[Editor’s Note: See the attached files for Barry Adler’s PowerPoint presentation from the 2010 Farmers Forum at the National Small Farm Trade Show and Conference in Columbia, MO; and tables with watering and harvest data.]
Growing operations are located on a small family farm of 9 acres in Central Ohio. Cropping is on approximately 1.5 acres with a mix of herbs, specialty vegetables, and fruit crops. The primary production area for this project involved 1 acre of intensive production of herbs and specialty vegetables established in 2005. Intensive cropping systems involved greenhouse aquaponics, trays, containers, in-ground raised beds and field raised beds. Crops are marketed locally within a 25 mile radius to restaurants, retail grocers, caterers and a vegetarian burger processor. Labor is primarily by the owner operator and several part-time helpers on a seasonal basis to assist with production, harvesting and processing. Year-round production of fresh crops has been continuous since the 2007 growing season with baby greens being harvested for local restaurants during the winter months.
I have been growing using organic practices for the past 40 years, including growing using biodynamic methods in the early 1970’s at the UC Santa Cruz Farm and Garden Project. After going back to college and earning a MS degree in Horticulture, I worked for 22 years at the Scotts Company spending several years in research developing outdoor garden products including some work with organic fertilizers. My career led to managing 3 departments, but I continued to grow a large home garden using organic methods. In 2004, I had the opportunity to develop a small growing enterprise on my farm and developed a design for a renewable energy greenhouse and began plans for a year-round operation to supply fresh herbs and specialty vegetables and fruits to local markets. In 2005, I received a SARE producer grant to assist with development of these year-round sustainable growing practices. These practices include vermicomposting, composting, organic fertilizers, aquaponics, rainwater collection, use of renewable energy for power and heating, biocontrols featuring use of predators and cover cropping.
• To measure production inputs and returns for 3 intensive production systems. Evaluation on a per square foot comparison to determine yields and net returns.
• To examine potential for market season extension for utilization of surplus in-season production yields by use of value-added processing options.
1. BioIntegrated Renewable Energy Greenhouse – (off-the-grid heating/cooling systems) aquaponics vs. containers
2. Passive Solar Greenhouse – (unheated, double-wall inflated plastic, subsurface insulation, interior row cover)
3. Intensive Raised Bed Field Production
1. Energy – heating/cooling, fuel, electrical, fuel for soil preparation
2. Labor – planting, harvesting, processing
4. Other expense items – fertilizers, biocontrols, equipment, etc.
Market Season Extension:
1. Identification of key surplus crops
Herbs – Basil, Oregano, Garlic Chives
Vegetables – Peppers, Tomatoes
2. Evaluation of Local Marketing Options
3. Evaluation of Methods and Processing Requirements
During the summer of 2007 some preliminary data was taken and methods were developed for record keeping and determining what were the key differences in inputs and which crops would be to measure for production efficiencies. The project was not finalized until 2008 with a late start to the season and data was not collected until mid-season. The local market demand helped with the choices of which crops to grow and the highest income potential. Key variables identified that showed some differences between cropping systems included yields, harvesting labor, water usage and length of harvest season. Focus during 2008 and the subsequent 2 growing seasons was on harvest labor, irrigation and yields. Other parameters such as biocontrols, fertilization and equipment usage did not vary to any noticeable degree between cropping systems and the decision was made to not make quantitative measurements. Energy usage was also somewhat difficult to quantify on a square foot basis by specific crops, so general records for supplemental heating were kept for the 3 cropping systems. Irrigation requirements were also determined to be a major source of energy input variation between the cropping systems.
During 2009, differences were noted within one of the cropping systems – the BioIntegrated Greenhouse (BIG) for the Arugula crop. So additional harvesting measurements were separated out for 3 methods –
1) growing in 3 inch pots in trays in the fish tank troughs,
2) growing in 3 inch pots on benches
3) growing in larger 1-3 gallon containers also on benches
A stopwatch and a digital scale were purchased at the beginning of the research project and become key tools in developing data for making cropping decisions. I would strongly recommend these tools in any growing operation to shed objective insights as to actual versus perceived labor inputs and yields. After one dry summer season and quantified measurements of time spent hand watering and weeding, all field crop beds and passive greenhouse beds were converted to drip irrigation and fabric mulches. The objective measurement of harvesting labor when compared to income when based on a sq ft comparison also was key to refining the selection of crops over the past 3 years.
