Carbon sequestration for better dryland productivity

The world rejoices over the award of the 2007 Nobel Peace Prize to those who focussed on climate change, yet even simple agricultural practices can greatly help mitigate this global challenge. Climate change occurs when there is a build-up of carbon in the atmosphere. However, if carbon is collected (or sequestered) in the soil and used to increase productivity, the results are three-fold — a reduction in atmospheric carbon levels, increased crop yields, and more inc ome for farmers.Ironic as it may sound, in dryland agriculture the availability of organic carbon in the soil is the key to increasing productivity. Hence, "look down at the soil to make your agricultural productivity look up" is the new motto of agricultural scientists, especially those working with natural resource management and watershed development. This, however, calls for massive investment by developed and developing countries to support dryland agricultural research and corresponding support systems.Although there is much attention and support being given to irrigated agriculture, drylands occupy 80 per cent of agricultural land and generate 58 per cent of the world's staple foods. In fact, most of the food for the poor in the developing countries is produced in dryland and rainfed areas. More than 95 per cent of the farm land in sub-Saharan Africa (SSA) is rainfed. In Latin America the figure is almost 90 per cent, in South Asia about 60 per cent, in East Asia 65 per cent and in the Near East and North Africa 75 per cent. In India, 66 per cent of the 142 million hectares of arable land is rainfed.Rainfed areas are also hotspots of poverty, malnutrition, and child mortality. Of the one billion poor people in the world, India accounts for 25.9 per cent and China 16.7 per cent. The rest of the Asia-Pacific accounts for 18.3 per cent. Asia is a hub where the poor, undernourished, and the vulnerable live. This is followed by sub-Saharan Africa, which accounts for 23.9 per cent.A close look at the rainfed regions shows a grim picture of water scarcity, fragile environments, drought, and land degradation caused by low rainwater use efficiency, high population pressure, poverty, poor infrastructure, and inappropriate policies. Drought and land degradation are interlinked in a cause-and-effect relationship, which in turn causes poverty. This unholy nexus among drought, poverty, and land degradation must be broken if we have to meet the Millennium Development Goal of halving the number of food-insecure poor by 2015.Added to this is the threat of climate change. It is anticipated that climate change will lead to more rainfall variability and increased frequency of extreme events, resulting in more and longer dry spells due to global warming.
Soil is the key
Innovative strategies are required to help the dryland farmer overcome these difficulties. As the world's top research centre for dryland agriculture, the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in Andhra Pradesh is working on increasing the organic carbon level in the soil through increased sequestration (accumulation from the environment).Soil organic carbon is the source of energy to fuel biological activities in the soil, which in turn control the availability of nutrients for plant growth as well as soil water availability — a critical yield component in tropical drylands.Long-term watershed management experiments at the ICRISAT campus at Patancheru over the last 33 years have consistently demonstrated that drylands can produce 5.1 tonnes of grain per hectare a year, supporting 21 persons as compared to 1.1 tonnes of grain per hectare a year supporting 4.8 persons in case of farmers' practice. Moreover, the system is still gaining at the rate of 78 kg of grain per hectare a year, and the new equilibrium is yet to be reached.Along with increased productivity, improved watershed management practices sequestered 330 kg of carbon per hectare a year up to a depth of 120 cm by intercropping sorghum and pigeon pea. Increased carbon sequestration not only increased nutrient supply and turnover capacity of the soil but resulted in substantial changes in the physical and biological properties of the soil, which increase water holding capacity and the ability to cope with longer dry spells during crop growth.Moreover, ICRISAT's research has shown that legumes in general and pigeon pea in particular have the ability to sequester more carbon in tropical soils. Through the adoption of improved water, soil and crop management options, carbon sequestration in legume-based systems can be improved further. If this is adopted within an integrated community watershed, the productivity of rainfed agriculture can be doubled, providing increased incomes to farmers.
Thirst and hunger
Tropical soils are not only thirsty but also hungry, particularly for micronutrients such as zinc, boron, and secondary nutrients such as sulphur, along with macronutrients such as nitrogen and phosphorus. ICRISAT's work has shown that by adopting integrated nutrient management after testing the soil for deficiencies and combining it with improved crop varieties and water management, rainwater use efficiency can be increased by up to 65-70 per cent along with increased productivity and improved livelihoods.ICRISAT has strengthened its research in partnership with the Indian Council of Agricultural Research under the National Agriculture Technology Project (NATP) funded by the World Bank. A study of 58 samples from 28 benchmark spots in the drylands of India revealed that black soils as well as red soils have the potential to sequester carbon by adopting suitable cropping with high-yielding varieties and legumes, along with management practices such as water management and the use of green manure. ICRISAT works with a consortium of partners including national agricultural research systems, State agricultural universities, civil society organisations and farmers' organisations. Along with accumulating carbon in the soil, our work has led to convergence, collective action and capacity building to empower dryland communities.ICRISAT's watershed development model has been widely accepted in India, China, Thailand, and Vietnam in Asia. It is also moving to Eastern Africa through South-South cooperation.
The hindu October 24
Bio-diesel plant using variety of materials as feedstock developed
A team of Pune-based entrepreneurs has developed a continuous processing bio-diesel plant against the batch-type plants presently in use. A pilot plant with a 1,200 litres per day capacity has been installed at Bhosari, and a US patent for the process has been filed for, Prof Kshitij Patukale, one of the team members says. This advantage of this new technology is that a variety of materials including acid oil, a waste product of the solvent extraction process, can be used as feedstock, says Mr Patukale.
Feedstock
"The bio-diesel industry is worried about availability of feed stock. Efforts in last several years have been concentrated on plantation of bio-diesel species such as jatropha, pongamia, simarruba, neem, etc. The Union and State Government agencies have actively promoted jatropha on thousands of hectares of land all over India. But what are the results? That jatropha is not a 'plant it, forget it' species as was believed. So one cannot depend solely on the non-edible oils as feedstock in India," he says, adding that other sources as feed stock for manufacturing of bio-diesel must be found. According to Mr Patukale, any available oil in large quality with any FFA and different chemical properties should get converted into bio-diesel."A large number of oils such as acid oil, palm oil, rice bran oil, rapeseed oil, soyabean oil, fish oil are available all over the world. Several eminent scientists are talking about castor as 90-day bio-diesel crop," he says asserting that the bio-diesel industry in India today is looking for the right technology to convert any oil into bio-diesel.
One of the major sources of bio-diesel, he points out is acid oil, 10 lakh tonnes per day of which is generated every day in the country as a result of refining of edible oils. Traditionally this is sold to the soap industry, but could be diverted for production of bio-diesel and can yield 98 per cent bio-diesel litre-on-litre. This product, if it meets the norms of the American Society for Materials and Testing, can replace diesel, and cost 10 per cent lower, Mr Patukale says. The pilot plant is presently installed at Jaypex Biofuel Processing Technologies Pvt Ltd, at Bhosari near Pune.

