Systems of Transition from Conventional to Organic Agricultural Production

Final Report for LNE99-123

Project Type: Research and Education
Funds awarded in 1999: $212,247.00
Projected End Date: 12/31/2003
Matching Non-Federal Funds: $88,125.00
Region: Northeast
State: West Virginia
Project Leader:
James Kotcon
College of Agriculture, Forestry & Consumer Sciences
Expand All

Project Information

Summary:

Low-input transition systems for converting from conventional to organic production were established using green manure and cover crops. These are being compared to high-input systems that rely on compost amendments from off-farm sources. The systems are being assessed in a market garden vegetable production trial and a field crop/livestock trial at the West Virginia University Horticultural Research Farm. Data on soil quality, pest incidence, yields, and economic inputs were compared. After three years of transition, most crop yields were comparable to national averages. Pest and disease incidence varied with crop, while compost improved certain soil quality indicators.

Introduction:

Organic farming and gardening have the potential to be sustainable agricultural systems. In addition, they address issues of food safety and environmental pollution. However, 3 years are required to make the transition from conventional production to a certified organic system. Net farm income may drop during this transition period and producers may be reluctant to make the change because of the short-term risks involved.
Because relatively little peer-reviewed research is available to assist growers in addressing problems encountered during the transition phase, the WVU Organic Research Farm project was established to compare farming systems for making the transition from conventional to organic production. The emphasis was on whole-farming systems research, with targeted research on specific component research needed to efficiently characterize key transition practices.
Results cover a wide range of agronomic factors, including yields, soil quality, pest management, and economic returns. In general, a high input system that combines cover crops, green manures and compost amendments tended to produce better returns than a low input system that relies primarily on on-farm inputs. Growers interested in converting to organic practices now have a more reliable basis for choosing among transition practices in order to overcome traditional barriers to transition while maximizing productivity and sustainability of their production systems

Project Objectives:

To compare intensive cover cropping and use of compost as methods to convert market gardening and field crop/livestock farming from conventional to organic.

Research

Materials and methods:

After having been managed for conventional fruit vegetable production for over 80 years, the WVU Horticulture Farm began a transition to organic management in Sept. 1999. The farm has predominantly silt loam soils with slopes ranging from 0 to 25%. A detailed soil survey of the farm was carried out in 1998, and the entire Farm was used for a variety of research projects to evaluate transition methods and organic practices.

4.A. FARMING SYSTEMS RESEARCH
Two replicated farming systems experiments, market garden and field crop/livestock, were conducted. Each compared two treatments for managing soil quality during the transition from conventional to organic practices: a low input transition using cover crops only, and a high input treatment using off-farm compost amendments with cover crops.
Low Input Transition treatment:
Plots were cover cropped intensively beginning in Fall 1999 and throughout the 2000 growing season. Rye, sown in fall, 1999, was followed by clover in spring, 2000 and by rye and vetches in the fall of 2000. All cover crops were plowed in as green manure. This treatment produced no saleable product in 2000, and was used solely to build soil quality. Market garden plots were cropped, beginning in 2001, with a 4-year rotation sequence of legumes (beans and peas), leafy vegetables (spinach and lettuce), solanaceous crops (tomato and pepper), and cucurbits (zucchini and pumpkin). Field crop plots were cropped to wheat, potato, forage soybean, or Brussels sprouts. A rye-vetch winter cover was planted each year on all plots, except those with an established overwintering crop.

High Input Transition treatment:
Following an initial rye/vetch cover crop planted in fall, 1999, plots were amended with dairy manure compost at 10 T/acre in the spring of 2000. Field plots were cropped to wheat, potato, forage soybean, or brussel sprouts while the cropping sequence in market garden plots included legumes (beans and peas), leafy vegetables (spinach and lettuce), solanaceous crops (tomato and pepper), and cucurbits (zucchini and pumpkin). Thus, the High Input treatment used off-farm compost to improve soil quality and produced saleable crops in the first year of transition. Compost was applied at 10 T/acre again in Spring 2001 and 2002 to High Input plots
The market garden had four replications of the two treatments and four crop families in all combinations (32 plots total). The field crop system had three replications, but included two additional treatments, with- and without-livestock, arranged in a factorial randomized block design with the two transition (high vs low input) treatments. The with-livestock system has plots with a 7-year rotation, 4 of which will be the same as the without-livestock system. The 3 extra plots in each with-livestock block were seeded to orchard grass and red clover for pasture and hay and sheep were used to graze these plots beginning in 2001. The three years of pasture/hay were included between the brassica and potato crop in the rotation for with-livestock treatments. Animal density was assigned to minimize or eliminate purchased off-farm feed. Three acres of additional pasture (hill land) were assigned to each with-livestock replicate. Lime was added as needed to maintain soil pH, and 10 T/acre of compost was applied to high input pastures to maintain available P and K at recommended levels on all plots.
Detailed records were kept of all operations in each experiment so that enterprise budgets can be produced. Inputs of materials, labor, equipment use and quantity and quality of harvests were recorded. Soil and plant samples were taken from plots and analyzed (see Monitoring Program below).
Pests were monitored and controlled uniformly on all treatments following organic standards, thus rotation and compost amendments were the primary treatments that varied across plots.

