2009 Annual Report for FNE08-632
Investigation of increased productivity of a hoop house through better use of space
Summary
The project we are proposing will look at increasing the productivity and cost effectiveness of growing more crops using a hoophouse by utilizing the overhead space of the hoophouse. Our investigation looks at using a hanging gutter system to raise selected crops over the existing in-ground crops. We are looking at cost effective design, operation, production strategies, cost of production, and profitability of such a system. The space above the in-ground crops is wide open and offers a large potential growing space that could offer greater returns to the operation of the hoophouse.
The farm has not changed except that vegetable acres have increased to about 3 and the percentage of certified ground has increased to about 75%. In addition to the variety of vegetables we grow, we produce field corn, hay, soybeans and small grains. There is a small herd of Angus cattle on the farm that my father owns and sister manages, as well as our small flock of 26 laying hens.
Kurt Forman, Clearview Farm owner-operator, and Robert Hadad, Cornell Cooperative Extension Regional Vegetable Specialist, have designed and built the system; Kurt is growing the crops day to day. Robert consults and scouts plant progress and pests. Kurt and Robert take data on days to harvest, marketable yields, sales, and costs of production and profitability. Both will look at overall design efficiency and updates.
Methodology
Our first step was to design the upper level hoophouse system. We investigated gutter design, the size and number of gutters to implement, suspension options, irrigation, and fertilization techniques – drip tape and fertilizer injection – how to set it all up and rates, how to raise and lower gutters. We decided on a soil type to use in the gutters and the amount (about 2.25 cu. ft.) and the source of soil. I focused on ground cherry production, because putting the plants up in the air would allow me to harvest them in a less difficult manner, by means of collection netting under the plants. We also intended to investigate the merit of growing other crops, like dwarf sugar snap, Asian greens, and lettuce. We used the gutters for early and late-season greens, cilantro, lettuce, and peas, as well as early- main -late season for the ground cherry plants, using at least 5 gutters with 30 plants and compare this with some grown outside. We monitored water usage and fertility, as well as pests and disease. We utilized a trickle irrigation setup and added netting for cucumbers and ground cherries. We intentionally oriented the gutters in a north-south fashion to help increase sunlight penetration to the crops below.
Objectives/Performance Targets
What remains to be done – We need to add a winch system and possibly add hoophouse supports, since it was rather difficult to hoist the gutters up in the air by hand, especially after watering the gutters. We intend to add a fertilizer injector, to give us more control over soil fertility. We plan to exchange baler twine for aircraft cable on all of the gutters, since the plastic twine frayed and broke over time, especially when it was windy. We expect to develop a more useful production strategy, growing crops that are suited to changing growing conditions. We will improve the soil mixture to allow greater moisture-holding capacity and fertility. We shall address different kinds of compost and the possibility of adding soil.
Results to date – We had problems with the SunGro potting soil mix. There was inadequate fertility and water-holding capacity. There were also watering challenges. It was necessary to attend to the gutters constantly while watering to avoid overwatering. Kurt had to install a pressure limiter for the short ten foot lengths of drip tape in each gutter, to avoid blowouts of the end of the drip tape. Managing temperature for cool and warm season crops was a challenge, since we were not very familiar with the daily changes in temperature inside the high tunnel. We used baler twine on some of the gutters which led to eventual fraying and breakage of the twine. Where we used steel cable, there were problems with coming loose on one gutter, when high winds occurred. We need to better secure cable to the gutter bottom. We discovered need for a winch, since the gutters were difficult to raise and lower, especially after watering.
Ground cherries seemed to need more soil mass and perhaps more fertility, but the small cucumbers did well. We planted lettuce, cilantro, spinach, peas, and Asian greens. We found that the Dwarf Grey Peas showed potential, while the Oregon Sugar Pod peas were a failure. Some Asian greens did well, while others did poorly. The lettuce and cilantro did reasonably well under cool conditions, but the tendency toward warmer temperatures in the high tunnel, made it more difficult to grow in the summer. Given the low volume of soil used, we found that frequent watering was necessary. The installation of drip tape addressed that problem. We suspected possible pH issues in the potting soil. Given that the soil mix dried out easily, daily attention is needed, especially in the summer. Adding compost and possibly some high-clay soil may help.
We had trouble with a pinched water line that ran through a culvert across the road between the water supply hydrant and the high tunnel. A piece of steel that acted as a header for the culvert dropped and crushed the water line. Kurt cut out the pinched section and replaced it with a new piece of pipe. A word of caution; some high tunnels may not have the structural strength to support the additional load incurred by a gutter. The size of the gutter can impact how much soil can be contained and the resulting weight on the high tunnel. We put one gutter under each hoop on 14 consecutive of the 25 hoops in the structure. We had no trouble with that arrangement. In some cases, we used some compost with some of the SunGro potting mix, which helped increase water-holding capacity and fertility. This year, we will explore differences between different soil mixes and attempt to optimize a recipe for the gutters. We will need to monitor soil pH throughout the growing period.
We intend to do an economic analysis of the gutter system by comparing the cost of each gutter and the resulting production and sales value of the crop in the gutter. We may do the same for different soil mixes. We came in low on materials expense for the gutters, but agreed to carry the project on into another year to fine tune the system, thus adding labor expense. In the end, we expect the project to come in close to budget.
We quickly found, once we built the gutters and grew crops, that there was a steep learning curve involved. This year we intend to improve on our growing techniques and develop a sense of the economic feasibility of the system. Follow-up could include investigating other crops that might fit in to this scenario. A larger gutter with more soil volume and water-holding capacity may prove valuable. Making this change could mitigate the management intensity needed. Different drip tape configurations (flow rate and emitter spacing) may be desirable, as well. There may very well be more opportunity for research to fine tune the system even further, once we work through the issues we have identified to date.