Business Line October 27

Oceans may be losing ability to absorb CO2

The world's oceans may be losing their ability to soak up extra carbon dioxide (CO2) from the atmosphere, with the risk that this will help stoke global warming, two new studies say.Absorption of atmospheric CO2 by the North Atlantic plunged by half between the mid-1990s and 2002-5, British researchers say in a paper published in the November issue of the Journal of Geophysical Research.The data comes from sensors lowered by a container ship carrying bananas, which makes a round trip from the West Indies to Britain every month. It has generated more than 90,000 measurements of ocean CO2.The finding touches on a key aspect of the global warming question, because for decades the ocean has been absorbing much of the CO2 released into the atmosphere from the burning of fossil fuels.
If the sea performs less well as a carbon sponge, or "sink" according to the technical jargon, more CO2 will remain in the atmosphere, thus accelerating the greenhouse effect.Ute Schuster, who led the research with Professor Andrew Watson of the University of East Anglia's School of Environmental Sciences, admitted she was astonished by the data."Such large changes are a tremendous surprise. We expected that the uptake would change only slowly because of the ocean's great mass," Schuster was quoted by the university in a press release Monday as saying.
Research last year pointed to rising acidification of the oceans as a result of CO2 uptake, highlighting the risk of carbon saturation as well as a looming peril for biodiversity.Schuster was cautious about drawing too swift a conclusion from the new research."Perhaps this is partly a natural oscillation or perhaps it is a response to the recent rapid climate warming," she said."In either case, we now know that the sink can change quickly and we need to continue to monitor the ocean uptake."

