Evaluation of the three designs involves analysis of the productivity of the two crops, measured in pounds of harvest, for each of the three years of the study. Productivity will be correlated with the type of house, the planting date and the location.

Fine tuning of the productivity analysis will involve temperature and moisture data. Each house contains equipment to monitor and log six data points of inside and outside air and soil temperature, sampled every 30 minutes between planting and final harvest.

It isn't enough to show that a good crop can be grown under New Mexico's winter conditions. The hoop-house approach must make economic sense, as well.

Evaluating the viability of hoop houses for actual producers involves weighing the costs of growing the vegetables, including the investment of building and maintaining an appropriately designed hoop house, against the anticipated income from the produce. That's the focus of Connie Falk, a professor in the Department of Agricultural Economics and Agricultural Business, and her graduate student Emmanuel Hecher.

"The economic analysis involves a risk simulation model, which estimates the probability of the returns from selling each crop in each of the designs at each site, exceeding zero," said Falk.

"We examine the probability of returns being positive for a range of possible prices observed during the experiment in different markets. The first-year analysis indicates that the probability of positive returns in Alcalde for all prices is lower than in Las Cruces."

When Falk and Hecher complete that analysis, farmers will be able to make an economically prudent decision about whether to build a hoop house and which model to select for their climate zone.

While definitive conclusions won't be available until after data from the 2011-12 harvest have been analyzed, some tentative conclusions can be gleaned from first- and second-year data.

For one thing, yields were higher for both lettuce and spinach crops planted in October, as compared with the crops planted in November. This was attributed to the longer days and warmer temperatures during the October crop's germination period.

In terms of which model hoop house makes sense for which climate zones, the preliminary report suggests that while the high-end version with two layers of plastic and the heat-conserving barrels kept the inside temperature closer to the optimum for production of these crops, the total production at the Leyendecker site was actually higher in the double-layer hoop houses without the barrels.

As with much NMSU research, this project is expected to offer benefits on many levels. The researchers are breaking new ground with the help of their students, for whom it is a great learning experience. The collaborating producers are not only learning as they go; Uchanski reports that some are also growing other vegetables, including bell peppers and radishes, during the rest of the year.

And the state's economy stands to benefit in the long run, as the results of the study help other producers increase their production by incorporating the optimal hoop house into their operations.