Use of the extra scale to measure fresh yields at the greenhouse which were compared with marketable yields of crops processed at a second location in our home kitchen also helped to underline the importance of crop quality and pest controls. Although differences between cropping systems were not significant, the difference between an actively growing healthy crop versus a crop that was under stress or suffering from insect or disease damage made a huge difference in processing time and saleable percentages. The labor input is significant in a triple rinse operation. When one has to do extra sorting to reject any defective leaves of herbs or greens, a decrease in quality also has a significant negative impact on labor and subsequent profit margin. By monitoring the fresh weight versus market yield, it was determined that some crops needed to be replaced or harvesting ended at a point when quality declined prior to the more visible demise of the crop itself.
With regard to market extension by processing of surplus crops, it was determined during the first season which key crops were being grown that exhibited growth flushes during the summer months and provided some surplus that was not readily absorbed by existing market outlets. These included tomatoes, peppers and basil. When selling to restaurant chefs and local grocers, a regular quantity of fresh produce was desirable on a weekly or twice weekly basis. Growth flushes of tomatoes, peppers and basil seemed to correspond to those of other local growers and typically when the market supply increased either the price drops or the orders placed by local outlets drops, as other growers make their products available to chefs and grocers. Farmer markets also compete for chefs dollars during the summer months.
Processing these surplus crops for sale during the off–season was evaluated as part of this project. During 2008, research into regulations regarding processing of crops for value-added products determined that any non-produce additives would require having a licensed kitchen and that the costs of this were prohibitive for a small scale grower. A local caterer that produces vegetarian burgers provided some guidance with this phase and provided an outlet for surplus peppers that could be incorporated into their burgers. Subsequent efforts during 2009 focused on drying herbs, peppers, and tomatoes. Analysis of labor requirements and fresh weight to dried weight yields helped focus efforts in the later part of 2009 to develop more outlets for the sale of fresh harvests, with the goal of alleviating any surplus and also to focus on growing more baby greens for year-round sales. Local restaurants tended to favor growers that could provide extended season crops on a regular basis and were reluctant to pay a premium for dried or otherwise processed items. Caterers were also seen as an outlet for surplus items since they already had approved licensed kitchens to process the fresh items into other food products. In fact one caterer was able to utilize all my surplus production of basil during the active growth phase and made a pesto base that they froze and used in a finished pesto at a later date. A simplified process of spraying chopped fresh basil with olive oil, then freezing in vacuum sealed bags was developed and has been effective in preserving the basil in a green state for almost 2 years without any color degradation. Another method of drying golden grape tomatoes resulted in a product that was very well-received by chefs, but due to lack of surplus during the 2010 growing season, this product still remains in the development stage.
Since this was primarily an on-site research program concerned with evaluating existing growing practices and yields, few personnel from other agencies or organizations were assisting directly with the project. Extension Service staff, aquaculturists (Bob Calala, who is the President of the Ohio Aquaculture Association) and college instructors have referred interested persons to me for more information. In addition to some individual tours, key public tours were provided in the spring and fall. See OUTREACH section for additional details. The fall tour was coordinated with Bill Spratley at Green Energy Ohio as part of the Ohio Solar Tour, as RainFresh Harvests growing operation uniquely features several forms of renewable energy, as well as energy efficiency design in an off-the-grid greenhouse. Peg McMahon from the Ohio State University has brought several groups of horticulture and environmental education students to these tours.
The number of our local clients has more than doubled over the 3 years of this project. At the end of the 2010 outdoor growing season, I was selling and delivering to 2 Whole Foods Stores, the Greener Grocer (a local retail market), two caterers (that is the name of the catering business run by 2 chefs), Luna Burgers (a caterer that makes vegetarian burgers and markets locally), Made From Scratch (a local caterer) and a dozen restaurants including: 2 Northstar Cafes, Third and Hollywood (also operated by the owners of Northstar), Tucci’s, Café del Mondo, Vincenzo’s, Matt the Miller’s Tavern, Z cucina, and J. Liu. All of these are locate within a 25 mile radius of our farm. Several of these chefs have provided key feedback into crop selection. During 2009, one chef encouraged me to test a variety of micro-greens and although the growing of many of these in my unheated greenhouses was a challenge during the winter months, one new crop of baby greens was selected for increased production in 2010 – Mizuna. This unique item has been a favorite of some of my local chefs and I am able to sell at a premium pricing that has resulted in the highest returns per square foot of any of the crops evaluated to date.
Results will be covered in two separate sections:
Production Systems and Growing Efficiencies: This portion of the research program produced a large amount of data accumulated over the 3 plus years of the project. The data and several summary spreadsheets is in the attached file (RFH SARE project FNC07-675 harvest data)
• Yields varied considerably from year to year and collecting data over a 3 year period and analyzing by averaging the last 2 years in more detail has provided some important insights.
