Effect of AQI on Agriculture, Crop Yield and Food Production
Air Quality index not only kills us, but also the plants and in turn affect food production
There was a time when farmers used to look up at the sky for rains. Now, they look up to see nothing but smoke and pollution. They feel helpless just like we do. We listen everyday about the deadly Air Quality Index or AQI. It is severe in most of the places near Delhi-NCR. We are aware that it has bad effects on our health, specially our breathing abilities. Same are the consequences for the plants, crops, soil, etc. as well.
The plants breathe in carbon dioxide and give away oxygen for our survival. But we need to understand that plants need CLEAN carbon dioxide. This is not the case in high AQI. It is affected by presence of toxic pollutants in the atmosphere containing harmful gases like Carbon Monoxide (CO), methane (CH4), carcinogenic polycyclic aromatic hydrocarbons, volatile organic compounds (VOC). All these and many more are the reasons behind low agricultural productivity, low crop yield, low soil quality, etc.
What high AQI means for agriculture?
Air quality is dependent upon the different pollutants that it has. Particulate matter (PM2.5 and PM 10) and Gaseous pollutants are considered health hazardous for human beings. High AQI means greater the level of air pollution and greater are the health concerns for humans as well as plants. For example, an AQI value of 50 or below represents good air quality, while an AQI value over 300 represents hazardous air quality. It is not only for the humans but also for plants and animals. Since agriculture sector suffers from high AQI and severe air pollution conditions, we suffer double. One because of the air pollution and second because of the low yield of food crops leading to low food production.
Dr. Siddhartha Singh, Scientist ‘E’ and In-charge of Ozone & Air Quality Unit at Environment Monitoring and Research Centre in India Meteorological Department helps us highlight that “There is a two way relationship between food production and air pollution. Food production contributes significantly to air pollution, in turn, air pollution can impact food production. Conversely, there is increasing evidence that food production is also threatened by air pollution.”
Root cause is Parali/Stubble during ?
We all know about parali or stubble burning and look at it as the biggest contributor in air pollution near Delhi. But have you even noticed that the parali burning has also caused severe ill effects on the agricultural crops around us. A study done by National Policy for Management of Crop Residues suggest that one-tonne stubble burning leads to a loss of 5.5 kg nitrogen, 2.3 kg phosphorus, 25 kg potassium and 1.2 kg of sulfur from the soil. Stubble burning also increases soil temperature, causing displacement or death of microorganisms. This also means that farmers have to spend extra money to regain the fertility of soil lost due to crop burning.
Dr. Bhupinder Singh, Principal Scientist at Division of Environment Science in ICAR-IARI opines that “Parali releases a lot of particulate matter and poisonous gases, which does not allow the radiation to reach crops canopies. It is almost 1/4th of the actual radiation that the plants will receive on a normal day. So, this will reduce photosynthesis, rate of transpiration, uptake of nutrients by the plants, accumulation or availability of carbon assimilates. As a result, not only the productivity, but also the nutrient quality will be reduced. This will however, depend on a number of factors like the frequency, duration, stage and number of times this situation persists.”
How farmer’s produce suffer from high AQI?
Paddy residue takes one-and-half months to decompose, as a result of which farmers are left with a very short window to prepare the field for the winter crop. Stubble burning is considered to be an effective way of getting rid of the residual stubble, thus it helps farmers prepare their field at a relatively beforetime. It is hard for farmers to dispose off the paddy stubble. Due to its low calorific value and high silica content, the stubble can’t be used as animal fodder. Crop burning is also considered to be an effective way to get rid of weeds on a farm. Another important reason is the cost-effectiveness of the process, as it costs farmers way less than having to remove the stubble manually or via the use of machinery.
High AQI leads to Ozone depletion
High concentration of air pollutants also cause earth’s protective ozone layer depletion. As a result forest, crops and vegetation are subjected to much higher rate of harmful UV radiation. Injury to the plants, visible marking on the foliage, damage to the living tissue, impairs photosynthesis, reduced growth & yield and premature death of the plant are some of the extreme consequences.
Experts believe that stubble burning also destroys organic matter and essential nutrients that make soil fertile. It reduces microbial activities and the land becomes more vulnerable to soil erosion. It leads to decrease in crops yields over the time and increase in the need for costly fertilisers. Dr. Bhupinder Singh adds that “Gaseous pollutants can be utilised as a source of sulphur and nitrogen by the plants. A lot of research studies at IARI suggest that there are some crops that are more tolerant as compared to others. For example, we find tomato is more tolerant, followed by wheat and spinach is least tolerant. Amount of damage we expect from the air quality on the crops is more likely in spinach and carrots rather than wheat or tomato.”
Dr. Siddharth singh also highlights various researches which suggest that “ozone depletion reduces the yield of wheat, rice, maize and soybean crops. Some crops have been found to be more sensitive than others to ozone exposure, with wheat and soybean being particularly sensitive. Potato, rice and maize being moderately sensitive, and barley has been found to be ozone resistant.”
How agriculture sector can cope up with high AQI?
Wise management of stubble can solve the issue to some extent. The Government is rigorously taking up the issue of pollution caused due to stubble burning. The Commission on Air Quality Management in NCR and Adjoining Areas (CAQM) has developed a framework and action plan for effective prevention and control of Stubble Burning. Our experts also helped us find some viable options. For example :
- Developing high yield and short duration paddy varieties
- Extensive use of bio-decomposer developed by IARI
- Staggered harvesting schedule i.e. Instead of planting the entire crop at once, you can plant part of the crop at the beginning of the growing season and then plant more vegetables after a week or two.
- Alternative usage of paddy straw in Biomass Power Projects, Thermal Power Plants, etc.
- Agricultural stubble can effectively generate energy via combustion, gasification, or methanation.
- Incorporate the stubble into the soil. It increases soil fertility, helps in maintaining its organic matter content and improves its nutrient levels.
- Stubble compost is rich in nutrients and therefore improves the productivity of the soil. It can improve crop yield by about 4-9 %.
- Production of Biochar from the crop stubble through the process of pyrolysis.
- Prohibition of stubble / crop residue burning
- Effective monitoring / enforcement
- Schemes to reduce the generation of paddy straw
- IEC activities for the plan of action
- Standard protocol for recording and monitoring of fire counts
Contact us: If farmers want to share information or experiences related to farming with us, then they can do this by calling us on the phone number 9599273766 or by writing an email to [email protected] or by sending your recording. Through Kisan of India, we will convey your message to the people, because we believe that if the farmers are advanced then the country is happy.