ASHS 2025 Conference

Maintaining soil health for open field and high tunnel (HT) production of vegetables has become prioritized by growers in recent years. In particular, there have been growing concerns about the sustainability of HT systems. Their hot and dry conditions, compounded by intensive practices, lead to challenges with soil temperature and moisture management, compaction, salinity, and ecosystem health. This report investigates how established and novel mulch types can help growers manage soil temperature, moisture, and health conditions across growing systems and climatic conditions. Tomato and lettuce trials were conducted from 2022 to 2024 in HTs and open-field plots to determine the effect of various mulch treatments (bareground, black plastic film, black woven fabric, paper mulch, white silage tarp and black silage tarp) on soil temperature, moisture, and health. Gravimetric and volumetric soil moisture content were determined weekly and bi-weekly in the lettuce and tomato trials, respectively. Soil temperatures were recorded at 10.2 cm depth throughout the growing seasons for both crops. EC, bulk density, and respiration data were collected at termination of all trials to assess soil health. In tomato, the application of black plastic mulch, fabric mulch, and black silage tarp was associated with higher average soil temperatures (23.7°C-28.9°C), compared to (22.4°C-26.8°C) under white tarp and paper mulch. In the lettuce trials, all mulch types retained soil heat in the early season (0.7°C-2.2°C) compared to bareground. The use of silage tarp maintained up to 21% more soil moisture than the bareground treatment for tomato and all mulches were effective at managing moisture loss. Limited effects on soil health criteria were observed, though higher measurements of bulk density and EC may be associated with increases in soil moisture. Results indicdate that mulch color and material affect soil temperatures and soil moisture in the summer, whereas in fall all mulches may reduce heat loss in the early period of the growing season and soil moisture (5-7%) in the late season. As growers address soil health concerns, an integrated approach will need to be adopted that utilizes multiple practices. This study shows that mulch color and type/material can be selected to alter the microclimate of the soil environment across production systems. More research is needed to determine how these impacts affect long-term soil health. The development of regional growing practices that ensure soil health will be instrumental to support a growing population and using mulches for vegetable production can help achieve this goal.

Evaluation of Soil Biodegradable Mulches used in Plasticulture System Under Different Climatic Regions of North Carolina With Tomato as A Model Crop E. Atley, G. Yang, and T. McGee, Department of Natural Resources and Environmental Design, North Carolina A

The widespread use of plastics in agriculture (plasticulture), including greenhouse films, plastic mulches, plastic pots, seedling trays, pesticide containers and drip irrigation systems, although contributing to short-term productivity, has long-term detrimental consequences for the ecosystem and human health. The accumulation of plastics in soil, chemical leaching from plastics and their degradation into microplastics (particles smaller than 5 mm) is one of the most serious environmental challenges, affecting soil fertility, plant health, and the human food chain. Micro- and nanoplastics and the additives used to enhance the performance and appearance of these plastics can potentially damage tissues and cellular systems by activating various chains of tissue function. Thus, various types of micro- and nanoplastics lead to inflammation, cytotoxicity, genotoxicity and immunotoxicity in cells and tissues. Reproduction is particularly affected by these pollutants, as many of these pollutants can cause endocrine disruption. Efforts to mitigate the negative impacts of plastics include recycling plastic waste, developing biodegradable alternatives, and improving waste management practices. In this regard, Behzist Danesh Narvan Company has used modern technology to produce biodegradable pots (Lignum Vitae) made from completely natural materials such as plant fibers and bio-based adhesive. These flower pots have many advantages as being breathable, 100% biodegradable and ecofriendly, rapid decomposition, having high percentage of organic matter, compatibility with different climates and reducing plastic pollution. These pots can act as a natural fertilizer and enhances plant growth after decomposition.