Final Report for LS92-049
There are ways to recycle and reuse agricultural wastes so they do not go to waste. This is particularly important in the South where agricultural waste products are so abundant. In Arkansas alone, the state’s poultry and cotton industries produce billions of lbs of by-products and wastes each year. In 1993 Arkansas’ billion broiler chickens produced 2 to 2.5 pounds of litter per bird. During ginning of the state’s 1.5 million bales of cotton, 100 to 150 pounds of gin trash were produced per bale. In this project our aim has been to take advantage of the availability of these materials by putting wastes to work improving soils on small scale vegetable farms.
University researchers and farmers worked together in this SARE/ACE project to evaluate availability, agroecological impact, and economic feasibility of agricultural wastes when used as soil amendments. The bulk of the research/demonstration work was carried out on small scale vegetable farms operated by African American growers in eastern Arkansas’ Mississippi Delta region. Farmers were directly involved in the planning of the research and implementation of the results. This allowed us to take research out of the controlled environment of the laboratory and agricultural research station and out to the farm to the people growing the crops.
Research has included work with animal manures and organic wastes from processing facilities such as cotton gins, rice mills, and fisheries. Field studies began in 1992 at the Demonstration Farm of the Arkansas Land and Farm Development Corporation (ALFDC) in Monroe County, and the farms of Harvey Williams (Phillips Co.), Ben Anthony, Jr. (Lee Co.), and Jim Burton (Monroe Co.). Additional sites added in 1993 and 1994 were the farms Randy Hardin (Jefferson Co.), Abraham Carpenter (Jefferson Co.), Arther Beam (St. Francis Co.) and Dennis Clark (Mississippi Co.). Studies with aquaculture wastes have been performed at the University of Arkansas at Pine Bluff Agricultural Experiment Station.
Because of widespread interest by farmers on effects of poultry litter on vegetable production, much of the field work has involved evaluations with litter (manure + bedding material such as rice hulls) from broiler and turkey production. Several demonstrations were made with raw litter, but a composted pelletized form of litter was used on most of the replicated trials. Pelletized poultry litter (PPL) with NPK analysis of 4-4-4, has been evaluated with 6 farmer cooperators on cabbage, sweet potato, tomato, okra, basil, watermelon, broccoli, turnip, and collard greens production fields. Benefits of using poultry litter have been most apparent in fields that previously had been precision leveled to improve irrigation efficiency. In these fields, topsoil has been disturbed and low pH (<6) is common. Significant crop responses also have been observed with shallow rooted plants (cabbage, collards, spinach) grown in light textured soils with low organic matter.
In several studies and demonstrations, we compared different sources of poultry manure (rates were adjusted to provide equivalent amounts of N). In replicated trials on the ALFDC farm with cabbage, no differences in yield were apparent between treatments of raw hen manure, pelletized hen manure, pelletized litter, composted litter, and raw litter. Although the pelletized products are easier to store and apply, high costs of these value added manure products precludes their use by many farmers.
Low cost agricultural wastes most available in the Delta are rice hulls and cotton gin trash. Our replicated trials with gin trash and rice hulls included studies to determine effects of cotton gin trash (raw and composted) and cover crops on yield of cabbage, broccoli, southern peas, snap beans and cucumbers particularly with marginal soils. Significant problems with weeds and plant disease resulted in green beans following use of raw gin trash. Composting alleviated these problems, and we found that composting didn’t necessarily have to require huge inputs of time by the farmer to produce an amendment that could improve productivity of the soil. Ben Anthony routinely hauls gin trash in his pick-up truck from a local gin to his cattle pasture where cows feed on the material over the winter. By summer’s end the trash has decomposed. We applied this decomposed (=composted) gin trash on damaged soil on his vegetable farm in 1994. Four tons/acre increased earliness and yield of his spring transplanted cabbage. In fall trials that year with turnips at the ALFDC farm, applications of 2 tons/ac of this composted gin trash + fertilizer (60 lbs N/ac provided with 13-13-13) resulted in significantly higher yield of greens compared to plots receiving fertilizer alone.
Additional studies with composted gin trash have included using the material as a potting media for growing watermelon and tomato transplants on the Ben Anthony Farm. Mixed in a 2:1 combination with perlite, tomato and watermelon transplants grown in composted gin trash were equivalent in plant height and color to plants grown in standard potting media; however root development was reduced compared to the standard. This resulted in significant problems pulling the plants during high speed transplanting with mechanical transplanters. In field trials with watermelons with Dennis Clark and Ben Anthony, once transplants were set, there were no differences in yield or quality in final harvests. In other work, composted gin trash was found to be a good material for production of potted ornamental plants, Swedish ivy and wandering Jew.
No significant improvements in yield of cabbage or collards have been observed with applications of raw rice hulls. The negative effects of over application of raw rice hulls were demonstrated on the ALFDC farm with spring transplanted cabbage when rates up to 10 tons/acre raw hulls resulted in nutritional deficiencies (primarily N). This demonstration was valuable to several farmers and area extension agents who had routinely recommended high amounts of rice hulls for garden plots.
Work with aquaculture wastes has included construction of composting units at the University of Arkansas at Pine Bluff Aquaculture Research Station. Applications of composted dead fish and remains and spoiled feed were evaluated on the UAPB research farm in replicated trials with collards and southern peas. Hairy vetch and rye were evaluated as winter cover crops in combination with compost. Cover crops had varying effects on southern pea yield in 3 years of trials, but there was no significant differences in yield. Results have been variable with collards, but significant increases in yield of spring transplanted collards were observed in 1994 following application of 2 tons compost/acre.
Education and outreach has been an important part of our project. The ALFDC has been instrumental in these efforts sponsoring several workshops, field days and conferences including the ALFDC Annual Conference in Fargo, AR held each October. In 1994 our research was highlighted in a special sustainable agriculture section held during the conference which included tours of research plots. Additional field days were conducted on the Ben Anthony and Abraham Carpenter farms. Project results have been presented at a number of professional and grower meetings including the 1995 Southern Sustainable Agriculture Working Group Annual Conference, and annual meetings of the Arkansas State Horticultural Society and the American Society of Horticultural Science.
