Sharing our advances: Evaluating the use of plastic mulch and trickle irrigation systems in Asian vegetable production

Final Report for ONE03-001

Project Type: Partnership
Funds awarded in 2003: $9,789.00
Projected End Date: 12/31/2004
Region: Northeast
State: Massachusetts
Project Leader:
Amy Carrington
New Entry Sustainable Farming Project
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Project Information


Recent immigrants with agricultural backgrounds offer great promise to become part of the next generation of farmers. The NESFP helps create a new generation of American farmers by combining the skills and resources of established farmers, farm organizations and academic institutions in order to meet the range of needs related to farming by immigrant populations.

NESFP farmer participants have practiced agriculture in their native counties of Cambodia, Laos, and Thailand. The NESFP programs build on participants’ farming skills and helps them to adapt these skills in order to farm in New England. The NESFP training programs encourage the use of sustainable alternatives to traditional practices by teaching farmers strategies to address water usage, weed management, and pest management.

The goal of this project and the on-farm demonstration was to teach immigrant farmers how to use trickle/mulch production system. In addition, we evaluated the best ways of introducing new agricultural technologies to immigrant farmers. Through this project the NESFP has also continued to evaluate how to bridge the gap between immigrant farmers and mainstream agricultural institutions.


The NESFP rents land on small training farm sites to immigrant farmers. Through this SARE grant the NESFP maintained a demonstration plot at one of the training farm sites during the 2004 growing season where trickle irrigation and mulches were used. In addition, participating farmers had the resources to introduce the use of trickle irrigation and mulches on their own plots/farms during the 2003 and 2004 growing seasons. Staff and farmers noted the effects of different irrigation methods in order to evaluate their effectiveness in Asian crop production.

The goal of teaching new, more sustainable, farming methods was achieved because the trickle/mulch production system demonstrated the potential for earlier harvests, increased seasonal production, reduced weed pressures, and water conservation, thereby promoting the use of this production system the in future.

Project Objectives:

1. Maintain the viability of agriculture in the region by assisting immigrant populations to successfully enter farming in Massachusetts.

2. Build economic self-reliance and food security among immigrant populations through production of locally grown foods by members of these communities.

3. Promote sustainable agricultural practices regarding water usage, weed management, pest management, and season extension techniques.

4. Assist immigrant farmers to remain economically viable through on farm demonstrations and implementation of new production methods and new technologies.

5. Determine best management practices for Asian crops by gathering yield data for different production methods.


Materials and methods:

The trickle irrigation and plastic mulch production methods considered in this grant have many benefits. Drip tape irrigation, called trickle irrigation, uses water efficiently – practically no water is lost to runoff or deep percolation, especially when used in combination with the black plastic mulching. It decreases water contact with leaves, stems and fruit, creating less favorable conditions for the onset of diseases. Trickle irrigation works well on fields with odd shapes or uneven topography, improving irrigation uniformity. The use of plastic “mulch,” especially in combination with drip irrigation, has many benefits. Plastic mulch increases the soil temperature while reducing evaporation. It reduces soil compaction; the soil remains loose, friable and well aerated so the roots have access to an abundant supply of oxygen. It reduces fertilizer leaching and reduces the drowning of crops because water is shed from the row area. With plastic mulching, there are reduced weed problems and an increased growth rate. A high level of CO2 builds up under the plastic and is released only through the holes in which the plants are growing, creating a chimney effect, abundant with CO2.

The plastic mulch and drip tape irrigation system were used to demonstrate the potential to decrease labor inputs while increasing crop production. Benefits of this system include increased yields, earlier harvests, reduced weed and disease pressure, and water conservation by placing water where it is needed. This demonstration will help promote sustainable alternatives to traditional practices, teaching farmers sustainable approaches regarding water usage, weed management, pest management and climate extension techniques. We also hoped to encourage farmers to consider factors such as labor hours and yield in order to find that one production method is more cost-efficient than another.

During the 2004 growing season the NESFP staff established a demonstration plot in which we grew bitter melon, sun jewel melon, narrow leaf and wide leaf water spinach, mustard greens, okra, cayenne peppers, Hungarian Hot Wax peppers, four varieties of eggplant (Kermit, Louisiana Long Green, Snowy and Orient Express), and three varieties of tomatoes (Big Beef, Sun Gold and Juliet) under varied conditions. All of the plants were irrigated using drip tape irrigation and were planted in plastic mulch. In addition, two rows of all of the aforementioned plants were irrigated using drip tape irrigation and were not mulched or were mulched partly with hay.

