Comparative analysis of different biodegradable mulch uses in hill-side strawberry production

Introduction

Plastic film (PF) is widely used in crop production, yet global environmental concerns urge for reduced plastic waste. Biodegradable and bio-based mulches emerge as promising alternatives, potentially crucial for sustainable agriculture. This significance is emphasized by the hypothesis that small farms prioritize sustainability and seek to reduce plastic waste in soil and food systems, especially if bio base mulch match or exceed the benefits of plastic mulch. However, there is limited data available on the effectiveness of biodegradable paper (BP) and bio-based film (BB) in small-scale crop production, especially the area frequently affected by heat and drought stress (Deschamps et al., 2021). Also, fewer research indicates that this bio-based films has competitive ability to influence yield and fruit quality compared to standard plastic film.

Objectives

➢ Investigate the impact of the different mulches on soil temperature, fruit yield and quality at harvest

➢ Identify the most appropriate bio-based film regarding yield and economics for growing day-neutral strawberries in Mediterranean climate for Inland Empire region

Materials and Methods

 Field experiment was conducted on a strawberry field in Redlands, San Bernardino County, California in 2023-2024. The trials were organized as a randomized complete split-plot design with four common mulches in small farms in California, polyethylene mulch (PE), landscape paper mulch (PA), Coconut liner mulch (CL), Biodegradable plastic mulch (BM-Black -88), and bare soil (control) with the most popular ever-bearing variety, ‘Albion’. There were 20 plants per plot, and each treatment was replicated three times. Mature fruit (90% to 100% red) was harvested twice weekly for total and marketable yield (fruit with no defects) and three harvests were evaluated for quality. To investigate the suitability and efficacy of these mulches, we recorded the soil properties (temperature, moisture, and pH) daily, fruit yield (fruit weight and fruits/plant) biweekly, and fruit quality (Soluble solid- Brix %) and color L* = lightness; a* = redness) at harvest considering farm stand or U-pick sale service.

Statistical Analysis

Data analysis was performed using SAS version 9.4. Normality was checked with Proc Reg and Univariate. Fruit yield was analyzed using a linear mixed model (PROC GLIMMIX) with LSD for mean separation. Fruit quality across three harvests was evaluated using PROC GLIMMIX, considering cultivar, mulch, year, time, and their interactions as fixed effects, with harvest as a random effect. For day 0 fruit quality, cultivar, film, and their interaction were fixed effects in PROC GLIMMIX.

Result

Table 1. Showing treatments effect on the two different strawberry cultivars yield

 Table 1. Showing two-day neutral cultivars ‘Albion’, ‘Portola’ fruits were harvested at 100% maturity twice weekly in 2023 and marketability was determined by fruit free from disease and pest damage, and rot, total and marketable fruit were counted and weighed each time and values are presented on a per plant basis. Foure different bio-based mulches were (Black plastic, Coconut Liner, Landscape Paper, Biodegradable mulch and Bare Soil) considered as treatment and bare soil was the control. Probability value for the overall ANOVA F-test using Type III hypothesis test where α=0.05 Means followed by the same letter are not significantly different according to LSD paired comparisons where α=0.05.

Table 2. Showing treatments effect on the two different strawberry cultivars fruit quality

Table2. A linear mixed model was used to test which factors and interactions had significant effects on the examined quality parameter (P ≤ 0.05). z Plastic mulch of four different (Black plastic, Coconut Liner, Landscape Paper, Biodegradable mulch and Bare Soil) plastic mulch Two day-neutral strawberry cultivars (‘Albion’, ‘Portola’) x The effect of mulch on fruit quality were measured only at day of harvest are not significant

Results and Discussion

In 2024, strawberries grown with coconut liner and biodegradable mulch had significantly higher total and marketable yields 38% and 33% greater, respectively compared to bare soil (Table 1). In contrast, black plastic and landscape paper mulches produced yields similar to bare soil. These results are consistent with previous studies showing that bio-based and organic mulches can improve strawberry yield by enhancing soil moisture, aeration, and microclimate conditions (Deschamps & Agehara, 2021; Salem & Helaly, 2019; Sharma et al., 2024; Luminare et al., 2024).

Despite the yield increase, fruit size was not significantly affected by mulch type. Similarly, soluble solids content (Brix) showed no significant differences among mulch treatments, with cultivar differences being the primary factor influencing sugar accumulation ‘Albion’ fruit had 31% higher Brix than ‘Portola’ (P < 0.0001, Table 2). This aligns with prior research indicating that mulch type generally affects yield but has limited impact on fruit quality parameters (Ahmed et al., 2024; Deschamps & Agehara, 2021).

Overall, coconut liner and biodegradable mulches offer a sustainable alternative to conventional plastic mulch, improving strawberry yield without compromising fruit quality in small-scale production systems.

Conclusion

Coconut liner and Biodegradable mulch result in the highest increase marketable fruit weight compared to other treatment. Albion resulted in significantly higher SSC-Brix -% on coconut liner and biodegradable mulch. However, varietal effect among the treatment of fruit composition also evident.

Summary

Overall, of using biodegradable mulch technique indicating a trend of higher yield and quality of day neutral strawberry varieties under trenching system or hill side production.

References

Deschamps, S. S., & Agehara, S. (2021). Metalized-striped plastic mulch reduces root-zone temperatures during establishment and increases early-season yields of annual winter strawberry. HortScience, 54(1), 110–116.

Salem, A. A., & Helaly, A. A. (2019). Impact of mycorrhizae and polyethylene mulching on growth, yield and seed oil production of bottle gourd (Lagenaria siceraria). Journal of Horticultural Science & Ornamental Plants, 9, 28–38.

Sharma, S., Pant, P., Sangwan, M., & Sahrawat, R. (2024). Effect of organic and inorganic mulch on growth, yield and quality of strawberry CV. Winter Dawn. International Journal of Environment and Climate Change, 14(3), 377–382.

Luminare, M.-C., Iaco Mi, B., Szilagyi, L., & Cristea, S. (2024). Research on the impact of the mulching system on strawberry yield. ResearchGate.

Ahmed, M., Duis, K. E., & Coors, A. (2024). Microplastics in the aquatic and terrestrial environment: sources, fate, and effects. Environmental Sciences Europe, 28(1), 1–25.

Acknowledgement

This research was funded by JEHOVAH JIREH F Mobile Farm and UC Cooperative Extension. The author thanks to support JJM farm for allocating the field to conduct this trial.