In this project, we have found that benefits from applying of low cost agricultural waste products include improvements in soil productivity making possible increases in farm profitability. The most outstanding results have been observed with crops grown on land that had been recently precision leveled and with crops with shallow root systems. An additional benefit is the contribution to solving waste disposal problems confronting the region.
This project was designed to evaluate availability, agroecological impact, and economic feasibility of agricultural waste products in vegetable production systems in the Mississippi Delta region. Application of low cost agricultural waste products as soil amendments can provide improvements in soil productivity as well as financial savings compared to purchasing synthetic chemical fertilizers. An additional benefit includes the contribution to solving waste disposal problems confronting the region. Waste materials in the region include animal manures, particularly from poultry, and wastes from agricultural processing facilities such as cotton gins and rice mills. Research results indicate that composting is an important step in using agricultural wastes. Positive responses to additions of soil amendments have been most apparent with crops with shallow root systems grown under environmental conditions conducive for micronutrient deficiencies such as light textured soils or in soils that have been damaged by precision leveling.
There had been little known about the effects of application of agricultural waste products as soil amendments for high value vegetable crops in production systems typical for small scale Delta growers. The benefits of poultry litter application to soils, particularly those damaged from precision leveling activities, has been documented for agronomic crops (7). Information on response of vegetable crops to applications of gin trash, rice hulls and aquaculture waste was largely unavailable. This SARE/ACE project was designed to address these and other questions regarding use of agricultural wastes for Delta vegetable growers.
Specific objectives of this project were:
1. Identify sources, composition, seasonal availability, variability and economic feasability of agricultural by-products/wastes in the Lower Mississippi Delta Region.
2. Evaluate available information and determine experience of cooperator farmers on agroecological impact of these agricultural by-products/wastes.
3. Determine, in collaboration with farmer cooperators, the cultural, environmental, and economic impact of selected by-products on vegetable production.
4. Conduct participatory research/demonstration programs with cooperator farmers to determine effects of selected management and marketing approaches for several cropping systems utilizing promising soil amendments and methodologies.
5. Disseminate cultural and economic information obtained in a manner sociologically and educationally accessible to this farmer clientele.
The Lower Mississippi Delta Region — Arkansas, Louisiana, and Mississippi, and parts of Illinois, Kentucky, Missouri and Tennessee — boasts some of the greatest agricultural industries in the world, yet its people are among the most impoverished in the nation (1). Arkansas epitomizes the problems and potential of the region (2,3). Agriculture is the major industry in the state, yet approximately 68% of Arkansas farms are considered small scale operations (annual sales less than $20,000) (4). Many of these farms in eastern Arkansas (the Delta region) are operated by limited resource growers who may have marginally productive land. Profitability of their small scale operations has diminished due to the economics of scale accruing to the benefit of large scale operators. In response, many of these farmers have or are investigating replacing all or a portion of their traditional crops of soybeans, rice or cotton with higher value crops such as vegetables. The production potential for crops that require well-drained, highly fertile conditions is limited if soils on their farms are damaged or marginal.
Application of low cost agricultural waste products as soil amendments can provide improvements in soil productivity as well as financial savings compared to purchasing synthetic chemical fertilizers that include micronutrients. Materials readily available in the region include animal manures and wastes from agricultural processing facilities such as cotton gins and rice mills. Appropriate handling of the waste materials as soil amendments also could aid in solving the massive waste disposal problems confronting the Midsouth.
A major producer of agricultural wastes in the state is the poultry industry. Poultry waste most commonly available in the Delta region comes from the state’s broiler industry. In 1993 Arkansas poultry industry produced over 1 billion broilers generating between 2 to 2.5 pounds of litter per bird. Litter is a dry waste consisting of a bedding material generally rice hulls or saw dust, and the broiler manure. This differs from the liquid waste generated by layers in egg production which does not include bedding material. Over 40 percent of Arkansas’ poultry litter is applied to the poultry producers land while another 40% percent is spread on “other” land (5). Litter from broilers and turkey production is primarily applied raw, but there are commercial operations which compost and even pelletize the material. This product is shipped bulk or bagged in 50 lb bags. Dried and pelletized manure from layer operations also is available commercially in the region.
Agricultural waste products generated and most available in the Delta are associated with the major agronomic row crops. This includes the state’s 1.26 million acres of rice and 900,000 acres of cotton which produce rice hulls during milling and gin trash during ginning. For the rice industry, the largest mills market their rice hulls to the poultry industry for use as bedding in broiler and turkey houses. Other rice processors simply dump hulls either on site or nearby fields. For the cotton industry, between 100 and 150 pounds of gin trash (sticks, burs, weed seed, some poor quality lint, etc.) are produced per bale of cotton. Arkansas cotton farmers produced 1.5 million bales of cotton in 1992 (6). Burning cotton gin trash is no longer permitted, and disposal has become more challenging for gin operators. Gin trash is commonly stored on the gin yard and later dumped on surrounding land. Some ginners may compress the gin trash into modules before transporting for disposal. A few ginners and farmers compost the material. Composting reduces bulk, making the product more easily transported. In addition, heat from the composting process reduces pest problems, weed seeds and plant pathogens, making the final product more desirable for use on farmland as soil amendments.
Another source of agricultural waste products are associated with the Midsouth’s aquaculture industry. In Arkansas, there are over 20,000 acres of catfish ponds worth over $20 million (6) in sales/ year. Fish kills, remains following fish processing and spoiled feed are all considered aquaculture wastes. The most common method of disposal of the waste generally is to bury it on site or leave it in the bottom of ponds. Better disposal practices and utilization of the wastes are needed. Composting aquaculture waste offers a practical alternative to current disposal practices.
Research has included work with poultry manures and organic wastes from processing facilities such as cotton gins, rice mills, and fisheries. The bulk of the research/demonstration work was carried out on small scale vegetable farms with farmers as research partners.