A map of the demonstration plot was created, with exact measurements for each row, and number of plants planted on each section of each row. This map was constantly updated when new seeds were planted or if some plants died or were eaten. A detailed log of the number of hours spent working on the plot was kept as well. The tasks recorded included bed preparation and mulching, weeding, watering, transplanting, harvesting, and other maintenance chores such as trellising the tomatoes. A record was kept of the weight of vegetables harvested from each section of the plot. It was especially important to note any difference in weight of the mulched and non-mulched yields as well as comparing the yields of the demonstration plot with the yields of the other farmers’ yields. Notes were also taken throughout the season on insect or animal problems, unusual weather patterns, and other factors that may influence crop yields.
On our demonstration plot, we used black plastic mulching that was laid down at the same time as the drip tape, with a tractor. Six rows, each approximately five feet wide, were covered with the black plastic, while two rows had only drip tape. Each row of plastic had two rows of crops planted in them, spaced about a foot and a half apart. The exceptions were the Sun Jewel Melons, which were planted in a single row, and the water spinach and mustard greens, which were planted in various arrangements.

The black plastic mulch was an extremely effective method of weed control; therefore, labor inputs for weeding were minimal in this production system. NESFP staff did not have the time to devote to the demonstration plot that most of our farmers do. However, due to the effectiveness of the mulch, the limited number of hours did not have a detrimental effect on yields. A total of 30 hours of labor was devoted to weed control over the entire growing season. The total number of hours is so low because we spread hay mulching over the soil around the crops that were planted in the rows without the black plastic mulching, to prevent weed growth. The hay was also spread between the rows to minimize weed pressure there. The thirty hours reflects time spent gathering and spreading the hay, managing weeds that grew up in the holes in the plastic where the plants were growing, and weeding plants that managed to grow through the layer of hay.

Early in the season we had an animal problem (possibly rabbit and/or deer) and lost several Kermit eggplants, all of the water spinach, and some okra). Some of the water spinach grew back, but was then eaten again and died. Most of the okra recovered, but a few plants from the mulched section were lost. We had enough extra Kermit eggplant transplants that we were able to replace the ones that were eaten. However, the most damage was done at the south end of the plot in the plastic-mulched row of Kermit eggplants, and the transplants that were planted over two weeks later never caught up.

Another problem with the south end of the demonstration plot was that the trees cast a shadow over a portion of the field. As a result, some of the crops did not receive direct sunlight until after noon each day. The crops affected were the Kermit eggplant and the Okra planted in the plastic mulch. The last four to six plants of the Okra and the last six to eight plants of the Kermit eggplants were the most affected; these plants were noticeably smaller than the others, and much less productive. The affected Kermit eggplants did not produce more than two fruit the entire season, compared to an average of five fruit per plant for the season in the other Kermit eggplants.

Research results and discussion:

Introducing new production methods and technologies to our farmers is one of the best ways to maintain economic and environmental viability on their small farms. Our intentions for this project were to expose farmers to the use of black plastic mulching and drip irrigation for a variety of crops as a way to decrease inputs while increasing production.

In spring of 2003 the NESFP upgraded irrigation systems at training farm sites and installed main lines for trickle irrigation systems. We had several on farm trainings on the use of trickle irrigation. In 2004 immigrant farmers operated the irrigation systems at training farm sites.
NESFP and U Mass staff visited the farm sites through out the 2003 & 2004 growing seasons to scout for pests and provide information on pest management options.

In 2003 the data gathered regarding the use of black plastic mulching and drip irrigation was exclusively qualitative. The immigrant farmers who participated in this project do not keep farm records; therefore maintaining quantitative measurements of crop production was difficult. The NESFP staff responded to this situation by providing all farmers with the New England Farm Account Book, including production and marketing record worksheets that were designed specifically for low literacy populations, and by discussing the many ways that farmers could benefit from good record keeping. During farm visits we experienced many situations where farmers would have benefited from looking at records from previous years. Discussing these examples at farmer meetings and having an ongoing discussion of farm records was one of the priorities throughout the growing season.