Monitoring Program:
In Spring 2000, soil samples were collected from research plots to establish baseline data on pesticide residues and soil factors. Pasture and cropped soils were sampled at 0-3 inches, 3-6 inches, 6-12 inches and 12-24 inches. Chemical properties monitored included organic matter content, pH, conductivity, nutrient ions (P, K, Ca, Mg, S, Cu, Mn, Zn, Fe, B, Cl, Mo), and cation exchange capacity, using analytical methods found in Klute (1986), Sparks et al., (1996) and Weaver et al., (1996).
Soil samples were collected to monitor soil invertebrates, focusing on earthworm fauna, plant parasitic nematodes, and predatory nematodes as indicators of soil biological activity and biotic community stability. Disease, weed, and insect pest monitoring was designed specific to the particular crops produced. In addition, monitoring for selected indigenous biological control agents (beneficial insects, nematode trapping fungi, etc.) was designed to correlate activity of biocontrol agents with pest populations under the various systems.

4.B. COMPONENT RESEARCH:
Eight small-plot experiments examined specific soil and pest management transition treatments in more detail.

Compost Rate Trials:
The main Compost Rate Trial plots were 2.4-x-4 m with 60-cm alleys between plots. The top 5 cm of soil was removed at the beginning of the experiment to prevent the decomposition of the existing sod from confounding treatment effects on soil organic matter content. There were five rates of dairy manure compost, 0, 2.5, 5, 10 and 20 tons dry matter/acre, (approximately 0, 0.2, 0.4, 0.8 and 1.6 cm depths, respectively) with four replications (20 plots), in two sets (40 plots total). Compost was applied just before planting and incorporated with a walk-behind rototiller.
The rotation sequence was, Set 1: Buckwheat, Buckwheat, Bush Green Beans, Fall Lettuce, Set 2: Millet, Millet, Buckwheat, Bush Green Beans. There was no weeding in the cover cropped plots (buckwheat or millet). Beans were hand-cultivated as needed. Buckwheat and millet seeds were broadcast and raked in. Bean plots were divided into quadrants and four varieties: Dragon Tongue (flat, Italian-style) Indy Gold (yellow wax), Purple Queen and Xera were planted in two rows, one variety per quadrant. Row spacing was 60 cm and seed were placed at 20 seeds per meter.
At harvest, buckwheat and millet plots were mowed to approximately 3 cm and biomass weighed in the field. Beans were hand-picked, twice a week for 3 weeks. Bean yield data were taken only from the interior row. The number of weeds in each of three categories (Purslane, Grasses, and Other Dicots) were counted in bean plots 3 weeks after planting in each of six quadrats per plot, (707 cm2 per quadrat).
Soil samples (0 – 10 cm) were collected before compost application, and approximately every 7 – 10 days throughout the growing season. Soils were air-dried, passed through a 2-mm sieve and stored until analysis. Soil pH (1:1 soil:water), and Mehlich extractable P, Ca and Mg were determined by ICP (Perkin Elmer P4000) and Na, K, by AA (Perkin Elmer AAnalyst 100).
A small plot compost rate experiment was established with two cut flower species selected for resistance to pest and drought stress. Celosia (var. Chief Mix) and Statice (var. Soiree Mix). Plots were 1.22-x-1.82 m and transplants were spaced on 30-cm centers. Each plot contained nine (9) Celosia and Statice. Five rates of compost were applied by volume corresponding to 0, 0.2, 0.4, 0.8 and 1.6 cm depths. Compost was incorporated with a front-end tiller. Weeding was done by hand as needed. All stems were harvested at ground level once at peak bloom. Individual stems were measured for mass and length. Marketable stems were defined as any stem greater than 30 cm.

Weed Management Alternatives:
Two treatments were established in 1.82-x-3.66-m plots, buckwheat as a cover crop versus compost amendments at a rate to supply 100 lb. N per acre. Six weed treatments were assigned to compost plots in 2000, and to both treatments in 2001: control (no weed control), intensive cultivation and hand-weeding (weed-free control), black plastic mulch, and straw mulch at 5, 10 and 20-cm thickness.
A second experiment evaluated acetic acid sprays and corn gluten application in 2002. Treatments included acetic acid applied at 4.5, 9.0, and 18% (vol/vol) as a directed post-emergence application and corn gluten applied at 99, 198, and 396 g/m2 (20, 40 and 80 lbs/1000 sq. ft., respectively), broadcast pre-emergent and incorporated 5 cm into the soil. Selected treatments from previous years (black plastic mulch, 10-cm straw mulch applied over newspaper, and hand cultivation) were also included in 2002.
Twenty pepper seedlings were transplanted into each plot. Weed counts, pepper yield (fresh weight and counts), pepper shoot and root length and dry weights were recorded. Data were subjected to analysis of variance (ANOVA) and means were separated using L.S.D’s (P=0.05). Correlation analyses were used to determine the effect of weed competition on pepper yield and the effect of various treatments on pepper growth attributes.

