Impact of Climate Changes on Crop production: Tools for Adaptation

Impact of Climate Changes on Crop production: Tools for Adaptation

Dr. Muhammad Tahir and Dr. Aziz-Ur-Rehman*

Department of Agronomy, University of Agriculture, Faisalabad, 38040, Pakistan.

*Corresponding Author: [email protected]

A change in global or regional climate patterns, particularly a change apparent from the mid to late 20^th century onwards due to increasing atmospheric carbon dioxide produced by the use of fossil fuels. Climate change and agriculture are linked with each other as biodiversity, crop yield; soil health as well as water use is directly affected by a changing climate. Climate change is affecting the Earth’s temperature, hydrological cycles and precipitation and this change is due to burning of fossil fuels. Changes are occurring continuously in the frequency and intensity of heat waves, precipitation and other extreme events, all that will affect agricultural production. Moreover, all climatic factors collectively can decrease plant productivity. Thus, resulting in price increases for many important agricultural crops due to their shortage.

Climate can be predicted as models have been developed which are considered economic and social factors (carbon emissions and population). Experts have developed climate scenarios by combining these factors with an understanding of global and regional climate science that expresses the potential for different behaviors to impact climatic patterns. Such climate scenarios have the potential to inform our choices about the likely impacts of precipitation, temperature and season for the production of food. To adapt to various climate consequences climate scenarios also allow us to teach and guide agricultural sectors with the best methods by identifying tradeoffs and evaluating impacts.

Impacts of Climate Changes

Now there are more intense and frequent droughts and floods in the hydrological cycle in many agricultural regions. Such events can destroy or damage crops. According to scientific prediction, the average temperature will increase by at least 1.0ºC and concentration of CO₂ will increase to about 450 parts per million by volume over the next 30-50 years. Anticipated regionally dependent changes include an increase number of warm nights and heat waves and a decrease number of the longer growing season and frost days in temperate zones. For C₃ (rice, soybeans and wheat) species CO₂ response is expected to be higher than on C₄ species (sorghum and corn), which account for more than 95% of world’s species.

For the most important cultivated crops like wheat, rice, soybeans and maize price will rise. This will lead to higher meat prices and therefore feed. As a result, climate change will result in greater food insecurity and reduce the growth in meat and cereal consumption. The net effect of climate change on world agriculture is likely to be negative, only some regions and crops will benefit, most will not. While in some crop species increase in atmospheric CO₂ is expected to improve water use efficiency and stimulate growth and climate impacts, particularly droughts, heat waves and flooding, will dampen yield potential. Indirect climate impacts include expansion of pathogens, increased competition from weeds and seasons and insect pest ranges, and other changes in crop agro ecosystems.

The effects of climate change on pastures and field crops will include:

• Increased variability and changes to seasonality of rainfall.
• Changes to the dynamics of weeds, diseases and pests.
• Increased heat stress/shock, which cause lack of soil moisture.
• Increased temperatures may permit the establishment of new insect pests in cropping areas and may cause the distribution of existing pests to widen. This will cause less production and increased pest control costs. High temperatures can also effect on plant growth and fruit earlier or extending ripening.
• Field crops will be more impacted by the climate change due to problems of water availability and hotter and drier conditions. Increase level of atmospheric carbon dioxide has potential to enhance crop growth, but the quality of produced may suffer. For example, in wheat grain high carbon dioxide level reduces the protein content. When wheat grain is used as stock feed, this can have follow-on result for the livestock industry.
• High levels of CO₂ in the atmospheric air could result in more pasture growth. Yet availability of other critical requirements such as soil nutrients and water also affects the growth. Therefore, if there is an average reduction in rainfall by around 10%, this will result in reduced pasture growth, which is important for animal production, so it will lead to potential environmental damage to some grazing lands.
• Under the future predicted climate change scenarios nutritional value of pastures will reduce and combinations of plants that make up current pastures may change in time. If pasture production for grazing animals will be affected by water availability due to climate change than price for grain and pasture will be high.
• In some areas, tropical or summer-active species can become important; climate changes can introduce new native plants and pasture plants that can be suitable at adapting changes in temperature particularly high temperature and low rainfall.
• If limited water availability and temperature prevent the healthy growth and survival of existed and traditionally introduced pasture species, then it is possible that there will be a natural shift toward modern weedy species and grass varieties.

Tools for Adaptation

Adaptation strategies include short and long-term alterations to those human activities that are responsible for the effects of changes in climate. In agriculture, adaptation will require cost-effective investments in emergency preparation in response to extreme weather events and water infrastructure. Adaptation improves land use techniques and management practices, development of resistant crop varieties that tolerate precipitation and temperature stresses.

For the development of new climate tolerant crop varieties, crop breeding is a key tool for adapting agriculture to a changing climate. History and current plant breeding experience show that within crops, natural biodiversity has allowed plants to adapt to changed conditions. Use of genetically modified organisms (GMO’s) can produce resistant varieties, allowing seeds to germinate according to a suitable condition.

Another tool, which can help the agriculture to adapt climate change, is cropping system. For example, the use of crop mixtures or growing of two or more crops at one time can help systems exhibit greater durability during periods of heat stress or high water.

Improvements in water use efficiency by the development of high efficiency irrigation techniques and plant nitrogen with the development of cost-efficient nitrogen uptake delivery systems. To assess the performance of existing and new genetic material, development of data collection and global testing sites and dissemination efforts by using standard data protocols.

Visiting and testing of field continuously to track climate changes, breeding for introducing new varieties having resistance to new pests and diseases. Assessment tools development that incorporates the biophysical constraints that affect agricultural productivity and include socioeconomic and climate scenarios, including developed and improved characterization of program and policy environments, management systems and options and in today’s range of agro climate conditions.