Crop Performance in Farming Systems Trial


In its 35th year of existence, the Farming Systems Trial (FST) at Rodale Institute continues to demonstrate, through scientific research data, that organic farming is superior to conventional systems with regard to building, maintaining and replenishing the health of the soil. This is the key to regenerative agriculture as it provides the foundation for its present and future growth.

FST is America’s longest running, side-by-side comparison of organic and chemical agriculture. It was established in 1981 to study what happens to soil health and agricultural productivity when transitioning from conventional to organic agriculture. While organic agriculture practices result in higher soil organic matter (SOM) contents and, in turn, higher nutrient- and water-supplying potential to crops, transition to organic farming typically involves a lag time of several years in which yields can suffer and input demands increase as rebuilding soil microbial communities compete with crops for nitrogen and other available nutrients (Simmons and Coleman, 2008). This was evident in the initial decline in yields at the FST during the first five years of transition. Beyond this period, the organic system rebounded and consistently produced corn and soybean yields that matched or surpassed the conventional system. Organic systems perform especially well during years of drought.  During a 5-year period between 1988 and 1998 when total rainfall from April to August was less than 14 inches (compared to 20 inches in normal years), average organic corn yields were 31% greater than conventional system. This performance can be attributed to greater SOM in organic systems. The pictures below, taken in September 2015 after a long dry spell, illustrates how corn can perform in the organic system compared to the conventional.

Figure 1: From left to right; corn in no-till organic legume system and soybean and corn in no-till conventional system. Compared to the organic corn, the conventional corn are showing symptoms of nutrient deficiency (see close up Figures 2 and 3 below). Photos taken on 9/4/2015.

Figure 1: From left to right; corn in no-till organic legume system and soybean and corn in no-till conventional system. Compared to the organic corn, the conventional corn are showing symptoms of nutrient deficiency (see close up Figures 2 and 3 below). Photos taken on 9/4/2015.

Figure 2 (left) and 3(right): A close-up of conventional corn from Figure 1 above with leaves showing signs of phosphorus deficiency

Figure 2 (left) and 3(right): A close-up of conventional corn from Figure 1 above with leaves showing signs of phosphorus deficiency.

Figure 4: Plot 822; corn in tilled organic legume system – taken on 9/15/2015

Figure 4: Plot 822; corn in tilled organic legume system – taken on 9/15/2015

Figure 4: Plot 832; corn in tilled conventional system – taken on 9/15/2015

Figure 4: Plot 832; corn in tilled conventional system – taken on 9/15/2015

The above pictures illustrate the importance of healthy soil in growing healthy plants. Healthy soil can be defined as soil that allows plants to grow to their maximum productivity without disease, fertility or pest problems that limit production, and without a need for unusual supplements or support. Analysis of FST data over a 35 year period has established that soil health in the organic system has continued to increase over time while the conventional system has remained essentially unchanged (Figure 5). Soil organic matter in tilled manure organic systems increased from 3.3% in 1981 to about 4.5% in 2013 representing a net increase of 27% (Figure 5). In the conventional system, SOM changed from 3.3% to 3.6% – a net increase of only 8%. Other farms within Rodale Institute have reported SOM concentration of up to 6% (Moyer, Jeff; Duffield Ross; Personal Communication). Soil organic matter is very important in crop productivity as it increases both nutrient and water use efficiency. Studies have shown that SOM can hold up to 20 times its weight in water (Johnson et al., 2005). Hudson (1994) showed that “for each 1% increase in SOM, the available water holding capacity in the soil increased by 3.7%”.

Figure 2: Changes in soil organic matter between tilled organic and conventional systems from 1981 and 2013

Figure 2: Changes in soil organic matter between tilled organic and conventional systems from 1981 and 2013

Addition of organic matter to the soil increases its water holding capacity mainly because organic matter increases soil macroaggregates, hence the number of micropores and macropores in the soil (Bot and Benites, 2005). Organic matter does this either by “gluing” soil particles together or creating favorable living conditions for soil microorganisms, which in turn can “glue” soil particles together through production of various organic compounds such as glomalin or by the action of fungal hyphae (Sylvia et al., 2005).

Analysis of 35 years of data from the FST also found that the volume of water percolating through the soil was 15-20% greater in the organic systems than the conventional system. This water not only helps to recharge ground water but is also available for crop use, especially in periods of water stress. Greater corn and soybean yields in organic systems compared to conventional system during drought stress periods can be attributed to greater soil water content in the organic systems, coupled with greater season-long availability of essential plant nutrients.

This material is based on work supported by the Wyncote Foundation.

References
Bot, A., and J. Benites. 2005. The importance of soil organic matter key to drought-resistant soil and sustained crop production. Food and Agriculture Organization, Rome, Italy.

Hudson, B. D. 1994. Soil organic matter and available water capacity. Journal of Soil and Water Conservation 49, 189–194.

Johnson, J. M.-F., D. C. Reicosky, R. R. Allmaras, T. J. Sauer, R. T. Venterea, and C. J. Dell. 2005. Greenhouse gas contributions and mitigation potential of agriculture in the central USA. Soil and Tillage Research, 73-94.

