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Managing water in rainfed agriculture
01 Jan 2007-
About: The article was published on 2007-01-01 and is currently open access. It has received 79 citations till now. The article focuses on the topics: Rainfed agriculture.
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TL;DR: In this article, the authors used a grid-based dynamic water balance model to estimate the green, blue and grey water footprint of global crop production in a spatially-explicit way for the period 1996-2005.
Abstract: This study quantifies the green, blue and grey water footprint of global crop production in a spatially-explicit way for the period 1996–2005. The assessment improves upon earlier research by taking a high-resolution approach, estimating the water footprint of 126 crops at a 5 by 5 arc minute grid. We have used a grid-based dynamic water balance model to calculate crop water use over time, with a time step of one day. The model takes into account the daily soil water balance and climatic conditions for each grid cell. In addition, the water pollution associated with the use of nitrogen fertilizer in crop production is estimated for each grid cell. The crop evapotranspiration of additional 20 minor crops is calculated with the CROPWAT model. In addition, we have calculated the water footprint of more than two hundred derived crop products, including various flours, beverages, fibres and biofuels. We have used the water footprint assessment framework as in the guideline of the Water Footprint Network.
Considering the water footprints of primary crops, we see that the global average water footprint per ton of crop increases from sugar crops (roughly 200 m3 ton−1), vegetables (300 m3 ton−1), roots and tubers (400 m3 ton−1), fruits (1000 m3 ton−1), cereals (1600 m3 ton−1), oil crops (2400 m3 ton−1) to pulses (4000 m3 ton−1). The water footprint varies, however, across different crops per crop category and per production region as well. Besides, if one considers the water footprint per kcal, the picture changes as well. When considered per ton of product, commodities with relatively large water footprints are: coffee, tea, cocoa, tobacco, spices, nuts, rubber and fibres. The analysis of water footprints of different biofuels shows that bio-ethanol has a lower water footprint (in m3 GJ−1) than biodiesel, which supports earlier analyses. The crop used matters significantly as well: the global average water footprint of bio-ethanol based on sugar beet amounts to 51 m3 GJ−1, while this is 121 m3 GJ−1 for maize.
The global water footprint related to crop production in the period 1996–2005 was 7404 billion cubic meters per year (78 % green, 12 % blue, 10 % grey). A large total water footprint was calculated for wheat (1087 Gm3 yr−1), rice (992 Gm3 yr−1) and maize (770 Gm3 yr−1). Wheat and rice have the largest blue water footprints, together accounting for 45 % of the global blue water footprint. At country level, the total water footprint was largest for India (1047 Gm3 yr−1), China (967 Gm3 yr−1) and the USA (826 Gm3 yr−1). A relatively large total blue water footprint as a result of crop production is observed in the Indus river basin (117 Gm3 yr−1) and the Ganges river basin (108 Gm3 yr−1). The two basins together account for 25 % of the blue water footprint related to global crop production. Globally, rain-fed agriculture has a water footprint of 5173 Gm3 yr−1 (91 % green, 9 % grey); irrigated agriculture has a water footprint of 2230 Gm3 yr−1 (48 % green, 40 % blue, 12 % grey).
1,664 citations
TL;DR: In this article, the potential of green water for increasing resilience to global change is explored for the future water availability for global food production and the potential for green water to increase resilience to climate change.
Abstract: Future water availability for global food production : the potential of green water for increasing resilience to global change
547 citations
TL;DR: In this article, the authors examined four sets of scenarios that vary in their focus on investments in rainfed agriculture and irrigation, and the role of international trade in adjusting for national disparities in water endowments.
369 citations
TL;DR: Risk assessment is essential in post-disasters situations and the rapid implementation of control measures through re-establishment and improvement of primary healthcare delivery should be given high priority, especially in the absence of pre-disaster surveillance data.
Abstract: Natural disasters may lead to infectious disease outbreaks when they result in substantial population displacement and exacerbate synergic risk factors (change in the environment, in human conditions and in the vulnerability to existing pathogens) for disease transmission. We reviewed risk factors and potential infectious diseases resulting from prolonged secondary effects of major natural disasters that occurred from 2000 to 2011. Natural disasters including floods, tsunamis, earthquakes, tropical cyclones (e.g., hurricanes and typhoons) and tornadoes have been secondarily described with the following infectious diseases including diarrheal diseases, acute respiratory infections, malaria, leptospirosis, measles, dengue fever, viral hepatitis, typhoid fever, meningitis, as well as tetanus and cutaneous mucormycosis. Risk assessment is essential in post-disaster situations and the rapid implementation of control measures through re-establishment and improvement of primary healthcare delivery should be give...
366 citations
TL;DR: In this article, the authors present evidence of increased yields and improved water productivity using conservation farming in semi-arid and dry sub-humid locations in Ethiopia, Kenya, Tanzania and Zambia.
Abstract: Improved agricultural productivity using conservation farming (CF) systems based on non-inversion tillage methods, have predominantly originated from farming systems in sub-humid to humid regions where water is not a key limiting factor for crop growth. This paper presents evidence of increased yields and improved water productivity using conservation farming in semi-arid and dry sub-humid locations in Ethiopia, Kenya, Tanzania and Zambia. Results are based on on-farm farmer and research managed experiments during the period 1999–2003. Grain yield of maize (Zea mays L.) and tef (Eragrostis Tef (Zucc)) from conventional (inversion) tillage are compared with CF with and without fertilizer. Rain water productivity (WPrain) is assessed for the locations, treatments and seasons. Results indicate significantly higher yields (p
323 citations