Potato Pest Management:
Sixteen plots, 2.7-x-4 m, were established to evaluate commercially-available organic pest management products on potato in 2001 and 2002. ‘Kennebec’ potato seed pieces were planted in rows 0.9 m apart at 30-cm spacings in the row. Compost was applied post-plant in 2001 and pre-plant in 2002.
Four replicate plots each were treated as follows in 2001:
1) Surround WP, a kaolin-based particle film spray (Engelhard Chemical Co.), was applied weekly for insect management and a soil drench of NemaStop (SoilTech Inc.) applied at labeled rates (26 oz/Acre) pre-emergence and at 14 and 30 days post emergence.
2) Surround WP alone.
3) Valoram, a garlic and pepper extract (SoilTech, Inc.), applied as a soil drench (with 0.5 cm irrigation) at labeled rates (96 oz./Acre) pre-emergence and at 7, and 21 days post emergence. Valoram was also applied to these plots as a foliar spray for leafhopper suppression at 7-day intervals (mid-June to mid-August) at 48 oz./Acre.
4) an untreated control (water irrigation only, no insect or nematode control).
Insect pressure, primarily potato leafhoppers, was rated three times during the growing season. Soil samples were collected for nematode evaluations. Yield was determined from ten hills dug from the center of each plot.
In 2002, new plots were prepared as in 2001 and treatments were revised to evaluate Surround WP with and without supplemental nitrogen, applied post-emergence as blood meal at 60 lbs. N/acre. Insect and yield data were collected as in 2001, and leaf petiole nitrate was measured using a Cardi Leaf nitrate meter on three dates.

Biological Seed Treatments:
Two seed treatments Kodiak (Bacillus subtilus, Gustafson Corp) and T-22 planter Box (Trichoderma harzianum, Bioworks, Inc) were evaluated for control of pre-emergence damping off in pea and spinach. A field trial was prepared in 2002 with four treatments: Kodiak applied as a seed treatment at 0.125 oz/100 lb seed; T-22 as a seed treatment at 8 oz./100 lb seed, T-22 as a soil drench at planting at 2 lb./acre; and an untreated control. Soil mesocosms were constructed by gluing nylon screen over one end of 3-cm lengths of 10-cm diam PVC pipe. Mesocosms were filled with 2.5 cm of field soil and buried to a depth of 2.5 cm in 8 replicate Market Garden plots each for spinach and peas. Ten seeds were planted in each mesocosm and percent emergence was evaluated at 14 days. Seed and root infection by pathogens were evaluated by recovering seeds and plants from mesocosms, surface sterilizing with NaOCl, and plating on Potato Dextrose Agar.
A second experiment was conducted in growth chambers to evaluate the influence of Kodiak on spinach emergence at two temperatures in sterile and non-sterile soils. Market Garden soil (150 grams) from eight spinach plots was placed in glass 250-ml beakers. Half of the beakers steamed at 100 C for one hour to eliminate pathogens. Ten spinach seeds, either untreated or treated with Kodiak) were planted in the beakers and incubated in growth chambers at 12 or 18 C. Two replicate beakers per plot of each treatment combination were prepared, for a total of 128 beakers. Seedling emergence was counted at 3, 5, 6, 9, 10, 11. 13 and 16 days after planting.

Apple Orchard Management:
Two insect management treatments were evaluated in a 2.7-acre block of 15-year-old apple trees. The block was split into six plots and managed with either Surround WP (kaolin clay-based spray) or Envirepel (garlic-based spray). Treatments were applied with an airblast sprayer in 100-gal water/acre on a 5-10 day spray schedule in 2001 and 2002. Insect counts on foliage and insect injury of harvested fruits were determined.

Tomato Intercropping with Resistant Cultivars:
A field plot experiment in 2001 evaluated the rate of early blight disease increase in the susceptible tomato cultivar ‘Brandywine’ when planted in monocultures versus intercropped with a resistant cultivar ‘Juliet’. Plants were spaced at 0.9 m in and between rows in five replicate plots of each treatment. Intercropped plots alternated ‘Brandywine’ with ‘Juliet’. Disease severity was rated weekly on ‘Brandywine’ plants.

