While each of the 34 organizations identifies farmland protection as an important objective, the degree of emphasis often varies. The names of land trusts and open space districts suggest this variation; the terms “agriculture,” “farmland” or “rangeland” are found in only 11 names, sometimes in combination with “open space” or other designations. Based on our review of mission statements and interview comments, we sorted the 34 organizations into three categories, according to differing agricultural emphases . Only a third of the 34 organizations are unwavering in their exclusive or primary focus on farmland. We included some trusts that focus on grazing cropland properties and others that are primarily interested in cropland. The California Rangeland Trust and Amador Land Trust concentrate on foothill ranch land, while the Monterey, South Livermore Valley and Yolo trusts focus almost entirely on orchards, vineyards, vegetable growing parcels and other croplands. In recent years, some organizations with broad or multiple conservation objectives have begun to emphasize farmland protection, perhaps motivated by new funding opportunities for farmland easements created by state government and other agencies. Some land trusts have also reassessed their conservation objectives to reflect community concern about farmland loss and increased landowner interest in easements. Two such programs are the Napa County Land Trust and the Mid-Peninsula Regional Open Space District , neither of which emphasized farmland protection in their original missions. Following a planning exercise conducted by its board, the Napa trust in 1999 established agricultural lands as its top conservation priority, partly to support the agricultural preserve created for the Napa Valley floor by county government policy. As a result of an advisory voter referendum and the encouragement of other conservation groups,ebb and flow trays in 2000 the Mid-Peninsula district extended its boundaries to an area of prime farmland along the San Mateo coast.Interviewees frequently commented on the connection between protecting agricultural activity and preserving natural resources such as habitat, wetlands and scenic views.
The same easements, some said, could accommodate both purposes. Others, however, discussed serious limitations, citing conflicts between cultivation and other aspects of commercial agricultural production, and the preservation of natural resources. At its most general level, the argument for compatibility simply views farmland as additional open space, a landscape free from human congestion and an antidote to urbanization.“If you are not working with ranchers and farmers, you are not going to get any open space,” noted the manager of a Bay Area program. Emphasizing the open space values of agricultural easements appeals to urban residents and helps build community wide support. “We realized that in order to appeal to more people, we have to recognize that agricultural land is also open space under private ownership,” the Bay Area manager said. It is a step further to focus on the compatibility of agricultural activity with specific plant and animal resources and landscape features . According to some managers of programs that concentrate on ranch land, cattle grazing has beneficial effects on local habitats. They note that controlled grazing helps to cut back nonnative grasses and reduce the possibility of wildfires. One land trust manager who works with ranchers said: “Our primary objective is to provide alternative ways to address the economic viability of rangeland agriculture and to conserve the natural balance of the ecosystem. We see the two as being intertwined. And so we try to provide services and education to ranchers about how they can integrate their economic needs with the environmental and ecological needs of their rangeland. I think there’s been a shift in the way the cattle industry looks at these issues. Many people are beginning to see that they’ve got assets on their ranch that are not necessarily related to the commodity that they produce, whether that’s open space, or recreational opportunities or watershed values” . There is far less compatibility for farm operations that involve intensive cultivation and chemical applications, including orchards, vineyards and vegetables and parcels devoted to confined animal production . While the potential for protecting natural resource lands is ever present in the easement priorities of organizations that focus on cropland, this clearly takes a back seat to their emphasis on protecting commercial agriculture.
The Yolo Land Trust makes a sharp distinction between two types of easements: “A farmland conservation easement contains restrictions to keep the land in agriculture. A habitat conservation easement is written to protect the habitat value of the land” . By these standards, intensive farming conflicts with efforts to preserve highly sensitive habitat, such as vernal pools, other wetlands and riparian corridors — conditions that also restrict cattle grazing in particular areas. A related but separate issue is the possibility of opening easement-protected properties to public access. Most farmers interested in selling an easement explicitly reject such use, citing liability problems and interference with farm operations. This severely limits the use of easement-protected farmland for trails and other recreational purposes, highly desired open space amenities for urban populations. Despite these incompatibilities, program managers we interviewed identified a number of examples of easements created primarily for the protection of agricultural operations, including crop production, that also serve habitat preservation purposes. Some cover sizable parcels that allow for the geographic separation of the different uses. For example, the Mendocino Land Trust acquired a 430-acre easement with 60% devoted to agriculture and 40% in preserved oak woodlands. Several easements held by the Yolo Land Trust are used mainly for crop production but are traversed by streams with riparian corridors closed to cultivation. Some interviewees suggested that easements are not the best option for preserving sensitive habitat and providing public recreation, because of the complications generated by private ownership. The better approach, instead, would be outright purchase and ownership by public or nonprofit agencies, simplifying management and perhaps allowing low-intensity agricultural operations on a lease basis. One land trust manager noted that government agencies and foundations that fund environmental easements usually prefer to support fee purchases, especially in areas removed from urban pressures where easement prices per acre tend to be relatively low. Indeed, several organizations in our study with significant non-agricultural goals both hold easements and own and manage large parcels as nature preserves or recreational sites.Thirty-four local conservation organizations in California seek to protect farmland via the acquisition of conservation easements. About a third focus exclusively or primarily on farmland, while the greater number fit this objective into broader conservation agendas that include the preservation of lands with natural resource values. The degree to which programs seek individual easements to achieve both farmland and resource protection varies.
