Rodale Research Center
Report Assesses Soil Improving Legumes
A recently-published legumes assessment report provides a summary and a brief description of key programs worldwide involved in research on the use of legumes for soil improvement. An international directory of personnel and organizations that provide support in terms of basic research or germplasm resources is also included in An Assessment of Current Activities on the Use of Legumes for Soil Improvement in World Cropping Systems. Each program synopsis includes the name of the institution, and in most cases a contact person, a brief description of the activities, information on relevant site characteristics, and a list of all leguminous species being used on the site. The projects are listed geographically, and based on the environment and cropping systems. The majority of research is focusing on legume screening for use in particular cropping systems or environmental conditions, and basic laboratory experiments on N-fixation.
This assessment on the current status of legume research, a publication of the Rodale Research Center funded by a grant from USAID, is based on site visits, personal communication and a review of the literature. It provides an overview of current research projects and their commonalities, the larger geographical systems they fit into, the potential of the research for technological transfer from site to site, and recommendations for future work.
Several widely shared problems are identified among screening trials of legumes for soil improvement, including the inability to obtain appropriate germplasm, and the lack of information to decide which germplasm may be appropriate.
There is a scarcity of information on the long-term effects of using leguminous green manures. The assessment calls for improved methodology for defining and quantifying soil improvement, to be more inclusive of formerly ignored biological factors in the soil.
The most successful programs included on-farm research as an integral component of the early or middle phases of system development, but the majority of all projects were experiencing success of some sort toward their objective. In most cases the research was closely linked to existing cropping systems, and the immediate appeal was the benefit from the legume to the following crop, mostly in terms of N, but occassionally weed control or soil stabilization was a major objective. Few projects were found to include indigenous legumes.
Communication between researchers and farmers was found to be insufficient, due to a lack of extension and education programs. Concerning the potential for the transfer of technology, the technologies that are the least site-specific will also be the most transferable. One example is pre-rice green manure which is relatively homogenous from region to region compared to other cropping systems. The assessment determines that the least transferable information will be how the legume fits into a particular farming system, as regional factors may vary widely.
This assessment recommends that future work focus on areas not only with the greatest need, but on areas with the greatest chance of success for transfering the technology to the farm. Successes in these areas will facilitate work in areas with greater constraints to the use of legumes for soil improvement.
Recommendations For Future Work On Soil-Improving Legumes
Ten specific recommendations are made for future work on soil-improving legumes:
1. Developing a methodology for adequately describing and quantifying changes in the soil resulting from soil-improving legumes.
2. Continued collection and evaluation of legume germplasm, and improved systems of providing this information and seed samples to those who are conducting screening trials.
3. Training in methodology of screening legumes for soil improvement for those in the process of identifying legumes to fit particular cropping systems.
4. Improved communication among those involved in the research and promotion of the use of legumes for soil improvement.
5. Increased effort in documenting indigenous systems that effectively use legumes for soil improvements.
6. More study of the socio-economic factors that are likely to affect farmer acceptance of new systems, including legumes for soil improvement.
7. Greater farmer participation in research trials with legumes. Research will be more useful if farmer participation is encouraged at early stages.
8. Increase in training and extension programs aimed at farmers; increased transfer of information from research programs into training materials.
9. Education of government officials and policy makers as to the potential benefits of using soil-improving legumes, and the need for government support in setting research and extension priorities.
10. Involvement of the private sector in making legume seed and inoculants available locally.
A legume data information bank is also being developed at the Rodale Research Center.
An Assessment of Current Activities on the Use of Legumes for Soil Improvement In World Cropping Systems, 1990, Marianne Sarrantonio.
For a copy of the Assessment report write to:
International Ag-Sieve, Rodale Research Center
611 Siegfriedale Road, Kutztown, PA 19530. $3.00 /copy.