Vegetable Intercropping:
A preliminary study was conducted in the summer of 2000 to screen companion crop combinations for effects on yield, pest incidence, and taste. Forty-eight raised beds (1.25-x-3.0 m) were prepared and planted with basil, bean, tomato, brussel sprouts or clover in monocultures or selected diculture combinations. All plots had five crop rows, spaced 25 cm apart, and plant densities ranged from 9-46 plants/m2, depending on the crop plant size. Periodic leaf surveys assessed phytophagous arthropod populations. Double blind tomato taste tests compared the flavor of tomatoes from monocultures versus dicultures. Above-ground biomass and marketable yield data were collected from all plots. Land Equivilency Ratios (LER) were calculated to compare diculture land use efficiency to that of monocultures.
In 2001 and 2002, three crops were evaluated in more detail for their potential as companions: tomato, Brussel sprout, and basil in mono- or dicultures. The six treatments were replicated four times using a randomized complete block design. Yield, land use efficiency, tomato flavor, and pest populations were recorded as above. Canopy light penetration and volumetric soil water content were measured periodically to assess competition for sunlight and water.

Compost and Compost tea for early blight management on tomato:
Early blight severity, tomato yield, and plant biomass were assessed in 3-x-6-m plots amended with 10 compost treatments with or without compost tea extracts in 2002. Four replicates of treatments were arranged in a split plot design with compost soil amendment as whole plots and tea treatments as subplots. Compost treatments used included: Seneca ® (Horse manure and wood shavings) @ 3.3 Tons/Acre; Dairy manure (contents not described) @ 3.3 Tons/Acre; Spent Mushroom @ 3.3 Tons/Acre; Premium ® (Dairy manure and pine shavings) @ 3.3 Tons/Acre; Yard waste compost @ 3.3 Tons/Acre; WVU (Dairy manure and yard waste) @ 3.3 Tons/Acre; WVU (Dairy manure and yard waste) @ 10 Tons/Acre; Hardwood bark @ 3.3 Tons/Acre; Hardwood bark @ 3.3 Tons/Acre + blood meal @ 60 lb N/Acre; and Blood meal alone @ 60 lb N/Acre. Compost teas were prepared from the respective composts by passive brewing in tap water for 48 hours, and were applied weekly beginning July 1 with a backpack sprayer. Early blight severity was determined on 10 dates between July 26 and Oct. 5 and tomato yields were determined from six weekly harvests.

Disease resistance of 16 heirloom and hybrid tomato cultivars:
Sixteen tomato cultivars were compared for susceptibility to early blight in 2001 and 2002. Plots of 4 plants of each cultivar, spaced 0.9 m apart within and between rows, were replicated five times in a randomized block design. Disease severity was rated twice per month and Area Under the Disease Progress Curve (AUDPC) was used to compare cultivars.

4.C. EDUCATION/OUTREACH ACTIVITIES:
On-going planning of research and education were coordinated through a Farm Plan developed with input from local organic growers. The Mountain State Organic Growers and Buyers Association (MSOGBA) designated a steering committee that is cooperating with WVU in all aspects of this research: designing transition systems, prioritizing research objectives, certification, and ongoing input into the farming techniques. A monthly newsletter column was dedicated to the WVU Organic Research Farm, to inform the organic community of progress and research results from the WVU farm. A MSOGBA Board of Directors meeting and annual steering committee meetings were held at the Organic Research Farm.
Four Field Days were held for growers, scientists, and students to demonstrate research results and farming practices under evaluation. Announcements of field days and feature articles on selected organic growing topics were sent to state and local newspapers.
The project maintains an Internet web-page devoted to organic farm research progress (available at: www.caf.wvu.edu/plsc/organic). A registry was maintained to develop mailing lists for those interested in regular updates and bulletins.
Outreach also included use of the Farm for teaching and demonstration purposes to WVU students and the general public. A demonstration home garden was available for hands-on learning opportunities for WVU students and other community members. Three summer interns were taught organic farming practices and contributed to research projects. Produce was available at local food outlets for the WVU College of Agriculture, with educational displays and/or brochures describing the activities and opportunities at the WVU Farm. A new course in Organic Crop Production was taught in 2001 and 2002.

Research results and discussion:

