Carbon-neutral farmingBetter agricultural systems can reduce greenhouse gas emission by 20 to 60 percent
The Dudh Koshi glacier basin in the Everest region will melt by 50 percent in 2050 and by 70 to 90 percent in 2100 if global temperatures continue to rise, a 2015 report issued by the International Centre for Integrated Mountain Development (Icimod) has predicted. This implies that the Indian Subcontinent is facing desertification. Furthermore, if proper measures are not taken to contain and bring down global temperatures, scientific communities have predicted that a ‘mega drought’ lasting more than three decades could hit the US by the middle of this century. It would dry up vegetation and lead to unprecedented wildfires, aggravating carbon accumulation. Compounded with the possible desertification of the Indian Subcontinent, the global environmental consequences are beyond comprehension.
Chances of food shortages cannot be overlooked. Efforts have been made to reduce the carbon footprint in the energy and transportation sectors, and agriculture is the next stop. Combating soaring atmospheric temperatures is an intricate process of lowering carbon emission, which involves capturing and sequestrating it in the soil to raise fertility. It has been suggested that this has to be devised on the fundamentals of bio-energy with carbon capture and storage (BECCS) technologies integrated with agriculture. The reason is that synthesising chemical inputs is extremely carbon positive, and more than 2 percent of the world power output is consumed solely to make ammonia, a major component. Furthermore, national grids emit carbon during electricity generation. Thus, modification of the farming system and substitution of chemicals should also integrate localised power.
Matching growing populations with expanded infrastructure development would occupy farmlands and water recharging systems. Global warming leading to rising sea levels has submerged low-lying areas, and irritant weather patterns resulting in devastating floods and storms have shrunk farmlands. At the same time, intensive use of chemicals has led to a drop in productivity. Thus, feeding swelling populations requires greater engagement in boosting crop yields with a sustained environment.
A French farm minister has estimated that, based on the statistics of the Intergovernmental Panel on Climate Change (IPCC), better forest and agriculture systems can be instrumental in reducing greenhouse gas (GHG) emission by 20 to 60 percent. Likewise, 10-15 million tonnes of carbon dioxide can be prevented from being released if livestock is managed properly. It is also essential to cut methane and nitrous oxide discharges from forest and agriculture systems including animal husbandry. The British and French governments, under the auspices of the Prince of Wales’ International Sustainability Unit, have launched initiatives to address emerging problems. Energy resilient BECCS should be incorporated when designing strategies. This will enhance farm productivity and help to combat hunger besides avoiding the use of pesticides that are hazardous to health. However, the sheer amount of compost per unit land area in cropping makes it impossible to replace urea.
Localised energy from pyrolysis and co-combustion of agricultural or forest waste will lead to self-sufficiency while the by-product can be applied as carbon sequestration material. This will supplement the Paris Climate Summit 2015 recommendations to increase soil carbon by 0.4 percent. In addition, it has the potential to hold five times its own weight in water in fields that can maintain moisture. This porous nutrient trapping material will control leaching and prevent eutrophication. The composition can also be used as artificial soil for indoor and stack farming in both rural and urban settings where cultivable land is limited.
Biological nitrogen fixation is a natural phenomenon.But the liquid growth system consumes a lot of water, and this can affect its universal acceptance. Thus, designing an innovative bacterial cultivation system that is farmer-friendly and incorporating additional micro organisms could be a solution. Moreover, it can be a critical unique feature in the creation of a micro environment that will be favourable to beneficials but hostile to pathogens. Metal, phosphate, potassium and silica solubilisation by microbes will provide minerals to plants besides helping to build resistance and immunity. In addition, the ability to fix carbon dioxide as calcium carbonate and silica solubilisation by one of the constituent organisms will lead to a cementing reaction in the outer membrane of plants. This will prevent biotic invasion and help to reduce application of pesticides and fungicides.
This can be a reward for farmers for growing organic foods. It can increase the total terrestrial carbon and help to prevent the assimilation of warming gases. Likewise, the use of natural gas in making urea will be prevented and energy use in the production of fertiliser will be minimised. The same concept can be used to make rumen feed to reduce enteric methane when devising eco-friendly agriculture systems. A prototype has been designed, and field trials are being planned.
Aryal has a post-doctorate from Vanderbilt University, US