The project was located in eastern Arkansas in the Southern Mississippi River Valley Bottom Lands. Soils range from poorly drained, level, loamy and clayey soils in broad slack water areas and flood plains to gently undulating to level sandy and loamy soils on natural levees and broad flats. Soils on cooperator and research farms range from silt loams to fine sandy loams. Topography varies from level alluvial area near the eastern state boundary to slightly rolling area westward at the Crowley’s Ridge area. Average annual temperature is in the low 60s. Temperature varies from the low 40s in January to the low 80s in July. The growing season is ca 232 days with the average date of the last killing frost in spring ranging from March 20 to April 10. First frost in fall generally occurs in mid-November. Precipitation near 50 inches/year is fairly well distributed throughout the year. Snow is almost a negligible form of precipitation.
Field studies began in 1992 at the Demonstration Farm of the Arkansas Land and Farm Development Corporation (ALFDC) in Monroe County, the Harvey Williams farm in Phillips County, the Ben Anthony farm in Lee County, and the Jim Burton farm in Monroe County. SARE/ACE funds were use to hire a full time farm manager at the ALFDC site, Mr. Harrison Locke. His responsibilities included research/demonstration projects as well as the educational program at the site and with nearby farmers. Additional sites added in 1994 were Randy Hardin’s farm and Abraham Carpenter’s farm in Jefferson County and the Author Beam farm in St. Francis and the Dennis Clark farm in Mississippi County. Studies were completed in 1995 on the ALFDC farm and Anthony farm. Greenhouse studies were carried out at the Marianna High School Greenhouse (adjacent to Mr. Anthony’s farm), the horticulture greenhouse complex on the ASU campus, and the commercial greenhouse facility at Burton Farms. Studies with aquaculture wastes were evaluated on the University of Arkansas at Pine Bluff Agricultural Experiment Station. Field studies began in 1992 at UAPB.
Availability of Wastes/Farmer Experiences
Product availability and location of cotton gins, rice mills, etc. in the region were identified. Chemical analysis of waste materials including all broiler and turkey raw litter, hen manure, and composted broiler litter, raw and composted gin trash, raw and composted rice hulls, and composted aquaculture wastes
Interviews with cooperating farmers concerning their experiences with waste products included actual field experience and anecdotal information. For example, farmers visiting the ALFDC farm reported experience with cotton gin trash in their garden scale vegetable production. They noted improvements in water holding capacity, increases in organic matter, and improvement in yield; however, despite these benefits, the farmers did not recommend the practice because of application problems and weed problems that result from using gin trash contaminated with weed seed. Weed pests mentioned as particular problems included several species of morning glory, pigweed, and common cocklebur. and Farmers who also had cotton production fields indicated that when cotton gin trash was applied raw in their fields they simply used higher rates of herbicides in the subsequent cotton crop. Other farmers reported problems with raw manure included offensive odors and weed problems.
Poultry Litter Studies
Because of primary interest by farmers on effects of poultry litter and manure on vegetable production, much on-farm work involved evaluations with poultry litter. Several demonstrations were made with raw litter, but a composted pelletized form was used on most of the replicated trials. A commercially available composted, pelletized poultry litter (PPL) (Organigro Corp., Mayesville, AR) with NPK analysis of 4-4-4, has been evaluated with 6 farmer cooperators in cabbage, sweet potato, tomato, okra, basil, watermelon, broccoli, turnip greens, and collard greens production fields. Composted, pelletized litter has many advantages over raw litter because of ease of application (dry pellets) and because of reduced risk of weed contamination and pathogens due to the composting process. The latter traits are extremely important for use in a crop such as spinach where mechanical harvesting requires minimal population densities of weeds. Also, risk of contamination by human pathogenic organisms must be minimized especially when product is grown for the fresh market. Use of the standardized pelletized form provides a consistent product to compare at multiple sites through time. There is tremendous variation in chemical analysis of raw poultry litter dependent on site collected in the poultry house, number of broods of birds produced over each per clean-out cycle.
Spinach – Replicated, on farm trials on the Jim Burton Farm in Woodruff County in Fall 1992 were conducted with spinach (var. Cascade) under high fertility conditions on a fine sandy loam soil with 0.75 % organic matter and pH ranging from 6.5 to 6.8. Mr. Burton’s fertilizer inputs included: preplant fertilizer of 15-0-75 NPK/ac with 10 lbs S and 0.5 lbs B/ac applied preplant with sidedress applications 3 wks after planting of 37 lbs N/ac and at 4 wks with 40 lbs N + 10.5 lbs S. PPL treatments were 0, 250, 750, and 1250 lbs /ac broadcast applied preplant incorporated in the first 3 inches of the soil. Plots were 10 ft wide, 25 ft long with 10 ft untreated buffer areas separating plots. The experimental design was a randomized complete block with 4 replications. PPL at rate of 250 lbs/ac significantly improved yield of spinach over control plots which received only the farmer’s fertilizer inputs (Table 1). Tissue analyses of spinach at harvest indicated no difference in accumulation of heavy metals in treatments receiving up to 1250 lbs ppl/ac compared to untreated control plots (Table 2).
Partial budgeting analysis for the use of poultry litter in spinach was performed based on a delivered cost of $70/ton for PPL, $5/ton spreading, and a price of $100/ton for processing spinach. A 2.28 ton/acre yield increase for 250 lbs/ac of PPL produced a $218.62/acre profit over the cost of the added inputs. For fresh market spinach, which on average is worth $600/ton FOB, the profit from $250 lbs/ac of PPL is $590.62/ac. The $70/ton delivered rice is 1996 bulk price on volume purchases. however, the yield response of 250 lbs/acre is great enough that a 100% cost increase in PPL would produce a positive net margin.