Throughout the 2004 season, growth rates and crop yields were recorded for the demonstration plot (see materials and methods section). This allowed us to compare the effects of the plastic mulch, hay mulch, and no mulch/ bare soil. Some of the plants in plastic mulch grew faster and taller overall, such as the bitter melon, okra, Juliet tomatoes, Sun Gold tomatoes, and Kermit Eggplant. The Mustard Greens grew at relatively the same pace in both the mulch and open soil, as did the cayenne peppers. The cayenne peppers in the plastic mulch experienced earlier fruiting, which resulted in a substantial increase in overall yield results per plant. The Big Beef tomatoes planted in the plastic mulch grew taller and faster than those not in the mulch. Fruiting was noticed earlier on all of the mulched tomato plants, on the bitter melon, as well as the Kermit eggplant.

As previously mentioned, weights were recorded during harvesting and the results were given in both pounds per plant and pounds per planted area. The Kermit eggplant and cayenne peppers produced significantly more in the rows mulched with plastic than those in the hay mulch or no mulch. The cayenne peppers yielded .94 lbs/ft2 (2.1 lbs/plant) in the mulched area, but only .27 lbs/ft2 (.69 lb/plant) in the hay-mulched area. For all three varieties of tomatoes, the average pound per plant and per planted area was lower in the rows mulched with plastic. The Sun Gold tomatoes produced 1.5 lbs/ft2 (3.69 lbs/plant) in the mulched rows, and 1.8 lbs/ft2 (4.53 lbs/plant) in the hay-mulched rows. This is because the entire demonstration plot was harvested just once each week, and only the fruit that could be sold was harvested and weighed. This meant that many tomatoes were over ripe in the rows with plastic mulch. This fruit was left in the field and was not counted in yield data. Bitter Melon and Okra also had slightly greater weight ratios in the areas not mulched with plastic; they also had many over ripe fruit in the rows with plastic mulch. The rows planted with mustard greens were comparable regardless of the type of mulching.

Research conclusions:

In 2003 twelve immigrant farmers/families started agricultural enterprises, producing ethnic herbs and vegetables on ten acres of farmland. Through on farm training, farmers meetings, and site visits with the Khmer-speaking intern (that was hired through the SARE grant), these farmers shared their knowledge and experiences related to starting a successful agricultural enterprise over a two-year period.

Demonstrating the appropriate use of a trickle/drip irrigation system has been the main challenges of this SARE grant project. As many farmers are either skeptical to try new methods or cannot understand how the new technique works without being able to see it first-hand, on-farm demonstration allows farmers to see both the benefits and drawbacks of new systems.

In 2003, five farmers used trickle irrigation and plastic mulch for the first time. In 2004, one of these farmers decided not to use plastic mulch again due to the amount of trash generated and the extra time needed for fall clean up. The four remaining farmers and two new farmers decided to use trickle irrigation and plastic mulch.

In 2003, farmers who used transplants purchased from a contractor were able to see earlier and increased crop yields compared to transplants produced in their homes. Due to the added benefits of purchasing transplants many farmers contracted for transplants in the 2004 season.
In April of 2003, the NESFP staff assisted farmers with the set up and management of a hoop house. In 2004 the responsibility for the hoop house was turned over to the farmers’ committee.

In April of 2004 the farmers had enough information and had gained the skills necessary to cover the hoop house on their own; it was used for transplant production as well as season extension in the fall. This new arrangement demonstrates farmers’ willingness to use new low cost technology once it has been proven to work.
In spring of 2003 one farmer contracted with a local farmer to lay .5 acre of drip tape and mulch that were purchased as part of this grant; the NESFP assisted four farmers with installing black plastic mulch for use in crop production. In spring of 2004 two farmers independently contracted with a local farmer to set up trickle irrigation and plastic mulch; the NESFP assisted two other farmers to set up a contract with a farmer to set up drip tape and plastic mulch. In addition, two farmers who do not have access to trickle irrigation laid plastic mulch by hand.

At the start of the 2003 growing season many of the farmers participating in this project believed that plastic mulch could only be used with crops that have an upright growth form (tomatoes, peppers, eggplants, etc.) and were reluctant to use plastic mulch with cucurbits/ vine crops. In 2003, one participant decided to try my recommendation of using plastic mulch and drip tape for his Asian cucumbers. This grower had success with his trail; he had significantly reduced the weed pressures and decreased the amount of time he spent on weeding and irrigating his drops. Other farmers visited his plot throughout the growing season and used this technique in 2004. In 2004 all of the farmers who used plastic mulch also had cucurbit crops under mulch. In addition, farmers tried the trickle/mulch system on other Asian crops such as lemon grass and Thai basil and discovered the potential for earlier and increased yields in these crops.

