Reasons for climate change
There are lot of impacts of climate change on crop productivity. Changes in climate directly and indirectly affects whole world. To obtain greatest possible production from the land, agricultural communities have developed and maintained ecosystems. Since the green evolution chemical fertilizers and chemical pesticides were used rapidly and because of this impact on environment had been severe.
Crop productivity is highly sensitive to climate and it is affected by rainfall, temperature and inter-annual climatic conditions. Due to these climatic changes some crops become more tolerant than other crops because of the stress level difference and because of this the yield obtain by each crop will differ from one another according to the climatic conditions. Because of this there will be some uncertainty of the yield of the crops according to the future climatic conditions.
There are lot of ways that cause impacts of climate change. Deforestation, depletion of ozone layer and green house effect can be mentioned as the major reasons that cause climatic changes.
Effects of climate change
The changing patterns in day to day weather situations, rising CO2 concentrations. Rising sea level, increasing environmental temperature is and indicative of the fact that climate change being encountered by the life of earth at present. Natural and anthropogenic factors caused climatic changes. Due to the periodic tidal pulls exerted by the astronomical bodies on earth’s atmosphere, climatic changes occurs naturally. Climate change is expected to adversely affect the sustainable development capabilities of most Asian developing countries by aggravating pressures on natural resources and the environment.
Changes in climate mainly affect on agroecosystems and it cause changes in crop productivity. Changes in crop productivity can be categorized as direct positive effects, direct negative effects and indirect negative effects. Increasing CO2 concentration increase photosynthetic rate in C3 plants and reduce transpiration due to decrease stomatal aperture. Higher temperature also accelerates plant development and shortens the growth period. Those can be considered as a direct positive effect.
The increased leaf area index may result in self shading and thus reduces the net assimilation rate. Increased CO2 results in higher leaf area index thus higher transpiring surface is available which might compensate the increased water use efficiency on per plant basis. Those can be considered as direct negative effects caused by climate change on crop productivity.
There may be about 6-8% reduction in maturity duration for each 1°C rise in temperature. Because of this flowering seasons can be changed. Not only that increased temperature during critical periods of crop development result in accelerated leaf senescence, decline in canopy photosynthesis and forced maturity in winter cereal crops. Increased temperature will increase the rate of senescence of flag leaf and reduction in grain filling period. Increased yield is counteracted by a higher temperature that causes moisture stress, delays the maturity of crops due to increased senescence and reduction in grain filling period.
Higher CO2 level will increase the photosynthesis rate and because of that water uptake from soil will be increased and it will reduce soil water level also. Increasing soil temperature will affect on important soil micro organisms that help to increase crop productivity. Not only that increasing temperature will evaporate water from soil and it will reduce soil moisture. Gradual sea level rising will increase salt level in soil by causing a not suitable environment for plant growth. UV-B radiation cause depletion of ozone layer and because of that crop productivity could be decreased. Those can be considered as indirect negative effects caused by climate change on crop productivity.
Other than those reasons agricultural pest number will increase because of these climatic changes and it will also affect on crop productivity. Aphids and weevil larvae prefer elevated CO2 levels in atmosphere. Soil erosion and reduction of crop diversity can be happen due to climatic changes. These reasons reduce total crop yield.
Because of sea level increase deltas which have high amount of soil nutrients will be affected and they will become uncultivated areas. Because of greenhouse gas emissions it will change atmospheric composition and it will affect to cause climatic changes. Extreme events such as floods and droughts can harm drops and it may reduce yield of the cultivation. Elevated temperatures at night time will reduce yield. Pollinators can be affected by high temperatures and because of this pollination will get reduce and the yield will reduce.
To overcome impacts of climate change on crop productivity, crop diversity should be increased by inter-cropping and appropriate cropping systems. Water conservation can be done in agricultural sites. Chemicals and biocides should be used in a controlled manner. Carbon fixation in soil should be increased using dee-rooted crops. Fossil fuel consumption should be reduced and regeneratable energy should be used instead of fossil fuel. Land conservation method should be followed which is suitable for various climates. Forest areas should be increased and it will help to prevent soil erosion and it will also enhance water resources.
Crops should be grown by considering the climatic conditions of the agricultural sites. Famers should be educated about climatic conditions and they should be trained to observe small climatic changes in their areas. Fertilizers should be used by considering the climatic conditions. Greenhouse gas emissions should be minimized and it will help to prevent increasing global temperature. Emissions from factories should be reduced and the emission gas should be filtered using filters before releasing into the atmosphere.
Right machines should be used in agriculture and in other fields to reduce CO2 emission. Organic fertilizer usage instead of chemical fertilizers should be promoted. Deforestation should be minimized in development projects and new plants should be planted. By doing these things it can reduce the impact on environment and it will help to maintain a good climatic conditions. Because of that crop productivity can be maintained in a good status .