Project success was evaluated through a number of indicators. Certification of the WVU Farm for organic production was achieved in 2003, after the three-year transition period. Production of peer-reviewed scientific publications is underway. The project tracked the number of articles published in organic farming newsletters, other agricultural publications, and in mainstream media. An Internet web site is on-line and a registry of interested users provide measures of interest in the project. Attendance at field days and participation by students and the public was recorded. These results produced a database of potentially interested growers who will be surveyed to assess use of the WVU Farm results and to identify additional needs and opportunities.
An important element of this project is to identify barriers to organic transition faced by growers, the need for and level of service provided by the WVU Farm to growers, and the level of adoption of WVU Farm recommendations by organic growers. Measurement of these indicators is on-going through a continuation of the project.
5.A. Farming Systems Research Results
Market Garden Vegetable Yields:
For most crops, yields were acceptable to good and comparable to national averages (Table 1). Spinach and pea yields suffered from poor stands due to seedling diseases, and cucurbit yields were low in later years of the experiment as incidence of cucumber beetle and bacterial wilt built up. Yield of tomato was reduced by late blight the first year, but use of a resistant variety eliminated the problem in subsequent years.
Yields in high input treatments were significantly greater than in low input treatments only for pepper, pumpkin and spinach in 2001, and for spinach in 2002. Differences in spinach yield between treatments were related to differences in disease levels which reduced plant stand more in low input plots than in high input plots.
__________
Table 1, yields (kg/hectare) of eight vegetable crops in low and high input systems during 2000-2002. This table is available by calling or e-mailing Northeast SARE. Ask for the report for project LNE99-123.
__________

Field Crop/Livestock Yields:
Yields of Potato and wheat were significantly greater in high input plots than in low input plots in 2001. Soybean did not respond to the compost treatments and potato yields in 2002 were very low.
Brussel Sprouts produced negligible yields and this crop was changed to a forage rape crop for the brassica portion of the rotation. RedClover/orchard grass plots in the high input system averaged 21 % greater yields of hay and forage than the low input plots over repeated cuttings in 2001 and 2002 (data not shown).
Sheep produced healthy lambs which gained an average of 313 pounds per acre in 2002. No differences in gain were found between flocks on low and high input systems. Intensive rotational grazing was successful in preventing infestations of internal parasites without use of anti-helminthics.
__________
Table 2. Yields (Kg/Ha) of field crops in 2001 and 2002 in low and high input systems. This table is available by calling or e-mailing Northeast SARE. Ask for the report for project LNE99-123.
__________

Soil Quality:
Over the 3-year transition period, soil pH increased in the Market Garden from 5.2 to 6.5, due to the addition of lime. Soil organic matter also increased slightly, from 4.5 % in 200 to 5.0 % in 2002. The increase was slightly greater in High input plots than in Low input plots, but the treatment effect was not statistically significant. Levels of K, Mg, and Na were greater in high input plots than low input, especially in the last two years of the study, indicating a build up of these elements from compost.
In Field Crop plots, increased from 5.7 to 6.6, due to the addition of lime. Soil organic matter was significantly greater in High Input plots (2.7 %) than in Low Input plots (2.4 %) in 2002, but differences were not significant in other years. Mineral nutrients P, K, Ca, and Mg were all significantly higher in High Input plots after 3 years of compost amendment than in Low Input plots.

Soil Biota:
Earthworm populations tended to be higher, and earthworm biomass was significantly higher, in plots receiving compost. Soil populations of plant parasitic nematodes did not differ among treatments and remained low throughout the period, implying nematode suppressive soils may occur. Populations and activity of nematode biocontrol agents also remained low and did not differ among treatments, thus the cause of nematode suppression remains unknown.

5.B. Component Research Results
Compost Rate Trials:
Extractable phosphorus had accumulated to excessive levels (>40 mg/kg) at the highest compost rate (1.6 cm) in the second year (Table 3). Potassium had accumulated to excessive levels in all plots receiving compost by the second year. There are no corresponding thresholds for Na accumulation, but there is evidence for Na accumulation in all plots receiving compost (Table 3).
Cover crop yields were higher (P<0.0001) in the second year (Table 4). Buckwheat fresh weight yields were higher (P<0.0001) than were millet fresh weight yields. Buckwheat yields responded more rapidly to compost rates than millet yields.
There were significant effects on bean yield due to variety (P<0.0001), compost rate (P<0.0001), and a significant variety x compost rate interaction (P=0.0068). Except at the highest compost rate (1.6 cm), Dragon Tongue was the highest yielding variety by mass (Table 5). The yields of all varieties responded positively to compost applications, with Xera being the most responsive and Yellow Wax being the least responsive. The compost rates that produced the maximum yields (Table 5) were larger than the standard farm compost rate of 0.4 cm.
All compost treatments (0.2, 0.4, 0.8 and 1.6 cm) had significantly lower grass and higher purslane populations than did the control (0 cm compost). There was no effect of compost rate on fractional population of Other Dicots. The two highest compost rates (0.8 and 1.6 cm) had significantly lower grass and higher purslane populations than did the three lowest compost rates (0. 0.2 and 0.4 cm). Purslane is a salt tolerant weed, so these results are consistent with soil test data showing an increase in salt accumulation in high compost treatments.
__________
Table 3. Mehlich extractable phosphorus (P), potassium (K) and sodium (Na)
during the first two years as a function of compost rate. This table is available by calling or e-mailing Northeast SARE. Ask for the report for project LNE99-123.
__________