The objectives are compatible or incompatible, depending on the agricultural commodities that are grown, cultivation practices and the natural resources to be protected. The smaller number of programs expressly focused on farmland, especially those concerned with protecting cropland, tend to make a sharp distinction between different conservation purposes, but on occasion they also recognize secondary resource values in some of their agricultural easements. Concerned primarily with identifying California’s agricultural conservation programs and their missions, we did not thoroughly examine issues of compatibility. A broader research approach is needed to for this purpose, one that examines in detail agricultural practices and impacts in different environmental settings and the application of sustainable agricultural techniques.Agriculture’s role in the process of economic growth has framed a central question in development economics for several decades . While arguments differ regarding the specific mechanisms through which agricultural productivity increases might contribute to structural change in the economy, it has long been theorized that advances in the agricultural sector can promote shifts in labor to higher productivity sectors that offer higher real incomes. Empirical work in more recent years has helped inform the conceptual arguments and underscored the long-term growth and poverty reduction benefits from agriculture, especially for the most extreme forms of poverty . At the same time, recent evidence has also underscored the role of the manufacturing sector in driving structural change and long-term convergence in incomes across countries . This and other evidence regarding agriculture’s relatively low value added per worker compared to other sectors has prompted some researchers to narrow the number of developing countries in which agriculture is recommended as a priority sector for investment in light of higher prospective growth returns in non-agricultural sectors . These debates present a first-order concern for understanding why some countries have not experienced long-term economic progress and what to do about it. If agriculture can play a central and somewhat predictable role within the poorest countries,ebb flow tray then it is a natural candidate for targeted public investment. The theoretical and empirical literature regarding structural change is vast, yet identifying the causal role of agricultural productivity is challenging because relevant indicators of structural change trend together in the process of development; impacts on labor force structure are likely to occur after a lag; and statistical identification is not amenable to micro-style experiments. Our contribution in this paper is to focus on the role of agricultural inputs as drivers of higher yields and subsequent economic transformation, using the unique economic geography offertilizer production in our identification strategy. Large-scale nitrogen fertilizer production occurs in a limited number of countries around the world, owing partly to the fact that the Haber-Bosch process requires natural gas. Transporting this fertilizer to each country’s agricultural heartland generates cross sectional variation due to economic geography, akin to Redding and Venables’ model of “supplier access” to intermediate goods, which is estimated to affect income per capita. Our identification strategy exploits this variation in supplier access as well as temporal variation in the global fertilizer price to generate a novel instrument for fertilizer use. To our knowledge this is the first application of economic geography towards causally identifying the relationship between agriculture and structural change. Our paper builds on the insights of Lagakos and Waugh , which highlight the gaps in understanding of cross-country variations in agricultural productivity. A variety of studies have estimated sources of total factor productivity in agriculture in the poorest countries, including in sub-Saharan Africa , but agriculture is such an input-intensive sector that TFP assessments only provide one piece of the overarching crop sector puzzle. Our econometric strategy proceeds in two parts. First, we empirically assess the inputs that contributed to increased productivity in staple agriculture, as proxied by cereal yields per hectare, during the latter decades of the 20th century.
Using cross-country panel data, this forms a macro-level physical production function for yield increases. We find evidence for fertilizer, modern variety seeds and water as key inputs to yield growth, controlling for other factors such as human capital and land-labor ratios. Second, we deploy our novel instrument to examine the causal link between changes in cereal yields and aggregate economic outcomes, including gross domestic product per capita, labor share in agriculture, and non-agricultural value added per worker. We find evidence that increases in cereal yields have both direct and indirect positive effects on economy-wide outcomes. The results are particularly pertinent when considering economic growth prospects for countries where a majority of the labor force still works in agriculture. The next section of this paper motivates the empirical work, drawing from the many contributions in the literature towards understanding structural change. Section 3 presents empirical models both for estimating the physical production function for cereal yields and for estimating the effect of yield increases on economic growth, labor share in agriculture, and non-agricultural value added per worker. Section 4 describes the data, Section 5 presents the results, and Section 6 concludes. At the most general level, agricultural output can grow through either increases in area planted or increases in output per area planted . In the agronomic science community, primary emphasis is placed on the latter, with land productivity usually measured in tons of output per hectare. The term “green revolution” is typically used to describe the early stage where yields jump from roughly 1 ton per hectare to 2 or more tons per hectare. The term was coined following the advent of South Asia’s rapid increases in cereal yields in the late 1960s and 1970s. Some researchers have argued that these green revolutions underpinned later stages of economic growth, and cite Africa’s lack of a green revolution as a key reason why the region has not yet experienced greater long-term economic success .