Demonstration of Root Zone Heating Supported by the Developed Biomass Greenhouse Heating System

View the project final report

Commodities

Practices

• Crop Production: greenhouses
• Energy: energy conservation/efficiency

There has been high demand for local food in western North Carolina. The purchase of local foods supports local farmers and local economies, provides improved health benefits, and has a positive environmental impact. However, the limited availability of locally grown food along with consistency and access hinders these benefits. There are several reasons for limited availability of locally grown food with consistency in this region. The rough mountainous terrain and frigid winter weather limit agricultural opportunities such as the size of farms, shorter growing season, and limited large-scale mechanized farming operations. In addition, dramatic weather change in mountain region increases risks in agriculture such as spring frost damage.  These result in Appalachian rural farmers’ low income and high rates of off-farm workers. Some Appalachia farmers dedicate a portion of their limited acreage to greenhouse production to maintain their profitability. Greenhouse production can extend growing season and prevent damages from dramatic weather change, but the requisite heating and energy costs exclude many producers from being able to afford a heated greenhouse. The main purpose of this study is to extend the growing season and to cope with dramatic weather change with biomass heated greenhouse as a solution for several challenges facing successful profitable farming in the mountains. Biomass energy, generated from all available feedstock from farm such as livestock manure, agricultural waste, wood waste and food waste, can be an affordable greenhouse-heating energy source for those seeking lower energy costs to extend growing season. Our research team built two pilot greenhouse heating systems at local farms. We have begun collaboration with two cooperative farms in Watauga County, NC: Springhouse Farm and Against the Grain Farm. Working with these farmers, our team has developed a preliminary design of pilot systems and greenhouse heat flow model. The pilot systems include biochar kiln, solar collector, food dehydrator, and heat storage tank. In addition, we have built a root zone heating (under bench heating) system at two farms. The initial results (2018 and 2019 winters) show significant energy savings that can promote the resource-limited farmers’ interest.

With the support from SARE’s on-farm research grant, we were able to demonstrate performance of our pilot system and root zone heating (RZH) system on the cooperative farms. We envision farmers in Appalachia can increase their profit with our biomass heating system by growing season extension with less energy cost and by increased crop yield with soil amendment.