Comparative Economic and Ecological Analyses of Lower Chemical Input Fruit Farms and Other Fruit Farming Systems

Objective 1: Make detailed whole-farm economic analyses of low chemical input fruit farms growing small fruits, for economic comparison with conventional and other fruit farming systems with similar crops in the same region.

See Economic Analysis.

Objective 2: Make detailed ecological analyses of the same low chemical input fruit farms for ecological comparisons with other fruit farming systems.

We have analyzed a number of ecological parameters for two growing seasons, including soil texture, organic matter, macro and micro nutrient content of soils and plant tissue, extractable nitrogen, soil microbiological activity, carbon/nitrogen ratios, nutrient content of soil and foliar amendments, relative arthropod activity and relative pest incidence, including weeds and diseases.

There were strong correlations of ecological function related to the kind of fruit farming system studied. It should be pointed out, however, that this information is of benefit mainly from a case study perspective, and that the lack of experimental control in measuring these parameters on-farm, on six very different farming systems, makes these observations less valid from a strictly statistical or experimental point of view. Regardless, the data gathered is somewhat compelling and should not be dismissed out-of-hand, as it does point to some important trends, which support a number of hypotheses and principles that have already been identified in previous experimental approaches in evaluating agroecological function.

We offer the following abbreviated description of some of our findings that may be of interest to the reviewers of this report. The volume of data gathered from this project is too great to be included in detail for a report of this kind. Inquiries are welcome.

Soil Organic Matter Content

The organic and transitional fruit farming systems have higher levels of soil organic matter, as illustrated in Figure 1 for strawberries. Similar trends were seen with raspberry and blueberry crops. The quality of this organic matter, as it relates to carbon and nitrogen content, or ratios of carbon and nitrogen followed similar patterns, as illustrated in Figure 2 for strawberries. Notice that in addition to the higher carbon content in organic and transitional systems, there were higher levels of nitrogen.

Extractable Soil Nitrogen

More exact measurements of extractable soil nitrogen, including nitrate and ammonia, were taken from each fruit farming system. To get a better idea of how farm management practices have impacted "native" soil nitrogen levels, similar samples were taken from unmanaged areas (mowed only, cleared of trees and shrubs). This is illustrated in Figure 3. The organic and transitional strawberry farming systems have enhanced native soil nitrogen pools (BMR, SC, DOR, WAR, HG), while the conventional strawberry system has nitrogen levels lower than native soil nitrogen, therefore has depleted soil nitrogen relative to the other farming systems.

Seasonal fluctuations of nitrate and ammonia between the six fruit farming systems were also distinct to the management type. Figure 4 is just one example of the differences seasonal nitrate levels seen between organic and conventional raspberries.

Other Soil Nutrients

Figures 5, 6 and 7 illustrate relative differences that were found in soil phosphorus, potassium and calcium. Again trends seen with organic matter and extractable nitrogen were also seen with these other macro nutrients, with the exception of phosphorus. In all cases, with strawberries and raspberries, the conventional fruit farming systems were able to maintain a higher level of soil phosphorus. The organic and transitional systems also had higher levels of soil magnesium.The relative differences in soil cation exchange capacity are illustrated in Figure 8. It would follow that soils with higher organic matter content will have higher cation exchange capacity.

Soil Microbiological Activity

Soil microbial activity was measured two different ways: 1) by measuring for mineralization of nitrogen (ammonia), and 2) by measuring dehydrogenase activity. There appeared to be considerable parity between farming systems when measuring potential for mineralization of nitrogen, as illustrated in Figure 9. There were differences seen between organic and conventional fruit farming systems during the spring of 1992, however, this was not consistent over the two year period of study.

More striking were differences seen via dehydrogenase assays, as illustrated in Figure 10 for four different strawberry systems. Data indicated that there were significant fluctuations in soil microbial activity in the organic strawberries between fall and spring. With the exception of fall 1993, the conventional strawberry system exhibited the lowest level of microbial activity over the one year period.