Cabbage – Studies on the Burton farm in spring 1993 with (bare root)transplanted ‘Gourmet’ cabbage were used to evaluate effects of PPL applications in combination with fertilizer transplant water applications. The experiment was arranged as a 2X2 factorial in a randomized complete block with 3 replications. Plots were 30 ft long 4 rows wide with 30 inch row spacing. Fertilizer transplant water treatments were NPK only and Golden Harvest Plus, (Stoeller Chemical Company, Houston, TX; 16-8-2 with 0.8% Zn, 0.4% Fe, 0.4 % Mn, 0.4% Mg, 0.2% Cu, 0.1% B, 0.05% Mo, 0.05% Co, and 2% S) at 1qt/100 gal water. Previous studies with broccoli on the Burton farm had shown highly significant response to transplant water fertilizer applications containing micronutrients including Golden Harvest Plus. The micronutrients, Zn, B and Mg, had been found to be particularly important on the coarse textured soils prevalent at that location (8,9). Results from 1993 cabbage trials indicated a slight increase in earliness associated with Golden Harvest Plus applications, but no effect from PPL applications. No significant differences were noted in final yields. It should be noted that Mr. Burton had initiated an aggressive liming program in the 2 years leading up to this trial, and soil pH values on his farm were steadily improving to levels above 6.5. During Mr. Burton’s diversification from agronomic field crops to vegetables, his crops had been plagued with fertility problems primarily associated with low soil pH resulting in problems with Zn, Bo, Mg deficiency and Mn toxicity in the Brassica crops and spinach. These conditions were not limiting when soybeans and corn were the dominant crops. Problems were not evident until shallow rooted vegetables were produced. Once his long term soil management program took effect, which took over 2 years, crop response to applications of micronutrients were less apparent on the farm. Such fertility problems have been a common problem in the Delta when producers of conventional agronomic crops initiate a vegetable program. Soil amendments may be particularly helpful in the transition period.
Sweet Potatoes – Soil amendments of 2 tons/acre of PPL improved yield and quality of sweet potatoes in an unreplicated strip trial on the Harvey Williams farm in 1992. His typed report is included in the appendix. PPL was applied at rates of 0, 250 and 500 lbs/ac in 1/4 acre blocks on ‘Beauregard’ sweet potatoes on a silt loam soil in 24 June 1992. Both yield and quality of sweet potatoes was increased when PPL was added to Mr. Williams traditional fertility program of 400 lbs of 10-20-20 fertilizer. Yield from 4 rows of each treatment are shown in Table 3.
The pelletized form allowed Mr. Williams to apply the material using a dry fertilizer distributor available from the local farmer cooperative. Mr. Williams expanded his use of poultry litter in 1993. PPL was the only fertility input in Mr. Williams first experimentation with organically grown vegetables in 1993. He and is wife increased this production in 1994 using composted broiler litter provided by the project for fertility inputs. He has found increased market demand for organically grown vegetables at his produce stand at the Lee County Coop Market, and poultry litter is allowing him to grow high quality vegetables without synthetic fertilizers to meet that demand.
Ben Anthony Demonstration – Poultry Litter – The vegetable production area of the Ben Anthony farm was precision leveled over the past 3 years to improve irrigation efficiency. Severe reductions in crop productivity resulted the leveling procedure. Production of okra, spinach, sweet potatoes and Brassica crops was significantly reduced. On this site in 1992 we added soil amendments of 1000 lbs/ac of PPL and 1 ton raw chicken litter for comparison. Total area involved in the trial was 7 acres. Both additions appeared to improve yield of okra in an unreplicated trial compared to soil receiving only NPK. Applications of PPL were made to his sweet potato plots had no significant effects on production in 1992; however with additional applications in 1993, plant growth in the treated area was visibly improved. PPL was applied at 4 rates to staked tomatoes in 1993. Problems with his irrigation system resulted in loss of the trial, however, and no data were recorded. Mr. Anthony cited one advantage of the pelletized litter was ease in application compared to raw litter. His current equipment, a modified John Blue applicator, was sufficient to apply the material as either a broadcast or directed sidedress. Cost is the major factor in deciding on adoption of soil amendments for his operation. Current prices for PPL are too high for adoption of this practice on his farm due to limited financial resources despite the benefits he has observed. Prices range from $5 to $8 / 50 lb bag of the PPL product. Evaluations with other waste products were included in his farm in 1993 and 1994 and are reviewed below.
Ben Anthony Demonstration -Transplant Water Trials – Studies on the Anthony farm included evaluation of composted poultry litter suspended in water to form a tea and applied in the hole prior to transplanting (transplant water). Application rates were based upon total N applied in standard N amounts in the standard Golden Harvest Plus applications in transplant water (Golden Harvest Plus at 1qt/100 gal water). Trials with fall cabbage (‘Gourmet), broccoli (‘Packman’) and collards (‘Blue Max’) on the Ben Anthony farm and at the ALFDC Demonstration Farm indicated no negative effects on crop establishment following application of compost tea, and no differences in crop establishment were observed at either site when compared to the Golden Harvest Plus standard. The Anthony farm experiments were lost due to insect problems, but the ALFDC crop was evaluated for yield response. Broccoli yields were significantly higher when transplant water contained either compost tea or Golden Harvest Plus compared to the water only control. Subsequent replicated studies in broccoli (ALFDC 1994), however, indicate that the Golden Harvest Plus synthetic fertilizer significantly improved early plant growth compared to the compost tea. In replicated trials with watermelon (Dennis Clark Farm 1994), PPL was applied at 0 or 500 lbs/ac with transplant water treatments of either water only, a 16% N mixture using Peters 20-20-20, a 16 % N mixture using Organagro 4-4-4 pelletized poultry litter (PPL was put into suspension with hot water) and Golden Harvest Plus (16% N). Plots were 60 ft long and 3 beds wide with 6.6 ft separating beds. Plots were harvested 2X weekly for 4 weeks. Melons ranged from 18 to 26 lbs. No significant differences in yield were observed; however, highest yields were observed with 500 lbs litter broadcast at planting with water only at transplant time. In greenhouse trials with watermelon and broccoli grown in sand alone and in soil collected from the Clark and Anthony farms, results indicate that Golden Harvest Plus and standard 20-20-20 NPK fertilizers result in more rapid early growth (1st 10 days after setting) in transplants than the compost tea. Use of compost tea was superior to using water alone.