Table 4. Buckwheat and millet yields for significant main effects and two-way interactions. This table, and the following tables, are is available by calling or e-mailing Northeast SARE. Ask for the report for project LNE99-123.
_________

Table 5. Green bean yields and pod densities for each variety and compost rate, and
calculated compost rate to produce maximum yields.
__________

Table 6. Marketable Stems.
__________

Celosia stems were longer and heavier than were statice stems (Table 6). Increasing compost rate led to increased marketable stem number, stem length, mean stem mass, bunch mass and bunch weight, (P<0.001). The highest compost rate resulted in 47% increase in marketable stem number, 65% increase in mean stem mass, and a 66% increase in cumulative stem length compared to the standard farm compost rate (Table 6). There was a significant Flower x Compost Rate interaction for mean stem length (P<0.02). Celosia mean stem length increased continuously such that the highest mean stem lengths were observed at the highest compost rate, whereas the highest mean stem lengths of statice were observed at the 0.2 cm compost rate (Table 6). Since celosia was generally more responsive to increasing compost rate, statice would be a better choice for low fertility transitional environments than celosia. Weed Management Alternatives:
Weed management trials in 2000 and 2001 evaluated plastic versus straw mulches in pepper production. Best yields and weed suppression were obtained with black plastic mulch (Tables 7 & 8). Hand cultivation produced higher yields than straw mulch, which tended to induce nitrogen deficiencies as the straw decomposed.
Trials in 2002 compared acetic acid spray versus corn gluten as a soil amendment. Neither treatment gave satisfactory, season-long weed suppression (Table 9).
There were significant effects on bean yield due to variety (P<0.0001), compost rate (P<0.0001), and a significant variety x compost rate interaction (P=0.0068). Except at the highest compost rate (1.6 cm), Dragon Tongue was the highest yielding variety by mass (Table 5). The yields of all varieties responded positively to compost applications, with Xera being the most responsive and Yellow Wax being the least responsive. The compost rates that produced the maximum yields (Table 5) were larger than the standard farm compost rate of 0.4 cm.
All compost treatments (0.2, 0.4, 0.8 and 1.6 cm) had significantly lower grass and higher purslane populations than did the control (0 cm compost). There was no effect of compost rate on fractional population of Other Dicots. The two highest compost rates (0.8 and 1.6 cm) had significantly lower grass and higher purslane populations than did the three lowest compost rates (0. 0.2 and 0.4 cm). Purslane is a salt tolerant weed, so these results are consistent with soil test data showing an increase in salt accumulation in high compost treatments.
__________
Table 7. Pepper yield and shoot and root dry weights as affected by mechanical weed control methods (2000). This table, and the following tables, are available by calling or e-mailing Northeast SARE. Ask for the report for project LNE99-123.
__________

Table 8. Pepper number and yield, and shoot dry weight in Low or High Input in 2001.
__________

Table 9. Effect of vinegar, corn gluten, and mulches on weed control and pepper growth and yield (2002).
__________

Potato Pest Management:
In 2001, Valoram and Nemastop treatments had no effect on population density of aphids, potato leafhopper, lesion, spiral, or dagger nematodes, nor on Mononchids (predatory nematodes), and no effect on yields. Yields from Valoram treated plots were slightly lower than untreated control plots but no differences were statistically significant.
Surround WP reduced populations of potato leafhoppers (P=0.07) only at the June 29 date (compared to plots without Surround WP), but had no effect on of aphids (P=0.29). Symptom severity of potato leafhopper burn on July 24 was lower (P=0.009) on Surround-treated plots than on untreated plots. Potato vine defoliation on Aug. 17 averaged 56 % on plots with Surround and 79 % on plots without (P=0.0008). Plots treated with Surround WP had higher total (P = 0.027) and marketable (P = 0.0159) tuber yields that untreated plots. Yields were 13 % greater, ~ 25 cwt/Acre, with Surround WP.
In 2002, yield were 9 % higher in plots treated with Surround than in plots without Surround, however, differences were not statistically significant (P=0.16). Plots with blood meal also had non-significant yield increases. Populations of potato leaf hopper and Colorado potato beetle were lower in Surround-treated plots at mid-season, but not in early or late season ratings.

Biological Seed Treatments:
No differences in emergence of either pea or spinach were found among seeds treated with either Kodiak or T-22 treatments, and untreated seeds had numerically greater emergence than any of the treatments, although differences were not statistically significant. In a growth chamber evaluation, spinach emergence was significantly greater in steam-sterilized soil than in unsterilized soils. Emergence was faster at 18 C than at 12 C, but the final proportion did not differ greatly in sterile soil. In sterile soil, Kodiak appeared to slow the rate of spinach emergence, but no differences in final emergence occurred.