Foliar Nutrient Analyses

In recent years, nutrient analyses of plant foliage has been seen as an invaluable tool for assessing plant nutrient status, as uptake of nutrients is influenced by a number of factors. Soil nutrient analyses is no longer considered sufficient by itself. Therefore, a number of foliar nutrient samples were taken throughout this study.

Overall, there appeared to be considerable parity in the nutrient status among all small fruits between organic and conventional farming systems. Looking at each fruit crop separately did indicate that there were some differences. With strawberries, the transitional fruit farming system had the best overall nutrient content, including nitrogen (Table 1). Potassium deficiencies were detected in all fruit farming systems studied. The organic and transitional strawberry farming systems also had higher levels of sulfur and phosphorus than the conventional strawberry farming systems. Similar trends were not seen with the raspberry farming systems. The conventional raspberry system generally had a higher nutrient level found in the foliage than that found in the organic raspberry foliage. This was especially true with phosphorus, potassium and iron (Table 2).

Arthropod Activity

There was a considerable amount of arthropod activity sampling done, utilizing a number of methods as outlined in Table 3. Not all methods were as useful in identifying differences in ecological function related to arthropods as others. Most useful and with the greatest potential for application by farmers themselves were sticky traps and sweep net collections.

Collected samples were either counted by order or by morphtype. Looking at morphtype data gave some indication of the differences in biodiversity between the six different fruit farming systems, as seen in Figure 11 from De-Vac data, which involves sucking up insects with a vacuum/blower from plant foliage, stems and fruit. This data however was not consistent throughout the two year period, as there were times when the conventional fruit farming systems had greater biodiversity. For certain species of Diptera, there were also very high counts of individual insects associated with the conventional fruit farming systems.

Looking at the sticky trap gives some indication of the qualitative differences in arthropod communities and the predominance of certain orders over others related to the different fruit farming systems, as seen in Figure 12. In June 1993, the organic strawberries and raspberries had the highest counts (by Order) compared to the other fruit farming systems. This was followed by the transitional strawberry system and then one of the conventional strawberry systems (HKS).

One incidence of note that was not seen again throughout the 2-year period, by any of the trapping systems, was a outbreak of springtails (Collembola) that occurred in the organic raspberry system, which made up approximately 80% of all insects collected from six sticky traps. Without the springtails, the counts from that system would have been as little as those seen from the conventional farming systems.

The Coleoptera were most prevalent in the organic strawberry system. The Hymenoptera were not significantly higher in one fruit system over the others, with them showing up in all of the fruit farming systems. The thrips were most prevalent in the organic and transitional strawberry systems. The Diptera were not counted for this sampling period as the numbers exceeded 200 for many of the samples collected from all of the fruit farming systems.

Insect Pests Encountered

In general, insect pests on the small fruits studied for the 2-year period were a non-event. There were no serious pest outbreaks for any of the fruit farming systems, with the following exceptions:

1. Clipper beetles started to become a problem in the fall of 1992 for one of the conventional strawberry growers (HGS), which continued in the spring of 1993. The grower was subsequently able to control the problem with timely sprays.

2. This same strawberry grower saw some spittle bugs in the fall of 1992 and spring of 1993. Again control was achieved.

3. Large black ants became a problem for the other conventional strawberry grower (HKS) during harvest of 1993, which was the result of heavy rains that forced the ants out of their colonies and led to their eating the ripened fruits. The grower was not able to control this problem due to the fact that this occurred during the harvest period.

4. The sap beetle was present at some level on all of the strawberry farming systems. Two of the conventional growers (HGS and HKS) sprayed to prevent a serious outbreak. Serious problems with the sap beetle were not seen with the other strawberry growers.

5. Thrips were prevalent on all of the fruit farming systems during the early summer of 1993. While these are not considered to be harmful to strawberries, they can be deleterious to raspberries. There were no control measures taken by either raspberry grower and there was no evidence that yields suffered as a result.