ALFDC Trials – Long term studies with poultry litter on soils damaged following precision leveling were conducted in replicated trials on the ALFDC Demonstration Farm in 1992-1994. These studies have included sequential plantings of fall transplanted ‘Blue Max’ collards (1992), spring ‘Royal Crest’ turnip greens (1993), fall transplanted ‘Bravo’ cabbage (1993), and fall direct seeded ‘Bravo’ cabbage (1994). Analyses of turnip and cabbage data, as well as effects on soil chemistry are not complete, but collards data are summarized below. Treatments included preplant applications of PPL of 0, 250, 750, 1250, and 1750 lbs./ac, fertilizer transplant water (Golden Harvest Plus at 1qt/100 gal water), and applications of 60-60-60 (N-P2O5-K2O) preplant. Treatments not receiving Golden Harvest Plus received equivalent amounts of NPK (20-20-20 source) in transplant water. Results from collards research indicate applications of 750 lbs PPL/acre significantly (ANOV p=0.05) improved yields over plots receiving just NPK. In the same study, in-furrow applications with fertilizer transplant water produced comparable yields to plots treated with litter. We interpreted this data as an indication that the crop response to litter applications was due to the addition of secondary and micronutrients from litter that are not available from applications of NPK alone. Data from plant tissue analysis on leaves and stems at harvest indicate elevated levels of some nutrients and other elements including As in some higher PPL treatments. Data were inconsistent, however, and no conclusions could be made from the first study. As the study progressed with accumulating applications of litter to 2 crops/year of turnip, collards or cabbage, results from plant tissue analyses showed no trends in increasing levels of As. At the conclusion of the 1995 study, effects of 3 yrs use (5 crops) of varying levels of litter (0 to 1750 lbs/ac) on damaged soils with crops of collards, turnips, collards, cabbage and collards indicated no increases in As, Ni, Pb, Sb, Se, Cr, Al, Ag, Be, B or Cd in plant tissues.
Cut Flowers – In response to interest by vegetable growers in opportunities available for cut flower production, soil amendment trials were expanded to include zinnia for cut flowers 1993 . Poultry litter applications were evaluated on non-disturbed soils (pH 6.5) on the ALFDC farm. Treatments were untreated control, 1500 PPL lbs/ac, 60-60-60 NPK, and 1500 lbs PPL + 60-60-60 NPK arranged in a randomized complete block with 3 replications. There were no differences in quality or yield of ‘Cut and Come’ zinnias associated with any PPL treatment. Highest yields were associated with NPK applications.
Randy Hardin, Auther Beam, and Abraham Carpenter Demonstrations – Poultry manure studies were expanded in 1994 to include 3 additional sites. Applications of dried hen manure were made on a 2 acre plot on the Randy Hardin farm in Grady. Mr. Hardin had found a source of the manure and was interested in how hen manure, which has no bedding material associated with it would compare to broiler litter. Fall pepper was planted on strips planted with both hen and broiler manure, but problems with disease reduced stand so dramatically that no evaluations were possible. The Carpenter farm demonstration involved assisting Mr. Carpenter with production of organically grown sweet potatoes. He requested assistance in procuring a pelletized 3-4-4 hen manure for fertility inputs. This demonstration was highlighted by Mr. Carpenter in the field day at his farm in September 1994. Although weed problems were significant in these plots, soil fertility did not appear limiting to Mr. Carpenter. Presently, he does not plan to continue with organic production. Arther Beam had significant problems with land that had been precision leveled for irrigation. Fall 1994 demonstrations on his farm included applications of a 3-4-4 pelletized hen manure on fall planted turnips, and transplanted collards, cabbage, and broccoli provided through the project. Production of Brassicas was not possible on the damaged site prior to manure application. Unfortunately, problems with irrigation timing left the study unsuitable for evaluation of yield, but early stand establishment indicated fair to good results from the soil treatments in collards. Each of the above demonstrations lead to questions related to relative value of each of the different types of poultry manure commercially available to vegetable producers in the Delta. A replicated trial at the ALFDC was initiated in fall 1994 with direct seeded cabbage to evaluate effects of PPL, composted broiler litter (pre-pelletized form of PPL obtained from Organigro), pelletized hen manure (3-4-4 commercial product, Sprinfield, MO), on yield and quality of cabbage. Analyses of the raw compost material indicted that it was essentially ½ the fertility input of PPL based on total N. The experimental area was in the damaged soil area of the ALFDC farm. Soil had received 2000 and 1000 lbs lime in the previous 2 falls. Soil pH ranged between 6.3 and 6.5. Plots were 6 rows wide and 30 ft long with 10 ft alleys. ‘Bravo’ cabbage was directed seeded on 20 July in single rows on raised 40” spaced beds. Plants were thinned to 10 to 12 inch spacing. Soil amendments were broadcast just before beds were formed, 4 days prior to planting. In addition all plots received the equivalent of 60 lbs N along with P and K applied as 13-13-13 broadcast. Soil samples from each plot were taken at planting and harvest time. Plots were furrow flood irrigated as needed. Harvest was conducted weekly over 4 wks. The harvest area was a 7 ft area in either row 3 or 4 in the center portion of the plot. Statistically significant differences in yield were observed with lowest yield observed in the pelletized hen manure treatments. The hen pellet material resulted in stunting of the plants.
On station work at the University of Arkansas Pine Bluff with composted fish and fish feed wastes was begun in summer 1992. Covered compost units made of lumber were constructed, and composting of dead fish, fish parts, and spoiled feed from the catfish and baitfish research and demonstration facilities begun. Straw was used in the composting process along the aquaculture wastes. The units offer a high visibility demonstration of composting methodology to catfish and baitfish producers and college students who visit the station. Composted material from these units was applied in replicated field trials with summer crops of southern peas and spring collard greens in a silt loam soil on the UAPB Agricultural Experiment Station. The experiments were laid out in 3X4 factorial design, randomized complete block with 4 replications. There were 3 treatments for cover crops: rye. hairy vetch, and no cover crop and 4 treatments of soil amendments/fertilizer: 40-40-40 lbs/acre (N-P2O5-K2O), 4000 lbs aquaculture compost, 40-40-40 lbs/acre fertilizer + 4000 lbs aquaculture compost and untreated control. Southern pea trials were conducted in 1992, 1993 and 1994. Transplanted collards (var. Blue Max) were evaluated in spring 1994. Compost applications significantly increased yield of collards (ANOV; p=0.05): cover crops had no effect on yield. Compost applications significantly decreased yield southern pea yield in 1993, but had no effect in 1992 and 1994. Cover crops had a positive effect on southern pea yield in 1992, a negative effect in 1993, and no effect in 1994.
