More irrigated land is devoted to rice than to any other crop. A method to save water in irrigated rice cultivation is the intermittent drying of the rice fields, known as alternate wet/dry irrigation (AWDI). This report reviews previous studies in AWDI, with a focus on mosquito vector control, water saving, and rice yields. Examples are provided from a number of countries.
Romanian exile Norman Manea’s internationally acclaimed memoir/novel, now available to English-language readers At the center of The Hooligan’s Return is the author himself, always an outcast, on a bleak lifelong journey through Nazism and communism to exile in America. But while Norman Manea’s book is in many ways a memoir, it is also a deeply imaginative work, traversing time and place, life and literature, dream and reality, past and present. Autobiographical events merge with historic elements, always connecting the individual with the collective destiny. Manea speaks of the bloodiest time of the twentieth century and of the emergence afterward of a global, competitive, and sometimes cynical modern society. Both a harrowing memoir and an ambitious epic project, The Hooligan’s Return achieves a subtle internal harmony as anxiety evolves into a delicate irony and a burlesque fantasy. Beautifully written and brilliantly conceived, this is the work of a writer with an acute understanding of the vast human potential for both evil and kindness, obedience and integrity.
This open access book is about understanding the processes involved in the transformation of smallholder rice farming in the Lower Mekong Basin from a low-yielding subsistence activity to one producing the surpluses needed for national self-sufficiency and a high-value export industry. For centuries, farmers in the Basin have regarded rice as “white gold”, reflecting its centrality to their food security and well-being. In the past four decades, rice has also become a commercial crop of great importance to Mekong farmers, augmenting but not replacing its role in securing their subsistence. This book is based on collaborative research to (a) compare the current situation and trajectories of rice farmers within and between different regions of the Lower Mekong, (b) explore the value chains linking rice farmers with new technologies and input and output markets within and across national borders, and (c) understand the changing role of government policies in facilitating the on-going evolution of commercial rice farming. An introductory section places the research in geographical and historical context. Four major sections deal in turn with studies of rice farming, value chains, and policies in Northeast Thailand, Central Laos, Southeastern Cambodia, and the Mekong Delta. The final section examines the implications for rice policy in the region as a whole.
Over the past decade, we have witnessed a growing scarcity of and competition for water around the world. As the demand for water for domestic, municipal, industrial, and environmental purposes rises in the future, less water will be available for agriculture. But the potentials for new water resource development projects and expanding irrigated area are limited. We must therefore find ways to increase the productivity of water used for irrigation. This paper reviews the literature on irrigation efficiency and on the potential for increasing the productivity of water in rice-based systems. It stresses the continuing confusion over the concepts of irrigation efficiency and water productivity. It identifies the reasons for the wide gap between water requirement and actual water input (both irrigation diversions and rainfall) in irrigated rice production systems and discusses potential opportunities for increasing water productivity both on-farm and at the system level. Based on the reported low farm and system level irrigation efficiencies, the potentials for water savings in rice production appear to be very large. But we do not know the degree to which various farm and system interventions will lead to sustainable water savings in the water basin until we can quantify the downstream impact of the interventions. Studies on the economic benefits and costs, and environmental aspects of alternative interventions are also lacking. This paper emphasizes the need to measure the productivity of water at farm, system, and basin levels, and to understand how the productivity at one level relates to the productivity at another. Without water balance studies to measure productivity at these different scales, it is not possible to identify the potential economic benefits of alternative interventions and the most appropriate strategies for increasing irrigation water p productivity in rice-based systems.
This is the first volume to provide comprehensive coverage of the biology of water use efficiency at molecular, cellular, whole plant and community levels. While several works have included the phenomenon of water use efficiency, and others have concentrated on an agronomic framework, this book represents the first detailed treatment with a biological focus. The volume sets out the definitions applicable to water use efficiency, the fundamental physiology and biochemistry governing the efficiency of carbon vs water loss, the environmental regulation of this process and the detailed physiological basis by which the plant exerts control over such efficiency. It is aimed at researchers and professionals in plant physiology, biochemistry, molecular biology, developmental biology and agriculture. It will also inform those involved in formulating research and development policy in this topic around the world.
Water level declines in the Mississippi River Valley Alluvial Aquifer (MRVAA) are attributed largely to withdrawals for rice (Oryza sativa L.) irrigation. This study was performed to determine if alternative irrigation strategies for rice could reduce withdrawal from the MRVAA without having an adverse effect on grain yield, grain quality, control of barnyardgrass, and profitability. Research was conducted in Stoneville, MS and 19 on-farm locations across the Delta region of Mississippi from 2014 through 2017 to determine the irrigation threshold for alternate wetting and drying (AWD) rice irrigation, the effect of AWD management on barnyardgrass control, and effects of irrigation water management practice, i.e., conventional flood via cascade (CONV), multiple side inlet (MSI), and MSI coupled with AWD, on aquifer withdrawal, rough rice grain yield, irrigation water use efficiency (IWUE), and net returns above irrigation costs. An AWD threshold of -20 cm below the soil surface had no adverse effect on grain yield or grain quality, reduced irrigation applied by 50%, and improved IWUE by 45% compared to a continuous flood (CF). Control of barnyardgrass in AWD was either maintained or improved compared to CF for both Clearfield and conventional rice production systems. At the production scale, up to 39% less water was applied to AWD compared to CONV and MSI. Rice grain yield for AWD was not different from either CONV or MSI, despite substantial reductions in water use. Relative to standard irrigation strategies, AWD maintained or increased net returns up to $238 ha−1 for pumping depths from 5.5 m to 122 m and diesel prices from $0.42 L−1 to $0.98 L−1. Irrigation water use efficiency was up to 59% greater for AWD relative to conventional systems due to the positive effects of the former on water use while maintaining yield. These data demonstrate that AWD can reduce withdrawal from the MRVAA while maintaining or improving yield and net returns relative to irrigation strategies currently employed across the midsouthern USA rice belt.