Other production and harvest techniques displayed by the staff and the demonstration plot were implemented by farmers; for example, one of the farmers began using green pint containers to sell his cherry tomatoes at the farmers’ market instead of selling them loose, as he had previously done.

Impact on non-agricultural audiences such as extension, private groups, general public:
The initial success of NESFP and U Mass pests scouting visits has resulted in a long-term plan to develop low literacy pest management training materials such as posters and pictorial fact sheets. In addition the NESFP developed a contract for U Mass to hire a part time staff member to assist NESFP participants in 2004. This staff person was able to begin introducing the low literacy pest management materials to NESFP farmers.

In 2003 and 2004 NESFP participants completed the FSA crop acreage reports with the help of the Khmer speaking intern. This initial step is a way to introduce immigrant farmers to USDA and other agricultural service providers.

In 2004 Casey Family Services, a community organization serving low-income residents, visited the farm sites to help promote cultural awareness. The visitors were able to take home crops from the demonstration plot.

All of the farmers who participated in the training farm site program in 2003 and 2004 sold their produce to ethnic stores located in their community. One farmer participated in the Lowell Farmers’ Market in 2003 and 2004 where he was able to provide ethnically appropriate foods for Farmers’ Market coupon recipients who preferred ethnic vegetables. In 2003 three farmers participated in “flea markets.” In 2004 this number increased to four. These open air marketing venues allow bargaining and bartering sales similar to markets in developing countries, therefore, farmers attending flea markets have cashed in on a market that has wide spread popularity among immigrant communities. With the assistance of NESFP’s Marketing Coordinator, several farmers attended urban farmer’s markets in 2003 and 2004, thus expanding their marketing outlets and helping to ensure the long-term economic viability of their farming practices.

Participation Summary

Education & Outreach Activities and Participation Summary

Participation Summary:

Education/outreach description:

Over the course of the 2004 growing season we had several educational tours of the demonstration plot and the farmers’ fields including an NESFP workshop, a CRAFT program tour, a cultural field day, and Heifer Project International staff tour.

The tours focused on production methods and how to use trickle irrigation and black plastic mulch. In addition, we have used the photo documentation taken throughout the season to share the success of our study with farmers and agricultural researchers across the country.

Project Outcomes

Project outcomes:

The inputs for a trickle irrigation system with plastic mulch have upfront costs because it is necessary to purchase materials and lay out the plastic in the beginning of the season. The upfront costs for a trickle/mulch production system will be offset by the savings in labor (for irrigation and weeding later in the season) and the increased sales resulting from earlier and larger yields.

Immigrant farmers have traditionally planted in bare soil and continued to cultivate and irrigate by hand throughout the season. This method has no upfront costs associated with it and allows labor costs to be spread out over the whole season. For limited resources farmers who are not hiring outside labor, traditional planting methods may sometimes be the only affordable option.

Teaching limited resources farmers to consider the financial value of their time is difficult. These farmers can more easily recognize the value of savings in seasonal labor when it allows them to spend more time marketing, because it allows them to put more money in their pocket. In the fall of 2003 the NESFP conducted trainings in business management, including two three-hour sessions focused on record keeping. Additional record keeping demonstrations and enterprise budget trainings will be needed in order for NESFP farmers to maintain financial records that consider the cost of labor in the future.

Assessment of Project Approach and Areas of Further Study:

Areas needing additional study

There is a need for more information regarding which crop varieties benefit the most from the black plastic mulch/drip tape irrigation system. More specifically, immigrant farmers would benefit from studying which ethnic crop varieties are more productive using this system.

The NESFP has found that the best way to convey new technologies to immigrant farmers (most of whom have limited English skills) is through on-farm demonstrations. Creating demonstration plots, while extremely effective for the farmers’ learning, is very costly. Service providers would benefit from finding a more cost-effective method of demonstrating new technologies to farmers.

Attendance at farm tours might be another option, however, these tours or “twighlight meetings” are most often focused on mainstream English speaking farmers and may not be appropriate for immigrant farmers who are just starting up a small scale operation.

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.