Cotton Gin Trash — Replicated trials with gin trash included studies to determine effects of raw and composted gin trash and cover crops on yield of cabbage, broccoli, southern peas, snap beans and cucumbers grown on disturbed soil at the ALFDC farm. Replicated experiments initiated in late 1992 and evaluated in spring 1993 include comparison of 4 rates of raw and composted cotton gin trash with a winter grain rye cover crop grown. Soil amendments and cover crops planted in fall 1992 followed by late spring snap beans and southern peas. The compost was obtained from the from the local gin at Cotton Plant, AR. The composted material was taken directly from the gin yard where it had accumulated for 2 to 3 years. This material is commonly found on gin yards and is available to be hauled away. Additional trials with composted gin trash include effects on cucumber yield when used in conjunction with a crimson clover cover crop. Initial results indicate significant problems with weeds and plant pathogenic organisms result following use of raw gin trash. These problems were not evident with composted material. If composted gin trash is collected from a gin site, risk of weed seed contamination will decrease with the age of the pile if samples are removed from inside the pile.
Other work with gin trash has been centered on the Ben Anthony farm. Mr. Anthony routinely hauls fresh raw gin trash in his pick-up truck from a gin located about 2 miles from his farm to his cattle pasture. His cattle feed on the material over the winter, and by summer’s end the trash has decomposed . In 1993 he requested assistance in evaluating the material as a soil amendment on the unproductive areas in his fields. To determine risk of weed seed contamination of the material, samples from outside and inside gin trash piles were evaluated in the greenhouse for presence of weed seeds. The composted material was evaluated plain, mixed 1:4 with potting soil and 1:4 with sterilized silt loam soil. Each combination was placed in a 9 inch pie pan and watered daily. Weed numbers were counted per pan after 2 wks. Weed numbers were low compared with samples of raw gin trash, and the risk of weed contamination from application of the material was considered acceptable. Gin trash compost was applied on severely damaged soil on the Anthony farm in spring 1994 and cabbage transplants set in the area. In this non replicated strip trial, 4 tons composted gin trash/ac increased earliness and yield of his spring transplanted cabbage. Similar rates and design were used on Mr. Anthony’s staked tomato trial. It was not possible to collect yield data, but plants in treated areas were larger and appeared more robust. Fruit set was higher in the compost treated areas.
In 1994 studies at the ALFDC Demonstration farm composted gin trash was applied at rates of 0, 2 and 4 tons/acre. Compost was obtained from the from the local gin yard at Cotton Plant, AR where it had accumulated for 2 to 3 years. The composted gin trash was applied in the field on 1 Sep 1994. In addition, all plots received applications of NPK (60-60-60 lbs/acre (N-P2O5-K2O) in the form of 13-13-13). After application plots were disked and beds formed with a disk bedder. ‘Royal Crest’ turnip was directed seed on the 20 Sep 1994 in Dubbs/Dundee silt loam (pH 6.1). The plots were 4 rows wide with 3.3 ft row spacing between rows. Plots were 30 ft long with 5 ft separating plots. The experiment was arranged in a randomized complete block with 4 replications. Between plants spacing was 12 inches with a single row culture comparable to that used by small scale, turnip farmers in the Mississippi Delta. Plots were irrigated as needed with furrow flood. Plots were hand harvested on 21 Dec in a 5 ft section in the 2 or 3 row. A once over, whole plant harvest method was employed. Mean yield of roots not significantly affected by addition of gin trash; however, yield of greens was higher in plots receiving gin trash. Composted gin trash at a rate of 2 tons/ac produced a significant yield increase of 1.76 tons of turnip greens/acre. A local small farmer, hauling his own gin trash from the local gin should be able to deliver and spread the material for $10/ton out of pocket expense. A yield increase of 1.76 tons of greens/ac is equilvalent to 176 boxes (20 lb) of fresh market greens. Based on a $5 FOB per box price, a gross profit increase of $860/acre was produced by using the 2 ton/acre rate of composted gin trash.
Additional studies with composted gin trash have included using the material as a potting media for growing transplants. Studies in Lousianna indicate that a 2:1 gin trash compost and perlite mix is an acceptable substitute for commercially available potting mix (10). For our trial the compost was obtained from the Anthony farm pasture. Plants were grown in a commercial greenhouse on the Burton farm as well as the ASU greenhouse and the greenhouse at the local high school where Mr. Anthony grows his transplants. To reduce potential of contaminating the commercial greenhouse with plant pathogens, the compost was autoclaved before use. Tomato and watermelon transplants grown in composted gin trash were equivalent in plant height and color to plants grown in standard potting media; however, root development was reduced compared to the standard media. This resulted in significant problems pulling the plants during high speed transplanting with mechanical transplanters. On the Anthony farm plants were set by hand, and speed of removing the plant from the flat was not critical. In on-farm field trials with watermelons with Dennis Clark and Ben Anthony, there were no differences in yield or quality in final harvests. In other greenhouse work, composted gin trash:perlite was found to be comparable to commercial media for production of potted ornamental plants, swedish ivy and wandering jew. The gin trash was significantly better than a 2:1 composted rice hull:perlite mixture and a turkey litter and pine bark mixture.
Rice Hulls – Other experiments initiated in 1994 included evaluations of raw rice hulls. On the ALFDC farm, the negative effects of application of raw rice hulls were demonstrated with spring transplanted cabbage. In the 4 row, 200 ft long strip trial, five rates ranging from 0 up to 10 tons/acre raw hulls in Oct 1993, with ‘Gourmet’ cabbage transplants set in March 1994. Effects of increasing rice hull rates were striking as signs of N deficiencies increased as rice hull rates increased. This demonstration was highlighted in field days in fall 1994 and provided valuable information to several farmers and extension agents who had routinely used or recommended high application of rice hulls for garden plots.
