Rice is a cereal grain and in its domesticated form, it is a staple food for over half of the world’s human population, especially in Asia and Africa. It is nutritious and a rich source of carbohydrates, the body’s main fuel source.
By Heman Zakaria
Carbohydrates can keep you energized and satisfied and are important for fueling exercise. Brown rice, especially, is an excellent source of many nutrients, including fiber, manganese, selenium, magnesium and B vitamins.
Rice farming is one of the most lucrative types of farming in Nigeria. Although it is classified as a cash crop for farmers, it is one of the most consumed staple food and important cereal in the country. Almost seven million tons are consumed per year in the country. The best time to plant the crop in Nigeria is in mid-March and mid-April. The rice planted are ready for harvesting after three to four months of planting. When it changes colour from green to brown, it is an indication that it is ready for harvest.
At the inception of the administration of former president Mohammadu Burari, in a bid to rejuvenate the economy and discourage importation of rice, the government put a ban on rice importation and rolled out various interventions programs and schemes to support local production and processing of the crop.
This research underscore recent studies conducted on rice and its contribution to climate change. The world is presently focusing on climate change, and most especially methane emissions due to increase in rice production in the sub-Saharan Africa.
In Nigeria, cities where rice is produced include: Lagos, Kano, Ibadan, Kaduna, Port Harcourt, Benin City, Maiduguri, Zaria, Jos, Ilorin, Oyo, Enugu, Abeokuta, Abuja, Sokoto Onitsha, Warri, Okene, Calabar, Uyo, Katsina, Ado-Ekiti, Akure, Bauchi, Ikeja, Makurdi, Minna, Efon-Alaaye, Ilesa, Owo, Umuahia, Ondo, Ikot Ekpene, Iwo, Gombe, Jimeta, Atani, Gusau, Mubi, Ikire, Owerri, Shagamu, Ijebu-Ode, Ugep, Nnewi, Ise-Ekiti, Ila Orangun, Saki, Bada, Awka, Ijero-Ekiti, Inisa, Suleja, Sapele, Osogbo, Kisi, Gbongan, Ejigbo, Funtua, Igboho, Buguma, Ikirun, Abakaliki, Okrika, Amaigbo, Lafiya, Gashua, Modakeke, Bama, Ilobu, Jalingo, Okigwe, Offa, Esuk Oron, Nsukka, Nguru, Hadejia, Ijebu-Igbo, Uromi, Birnin Kebbi, Pindiga, Azare, Nkpor, Ikere-Ekiti, Lafiagi, Kontagora, Kuje, Yola, Biu, Olupona, Lere, Wukari, Igbo-Ora, Emure-Ekiti, Isieke, Ifo, Igede-Ekiti, Effium, Idanre, Potiskum, Keffi, Makoko, Epe, Gamboru, Ogaminana, Ihiala, Ipoti, Lalupon, Ughelli, Bende, Oke Mesi, Kafanchan, Ikom, Agulu, Daura, Numan, Kagoro, Ode, Igbo-Ukwu, Aramoki-Ekiti, Igbara-Odo, Ozubulu, Aku, Oyan, Jega, Asaba and Ohafia-Ifigh among those under sub-Saharan Africa.
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In prior research, it was discovered that methane is the second most important greenhouse gas (behind carbon dioxide). It was found to have more radiative properties (it holds in heat better) than CO2. This means that even though far less of it is emitted into the atmosphere, it still plays a major role in global warming. The research also shows that agricultural activities (from crops and livestock combined) account for approximately 25% of all human caused methane emissions into the atmosphere. Waste disposal and fossil fuel production account for most of the rest.
A study of many publications by Heman Gabriel has shown that growing rice in sub-Saharan Africa doubled in production from 2008 to 2018. A good trend for feeding people (it currently accounts for approximately 9% of the continent’s caloric intake) but not so good for the environment. Growing rice releases very large amounts of methane into the atmosphere.
Researchers in another study started with numbers representing Africa’s total greenhouse gas emissions prior to 2008 and then added in the amount that has been emitted due to factors involved in growing rice, such as irrigation, flooding patties, burning fields, and harvesting. As part of that effort, they assessed the rice growing extent, which included more accurately outlining rice growing land and the number of days rice fields in Africa emit methane. They used what they had learned to calculate new estimates of methane emissions into the atmosphere for all of Africa. Their research team found that the increase in rice production in Africa accounted for approximately 31% of the increases in methane emissions for all of Africa from 2006 to 2017, and seven percent of the global rise in methane emissions for the same period.
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How Nigerian farmers can reduce methane emissions
Livestock, petroleum industry and landfills are all leading producers of methane, a potent greenhouse gas. But another significant but less well-known contributor is one of the world’s most popular crops: rice. Rice plants transport methane from the flooded rice fields into the atmosphere. A new paper from researchers at the Alliance of Bioversity International and CIAT finds that it is possible to lower emissions by developing new varieties of rice.
According to the World Bank, rice farming is responsible for 10% of global methane emissions and is also a contributor to nitrous oxide and carbon dioxide emissions. Despite this, greenhouse gas emissions is from rice systems, particularly in Nigeria and Sub-Saharan Africa which has been a largely untapped research area for the reduction of global emissions. However, the transition to low emission rice production systems can be accelerated by using differences in productivity and root qualities to breed a variety of rice that can maintain current yields but lower overall greenhouse gas emissions.
María Fernanda Álvarez explained that although the higher yielding hybrids they studied have a higher absolute methane emission than current varieties, they produce similar methane per grain of rice. This implies that by adopting rice hybrids, farmers can achieve food security goals without significantly increasing the methane emission per grain of rice compared to lower yielding varieties. “We must acknowledge that it’s not easy to reduce methane emissions and maintain productive rice systems, but our results suggest that there is hope,” Álvarez said.
Reducing rice emissions
When soil is flooded, as in rice production, this produces low-oxygen (anaerobic) conditions in which methane producing bacteria thrive. The rice plant uses aerenchyma, a spongy chimney like plant tissue, to allow oxygen to move down into the roots and the methane producing bacteria in the soil are using the same tube to send methane up into the atmosphere.
Paul Abayomi S. Soremi, a lecturer at the Federal University of Agriculture in Abeokuta, Nigeria, explained that under submerged conditions, the roots of plants in general and rice in particular are responsible for taking up and expelling gases, including methane. “The challenges to decrease methane emission through the expression of aerenchyma include the non-availability of adequate and up-to-date equipment to characterize aerenchyma, huge consumables requirement and inadequate human capacity,” he said, “This requires huge financial investment.”
Ngonidzashe Chirinda, a professor of sustainable tropical agriculture at Morroco’s Mohammed VI Polytechnic University and an expert in the greenhouse gas impact of agriculture said that further research into the physiology of the plants was needed to develop the next generation of low-emissions varieties.
Conclusion
In conclusion, investment by private, government and nonprofit organizations and bodies should not just be centred on production but on developing highbrid variety seeds and a systematic and climate-smart production of rice in Nigeria, most especially rice producing communities.
