville, the other mulch treatments were statistically equivalent, whereas at Mount Vernon, BioAgri had among the highest yields (66 × 10<jats:sup>4</jats:sup> fruit/ha and 16 t·ha<jats:sup>−1</jats:sup>). There were no differences in tomato yield resulting from mulch type at Lubbock.</jats:p>

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

“…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). Unfortunately, paper-based mulches often degrade too quickly during the growing season, especially the buried edges of the mulch, leading to weed infestation and reduced crop yield (Weber, 2003;Martin-Closas et al, 2008;Miles et al, 2012;Cowan et al, 2014). Degradation of paper-based mulch can be slowed through polymerization (e.g., adding oil to the paper), but this adds considerable mess, time, and expense to the mulching operation (Shogren and Hochmuth, 2004).…”

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

“…SB (spunmelt) nonwovens are prepared in a continuous process consisting of extrusion and spinning of a polymer melt, collection of the fibers on a conveyor belt, followed by heat bonding, and are comprised of strong, thermally point-bonded webs of continuous filaments with fiber diameters of 12-15 lm [23][24][25][26][27]. SB mulches have been shown to be robust for long-term agricultural uses, undergoing minimal deterioration during recently conducted 28-month and 30-week soil burial studies [23,34] and in field studies conducted in Tennessee, Texas, and Washington [35][36][37]. Although white-colored SB mulch was ineffective for weed control in 2010 at all three locations, black-colored SB mulches demonstrated weed prevention that matched the performance of commercially available biodegradable mulches in 2011 and 2012 [36,37].…”

Soil Degradation of Polylactic Acid/Polyhydroxyalkanoate-Based Nonwoven Mulches

“…In contrast, BioTelo underwent a lower, 29 %, loss of tensile strength after 10 week. However, Experiment A does not take into account the effect of weathering as a pretreatment on soil degradability, noting that both MB and BioTelo mulches undergo substantial degradation when exposed to sunlight, moisture, temperature fluctuations, and other weather-related forces [19,20,56]. Tensile strength could not be measured for the MB mulches, nor for BioTelo, retrieved after 30 week of soil burial due to the extensive fragmentation that occurred (Fig.…”

“…1. Commercially available BDMs possess several disadvantages: relatively high cost (2.5-fold more expensive than conventional PE mulches), uncontrollable and unpredictable macroscopic deterioration during growing season (e.g., rips and tears) [18][19][20][21], and inclusion of fossil fuel-derived components [3,8]. The literature contains mixed results on the biodegradability of commercially available BDMs under ambient soil conditions [3,8].…”

“…In 3-4 month long field studies conducted in 2010-2012, black-colored SB mulches were equally as effective as commercial BDMs for the prevention of weeds and minimally underwent deterioration [19,21,40,41], due in part to superior mechanical strength. In agreement, SB mulches subjected to laboratory-scale simulated weathering (ASTM G155 [42]) underwent only minor changes in physicochemical properties (e.g., tensile strength and fiber diameter), suggesting the long-term stability of SB mulches is not compromised by weathering [43].…”