Simmons, B. L., and D. C. Coleman. 2008. Microbial community response to transition from conventional to conservation tillage in cotton fields. Applied Soil Ecology 40, 518-528.

Sylvia, D. M., J. F. Fuhrmann, P. G. Hartel, and D. A. Zuberer. 2005. Principles and Applications of Soil Microbiology, 2nd Ed. Prentice Hall

16 Responses to “Crop Performance in Farming Systems Trial”

  1. Jim Sanderson

    Could I schedule a follow up call to discuss your findings in more detail. Specifically, I am hoping to get up to speed on whether these techniques are gaining traction in drought regions, either in California or elsewhere? A few questions I would ask:
    Is improved SOM strong enough to actually result in a large enough reduction in water needed for harvesting for most common fruits and vegetables to become a credible solution? What about nut trees, vineyards? How would a conversion to FST impact long-term harvest businesses. For wine / almonds, could a X-year reduction in yield be too destructive to sales & profits to be a feasible option or would the reduction in water be the offset to make this option credible?

    Clearly I have a lot of questions, but not a lot of answers. I hope we can talk soon. Best regards,

    Jim Sanderson
    Managing Director
    Arthur Wood
    http://www.arthurwood.com
    617 994 0404

    Reply
  2. Sherman Reed

    Please send a yield comparison chart of organic / conventional corn of each trial year.

    How do you side dress corn / top dress wheat with nitrogen with out using synthetic fertilizers? Explain your organic methods for corn and wheat.

    Please consider my requests.

    Regards,

    Sherman

    Reply
  3. Bill Powers

    While these results are encouraging, SOM is not the only indication of healthy soil. Also, and at least equally important, are the microbial populations. It seem that manure sites were tilled. Everyone I am aware of recommends against such practices for the sake of that microbial communities. It would be interesting, too, to know in more detail how these plots were farmed. Thank you for your important work.

    Reply
  4. Bill Powers

    I might add one further comment. It is becoming increasingly difficult to obtain manure in my area. One of the reasons is the increase of manure regulated operations (e.g., CAFOs). Such operations are bound by regulation to distribute their manure only in a manner previously established. Additionally, there is a decrease in the number of livestock operations. As such, many of us to do not have access to manure and must resort to other methods. Cover crops are available to cropping operations. But what ought pasture/haying operations do? It is not clear to me that having livestock is the answer.

    Thanks,

    Reply
  5. Katrina Dunnings

    It would be interesting to see how much could be achieved if animal farmers and organic farmers could cooperate. Animals eating left over crops or stubble and manure (which would then be purer) being given to the organic farmer. Have any studies been done to see how much land per animals would be required for this to be feasable. Naturally the government regulators would have to cooperate and support this system which would probably be the most difficult part!!

    Reply
  6. Rodney Graham Oxbow Organic Farm

    Figure 4: Plot422 states tilled organic. I always associated Rodale w/the crimp and plant into a cover crop. What form of tillage are you using. I have been cert. organic 19 years and have attended Rodale field days. Continue the good work and if you are interested in field trials in New York please consider me.

    Sincerely,

    Rodney

    Reply
    • Rodale Institute

      Thank you for contacting Rodale Institute! We’re happy to hear about your successful 19 years as an organic farmer and hope to see again this year at field day! Please contact info@rodaleinstitute.org to be directed to a staff member who can answer your question.

      Reply
  7. P. Waidyanatha

    Please let me have the following information for the two systems, conventional and organic(no till)
    1. Seasonal quantities of organic matter and chemical fertilizer applied /ha for the two systems
    2. the nutrient composition of organic matter
    3. the comparative crop yields for the last 10 years
    4. the comparative costs of production for the same period
    Thank you
    Parakrama Waidyanatha

    Reply
  8. Larry Powell

    Dear Rodale,

    Thank you for all your years of research. To let you know where I’m coming from, I grew certified organic veggies on my market gardens for years in MB. I am a staunch supporter of the organic way.

    So please accept my next Q in the spirit in which it is asked.

    Since chemical methods still saw an INCREASE IN SOM, however slight, would it be technically correct to say that prolonged conventional (chemical) methods actually DEPLETE the soil?

    The reasons for growing organically are clear in the results of your study.

    So the only reason I ask this is, I am a journalist who writes about organic vs. conventional methods and try to be as careful/objective as possible in the terminology I use.

    Thanks for your attention.

    Reply
  9. Mike Verellen

    We have been very successful at growing high yeilding organic corn (200+) bushels in 100lb per ac cereal rye crimped. We used granular (ground soybeans) and liquid fish, molasses, micros ,mikrozial fungi,and azotabactor. Have u tried similar applications with + results. Also the organic matter jumped almost a percent over season and nutrient availability doubled. The sugars were educating off the roots almost all the time once the corn started to Tassie. My organic matter started between 3.5 and4 in that field.

    Reply

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