A replicated trial with rice hulls was conducted on the ALFDC farm in fall 1994. ‘Bravo’ cabbage was directed seeded in the Dubbs/Dundee Silt Loam (pH 6.3) field 20 July 1994. The experiment was arranged as a 2 X 2 X 3 factorial in a randomized complete block with 4 replications. There were 2 cover crop treatments: fall planted crimson clover and no cover crop; 2 fertilizer treatments: NPK (60-60-60 lbs/acre (N-P2O5-K2O)) and no NPK and 3 compost treatments: 0, 2 and 4 tons/acre. Clover was planted 12 October 1993. The rice hulls were obtained from Riceland Foods in Brinkley, AR and were applied 11 May 1994 at which time all plots (including cover crop) were disked and beds formed with a disk bedder. The NPK was broadcast pre-plant 18 July 1994. Plots were 4 rows wide with 3.3 ft row spacing between rows and were 30 ft long with 5 ft separating plots. Samples and yield evaluation were made in the center 2 beds. Between plants spacing was 12 inches with a single row culture comparable to that used by small scale, cabbage farmers in the Mississippi Delta. Plots were hand harvested on 11 Nov in a 5 ft section in the row 2 or 3. No significant differences in yield or quality were associated with the cover crop or rice hull addition. There no significant interactions. While there was no detrimental effect observed with rice hulls application in this experiment, there was no indication of benefit.
Educational & Outreach Activities
Teague, T. G. 1994. Poultry litter compost effects on fall spinach production. Arkansas Soil Fertility Studies, University of Arkansas Research Series, Fayetteville, AR, 436:5-7.
Teague, T. G. 1994. Field trials with composted poultry litter with collards and spinach. HortScience 29 (5) 523.
G. S. Lee and T. G. Teague. 1995. Fertility studies on Brassicas grown in acid soils. HortScience 30 (4) 864.
Teague, T. G. and G. S. Lee 1995. Cotton gin trash, rice hulls and poultry litter as soil amendments in Midsouth vegetables. HortScience 30 (4) 894.
Project research summaries have been reported in a variety of state, regional and national forums, with the majority of presentations made to farmer based organizations with the specific Delta vegetable grower clientele targeted. Invited presentations were made at the annual University of Arkansas at Pine Bluff Rural Life Conference. This meeting had attendance of over 300, including farmers, students, and state and federal agricultural workers. Project results also were summarized at an invited presentation at the Arkansas Land and Farm Development Annual Conference in a workshop presentation in 1993 and with a poster presentation 1994. Attendance at the conference was over 600 in 1993 and 800 in 1994 including farmers, community leaders, state and federal agricultural professionals and Arkansas Governor Jim Guy Tucker (1993) and Congresswoman Blanche Lambert (1994). In addition, 7 presentations have been made at the Arkansas State Horticultural Convention and Trade Show in 1993 and 1994. Project findings also were summarized in an invited presentation to agricultural researchers at the Poultry Litter Utilization Workshop sponsored by Winrock International in Fayetteville. The audience consisted of researchers and other agency representatives from the Midsouth working on poultry litter. Project results also were discussed at an invited presentation to the Northeast Arkansas Rural Development Forum. Representatives from rural development organizations, SCS, ASCS, cooperative extension, as well as Congresswoman Blanche Lambert and Senator David Prior also participated in the conference. National and regional presentations included an invited presentation made at the Sustainable Agriculture Section of the Oklahoma Horticultural Industries Show in January 1994. Work with poultry litter was summarized in a presentation at the annual meeting of the American Society of Horticultural Science in Corvallis, OR in July 1994. In January 1995 project summaries were be presented at an invited presentation at the Southern SAWG meeting in Alabama. Project summaries were presented at the American Society of Horticultural Science in Ontario, Canada in July 1995.
Project results were presented in 4 field days at cooperator farms in 1994. Field days were held on the Ben Anthony farm and Abraham Carpenter farms in mid summer 1994. Two research tours were held on the ALFDC demonstration farm in mid July and in October. All field days had excellent attendance (between 40 and 100 farmers, agricultural professionals and community members attending). In January 1995 project highlights were presented at the Southern Sustainable Agriculture Working Group meeting in Gulf Shores, Alabama. Approximately 200 persons including farmers and activists in sustainable agriculture were present at the meeting. The project provided funding for 4 farmers, Harvey Williams, Ben Anthony, Harrison Locke, and Norman Banks to attend the meeting.
In addition to field days and meetings, results from the project have been discussed on at least 6 broadcast of the radio program, From the Ground Up, a weekly discussion of sustainable agriculture by T.G. Teague aired on the 100,000 watt public radio station KASU in Jonesboro (the most powerful public radio station in the Midsouth). The program can be heard in 4 states in the Mississippi Delta within a 250 mile radius of Jonesboro.
Teague, T. G. 1992. Pelletized poultry litter effects on vegetable production in Eastern Arkansas. Poultry Litter Utilization Workshop, Winrock International Sustainable Agriculture Program, 2 June 1992, Fayetteville, Arkansas.
Teague, T. G. 1993. Use of organic soil amendments for vegetable crop production on the ALFDC Demonstration Farm. Culture, Issues and Services Workshop at the Arkansas Land and Farm Development Corporation 12th Annual Conference. 22 October 1993, Fargo, Arkansas.
Teague, T. G. 1993. Vegetable crop yield response to poultry litter applications. Arkansas State Horticultural Society Annual Convention and Trade Show, 16-17 November 1993, Fort Smith, Arkansas.
Langlois, A. J. and T. G. Teague. 1993. Effects of composted, pelletized poultry litter applications on production of field grown zinnias. Arkansas State Horticultural Society Annual Convention and Trade Show, 16-17 November 1993, Fort Smith, Arkansas.
