A farmer-researcher collaborative effort to design no-till systems appropriate for small-scale organic producers in Alabama and the Deep South

A farmer-researcher collaborative effort to design no-till systems appropriate for small-scale organic producers in Alabama and the Deep South

Summary

The purpose of this project is for researchers and farmers to collaborate in the development of effective strategies for organic no till management in small scale vegetable production systems. Since each farm is unique in its location, climate, soil type, and crops grown, it is unlikely that a growing technique can be developed on a research station that would be applicable to all small scale organic farms. Also, since the farmer is the expert about his/her particular farm ecosystem, he/she would have the best chance at success. In this project, we are using the term “organic” to include farming practices that would be acceptable in certified organic systems, those that do not use chemical inputs such as herbicides, insecticides, or fertilizers. No till farming techniques have been worked out for large scale conventional farmers that rely on the use of herbicides and roller crimpers to kill the cover crop, chemical fertilizers to make nutrients more available to the emerging cash crop, and no till seeders and transplanters for planting the cash crop into the cover crop residue; but appropriate techniques have not been developed for small scale farmers who do not have these chemical inputs and large equipment at their disposal. Consequently, there are significant challenges in adopting the practice to organic systems. For example, timing becomes critical in organic systems. Without the use of herbicides, the cover crop must be terminated by rolling and crimping or mowing at the exact time when it is most vulnerable to being killed, that is, at the soft dough stage of grains, for example, and it must be left to dry down for a couple of weeks before planting the next crop into the residue. Since fast-release chemical fertilizers are not used in organic systems, nitrogen and other nutrients that will be needed for the subsequent cash crop to get a fast start, will have to be supplied by either a legume in the cover crop mix, or compost and/or commercial organic fertilizers. Since herbicides and tillage are not available in the tool box of organic no-till farmers, the system relies on a heavy cover crop residue to keep weeds from emerging in the cash crop during the growing season. Also, most small scale farmers do not have the need for or access to the large, expensive implements that have been designed for NT farming on a large scale. Category 1 tractors, which are appropriate for small scale production may not be large enough to operate some of the NT equipment. So, another aspect of this project is to design equipment suitable for small scale NT farming, and for farmers to invent their own ways to get the job done. For example, one farmer in NC uses his tiller with the tines unengaged to roll and crimp his cover crop.

Objectives/Performance Targets

1. Establish a collaborative effort between farmers and researchers to identify NT production methods that are appropriate for a variety of crops, soil types, and farming scales suitable for organic vegetable production in the Deep South.
2. Evaluate the effectiveness of various high residue cover crops and mixtures for ease of growth, maintenance of soil fertility, and weed control.
3. Evaluate tillage treatments across various soil types, cash crops, and cover crops, with respect to soil fertility, weed control, crop yield, and farmer acceptance.
4. Evaluate the effects of different pre-plant fertilizer rates on crop yield, weed populations, and cover crop growth.
5. Expand NT production practices in AL by assisting small-scale farmers in the state with the implementation of organic NT practices.

Accomplishments/Milestones

A roller crimper was designed by a project participant, Ted Kornecki, engineer for the USDA-ARS Soils Dynamics Lab (NSDL, for a BCS walk behind tractor. This implement is suitable for small scale growers, which include most of the organic farmers in this state. The roller crimper was demonstrated at 2 field days held during 2012 and it was displayed during the Southern Sustainable Agriculture Working Group Conference in Arkansas.

The USDA ARS Soils Dynamics Lab transported no till equipment to two field days: one at Red Root Farm in Banks and the other at Whirlwind Farm in Geraldine. At Red Root Farm a sunflower cover crop was rolled with a roller crimper and millet was direct-seeded into the residue with a no till drill. At Geraldine, a sunn hemp cover crop was terminated with the roller crimper and the no till transplanter was used to plant brassicas into the sunn hemp residue. One of the participants of the second field day reported using a board and chains that he dragged over his rye cover crop to roll it by hand.

Participating farmers tried various types of cover crops and cash crops in their NT systems.

Farmer 1:
Farmer 1 planted a rye cover crop in the fall and in the spring it was rolled with a roller crimper by the NSDL (USDA-ARS National Soils Dynamics Lab). The farmer planted okra into the cover crop residue. He also planted okra into a conventionally tilled area of the field nearby. The okra in the conventionally tilled (CT) area outperformed the NT okra. This farmer has very poor soil that is sandy and low in organic matter. It has not been in production long. The rye cover crop did not produce a lot of biomass. The NT okra appeared stunted and produced a low yield. It had been fertilized with fish emulsion delivered by the drip irrigation system. The farmer was disappointed in the results and stated that he would probably not try NT again.