Nematode Count Results

There was not one nematode found in one of the conventional strawberry systems (HKS). Otherwise, the numbers of variety of nematodes present varied considerably between fruit farming systems (see Figure 13). The organic blueberry system did have the highest number of nematodes present, with an unusually high number of ring nematodes. This was followed by the transitional strawberry systems, which were predominated by pin nematodes, with the remaining fruit farming systems showing less than 200 nematodes per pint of soil evaluated.

Objective 3: Disseminate information from these on-farm studies through Field Days, Demonstrations/Workshops, a Farmer-to-Farmer Mentorship Program, and printed information.

The Ohio Ecological Food and Farm Association, in collaboration with the Stratford Ecological Center and the Sustainable Agriculture Program at the Ohio State University, planned and held a number of field days, farm tours and workshops in 1992, 1993 and 1994 on a number of farms around the state, including the participating fruit farms and the ODA/OSU Demonstration Farm. A number of winter workshops utilizing the "Farmer-to-Farmer" format for information exchange between farmers were also conducted.

Several hundred people, including farmers, researchers, educators, grade school to high school students, undergraduate and graduate level students, have visited and/or participated in a number of classes, workshops, and field days held at the ODA/OSU Demonstration Farm alone.

We were also able to take advantage of a significant multiplier effect by reaching over 50 high school science and vocational agriculture teachers involved with in-service training on agriculture and the environment. These teachers will potentially be able to reach over 1,700 high school students from the entire state during the coming school year. We hope to have a number of these students visit these farms in the near future, either for one-day events or for 10-12 internships in sustainable agriculture.

This Demonstration Farm and the Beam Road Berry Farm also hosted farm tours for the "NCR Workshop on Sustainable Agriculture."

A major workshop on "Organic Small Fruit Production in an Integrated Farming System" was given on August 29, 1993, to over 40 participants on one of the cooperating farms (see attachments). Preliminary information from this study along with basic and applied information on sustainable small fruit farming systems was presented through lecture, discussion and handouts.

A similar presentation was given at the Annual OEFFA Conference held at Ohio Northern University in Ada, Ohio.

Publications from this study are presently being worked on along with a PhD dissertation that is scheduled for completion during 1995.

Objective 4: Develop long-term demonstrations of lower chemical input fruit farming systems for continued economic and ecological evaluation and for on-going display and education for fruit farmers and the general public.

In 1992, six different long-term demonstrations of fruit production systems, each one-sixth acre, were established at the ODA/OSU Demonstration Farm in Reynoldsburg, Ohio. Three of these systems are of two different strawberry varieties grown under three different fruit management systems, including a higher chemical input conventional system, an integrated lower chemical input system, and an organic system for strawberry production. These three systems were also utilized to set up the remaining three long-term demonstrations in two different raspberry varieties.

Very detailed economic data is being maintained on all six of these systems to monitor comparative economic performance of the three different management systems being studied. A biennial report on the last two years of production is presently being drafted and should be available by April 1995.

In essence, this project involved conducting six different case studies, involving both economic and ecological data collection and analyses.

General Description of the Six Fruit Farm Systems

Six fruit farms that grow small fruits, including strawberries, raspberries, and/or blueberries were selected from Ohio growers. Four of the farms, two organic and two conventional fruit farming systems, are in central Ohio, with the remaining two farms, one organic and one conventional fruit farming system, in northeastern Ohio. Table 4. gives a general description of the six different fruit farming systems.

There are relatively few similarities between the six fruit farms beyond their growing small fruits. Additionally, one organic and one conventional fruit system in each of three pairs of fruit farms experienced similar weather conditions, in particular with temperature, but also with precipitation, as both farms were proximal with each other. However, there were some significant differences in precipitation with some of the pairs on occasion. For example, in 1993 the organic farm in Richland County, experienced a drought that led to the loss of 90% of its raspberry crop, while excessive rain on the other end of the county lead to a 50% crop loss of strawberries on the conventional farm. This study, while cognizant of weather conditions, does not attempt to correlate ecological data with weather conditions.