Teague, T. G. 1993. Utilization of pelletized chicken litter in a fertility program for vegetables. 38th Annual Rural Life Conference, University of Arkansas at Pine Bluff, 29 January 1993, Pine Bluff, Arkansas.
Teague, T. G. 1994. Agricultural wastes as soil amendments in sustainable vegetable production systems. Oklahoma State Horticulture Industries Show, 6-7 January 1994, Tulsa, Oklahoma.
Teague, T. G. 1994. Agricultural wastes as soil amendments in sustainable vegetable production systems: Identifying alternative uses for agricultural and environmental resources workshop. Northeast Arkansas Rural Development Forum. Arkansas State University, 4 April 1994, Jonesboro, AR.
Teague, T. G. 1994. Putting wastes to work….Soil amendments for vegetable crops from agricultural waste products. Arkansas State Horticultural Society Annual Convention and Trade Show, 15-16 November 1994, Fort Smith, Arkansas.
Stasi, C. and T. G. Teague. 1994. Watermelon response to poultry litter and fertilizer transplant water mixtures. Arkansas State Horticultural Society Annual Convention and Trade Show, 15-16 November 1994, Fort Smith, Arkansas.
Cowen, Milton and Owen Porter. 1994. Composted aquaculture wastes as a soil amendment in a vegetable production system. Arkansas State Horticultural Society Annual Convention and Trade Show, 15-16 November 1994, Fort Smith, Arkansas.
Cochran, Angela, A.J. Langlois and T. G. Teague. 1994. Comparison of different soiless media including composted agricultural wastes in greenhouse production of ornamental plants. Arkansas State Horticultural Society Annual Convention and Trade Show, 15-16 November 1994, Fort Smith, Arkansas.
Teague, T. G. 1994. Field trials with composted poultry litter with collards and spinach. Annual Meeting of the American Society for Horticultural Science. Corvallis, OR. HortScience 29 (5) 523.
Teague, T. G. 1995. Sustainable agriculture research you can use on your farm: SARE research using wastes for soil fertility. Invited lecture to the Southern Sustainable Agriculture Working Group Conference. 13-15 January 1995, Gulf shores, AL.
G. S. Lee and T. G. Teague. 1995. Fertility studies on Brassicas grown in acid soils. Annual Meeting of the American Society for Horticultural Science. Montreal, Quebec, Canada. HortScience 30 (4) 864.
Teague, T. G. and G. S. Lee 1995. Cotton gin trash, rice hulls and poultry litter as soil amendments in Midsouth vegetables. Annual Meeting of the American Society for Horticultural Science. Montreal, Quebec, Canada. HortScience 30 (4) 894.
In this project, we have found that benefits from applying of agricultural waste products such as composted poultry litter, aquaculture wastes and gin trash includes improvements in soil productivity and increases yield and quality which may lead to increased farm profitability. Gin trash is the most accessible material. It is free and locally available. Costs for transportation and application are appropriately low for limited resource farmers. Additional benefits are the contribution to solving waste disposal problems confronting the region.
While poultry litter resulted in improved yields, the delivered cost of poultry based soil amendments used in this study were prohibitive for most limited resource, small scale farmers. Accessiblity of aquaculture wastes to limited resource farmers is very limited, and transportation of the raw material is difficult.
Utilization of composted gin trash as a soil amendments by the Mississippi Delta’s limited resource vegetable farmers could lead to increased adoption of sustainable soil management practices that improves long term soil productivity. Improvements in soil health would be expected to increase profitability of these small scale farms to the benefit of the farmers and the region. Increases in productive capacity of land to the point that vegetable production from this group of farmers becomes competitive locally (and with other regions) can increase economic activity in a rural community to levels far exceeding the activity produced by increases in productivity on land devoted strictly to traditional agronomic row crops. While cost of production up to the point of harvest may be similar for many vegetable crops compared to agronomic row crops, harvest and post harvest handling labor and value added packaging inputs for fresh vegetable production are significantly higher for the producer in terms of $/acre than the agronomic crops. Also, application of appropriate soil amendments is more economically favorable for a small scale farmer producing a relatively high value crop than for a farmer with much larger acreage producing a lower value agronomic crop.
Areas needing additional study
(1) Clinton, Bill [Commission Chairman]. 1990. Delta Initiative: Realizing the dream…fufilling the potential. Report of Lower Mississippi Development Commision. Agri-Center, Memphis, TN.
(2) Gunderson, Ralph O. and Enrique Ospina. 1987. Agricultural and socioeconomic perspective of Arkansas. Winrock International Institute for Agricultural Development, Morrilton, Arkansas.
(3) Nash, Bob. 1991. Pass the peas, please. Rural Community Development Update Vol. 4, No. 6. Arkansas Industrial Development Commission. Little Rock, AR.
(4) Gunderson, Ralph O. and Enrique Ospina. 1986. The structure of Arkansas agriculture: A taxonomy. Winrock International Institute for Agricultural Development, Morrilton, Arkansas.
(5) Tharp, C. and W.P. Miller. 1994. Poultry litter practices of Arkansas Poultry Producers. Staff Paper, Department of Agricultural Economics and Rural Sociology, University of Arkansas, Fayetteville, AR.
(6) Arkansas agricultural statistics. 1993. Ark. Agri. Exp. Sta. Rep. 320. Fayetteville, Ark.
(7) Miller, D. M., and B. R. Wells. 1991. Identifying the causes of poor rice growth on precision-graded soils. Arkansas Rice Research Studies. 1991. Research Series 422(19991):108-114.
(8) Teague, T. G. and G. S. Lee. 1993. Broccoli response to fertilization with micronutrients. Arkansas Soil Fertility Studies, University of Arkansas Research Series 398:32-36. Fayetteville.
(9) Lee, G. S. and T. G. Teague. 1993. Micronutrient fertilization of broccoli in a sustainable system. Arkansas Soil Fertility Studies, University of Arkansas Research Series 398:37-40. Fayetteville.
(10) Buckley, Blair. 1993. Cotton gin trash compost as a media component for production of vegetable transplants. Arkansas State Horticultural Society, 1993. Ft. Smith, AR.