Switching Varieties or Crops

A second possible farmer adaptation to climate change is to switch varieties or crops to something better suited to the new climates they face. A farmer currently growing maize might switch to a faster-maturing maize variety if drought becomes more common, or might choose to grow a potentially more drought-tolerant crop like sorghum. But such decisions will not be made on the basis of climate alone. Different varieties and crops have different input requirements and costs associated with their...

References

Ahmad H, Bajelan B (2008) Heritability of drought tolerance in wheat. Am Eurasian J Agric Environ Sci 3 632-635 APA (2004) Population and society issues, research, policy. In 12th Biennial Conference, Australian Population Association, Canberra, 15-17 September 2004 Ashraf M, Foolad MR (2007) Roles of glycine betaine and proline in improving plant abiotic stress resistance. Environ Exp Bot 59 206-216 Banziger M, Setimela PS, Hodson D, Vivek B (2004) Breeding for improved drought tolerance in...

Farmer Adaptation to Climate Dealing with Variability

The explicit focus of this book is on climate change - i.e. the potential shifts in the longer-run mean and extremes of temperature, precipitation, and other meteorological variables in a given area. And while longer-run climate exerts significant influence on agricultural decision-making, affecting what crops farmers grow and when and where they grow them, the actual amount of food produced in a given year depends on the specific realization of meteorological variables in that year....

Expansion of Irrigation Infrastructure

Irrigation was discussed above (Section 8.4.3) as a possible autonomous adaptation, but in many cases major public investments will be needed to provide farmers access to water. Some of these investments would undoubtedly happen even without climate change. For example, as part of its recent outlook assessment, the FAO projected changes in irrigated area for 93 developing countries notwithstanding climate change (Faures et al. 2002). Overall an additional 40 Mha in irrigated area was...

Changes in Yield Quantity at Elevated [CO2

The large number of experiments in controlled environments has allowed yield dose response curves to be calculated for the major C3 food crops, soybean, wheat and rice. In Fig. 7.2, the ratio of yield at elevated CO2 relative to ambient CO2 was calculated from all available studies of soybean, wheat and rice grown to maturity at elevated CO2 in controlled environments and open-top chambers (for original references, see Ainsworth et al. 2002 for soybean, Amthor 2001 for wheat, Ainsworth 2008 for...

Breeding Wheat for Adaptation to Moisture Stress and Increased Temperature

The first step in breeding crops with improved response to water and temperature stress is identification of genetic variability governing the plant response. This response may be environment specific and its genetic control is likely to be complex. Soil type and associated water holding capacity and infiltration rates, crop management practices, timing of water stress during the plant growth cycle, temperature and biotic constraints will all influence plant response to drought. Determination...

Trend Removal

Figure 5.1a shows average yields over the study period. The most obvious feature of this time series, and time series of yields for most crops in most regions, is the highly significant positive trend with time. This trend results largely from improvements in technology, such as adoption of modern hybrid cultivars and increased use of fertilizer. Given that so much of yield variation between years in different parts of the record occurs because of technology differences, the effect of climate...