Impact of Climate Change on Agronomic Crop Production
Muhammad Nasir*, Hafiz Muhammad Arslan Abid, Muhammad Tayyab, Sajjad Manzoor
University of Agriculture, Faisalabad, Pakistan
*Corresponding author: [email protected]
INTRODUCTION:
Crops are dependent on temperature, light, moisture and CO2 to produce grains and other crop products to satisfy the basic human needs. Climate change is very likely to affect food security at the global, regional, and local level. Climate change can disrupt food availability, reduce access to food, and affect food quality. Increases in temperature, changes in precipitation patterns, changes in extreme weather events, and reductions in water availability may all result in reduced agricultural productivity.
CO2 Concentration:
Higher CO2 levels can affect crop yields. Some laboratory experiments suggest that elevated CO2 levels can increase plant growth. Though rising CO2 can stimulate plant growth, it also reduces the nutritional value of most food crops.
Extreme Temperature:
More temperature both high and low and precipitation can prevent crops from growing. Extreme events, especially floods and droughts, can harm crops and reduce yields.
Anthropogenic Activities:
These are a source of rising concentration of greenhouse gases which in turn are the major reasons of global warming and other changes in climate (Zilberman et al., 2004). The climate change is characterized by rising temperature, erratic and lower rainfall declined frequency but with greater intensity, changing seasons, and occurrence of extreme events floods and droughts.
Major Impacts:
- Rising levels of atmospheric carbon dioxide reduce the concentrations of protein and essential minerals in most plant species, including wheat, soybeans, and rice. This direct effect of rising CO2on the nutritional value of crops represents a potential threat to human health.
- Elevated CO2has been associated with reduced protein and nitrogen content in alfalfa and soybean plants, resulting in a loss of quality. Reduced grain and forage quality can reduce the ability of pasture and rangeland to support grazing livestoc
- Human health is also threatened by increased pesticide use due to increased pest pressures and reductions in the efficacy of pesticides.
- Many weeds, pests, and fungi thrive under warmer temperatures, wetter climates, and increased CO2 The ranges and distribution of weeds and pests are likely to increase with climate change. This could cause new problems for farmers’ crops previously unexposed to these species.
However, other factors such as changing temperatures, ozone, and water and nutrient constraints, may counteract these potential increases in yield. For example, if temperature exceeds a crop’s optimal level, if sufficient water and nutrients are not available, yield increases may be reduced or reversed.
These changes pose serious threats to various sectors of economies. However, the agriculture sector is more vulnerable to these changes, since around 60 percent of agricultural production is determined by the suitability of weather conditions (Deshmukh and Lunge, 2012).
Production of crops is primarily affected by the availability of water, which in turn mainly depends on the precipitation (monsoon seasons). Crops like rice and cotton are grown in summer which is characterized by very high temperature in most areas of Pakistan.
Impact on Cotton:
Pakistan’s Agriculture is both rain-fed and irrigated but cotton crop is normally sown in the irrigated and semi-arid areas due to its water requirement for proper growth (Naheed and Rasul, 2010).
Cotton crop of Pakistan has faced many challenges like pest attack, climatic variation and price volatility. Although, the problem of pest attack has considerably been reduced by the introduction of Bt. (Bacillus thuringiensis) cotton but the climatic variations which have been independent of this new cotton innovation do have serious implications for the cotton production system.
Although, Pakistan is not a very active contributor in greenhouse gas emission but is highly vulnerable to climate change due to its geographical location
Pakistan is the fourth major producer of cotton in the world .The cotton belt is spread over the 1200 km of Indus delta. The soil characteristics vary from sandy loam to clay loam. Irrigation is adapted to meet the primary water requirement of crop in high temperature and low rainfall as a supplementary source. High temperature also makes the crop more vulnerable to pest attack and usual response of crop is loss of vegetative and fruiting parts.
