A Comparison of the Profitability of Subsoil Heated and Unheated Hoophouse vs. Field Production of Cool-Climate Salad Crops in Central Lower Michigan
The use of unheated plastic film hoophouses (also called high-tunnels) over natural soil for production of cool season vegetables, nearly year-round, in central-lower Michigan and at similar latitudes has recently been demonstrated by local university workers (John Biernbaum et. Al. Michigan State, William Lamont et. Al., Penn State). A few local farms have also recently begun using hoophouses for production.
This technology offers the possibility for small farms to produce over a longer period of the year and potentially optimize profits in the off-season. Such production could result in an important market niche and increase farm profitability while increasing the availability of locally-produced food. It is important to realize, however, that actual profitability using such technology has not been described in detail and remains a critical component in the decision to adopt it. The question of overall profitability after additional materials and labor costs has not been clearly answered.
While costs of the hoophouse structure itself are fairly easy to determine, information on various other farm costs, including labor, seeds, pest and fertility management, etc. and profits as a result of sales in the various markets in our region are not available. Is production and profitability in a hoophouse sufficient to offset structure and labor costs? What are the actual profit differences? This project will address the question of profitability of the cool-season hoophouse method of production, compared to conventional field culture. Profitability will be addressed in the context of the various markets utilized and these will be compared and contrasted.
This project will utilize three production methods to determine yields of cool season crops (lettuces, Swiss chard, radish, carrot, and kale) and profitability under plastic-film protection with soil heat (method 1), without soil heat (method 2), and under standard field production methods without protection (method 3). Fabric row covers will be used inside and outside for frost protection.
Funds were used to pay for labor and equipment costs to prepare a site for an unheated hoophouse. First, the site was cleared of brush and generally leveled with a bulldozer. Next, the site elevation was measured with a land surveying level and final grading was done with a tractor with a bucket attachment and topsoil applications.
This was followed by applications of horse manure and sawdust compost, straw and cow manure compost, chicken manure compost, and amendments including rock phosphate, green sand, and azomite to bring soil nutrient levels within satisfactory ranges per soil testing.
After amendments were applied, materials were incorporated and deep tillage was done with a Granholm plow. The site was then disked and allowed to settle. This whole process was completed between Fall 2004 and Spring 2005.
Difficulties arose primarily in receipt and installation of the unheated hoophouse structure (Grant covered 40 percent of the cost of the hoophouse). After the (above) process was completed, spring 2005, it was discovered that rafter diameter was incorrect (and therefore all accompanying parts except purlins were also not appropriate). After returning and receiving replacement hardware (a three-step process), construction was delayed and compromised the project for 2005 (thus the deferment in finalizing the project). Erection of the new hoophouse was finally completed late 2005, and the site was partially planted for 2006. The remainder will be planted late winter 2005-2006.
Although the unheated hoophouse results for 2005 were not available as a result of the delay, the heated hoophouse versus field grown crops revealed clear differences in yield and profitability. Overall yields of lettuce were four times higher per square foot in the heated hoophouse versus field grown crops because of higher temps in the spring and because soils were more fertile, water holding capacity was higher, and weed pressure was lower. This was likely due to the use of artificial organic media.
Inputs were more intensive in the heated hoophouse resulting in higher yields and better lettuce quality. Heating and media costs offset profitability by about 50 percent. This would be important on a strict comparison basis but were offset because the heated area is used for other valuable crops including seedling production. Structure costs also offset profits, however depreciation of these input costs results in a gradual increase in profitability over the life of the hoophouse. The existing heated hoophouse has been in place for nine years. The poly covering is the main cost over time as it needs to be replaced every 5 or 6 years. The frame structure itself should last in excess of 30 years.
WORK PLAN FOR 2006
Heated hoophouse growing beds were planted September 2005 with good lettuce establishment and one harvest. This crop continues to grow and will be harvested 2006 also, if plans succeed. Additional plantings will be made at the end of February. This data will be collected throughout the project period.
Harvesting will be conducted and data collected in 2006 of unheated hoophouse crops. The remaining unheated hoophouse beds will be planted late February, the same time as the additional heated hoophouse plantings.
Crops grown in the field will be planted as soon as weather permits.
Optimum cultural techniques will be utilized and production and cost data will be collected on all three cropping scenarios. Data will be analyzed with the assistance of an agricultural economist.
During the growing season, tours of the project will be organized and conducted and the farm will be open for observation on an informal basis. Results will then be published and field days will be organized with Michigan State University faculty.
In 2005, a workshop on hoophouse production was organized and conducted by Susan Houghton of Giving Tree Farm. Part of the workshop included site preparation and was conducted at our farm.
Information on production and failures was shared on an informal basis with other farmers. Plans in place for 2006 include one or more farm tours. More formal talks and field days include one field day in August where production methodologies and results to date will be provided. In November, information will be written up in a budget format so it can be easily understood. Information will be disseminated through printed media (local and industry newspapers), through field days, at subsequent dates and variously through collaborations with local agricultural extension and industry personnel. All steps of the operation will be photographed/videotaped and documented for use in presentations at various meetings or conferences as agreed upon with various groups. Also local newspapers will be contacted to utilize the project as a focal point for public interest to help increase awareness of local food issues, as suggested previously.
The project will address the profitability of producing cool climate crops (lettuces, chard, radish, carrot and kale) in a hoophouse, using heated and unheated soil, versus conventional field production. The project will compare costs and revenues of the various production methods.