Apple Orchard Management:
Both Surround and Envirepel gave satisfactory control of spirea aphid, rosy aple aphid, leaf hoppers, and leaf roller insects, however very high levels of injury from plum curculio, coddling moth and tufted apple bud moth occurred with both treatments in both 2001 and 2002. Surround WP-treated trees had fewer plum curculio scars on fruit, lower speckled green fruitworm incidence, less tufted apple budmoth damage, and higher levels of aphid natural enemies than Envirepel-treated trees.

Tomato Intercropping with Resistant Cultivars:
The rate of disease increase of Tomato Early Blight on susceptible ‘Brandywine’ tomato was lower when intercropped with the resistant cultivar ’Juliet’ than when grown in monoculture and yields per plant were 17 % greater.

Vegetable Intercropping:
Three of the seven dicultures tested had a LER above one, suggesting a companion planting yield advantage (Table 10). Tomato dominated the secondary crop in all of these cases (Table 10).
Tasters found tomatoes grown in brassica and clover dicultures less acidic than those grown in monoculture. No significant differences were observed for other companion crops or criteria tested.
Counts of the most common pests on tomato (potato aphid) and bean (thrips, potato leafhopper, and aphids) did not differ significantly between monoculture and diculture beds. The palestriped fleabeetle was more prevalent on basil in monoculture than on basil grown in diculture with tomato. Common pests of brassicas that were more prevalent in monoculture than in some dicultures included cabbageworms (Table 11) and other non-lepidopteran pests (Table 12).
__________
Table 10. Contributions of component crops to total Land Equivalence Ratio (LER) for seven companion plant combinations. This table, and the following tables, are available by calling or e-mailing Northeast SARE. Ask for the report for project LNE99-123.

__________

Table 11. Cabbageworm counts from brassica leaf surveys. Insects per leaf ( ± S.E.)*
__________

Table 12. Counts of common non-lepidopteran pests from brassica leaf surveys. Insects per leaf ( ± S.E.)
__________

All dicultures tested in the 2001 trial had a LER above one, suggesting a companion planting yield advantage (Table 13). Basil competed poorly with tomato and Brussels sprout in diculture, producing a much lower yield than in monoculture, but not reducing the yield of its companions. Canopy light penetration and soil moisture readings had similar patterns, indicating the least competition for light and water in basil monocultures, and the most competition in beds growing Brussels sprouts. Taste panels found no significant differences between tomatoes grown in monoculture and those grown in diculture.

__________
Table 13. Contributions of component crops to total Land Equivalence Ratio (LER) for three companion plant combinations.This table is available by calling or e-mailing Northeast SARE. Ask for the report for project LNE99-123.
__________

The potato aphid was again the most common insect pest on tomato, and was not affected by companion planting. Palestriped fleabeetles were again more common on basil grown in monoculture than on basil grown in diculture. The imported cabbageworm was the only lepidopteran pest of Brussels sprouts that responded to companion planting: It was more common on plants grown with basil than on plants grown in monoculture (Table 14). The striped fleabeetle was also most prevalent on Brussels sprouts grown in basil diculture.
__________
Table 14. Counts of commonly occurring phytophagous insects found on Brussels sprout leaves during systematic leaf surveys.
Insects per leaf ( ± S.E.).* This table is available by calling or e-mailing Northeast SARE. Ask for the report for project LNE99-123.

Compost and Compost tea for early blight management on tomato:
Yields were significantly lower (P<0.01), and plants were visibly stunted, in plots amended with hardwood bark compost or blood meal than with a dairy manure or yard waste compost. Early blight severity (AUDPC) varied significantly among compost treatments (P<0.05) and was positively correlated with shoot biomass at the end of the season (P<0.01). Compost teas had no significant effect on tomato yield or early blight severity.
Disease resistance of 16 heirloom and hybrid tomato cultivars:
Significant differences in early blight severity were observed among tomato cultivars in 2001 and 2002. ‘Brandywine’, ‘Daybreak’, ‘Johnnys 361’, and ‘Valley Girl’ were among the most susceptible both years, while ‘Matts Wild Cherry’, ‘99197’, 99203’, ‘Juliet’, ‘Red Currant’ and ‘Sun Gold’ showed significantly less disease in both years. The response of ‘Green Zebra’ and ‘Prudens Purple’ varied substantially from one year to the next.

5.C. Education Outcomes
The WVU Organic Research Farm project has been identified as one of the top organic research projects in the country by the Organic Farming Research Foundation’s State-Of-The-States report. Numerous news media stories have assisted in the educational outreach of the project, and have helped to acquaint growers with the results of the project.
Graduate and undergraduate students at WVU and other schools in the Mid-Atlantic region have participated in learning activities, either directly through hands-on research and internship projects, or through formal classes, field trips, and participation in field days. The Organic Crop Production course has had 25-35 students enrolled each of the last three years. These include a variety of local growers, extension personnel, and “Master Gardener” participants as well as traditional students.
Field days have been held each year and attendance has increased from 120 in 2001 to approximately 180 last year. Field Days include tours of research plots, demonstrations of management practices, and presentations of research results. A scientific outreach field day occurred in July, 2002 when the NorthEast Branch of the Agronomy Society of America was hosted at the farm.