Business Line October 22

Trees with rabbit genes accelerate cleaning of soil

Genetically modified plants that can break down pollutants may be an effective way to clean soil contaminated by industrial chemicals and explosives used by the military, say scientists.Tests on six-inch tall GM poplar cuttings which had a gene from a rabbit inserted into them showed that they could remove up to 91 per cent of a chemical called trichloroethylene from the water used in their feed. This chemical, used as an industrial degreaser and one of the most common contaminants of ground water, was broken down by the plants into harmless byproducts more than 100 times faster than by unaltered plants."In view of their large size and extensive root systems, these transgenic poplars may provide the means to effectively clean sites contaminated with a variety of pollutants at much faster rates and at lower costs than can be achieved with current conventional techniques," wrote Sharon Doty, of the University of Washington, Seattle, on Monday in the Proceedings of the National Academy of Sciences (PNAS).
The GM poplars also broke down other common environmental pollutants such as chloroform, a byproduct of the disinfection of drinking water, the solvent carbon tetrachloride, and vinyl chloride, used to make plastics. Poplars use an enzyme called cytochrome P450 to break down contaminants. Trichloroethylene is turned into a harmless salt, water and carbon dioxide.After Dr. Doty's team inserted the gene into the tree from a rabbit they also produced P450, but at a much faster rate. Ultimately, the scientists would like to manipulate the plant's own genes to achieve the same goal.
Another study, also published in the PNAS, demonstrated a way to break down the military explosive RDX. "Widespread contamination of land and ground water has resulted from the use, manufacture, and storage of the military explosive ... RDX. This contamination has led to a requirement for a sustainable, low-cost method to remediate this problem," wrote Neil Bruce, of the University of York. "One of the biggest concerns of RDX as a pollutant is that it migrates readily through soil into the ground water and subsequently contaminates drinking water supplies." His team genetically modified Arabidopsis plants to express enzymes called XplA and XplB, which are known to break down RDX. At their best, the plants reduced RDX concentrations from soil by up to 97 per cent in one week. Though the GM plants may be an effective way to treat pollutants, Dr. Doty acknowledged that people might have concerns at the thought of forests of GM trees. In the United States and Britain, such plants can currently only be grown for research purposes. Dr. Doty added that poplars were fast-growing and could grow for several years without flowering, so there was reduced risk of their genes being transferred into wild populations of the tree. — ©Guardian Newspapers Limited, 2007

The Hindu October 17

Tsunami early warning centre dedicated to nation

India is likely to become the first country in the world to acquire capabilities of predicting the likelihood of a tsunami in seven minutes after any major earthquake in Indian Ocean soon."Now, we have systems in place to predict the likelihood of tsunami within 30 minutes after a quake in Indian Ocean system. Efforts are on to bring this down to seven minutes," Mr Kapil Sibal, Union Minister for Science and Technology, said after dedicating the Tsunami Early Warning Centre set up at the Indian National Centre for Ocean Information Services (INCOIS) to the nation here .As per the existing system, six Bottom Pressure Recorders (BPRs) installed in the Bay of Bengal and Arabian Sea would collect data about the intensity of a quake which would be transmitted to the ground station for further analysis. "If we could analyse the data in BPRs themselves, possibly the time could be brought down to seven minutes and we will do it," Mr Sibal explained.
More dedicated centres
The INCOIS, under the Ministry of Earth Sciences, would be expanded with the addition of two more dedicated centres for study of marine mechanisms and operational oceanography, he added.
The Chief Minister of Andhra Pradesh, Dr Y.S. Rajasekhara Reddy, said the State Government would grant 10 acres of land for expansion of INCOIS campus. Mr P.S. Goel, Secretary, Ministry of Earth Sciences, said six more BPRs would be installed in the Bay of Bengal and Arabian Sea soon to increase the efficiency of the centre.Mr Shailesh Nayak, Director, INCOIS, said the Early Warning Centre's predictions proved to be correct and authentic in the case of a small tsunami wave in Indian Ocean on September 12, 2007.
The Early Warning Centre, set up at a cost of Rs 125 crore, receives real-time seismic data from the national seismic network of the India Meteorological Department and other international seismic networks. It detects all earthquake events of over six point magnitude occurring in the Indian Ocean while the BPRs confirm the triggering of a tsunami. On the basis of this information, the centre would generate and disseminate timely advisories to the control room of the Ministry of Home Affairs for further dissemination to the public.

Business line October 16