• The 3 cropping systems include the BioIntegrated Greenhouse (BIG), the Passive Solar Greenhouse (PSG) and raised bed Field Crops (FC)
• Overall Energy Usage was highest for the BIG, followed by the PSG and then the FC.
The BIG is primarily powered by renewable energy sources including solar photovoltaics and a wind turbine for electricity and solar thermal collectors and retractable curtains for winter heating and heat retention. Some supplemental heating with propane was required during the coldest weeks of winter when temperatures dropped into the low teens and especially after several days without sun or wind to keep temperatures above the freezing mark to prevent damage to water lines. Watering also required the most labor in the BIG due to cropping in containers which are not readily converted to drip irrigation and the lack of a sprinkler system on a timer. Some of the trough irrigation and recirculation was automated on a sump pump/gravity recirculation system in the aquaponics component, however, due to evaporation; supplemental hand watering was also regularly required during summer months.
The PSG unheated high tunnel required more energy than the outdoor FC beds due to greater water demands during the summer months. During the last 2 growing seasons, with the exception of about 3 weeks in both years, rainfall was fairly evenly distributed throughout the growing season and maybe in excess during the spring and summer months at times. Even during the first growing season in 2008, which was much dryer, the PSG tended to be hotter and therefore required more watering to keep plants growing optimally. Excessive heat did not appear to translate in to significantly higher yield for warm season crops in the PSG, and at times possibly due to water stress, yields were reduced. Energy was also required year-round to operate the inflator fan to keep the 2-layers of the greenhouse plastic film separated.
• Drip irrigation did significantly reduce labor inputs for all crops in the PSG and FC areas
as compared to the BIG which was watered by hand or recirculating aquaponics. A floating raft system was tested with mixed results for spearmint in floating trays on the outdoor pond and additional efforts are needed to refine this method for possible use in greenhouse fish tanks.
• Drip irrigation did not reduce energy usage, in fact, due to the limitations of using the
same pump for either drip irrigation or hand watering, the drip irrigation which ran for
generally 4 times longer utilized significantly more energy to deliver only slightly more
water to the plants.
• Overall Water Usage was highest for the BIG, followed by the PSG, then FC. In the BIG,
the pots in trays on benches used the most water, followed by pots in fish tank troughs, then the larger containers. The larger containers had a better root media to tops ratio and appeared to have less transpiration and evaporative loss.
• Use of fabric landscape mulch in the beds and pathways significantly reduced labor
required for weeding and is highly recommended, also demonstrating some control of
flea beetles that generally need access to soil for multiple generations.
• Row cover fabric significantly extended the growing season both in the PSG and for FC
beds. Arugula was grown as a late fall/early spring crop with simple covering by the row cover in FC beds. Wet conditions in the spring of 2010 and early winter conditions prevented similar success that was realized in 2009. A low tunnel was tried in late fall of 2010 and was blown off due to snow and winds in January thereby ruining what looked like a promising spring crop. Row cover fabric also reduced flea beetle damage in the spring time on the Arugula FC bed.
• Overall cropping yields and harvest labor involved considerable data collection the details
of which can be found in separately attached spreadsheet files.
The following table is extracted from this data and lists crops included during the 3 year study and summarizes gross income on a sq ft basis. Further analysis of the data was completed for the key crops (see Table 2) – Basil and Baby Arugula – to also consider yields and harvest labor inputs.
Table 1. Summary table for crop income per sq ft
Crop Ave $/sq ft
Garlic Chives $6.767
Red Amaranth $5.313*
Baby Arugula $4.094
Mixed Red Lettuce $2.411*
Curly Cress $2.188*
Heirloom Tomatoes $1.525*
Gold Grape Tomatoes $0.982
Sport Peppers $0.938*
French Tarragon $0.548*
Jalapeno Peppers $0.543*
Italian Flat Leaf Parsley $0.408*
Paprika Peppers $0.349
Chive Flowers $0.242*
Asian Pears $0.090*
less than 3 full years of harvest data
Some of these higher value items such as garlic chive, rosemary and thyme require significant harvest labor per pound and require further analysis before concluding their economic viability.
An evaluation of crop returns shows promise for increasing Mizuna, Spearmint and micro-greens for future expansion. Items such as peppers and berries showed less favorable returns due to low total weights and shortened harvest seasons. One surprise was the higher value of the harvested heirloom tomatoes which sold at a lower price than the grape tomatoes. Heavier weights resulted in greater total returns per sq ft. Any extrapolation of the sq ft analysis should be limited to similar growing conditions and practices.