Farm 2:
Farm 2 experienced success with planting tomatoes and melons into rolled black oat and lupine residue in the summer of 2010, but weeds began to be a problem toward the end of the growing season. The weeds depressed yields and made harvesting more difficult. The farmer decided not to plant a cover crop on most of his land this year, but to use fallow and frequent tillage to manage the weeds. In the NT plot, he had planted Austrian winter pea with the goal of trying again to plant early spring crops, lettuce and string beans into the standing cover crop using a row tiller and vinegar to control weeds.

Farm 3 did not participate this year.

Farm 4: This farmer failed to establish a successful fall cover crop again this year. She was reluctant to till at the beginning in order to establish the cover crop, did not fertilize the cover crop, and as in former years, the cows got into the field and ate the cover crop that did manage to grow through the bermuda grass. She planned to plant sunn hemp for a summer cover crop in 2012 and plant a fall crop into the residue but due to drought and other factors, the sunn hemp cover crop failed and the NT experiment was terminated.

Farm 5:
This farmer planted sunn hemp for a summer cover crop and transplanted brassicas into the residue. The brassicas were very small and they had been grown in soil blocks. The farmer reported that the survival rate was low and that many of the transplants had to be replanted by hand. She had greater success with larger transplants. The farmer liked the sunnhemp as a cover crop and plans to use it again. She reported that it did a good job of suppressing weeds and providing nitrogen. This farmer’s major obstacle to NT is bermuda grass. She has not been able to get it under control. She plans to continue refining her NT system and plans to include mulching with leaves as a supplemental method of weed suppression and soil building.

In summary, organic NT requires close attention to detail, such as planting the cover crop at the proper time, making the effort to ensure a successful cover crop stand (fertilizing, tilling to establish it in the beginning), terminating the cover crop at the optimum time, making sure that the subsequent crop gets off to a good start, and some supplemental weed control. None of these farmers invested the time required for success in vegetable row crops. It still requires some specialized machinery to implement NT: a seed drill is practically a necessity. Broadcasting seed is not consistently success. For large fields a transplanter is also handy. Terminating the cover crop is the easiest part of the process to implement with equipment that most small scale farmers have on hand, such as a front end loader bucket or tiller with tines unengaged.

E.V. Smith Research Station:
The tillage trials at E.V. Smith were implemented in September of 2011. There are 3 tillage treatments: mowed, mowed and incorporated, and rolled. Sunn hemp was planted NT over the whole project area during the summer of 2011 prior to setting up the tillage treatments. Half of the fall tillage plots were planted to rye and half to Siberian kale. The kale was sampled before the end of 2011 and the rye seed was harvested in May of 2012. The experiment was duplicated in 2012, except that the NT drill was adjusted the latter year in order for the small kale seed to make better contact with the soil through the course sunn hemp residue. The results of the first yearis experiments were that there was no difference in rye seed yield between the tillage treatments. However, the kale did not perform well in the NT treatments. The second year (2012) after making adjustments to the NT drill, there was no difference in kale biomass between the tillage treatments. The rye has yet to be harvested.

North Alabama Horticultural Research Station did not participate this year. The supervisor did a presentation of the NT research at Cullman during the Alabama Sustainable Agriculture Conference in Gulf Shores.

Impacts and Contributions/Outcomes

The farmers who participated in this project did not achieve much success with organic no-till. It seems that the organic no-till system requires too much planning and attention to detail. Also, when large areas are left bare, such as the inter-row areas of vegetable row crops, weeds grow through the surface mulch very rapidly. Many of the crops that I saw in NT plots were stunted and appeared to be suffering from low soil nutrient levels. None of the farmers adopted the compost mulch method that we used with such success at the North Alabama Horticultural Research Station. I did not observe a large compost pile at any of the farms. In summary, all most of the farmers in most years did not do well at growing cover crops, and the ones who did grow a good cover crop still reported significant weed management problems.

The research at E.V. Smith Research Station has produced some promising results. This year’s NT kale and rye performed as well as the CT crops. It required some close examination of the first year’s results and making appropriate adjustments to the seeder to compensate for the problem so that the seed could make good contact with the soil. This experiment was planted as a field crop, with the rows close together. There were no aisles left unplanted for weeds to invade. Other factors responsible for the success of the second year could probably be attributed to the ability of sunn hemp to suppress summer weeds and also to the fact that we were growing winter crops which are not subjected to weed competition to the extent that summer crops are. At this point we have one year of research showing that the NT plots did not perform as well as the CT plots and one year, following adaptive management, showing that the NT plots performed as well as the CT. If this year’s techniques and results can be repeated again next year we will be ready to make recommendations to organic farmer about how to be successful with NT using high residue summer cover crops followed by fall planted field crops.

Collaborators: