Agricultural Productivity

Most food-deficit countries allocate a large proportion of their domestic food production to food consumption, since a very small share of domestic consumption is provided by imports. Agricultural products are also a very important source of foreign exchange earnings to support the growing need for imports. Agricultural production growth depends on the availability and quality of resources. And in low-income, food-deficit countries, this means land and labor because of limited use of new...

Maize And Agricultural Vulnerability In Mexico

Maize is the staple grain of Mexican cuisine and is the most essential contribution to the nutrition and sustenance of Mexico's population. By some estimates, maize contributes up to 50 of total calories consumed in Mexico, and up to 70 in rural areas (Fritscher Mundt, 1999). Maize also has great cultural significance. From its initial domestication, it has had a central role in the evolution of Mesoamerican religion, mythology, social organization, and economy (Le n-Portilla, 1988). In the...

Designing Soil Carbon Contracts for Farmers in Developing Countries

There has been considerable discussion in the literature about how contracts for soil sequestration might be designed in the context of the United States (Antle et al., 2003 Antle and McCarl, 2002). Some discussion of how carbon sequestration incentives could be created for farmers in developing countries (Antle and Diagana, 2003) is also now in the literature. In a country with well-defined property rights and corresponding financial institutions, farmers can participate in domestic or...

Criticisms of the Green Revolution

The Green Revolution has been a much-debated subject. The initial euphoria during the late 1960s of the high-yielding wheat and rice varieties and more intensive crop production practices was followed by a wave of criticism. Some criticism reflected a sincere concern about social and economic problems in rural areas that were not and cannot be solved by technology alone. Some criticism was based on premature analyses of what was actually happening in areas where the Green Revolution...

Deriving Model Parameters

A specific model incorporating a state-variable approach was used to predict soil organic carbon under different conditions. The model was based on the concept of buildup and breakdown processes that depend on the soil organic carbon content of the system. The soil organic carbon build-up rate (R) was described by the following mathematical function ACh Haplic Acrisols ANm Mollic Andosols ARl Luvic Arenosols FLe Eutric Fluvisols FRh Haplic Ferralsols FRp PLinthic Ferralsols LPe Eutric Leptosols...

References

Adams, R.M., Hurd, B., Lenhart, S., and Leary, N. 1998a. The effects of global warming on agriculture an interpretative review. J. Climate Res., 11 19-30. Adams, R.M., McCarl, B.A., Segerson, K., et al. 1998b. The economic effects of climate change on U.S. agriculture. In R. Mendelsohn and J. Neumann, Eds. The Economics of Climate Change, Cambridge University Press, London New York, pp. 18-54. Adams, R.M., Hurd, B.H., and Reilly, J. 1999. Agriculture and Global Climate Change A Review of...

Alternative Technologies

Since the crucial issues in the three regions of SHMP are lack of sufficient food and soil conservation, the principal objective of the SHMP research unit is the design and generation of sustainable alternative technologies for the milpa system, assuming a permanent agricultural system as opposed to the current shifting system (Cort s et al., 2001). Sustainable farming systems conserve and protect the essential agroecosystem resource base including soils, water, and genetic diversity provide...

Climate Change and Length of Growing Season in 20th Century

Length of growing season is the length of time during the year that soil temperature and moisture are suitable for crop growth. It depends primarily on local temperature and precipitation. In this section the pattern of annual growing season lengths on current cropland during the 20th century are estimated and evaluated. Both long-run trends in length of growing season and their potential interaction on length of growing season during El Ni o Southern Oscillation (ENSO) cycles are assessed....

Predator Prey Interactions

Climatic conditions (especially microclimate) also have a very big impact on arthropod predator-prey interactions. This interaction is important because natural predators and parasitoids in agricultural settings often limit abundance levels of insect herbivore pests on crops (Cornell et al., 1998 Rosenheim, 1998 Gutierrez, 2000), including successful bio-control efforts. The chain of events linking predators with prey species that affect predation success is large, and disruption at any level...

Consequences of Altered Plant Nutrition

Environmental stresses have large effects on the nutritional quality of host plants to insect herbivores. The nutritional Figure 13.3 (opposite page) Performance niche responses. (A) Population growth responses by the grain beetles Calandra oryzae and Rhizopertha dominica for temperature and moisture content of wheat. (Data from Birch, L.C. 1953. Ecology, 34 698-711 figure from Maguire, B. Jr. 1973. Am. Naturalist, 107 213-246. With permission.) The dashed line indicates conditions that...

Milpafruit Tree Intercropping System In Sustainable Hillside Management Project

A major objective of this project was to identify alternative technology options for the target regions. Since no previous agronomic research had been conducted on intercropped staples and fruit trees, development of the MIFT system took into account the management of peach trees in the Puebla Valley and local cropping patterns for maize and beans, and assumed that soils on slopes greater than 20 would be a common condition. These slopes are in contrast to moderate Figure 23.3 Living wall...

US Response to Climate Change and Kyoto Protocol

Although the Clinton administration negotiated the Kyoto Protocol, the Bush administration has thus far refused to ratify it. In his public remarks, President Bush has disagreed with both the form of the Kyoto Protocol and the scientific evidence that prompted other governments to ratify the treaty. In 2001, he stated that the emissions targets established by the Kyoto Protocol were arbitrary and not based on science, and further claimed that no one can say with any certainty what constitutes a...

Economic Feasibility

Knowing how much carbon can be stored and the extent to which crop yields can be increased under various management scenarios is only the first step in a feasibility assessment. The second step is to evaluate whether farmers would in fact be able to afford to implement promising practices. Limited investment capital among smallholders has been recognized as major obstacle to adoption of soil fertility management strategies, regardless of their long-term financial and social profitability (Izac,...

Soil Carbon Dynamics

Several important carbon management strategies exist, including the adaptive and mitigative options found in Figure 5.1. Adaptive options are based on better management Figure 5.1 Adaptive and mitigative strategies of carbon management and sequestration to address global climate change. Figure 5.1 Adaptive and mitigative strategies of carbon management and sequestration to address global climate change. of terrestrial and aquatic ecosystems, desert lands, and wetlands. Adopting RMPs such as...

Bulk Density

Soil bulk density (p6, Mg m-3) is the ratio of the mass of dry solids to a bulk volume of soil (Blake and Hartge, 1986). Its determination is essential to calculate the mass of soil organic carbon (SOCm, Mg C m-3) from SOC concentration (SOCc, Mg C Mg-1) Although p6 is a relatively straightforward measurement, its evaluation can be subject to errors. Blake and Hartge (1986) and Culley (1993) offer excellent descriptions of the various methods that can be used to determine p6. In the extractive...

Soil Organic Matter Soil Carbon and Carbon Sequestration in Zambia

Soils under almost all farming systems in Zambia are low in N, P, and SOM (Stromgaard, 1984). It has been easy to detect and demonstrate evidence of N deficiency in cropped soils, but declines in SOM have been rather difficult to identify and quantify (Lungu, 1987). On the other hand, when crop residues are returned to the soil and legume cover crops are grown, they lead to increased organic C content and improved water retention. The contributions of decomposed legume litter to SOC were...

Potential For Sequestering Soil Organic Carbon In Zambia Soils

The SOC contents in most agricultural soils are below their potential levels, especially soils in developing agricultural systems (Lal, 1999). Carbon content of Zambian soils is low, ranging between 0.5 to 1 organic C (Singh et al., 1990), with an average of 0.8 (Silanpaa, 1982). In the three agro-ecological regions of Zambia, benchmark data of organic C content (Table 25.1) range from a low of 0.15 to 1.11 for bottom soils (38- to 70-cm depth) to a high of 2.45 to 3.0 for topsoils (0- to 8-cm...

Case Study 1 Nigeria

Nigeria comprises some of the most densely inhabited areas of semi-arid West Africa Harris, 2000 . As a result, the soils of this region have been cultivated for long periods. Plant Table 21.1 Main Characteristics of Study Sites Soil type Ferrugineous tropical soils, sandy, poor water holding capacity WHC and low-nutrient organic matter content Farming Smallholder farming systems Intensive permanent annual or biannual cultivation cropping intensity gt 60 Less intensive shrub short-bush fallow...