Table 2. Summary table for Arugula and Basil for 2009 and 2010 growing seasons
Crop Cropping System Ave Fresh Wt/ Sq Ft Ave Income/Sq Ft Ave Cost/ Sq Ft Ave Net/ Sq Ft
BIG — Container 0.446 $3.74 $0.38 $3.36
BIG — Trays on Benches 0.241 $2.02 $0.31 $1.71
BIG — Trays over Fish Tanks 0.290 $2.44 $0.31 $2.12
ALL BIG Combined* 0.613 $5.14 $0.30 $4.85
PSG Bed 0.383 $3.21 $0.21 $3.00
Field Crop Beds 0.161 $1.35 $0.05 $1.30
Arugula Ave for All Areas 0.356 $2.98 $0.26 $2.72
PSG Beds 0.426 $2.82 $0.60 $2.21
Field Crop Beds 0.661 $4.37 $0.88 $3.49
Basil Ave for All Areas 0.543 $3.59 $0.74 $2.84
*ALL BIG combined areas refers to earlier preliminary data from 2008, subsequent data from 2009 and 2010 more closely reflects averages for the actual total harvested area as opposed to a more limited analysis that did not account for grow out areas when the crop was not being harvested.
• Cooler season crops such as Arugula favored the BIG and PSG due to significantly longer harvest seasons.
• Rooting depth, moisture and temperature were all factors that explain the differences of Arugula production methods. Containers significantly yielded the best results. Pots in trays over the fish tanks had a slight advantage over the trays on benches due to release of heat from fish tanks during winter months during cold nights and possible a slight improvement in moisture regulation.
• Basil had generally higher yield rates per sq ft even though harvested over a shorter season than cooler season crops. Cooler season crops had comparable overall net returns due to the longer harvest season.
• The Basil FC beds not only had a higher overall yield than the PSG, but also were harvested over the shortest period of time. Most likely this was due to summer heat stress in the PSG. Season extension of harvests of several weeks in both the spring and fall were average for the Basil in the PSG, however this did not increase but actually showed lower net returns per sq ft.
Additional analysis of the data will continue to develop insights into the interaction between the cropping systems, harvesting process and subsequent profitability.
The need to provide fresh produce grown in the local food shed is of critical importance in the North Central region. The challenge is to be able to do this in a sustainable manner that works to preserve precious natural resources of energy, water and organic matter while being economically feasible for local farmers.
This project provided some extra funds that allowed me to more closely examine the inputs and yields for a variety of crops grown using several promising cropping systems to help determine which practices and crops have the greatest economic viability in the local marketplace and which crops and practices are the most effectively grown with respect to natural resource conservation. The project also supported exploration of a variety of season extension options that could utilize any surplus crops from the growing season to be sold at a later date to supplement the income stream while economically obtaining the highest possible value for those crops.
I learned which of the crops grown had the highest returns per sq ft over a range of cropping systems. I was also able to identify key labor, water conservation and energy factors that helped to guide me into a better selection of crops and practices to become more efficient in the growing of these crops.
I also learned that processing of surplus crops could be challenging due to state regulations regarding modification of fresh items with any additives and that the labor and energy inputs had a significant impact on costs of producing these season extending products. Several novel methods were refined during the course of this project, but the bottom line of economic competition with products already available from other larger producers pointed me towards developing more outlets to handle the surplus production as fresh product. Clients that already had licensed kitchens for processing and were seeking locally grown produce were the best fit. It was determined that when addressing the challenge for season extension that it was more appropriate to work on how to grow more crops during the off-season when the typical growing season was not yielding any product than how to preserve surplus produce for sale later.
Of the cropping systems examined, each had certain advantages and disadvantages.
The BioIntegrated renewable energy greenhouse (BIG) was seen as having the longest period of harvesting but also had the highest energy usage and investment cost. The supplemental heating by the use of a small propane space heater, although minimal when compared to standard greenhouse growing, did impact the economics and returns per sq ft were seen as poorest of the 3 methods examined. There were competitive advantages with client restaurants that secured a commitment to support purchases on a longer term basis that allowed for scheduling production based on a consistent demand. Baby greens were ideally suited for the facility and scheduled sequential plantings was an effective method for ensuring a more or less continuous cropping season year-round. Although higher per sq ft returns were realized on these crops, especially Mizuna, the dollars represent gross sales dollars and even with the reduction for labor costs, these numbers can be somewhat deceiving since they do not reflect the capital investment needed for this building.