There are sufficient similarities between the soils studied on the six fruit farms. All soils can be considered loams. There are some minor exceptions to this, however, as the Hickerson soils are more silt loams, while both farms in Portage County are more sandy loams. When comparing soil textures between farms growing the same fruits, there are differences that should be recognized when considering the results of the ecological data. For instance, Hilgert's soils may have the benefit of better soil drainage due to the higher sand content. This extra drainage may also benefit disease management strategies and allow the fruit grower to get into the fields for work earlier than the other strawberry growers. The higher sand content can also have negative effects on nutrient and organic matter management. There is potential for greater leaching of nutrients and more rapid oxidation and decomposition of organic matter. This combined with the differences in clay content can have an overall effect on the cation exchange capacity.

The same arguments can be made for the differences in soil texture that is seen between the two raspberry fruit systems. The conventional raspberry system has a significantly higher sand content, while the organic raspberry system has a greater silt content. It may be anticipated that the loss of soil drainage capability in the organic raspberry system may result in higher soil born disease incidence. However, the organic system should be able to build soil organic matter much more easily, along with having a greater cation exchange capacity. The organic raspberry grower will also have much more difficulty in getting into their field early during a wet spring.

Beyond these similarities, the differences between the six fruit farming systems are significant and need mention and further consideration.

There are differences on percent slope on the six different fruit farming systems. While all plots sampled on each fruit farm in this study had 0-2% or 2-6% slopes, there were parts on these farms with higher percent slopes that were not studied. For example, the Hickerson farm has 12-18% slopes, while Hilgert's farm had some 2-6% and 6-12% slopes. Hopefully choosing flat areas on these farms minimized the effect of these slopes on the comparative data. However, there are proximal effects of these slopes on the flatter areas that can not be ignored, including effects on surface drainage, which effects soil drainage, air drainage, and microclimate (including aspect and orientation of the planting relative to the sun and shading effects), in and out and around the areas that were studied.

One the most significant differences between the six fruit farming systems is in the scale of each fruit farming system. Table 5 describes the relative differences in size of each fruit farming system.

This study was conceived and funded based on experience of small fruit growers in the mid-south, including Arkansas and Missouri, where there are many small fruit growers producing on multiple acres of strawberries, blueberries and raspberries. This study does not adequately reconcile these differences as there are also differences in economies of scale, levels of capitalization, and subsequent debt service and repair and maintenance. Therefore, all economic data has been presented on a per acre basis as close to real terms as possible.

Another major difference in the six fruit farming systems is in the management approach of the six different families operating these farms. For example, the Hickerson's primary focus of production is strawberries, with additional enterprises in apples and cut dried flowers. The primary focus has enabled them to provide timely and intensive management of the strawberries year after year, getting field work done early and on a timely basis, including mowing, spraying, and fertilizer applications. This is in sharp contrast to the remaining farms that do not have a primary focus on a single fruit crop, needing to split their attention and energies to a number of other enterprises and off-farm responsibilities.

Additionally, the differences in the perceived importance of specific management practices had led to distinctly different impacts on the economic and ecological functioning of these six fruit farming systems. For example, one farmer may feel it is important to mow around the fruit planting on a weekly basis, while to another, it could be once a month, or a few times a season. This is also true in the use of chemical fertilizers and pesticides, also in whether the work was done mechanically or by hand.

The planting densities also varied between fruit farming systems. This has a direct impact on establishment costs in addition to having more ecological impacts, including effects on microclimate and the "edge effect." The "edge effect" is a phenomenon experienced by strawberry growers in general that greater yields and greater quality berries occur along the edges of the planting, where there is typically more sun available. A less dense strawberry planting will have a greater number of edges, which has a direct effect on yields. Of course density also has an influence on air flow through the planting and the potential for disease. In contrast, less dense plantings also have more bare ground between the plants, therefore greater potential for weed infestations and a greater need for cultivation and handweeding.

Finally, it should be noted that there are varietal differences between the farms growing the same fruits. This can have a significant effect on yield, in addition to differences in tonnage versus volume due to size of berry for that variety. The timing of fruit maturity relative to the growing season can also be impacted by the seasonal fluctuation of weeds, disease and insects.