Research

1) What drives change (specifically, diversification) of activities in the agricultural sector (including crop systems, aquaculture and livestock), and what is diversification's role in sustainability and vulnerability to change?

The Yaqui Basin is undergoing rapid development in terms of changing cropping systems, increasing use of agricultural inputs, increasing livestock operations, and increasing aquaculture development. We are aware that these changes are occurring; however, we have not yet identified all of the major factors driving the changes, the extent of and reasons for variability of the response capability among landowners and other stakeholders, or the potential environmental consequences of these changes.

Answers to these questions will give us insight into decision making and sustainability of agriculture in the Valley, and an increased ability to suggest appropriate trajectories for the future. Importantly, they will also allow us to examine a broader hypothesis concerning one of the most important unanswered questions in sustainability science - what determines the vulnerability of the system to external forces, and how can systems be managed to reduce vulnerability and increase sustainability?

Vulnerability and Response. We hypothesize that the ability of land owners to respond to changes in external forcings (e.g., drought, global market changes) will differ across the region; those who respond successfully by diversifying practices require both social/economic and natural capital. For example, the ability of farmers to respond to drought by changing crops or diversifying into other activities may be equally dependent on the biophysical nature of the land (e.g., salinity and productivity of soils) as on the individual's economic wealth or access to credit or land.

We will use a combination of surveys and remote sensing analysis to determine Valley-wide current and past agricultural practice, and the location and timing of development of livestock operations and aquaculture. Such information will be overlaid on our geographically-based information on soil type and salinity characteristics, land ownership, surface and groundwater characteristics, and other information. Using this information base, we will design surveys to evaluate agricultural change in the context of variation in resources, land ownership, and relative economic wealth. We also will evaluate the effects of these changes in fertilizer and manure use, salinity, and crop types on biogeochemistry, emissions of environmentally-critical gases, solution losses of nutrients from the landscape, and their consequences for water quality and ecosystem health.

Policy Environments. We will also ask questions about the importance of external policies in driving agricultural change. What are the effects of macro and agricultural policy changes in the Yaqui Basin on the type of agriculture that is developed, and what are the consequent effects on incomes and the environment? For example, with the opening of borders, will the livestock economy change? Will the new price ratios in Mexico, and possibly tougher environmental regulations in the US, cause the pork industry to move South? If so, how might environmental quality of the Valley be affected? What is the relative importance of price supports and changes in them on the decision making regarding use of inputs and types of crops?

Research on policies and their effectiveness is critical as we seek to develop decision rules and advocate policy changes that move the Valley toward sustainability. We will also draw lessons - both positive and negative - from the adjoining Hermosillo Valley. The latter region succeeded in moving into demand-driven, high-valued crops, but with devastating consequences for the groundwater system. This portion of the research will require much greater understanding of the institutional requirements that govern sales and contracts, especially for those products destined to niche markets in the US. Meeting with various kinds of brokers in cities like Nogales, therefore, will also be an important dimension of the research design.

Fertilizer. Our past research has indicated that win-win solutions are possible in the Valley - that farmers could reduce fertilizer applications and save money, while at the same time reducing off-site environmental effects. Unfortunately, recent surveys suggest reductions in fertilizer use have not occurred (Naylor and Falcon, unpublished data). What drives the continued use of high levels of fertilizer inputs, despite price signals and technological alternatives? What is the role of the bank/credit sector in decision making? Can management indicators (e.g., for residual soil N or plant N) that provide information about crop needs for N be developed, and will the availability of such indicators actually result in changes in farmers' decisions and selection of more sustainable practices?

We will use a combination of interviews and surveys of farmers, creditors, fertilizer industry representatives, and consultants and extension agents, as well as analysis of loan requirements and other documents to determine the direction and quality of information flow about fertilizer use. We will also continue our field studies of indicators of fertility and residual N, and the degree to which they can and will be adapted by farmers in their decision-making process.