The intensity of impact of climate change on crop production depends on the environment under which the crop is currently being grown. Cotton is grown in the hot areas of Pakistan. The adverse impacts of climate change on productivity vary according to the occurrence of events during different growth stages of the plant (Doherty et al., 2003).
The effect of climate change on crop productivity is estimated including the physical inputs variable fertilizer use, area under cotton and of total precipitation during different stages of growth.
The changing pattern of climate would have serious implications for the cotton economy of Pakistan. This crop is a very labor and capital intensive enterprise in Pakistan on one hand and 2/3 rd of our total exports are dependent on this crop on the other.
Therefore, agricultural research efforts should be concentrated on developing heat tolerant verities having high productive potential as well as resistant to insect pests’ attacks and to diseases.
The climate variability has affected the agriculture production all over the globe. This concern has motivated important changes in the field of research during the last decade. Climate changes are believed to have declining effects towards crop production in Pakistan.
Impact on Rice:
Major crops of Pakistan are affected by changing climate (Siddiqui et al., 2012) found the susceptibility of four major crops of Punjab, Pakistan, when they were exposed t o climatic changes . Temperature rise was found important for rice production at first, but when temperature increases beyond certain level, the increase became destructive towards its production.
More than 90% of the total acreage of rice is in Punjab province. In Sindh province, primary rice growing districts are Larkana, Jacobabad and adjoin district of Nasirabad of Balochistan province. In Punjab, Gujranwala, Sheikhupura and Sialkot districts are primary producer of rice. Shikarpur, Dadu, Thatta, Badin in Sindh and Okara, Gujrat, Sargodha, Lahore, Kasur and Sahiwal districts of Punjab are secondary rice growing districts.
(Peng et al., 2004) observed very close connection between rice yield and average minimum temperature. Rice production is exhausted by 10% when average minimum temperature is increased by 1 °C.
Climate change is being countered all over the world and also portraying its physical impacts everywhere. It is therefore necessary to evaluate the impact of these changes on crop productivity.
Conclusion:
It is thus concluded that this evolving risk of climatic change will stress the production of rice in Pakistan. Rainfall and mean temperature increase would be beneficial for healthier rice production but will produce negative effects if these climatic variables are increased too much in future decades as evident from the simulation scenarios. Increase in mean maximum temperature will impair rice production while increase in minimum temperature will raise rice production. Varieties which are tolerant to high temperature and drought should be developed so that losses could be avoided. The temperature component may shorten the growth periods; therefore the cultivating time should be adjusted accordingly.
References:
Deshmukh, D.T. and H.S. Lunge. 2012. Impact of Global Warming on Rainfall And Cotton Lint With Vulnerability Profiles of Five Districts in Vidarbha, India. Int. J. Sci. Tech. Res. 1(11):2277–8616.
Doherty, R.M., L.O. Mearns, K.R. Reddy, M.W. Downton and L. McDaniel. 2003. Spatial Scale Effects of Climate Scenarios on Simulated Cotton Production in the Southeastern USA. Climatic Change 1(2):99–129.
Naheed, G. and G. Rasul 2010. Recent Water Requirement of Cotton Crop in Pakistan. Pak. J. Meteor. 6(12):75–84.
Peng, S., J. Huang, J.E. Sheehy, R.C. Laza, R.M. Visperas, X. Zhong, G.S. Centeno, G.S. Khush and K.G. Cassman. 2004. Rice yields decline with higher night temperature from global warming. Proc. Nat. Acad. Sci. 101(27):9971-9975.
Siddiqui, R., G. Samad, M. Nasir and H.H. Jalil. 2012. The Impact of Climate Change on Major Agricultural Crops: Evidence from Punjab, Pakistan. The Pakistan Develop. Rev. 51(4):261-276.
Zilberman, D., X. Liu, D.R. Holst and D. Sunding. 2004. The Economics of Climate Change in Agriculture. Mitigation and Adaptation Strategies for Global Change 9(4):365–382.
