Climate change is now an integral part of human life. During the month of March-April this year, we witnessed widespread rain,hail storm, snowfall in the Himalayan region. Hailstorm and storm caused loss of wheat crop, mustard, sugarcane, fruits and vegetables in North-West India. But only loss has occurred, no gained has happened. This is also not true. Cool weather prevailed in March 2016 that increased wheat productivity. In 2014 during March there was heavy rain. As a result food grains production increased. However, in 2015 there was less rainfall as a result the food grains production reduced by 13 million tonnes(Mt).
Research results indicate that after Industrial revolution (1780-1850), the Carbon dioxide(C02) content was in between 170—280 part per million (PPM). At present the carbon dioxide content of the air is 387 ppm. That means in 160 years carbon dioxide content has increased very rapidly. By 2100, temperature is expected to increase by 2.5 to 7 degree Celsius In every decade, increase is 0.2- 0.3 degree Celsius. Sudden change of weather parameters is called climate change.
Water vapour, carbon dioxide, hydrocarbon, nitrous oxide, etc are called green house gases(GHG). They create hindrances in spreading out infrared. As result, temperature of the world increases. Under normal condition natural gas keeps the world temperature at 33 degree Celsius which keeps water in liquid phases and also allows life to exist from equator to pole. It is thus observed that earth climate is a function of incoming energy from the sun and the outgoing energy radiated from the earth and exchange of energy among the atmosphere, land, ocean, ice, and living beings. Some gases and aerosols (very small particles) also affect the flow of incoming solar radiation and outgoing energy infrared radiation.
Human activities are the main reasons of climate change. Observations made over last 50 years indicate that about 0.10C per decade increase in temperature has taken place. Production of cement, steels, plastic materials, household cooling, transportation, generation of electricity etc are the main human activities responsible for the increase in temperature. Burning of fossil fuels for the human activities and deforestation of release of carbon dioxide are the key components of global warming. Methane, nitrous oxide, some other gases are responsible for global warming. It may be noted that carbon di-oxide (C02) is the key component of climate change.
Unfortunately agriculture also contributes green houses gases (GHGs) causing global warming. Of late, concentration of GHGs is increasing very rapidly. And this is in fact cause of concern. Carbon dioxide, methane, nitrous oxide, etc are main contributing factors to climate Change.
It is difficult to attribute any major role of agriculture in increasing carbon dioxide content in the atmosphere. Agriculture practices which results in soil erosion, loss of organic matter or cleaning of forest agriculture would certainly increase the concentration of carbon dioxide in the atmosphere. Mass scale cleaning forest areas for crop cultivation in Brazil has created environmental problem.
Of late, more emphasis has been given on conservation agriculture with minimum tillage, proper soil and water conservation, forestry and agro forestry. Sri Ram Chandra Mission(SRCM) with World HQ at Mappakam, Chennai has recently developed a very good model of soil and water conservation, forestry wherein the forest and soil and water conservation department of Government of Telangana has actively participated. The name of the place is Kanha Santi Vanam, SRCM , Village Chegur, near Hyderabad. This place is likely to change the agro-climate of the area. The spiritual component of SRCM leads to the real transformation of India through physical, mental and inner transformation of human beings.
Atmospheric methane is increasing at rate of one per cent per annum. Earlier assessment of Intergovernmental Panel on Climate Change (IPCC) indicates rice cultivation increases the atmospheric methane. Indian researchers disprove their finding. In India, out of a bout of 44million ha under rice, we have up land rain fed rice, low land rain fed waterlogged rice, deep water rice, some area may be floating rice, irrigated rice which gives stable high yield. Any agency without the in depth knowledge of each of the situations if ventures into the estimation of the contribution of rice cultivation in methane production in Indian subcontinent is likely to commit mistake. Natural waterlogged area always produces methane with or without rice culture.
Emission of carbon di-oxide, and methane at the atmosphere is not directly related with the use of fertiliser but nitrous oxide, a component of GHGs has direct relation with nitrogenous fertiliser use. The problem of nitrous oxide(N20) emission to atmosphere can be reduced through efficient use of nitrogenous fertilisers. One hundred two agriculture research institutes (102) under ICAR, more than 80 state and central agricultural universities are engaged in the development of new technology to improve nitrogen fertiliser use efficiency.
Impact of climate Change on Agriculture and fertiliser use
As mentioned earlier, it is very difficult to predict the impact of climate change in agriculture. Although, it can be safely said that mixed impact is expected. Area near equator (hot and humid area) is expected to be affected badly while the area (cold) far away from equator will gain because of increase in temperature. India, Sri Lanka, Vietnam, Malaysia, Indonesia, Philippines, all countries in middle Africa like Ethiopia, Tanzania, Zimbabwe, Nigeria, Ghana , sub Saharan countries, Brazil and all Latin American countries, etc will suffer a setback while cold countries like Canada, USA, Russia, Mongolia, North China, Japan, North Europe etc will be benefited.
Fertiliser is the key input to increase agriculture production. According to FAO of United Nations (UN) 50% increase of food grains production can be safely credited to fertiliser use. To compensate the loss in agriculture production in tropical climate due to climate change and to match the higher demand of fertiliser due to increase cropping intensity in temperate climate(cold climate ) more fertiliser would be needed. The C4 plant like maize has the capacity to produce more in high carbon dioxide concentration. Researchers in genetic engineering are in progress to incorporate the quality of higher production in rice in higher carbon dioxide concentration and very soon such a variety of rice would be available for cultivation which will increase fertiliser use. Studies conducted by the International Fertilizer Association (IFA) and Indian Agricultural Research Institute (IARI—PUSA Institute) confirm the statement made herein.
(Dr Bimal C Biswas has been the ex-Additional Director, Agriculture Sciences of The Fertiliser Association of India, FAI and also the ex-principal of Divyayan KVK, RKM Aashram, Jharkhand.)