Participation Summary

Education

Educational approach:

In 2000, grower outreach and student education projects included three internships for undergraduate students, a training session for organic certification inspectors, and weekly farm sales of organic farm produce to local restaurants as well as direct marketing to the public.
Grower outreach was expanded to include field days held Aug. 2, 2001 and on July 18, 2002. Over 120 people attended both events and favorable comments were received in participant evaluations. Three student interns were registered in 2001 and four students in 2002. A WVU student field day Sept. 8, 2002 was held, with about 12 students attending. A one-semester course in organic farming and gardening is being offered at WVU and had 28 students in 2002 and again in 2003. A webpage on the organic farm project was established in 2001 and is available at: www.cafcs.wvu.edu/plsc/organic.
Presentations to growers also occurred at annual meetings of organic growers, at extension field days, and through news media reports. Organic growers have responded enthusiastically to the project.
Scientific papers reporting results from the project were presented at meetings of the International Federation of Organic Agriculture Movements (IFOAM), the American Phytopathological Society, and the Agronomy Society of America (Northeast Branch). Fact sheets are in preparation, with assistance and support from the West Virginia University Cooperative Extension program.
Slides and photos are available at the WVU Organic Research Farm webpage: www.cafcs.wvu.edu/plsc/organic.

Project Outcomes

Economic Analysis

Economic analyses have focussed on the Market Garden experiment to determine the economic and financial feasibility of an organic market garden during the 3-year transitional period. Standard economic and financial tools were employed. We draw the following preliminary conclusions:
1) Using fairly conservative price and yield assumptions, the market garden is profitable even on a small scale (the 1/2 acre unit investigated in this study). A larger area will be needed if the market garden is to represent the main income source.
2) A market garden can be operated profitably as a “stand-alone” activity, or as an “add-on” in conjunction with existing enterprises such as livestock (desirable, both from a diversification standpoint, and as a source of compost), fish farming or other such activities.
3) Additional study over a longer time period is needed to reinforce these conclusions for other parts of WV (the study area). In addition, this study can be extended to investigate such aspects as the profit-risk tradeoffs of a market garden as a “stand-alone” activity versus an “add-on” activity.
4) The demand for organic foods is growing rapidly, fueled in part by growing health consciousness, food safety concerns, and preference for locally-grown products. Vegetable sales, for example (which represent a large segment of the organic market), amount to over $6 million annually across the state. By virtue of its linkages with other sectors of the economy, a $1 million increase in vegetable production can increase total output in the state by an estimated $1.4 million annually, generate $1.8 million in income, and add 36 jobs.
5) While both the Low and High Input systems are estimated to return a net profit in the Market Garden, the lower overall yields and the absence of a marketable crop during the first year made the Low Input system significantly less profitable during the transition period.
6) Improvements to soil quality in the High Input system are cumulative, even though differences are not always measurable in the early years. Use of compost in combination with winter cover crops (High Input) appears to provide significantly higher returns over the transition period than the green manure/cover crop treatments without added compost.

Farmer Adoption

Farmer adoption of the practices evaluated under this project varies depending on the specific tests. Existing organic growers are readily adopting individual practices for pest management, and have long been practitioners of crop rotations, compost use, and similar farming practices. However, changes in organic certification practices and implementation of the USDA National Organic Program have made it difficult to evaluate the number of conventional growers that are transitioning to organic production. For example, the Mountain State Organic Growers and Buyers Association has not had the financial resources to become an accredited certification agency, thus West Virginia growers must seek certification from outside the state. As such, while markets for organic produce have increased, it is not clear how many growers have begun the transition, or even how many existing organic growers remain certified for organic production.
Growers have many reasons for transitioning to organic production, and the availability of technical advice and production information helps to remove a major constraint from achieving that goal.

Areas needing additional study

Improved pest management tactics are often a limiting factor in organic production, as was identified in this study. Additional study is needed on:
Organic management practices for early season seedling diseases, and late season foliar diseases.
Management for insect pests in apple, potato and cucurbits.
Economical weed management in field crops improved techniques.
Effects of cultural practices on native biological control agents for diseases and beneficials attacking invertebrate pests.
Cultivation practices that minimize soil compaction need to be evaluated.
Long-term effects of farming systems on soil fertility, crop yields and pest population dynamics. This project identified changes in soil nutrients that required at least three years before becoming apparent, but longer-term build-up of salts and mineral nutrients, and management practices to address potential problems remains unknown.
Economic sustainability of organic practices. In particular, research that can identify critical practices and their economic impact on growers.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.