79 research outputs found
Spatial variability of fertilizer management and response in rainfed rice of Nepal
No full textAbstract not availableS.M. Haefele, B.K. Bhattachan, B.B. Adhikari, C.C. Abon Jr., S.M. Shrest
Climate change and unfavorable rice environments: overview of approaches to assess trends and future projections
No full textThe likely impacts of climate change on rice-based agroecosystems in Asia are uncertain, especially for rainfed rice systems in theunfavorable environments that are vulnerable to precipitation changes. Regional impacts of climate change are typically assessedquantitatively through spatially downscaling a global circulation model (GCM), but this approach is inherently biased through the GCMselected, which is typically not more than one. In this paper, we pursue a different approach that is based on an ensemble analysisof several GCMs. In the first section, the ensemble analysis is illustrated by using two rainfed rice environments (in eastern India andBangladesh) as examples. Although the different GCMs showed a similar overall trend of declining precipitation, major discrepancieshave occurred in seasonal aspects of climate change. The spatial downscaling of predicted changes in precipitation projected thatthe changes are varying throughout the months and regions, probably further increasing the severity and the areas already plaguedby floods and droughts. The second section of the paper assesses the potential and constraints of seasonal forecasting as a meansto alleviate losses in rice production. Drought is a major production constraint in rainfed rice, so that forecasts on drought occurrencecan be used to alleviate losses. In a broader sense, short-term and long-term climate projections could be a key for achieving rising productivity in unfavorable rice environments.Kay Sumfleth and Stephan M. Haefel
The right rice in the right place: systematic exchange and farmer-based evaluation of rice germplasm for salt-affected areas
No full textAbstract not availableR.K. Singh ... S.M. Haefele ... et al
Agro-economic evaluation of fertilizer recommendations for rainfed lowland rice
No full textAbstract not availableS.M. Haefele, N. Sipaseuth, V. Phengsouvanna, K. Dounphady, S. Vongsouth
Effects and fate of biochar from rice residues in rice-based systems
No full textAbstract not availableS.M. Haefele, Y. Konboon, W. Wongboon, S. Amarante, A.A. Maarifat, E.M. Pfeiffer and C. Knoblauc
High-yielding, drought-tolerant, stable rice genotypes for the shallow rainfed lowland drought-prone ecosystem
No full textAbstract not availableA. Kumar, S.B. Verulkar, N.P. Mandal, M. Variar, V.D. Shukla, J.L. Dwivedi, B.N. Singh, O.N. Singh, P. Swain, A.K. Mall, S. Robin, R. Chandrababu, A. Jain, S.M. Haefele, H.P. Piepho and A. Rama
Soil quality in rice-based rainfed lowlands of Asia: characterization and distribution
No full textOrganized jointly by the International Rice Research Institute (IRRI) and Indian Council of Agricultural Research (ICAR), the theme of this congress is "Science, technology, and trade for peace and prosperity". It comprises four major events: the 26th International Rice Research Conference; the 2nd International Rice Commerce Conference; the 2nd International Rice Technology and Cultural Exhibition; and the 2nd International Ministers` Round Table Meeting.The rainfed lowland rice production system in Asia covers about 46 million hectares, which is almost 30% of the total rice area worldwide. Production in much of this system is hampered by drought, submergence, and multiple soil constraints. The Green Revolution largely bypassed these difficult environments and they continue to be characterized by low agricultural productivity and widespread poverty. More recently, there has been some success with technology development and adaptation. However, the potential and realized benefits from research and development efforts in the rainfed lowland ecosystem will continue to strongly depend on indigenous soil fertility and soil-related constraints. As a first step in our effort to better characterize soil and water resources in rice-based rainfed lowland systems at the regional and landscape level, we characterized the distribution and frequency of soil constraints in rainfed lowlands. Seven percent of rainfed rice is grown on problem soils such as acid-sulfate soils or saline soils. One-third of rainfed lowland rice is grown on relatively fertile soils, slightly less than one-third grows on soils with low indigenous soil fertility, and slightly more than one-third grows on soils with considerable soil constraints often combined with very low soil fertility. Rainfed lowland rice in Southeast Asia is much more likely to be on poor soils with various soil constraints than in South and East/Northeast Asia.S.M. Haefele and R.J. Hijman
Yukon passive water treatment workshop (2014): Event summary report
No full textThe goal of Yukon Passive Water Treatment Workshop was to foster discussions between mines environmental personnel, regulators, project managers, consultants, design engineers, and other affected stakeholders to identify the gaps that need to be addressed.
The specific objectives were:
1. Facilitate communication between stakeholders and set up an environment for constructive discussion on progressing passive water treatment systems in the Yukon.
2. Identify constraints, gaps, and reservations that industry, regulators, and researchers encounter.
3. Increase knowledge-sharing
4. Encourage the development of plans on how to address these issues.
This event was planned and organized by Amelie Janin, NSERC Industrial Research Chair at Yukon College, Bob Truelson, Manager, Water Quality Section with Environment Yukon, and Martin Haefele, Permitting Manager at Capstone Mining Corp. Forty-seven participants attended the workshop, representing the various stakeholders.Peer reviewedRepor
Molecular breeding for phosphorus-efficient rice
No full textPublished Online: 11 OCT 2013Rice is the main staple food for more than half of the world’s population and the main source of calories in most Asian and many African countries. Since many rice-dependent countries are poor, it is critically important to keep rice prices low and increase productivity to provide sufficient food for a growing population. However, a sustainable increase in rice production is possible only if nutrients removed with the harvest are replaced by application of either mineral fertilizers or manure. Since fertilizer costs are rising, depletion of soil nutrients is an increasing problem, especially in the developing world where most farmers do not have the resources to purchase sufficient fertilizer or do not have access to fertilizer. In addition, the majority of rainfed rice in Asia is produced on poor quality and problem soils that are often low in nutrients or have properties, such as low pH or high aluminum and iron, that render phosphorus (P) unavailable to plants. On those soils, very high fertilizer doses have to be applied to provide sufficient plant-available P. Given that currently known rock phosphate reserves, the source of P fertilizer, are limited it can be expected that P deficiency will aggravate and will increasingly limit productivity, especially in poor countries. One way to address this problem is to develop crops that are more efficient in acquiring P from the soil and applied fertilizer, or crops with higher internal P-use efficiency, that is, with higher biomass production per unit P. In this paper, we provide a brief comprehensive overview on P-related aspects of rice production and highlight the potential of molecular breeding approaches to improve P-efficiency. As an example, we describe the major quantitative trait locus Phosphorus uptake 1 ( Pup1 ), which confers tolerance of P deficiency.Sigrid Heuer, J.H. Chin, R. Gamuyao, S.M. Haefele, and M. Wissuw
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