Using Crop Diversity in No-till and Organic Systems to Reduce Inputs and Increase Profits and Sustainability in the Northern Plains
A major deterrent to adopting no-till or organic crop production in the Northern Great Plains is concern about weed management problems during the transition from conventional systems and moisture conservation associated with crops as alternatives to fallow. A large-scale experiment was established at Moore, MT to compare reduced-input no-till and organic systems to conventional small grain production systems (Table 1). A similar systems experiment was established at Bozeman, MT (Table 2). The goal was to evaluate farm profitability and sustainability within a system that increases crop diversity and reduces off-farm inputs. Thus we have been quantifying production, profitability, and weed population dynamics among the production systems in the experiment at Moore and on farms in north central Montana.
1. Understand weed dynamics to predict species shifts within organic and no-till production systems.
2. Determine crop performance and water-use efficiency within organic and no-till systems.
3. Quantify input levels and costs for organic and no-till systems, including both purchased and operator-supplied inputs.
4. Quantify profitability (net return) of organic and no-till systems.
5. Educate producers on potential benefits of organic and no-till systems through dissemination of research results.
We have made excellent progress and have some exciting results that are beginning to be summarized in a series of journal articles. Andrew Hulting completed a Ph.D. dissertation associated with the first two objectives of this project and has two papers that are nearly ready to be submitted. We have followed that work with an extension of the first objective. Upon observing differences in the diversity of the weed communities from conventional to organic systems, but surprising little difference in crop yields between these systems we have started to look at the mechanisms that allow high weed species diversity and low crop impact. We have had a series of graduate students participating in the expanded Objective 1. Objective 2, primarily conducted by Dr. Miller and his students have completed data gathering and analysis, but will require some more time to complete the papers associated with that work. Objective 3, economic analysis, is still in progress under the direction of Dr. Buschena and his students, but is targeted for completion by September 2005. Drs. Maxwell, Buschena and Miller as well as several graduate students have presented results to growers interested in transitioning to organic production at several meetings and field tours. In addition, we have and will continue to present our results at a wide range of grower meetings from January to May 2005.
Results from Hulting’s research were presented at the Ecological Society of America annual meeting in Portland, OR in August 2004. Other results from experiments were presented by Drs. Maxwell and Miller at a field tour at the Post Agronomy Farm near Bozeman, MT.
Maxwell, B., A. Hulting, C. Repath, and L. Rew. Linking spatial and temporal dynamics to estimate invasiveness of non-indigenous plant populations. The Ecological Society of America Conference August 1-6, 2004 Portland, OR. p88.
Economic assessments by P.I. David Buschena:
There are two parallel efforts to evaluate the economic returns to organic and no-till crop rotations. The first method evaluates controlled plot studies on University carried out by researchers involved in this project. The second utilizes surveys of no-till and organic producers in central Montana to ascertain their rotational experience concurrently with the plot studies.
Method 1. Data from Miller’s experimental plots on the Post Farm in Bozeman, MT have been evaluated for the period 2000-2003. Detailed data for input use, tillage practices, yields, and crop quality have been used to assess the relative net returns of three no-till rotations, one organic rotation, and a continuous crop-conventionally tilled wheat rotation. Returns for the organic rotation were evaluated under both representative organic premiums and under no premiums. The no-till rotations included a spring-wheat based rotation, a winter wheat-based rotation, and a diverse rotation.
The average per acre net returns (abstracting from returns to labor, land, management, and machinery ownership) from all five rotations considered for the Post Farm site are illustrated in Figure 1. Returns from the organic rotation with premiums are consistently higher than those for the competing rotations, largely due to the reduced herbicide and fertilizer inputs. The importance of the organic premiums is clearly shown by the differences in the net returns for the premiums case vs. the no premiums case in the organic rotations. The spring wheat-based and the diverse no-till rotations provide the highest average returns of the remaining rotations.
Additional data from experimental plots in Moore, MT are expected to be available early in 2004. The net returns from various crop rotations using data will be evaluated in a manner comparable to the analysis used for the Post Farm data.
The plot data discussed above provide some very useful comparisons of returns from various rotations in a scientifically controlled setting. With these relatively new rotations, however, come numerous questions regarding how effectively an experimental study matches the practices and experiences of commercial producers. To address these questions, a parallel effort gathered survey data from a number of long-time organic and no-till producers in Central Montana. These producers’ yields and production practices were elicited for years 1999-2003. Of particular interest for these survey interviews were the responses by these producers to the extensive and severe drought conditions experienced during crop years 2001, 2002, and to some extent, 2003. These interviews were completed in December, 2003, with some follow-ups that were carried out early in 2004.
The crop input and yield data will be evaluated in 2005. The qualitative data on responses to drought conditions revealed that both no-till and organic producers generally reduced their cropped acreage (utilized more fallow). No-till producers experienced less wind erosion than did organic producers and neighboring farms using conventional tillage. This wind erosion varied considerably across the region, with some areas experiencing very little erosion and others experiencing considerable erosion.
Impacts and Contributions/Outcomes
The predominant small grain cropping system of the Northern Great Plains has utilized a crop fallow rotation under an assumption of moisture conservation. More sustainable systems may include the use of more diversified and organic systems that reduce inputs. The transition to more sustainable systems represents a challenging step for producers and requires prediction of how crops and weeds will perform. Weed population dynamics in response to more sustainable agricultural systems on the Northern Great Plains is critical to implementation of these systems. This study has already begun to show significant differences in weed behavior under different crop management and promises to allow prediction of weed responses to a wide range of management approaches from organic to high-input conventional. To our knowledge, there are no other studies that have simultaneously measured spatial and temporal dynamics of weed populations. Thus, there has been limited ability to predict the economic thresholds or distributions that determine optimum weed management under most conditions.