The passive solar greenhouse (PSG) is very similar to typical high tunnel but has a few modifications that help with year-round growing. These include panel insulation in the ground on the perimeter outside of the greenhouse to help contain and direct the heat in the soil into the greenhouse, a double inflated roof and partial sides, roll-up ventilation for the lower 3 ft of the sides, a custom designed mechanical temperature activated pivot vent at either end of the high point along the end walls to assist with automatic cooling when temperatures spike. For a farmer just getting started and desiring to produce year-round, a similar structure is recommended as being more cost effective however, unless there is access to power near the structure, a renewable energy source or some other source of power will be needed for inflation of the double layered covering and for irrigation purposes. Irrigation is critical in this covered environment that is more subject to temperature fluctuations than the BIG. The primary advantage for the PSG was seen during early spring and late fall with higher yields during these periods due to better light and in-ground raised beds as compared to the BIG and providing a significantly longer harvest period as compare to Field Crop (FC) raised beds. Less of an advantage was seen during the summer months when excessive heating and drying even with regular watering tended to reduce yields. The focus for future PSG cropping will be with cooler season crops.
The Field Crop (FC) raised beds had yield very similar to the other cropping systems per sq ft, but those yields were more concentrated during the shorter growing season. The advantage of irrigation by regular rainfall during 2 of the 3 seasons did reduce labor significantly and provided an ideal growing environment for most of the season. Heavy spring rainfall did delay plantings in all 3 seasons and during 2010 continuous wet conditions even during the summer months promoted the growth of downy mildew that significantly reduced yields for that season. The raised beds were critical for allowing added drainage during these wet periods and other local farmers that did not have raised beds suffered even greater loss.
The use of row covers and low tunnels is seen as a viable option for extending season harvests, however success in 2009 was not duplicated in 2010 due to a wet spring that delayed planting and an earlier than usual late fall cold snap followed by heavy snow cover and winds. Additional work will be done to refine the use of these in 2011.
The other area for future consideration is to develop higher return crops for the BIG to take advantage of the year-round growing conditions and summer temperatures that were cooler than the PSG which would be ideal for micro-green production. Efforts are currently being made to develop a low-water growing media that will allow for greater flexibility with watering schedules and reduced water usage. After energy and labor, water is seen as the most critical input item that needs further research. Intensive crop production currently relies on high water usage. Drip irrigation, floating raft culture and reduced water usage media as seen as important practices with potential for improving water use efficiency.
Information was shared about sustainable growing and renewable energy used for year-round production in greenhouses.
During 2009, several field day tours were offered to the general public and also for inquiring groups that were interested in sustainable greenhouse growing, including the following dates and numbers attending:
• May 9, 2009 – Spring Open House and Tours. Estimated 88 persons attended, including 40 students from Ohio Dominican University.
• June 24, 2009 – Union County Master Gardener’s Tour 27 people.
• September 30, 2009 – Participated with a demo table at the Vendor Fair at Whole Foods Team Member Meeting with John Mackey. Approximately 250 people attended this event.
• Oct 3, 2009 – Fall Ohio Solar Tour in cooperation with the national tour sponsored by the American Solar Energy Society and the state tour organized by Green Energy Ohio. Estimated 45 persons attended this tour.
• October 5, 2009 – Twenty-three (23) students and professors from Dennison University’s MacPhail Center for Environmental Studies toured the farm.
During 2010, field day tours were offered to the general public and also for inquiring groups that were interested in sustainable greenhouse growing, including the following dates and numbers attending:
• Spring Open Greenhouse Tours on May 8th. Cold weather limited attendance to about 46 attendees this year.
• 2010 Ohio Solar Tour, Oct 2nd — Fall Open Greenhouse Tours in cooperation with Green Energy Ohio. A total of 58 visitors including a large school group of 23 students and instructors from Ohio State University.
• Provided a tour on October 21st for Tom Barnhardt working with the Marysville Food Pantry to develop a year-round aquaponics greenhouse.
• Speaker at the Farmers Forum for the 2010 National Small Farm Trade Show & Conference on Saturday, November 6th in Missouri. PowerPoint Presentation –Intensive Production and Value-Added Products Evaluations for Year-Round Production in Central Ohio.
• Several other requests during the year were deferred to the 2 main tour/open house dates to be more efficient and allow networking between participants at those tours.
• Two Open Greenhouse Tours are planned again for 2011 in May and October.
• Improved networking between local growers with similar interests
• Streamlining of the multiple reporting forms