نتایج جستجو برای: irrigated cropping
تعداد نتایج: 18623 فیلتر نتایج به سال:
Conventional field cropping systems have been criticized as being unsustainable because they contribute to on-farm and off-farm environmental degradation, and are often economically uncertain. Methods to increase environmental and economic sustainability are needed. There is a critical need to develop management technologies to maximize yield and crop quality yet improve environmental impacts o...
We evaluated the eff ects of irrigated crop management practices on nitrous oxide (N2O) emissions from soil. Emissions were monitored from several irrigated cropping systems receiving N fertilizer rates ranging from 0 to 246 kg N ha−1 during the 2005 and 2006 growing seasons. Cropping systems included conventional-till (CT) continuous corn (Zea mays L.), no-till (NT) continuous corn, NT corn–dr...
Changes in surface land use may threaten groundwater quality and ecosystem integrity, particularly in shallow aquifers where links between groundwater and surface activities are most intimate. In this study we examine the response of groundwater ecosystem to agricultural land uses in the shallow alluvial aquifer of the Gwydir River valley, New South Wales, Australia. We compared groundwater qua...
This study presents a global scale analysis of cropping intensity, crop duration and fallow land extent computed by using the global dataset on monthly irrigated and rainfed crop areas MIRCA2000. MIRCA2000 was mainly derived from census data and crop calendars from literature. Global cropland extent was 16 million km around the year 2000 of which 4.4 million km (28%) was fallow, resulting in an...
The role of urban agriculture in global food security is a topic of increasing discussion. Existing research on urban and peri-urban agriculture consists largely of case studies that frequently use disparate definitions of urban and peri-urban agriculture depending on the local context and study objectives. This lack of consistency makes quantification of the extent of this practice at the glob...
The multiple cropping practice is essential to agriculture because it has been shown to significantly increase the grain yield and promote agricultural economic development. In this study, potential multiple cropping systems in China are calculated based on meteorological observation data by using the Agricultural Ecology Zone (AEZ) model. Following this, the changes in the potential cropping s...
We evaluated the effects of irrigated crop management practices on nitrous oxide (N(2)O) emissions from soil. Emissions were monitored from several irrigated cropping systems receiving N fertilizer rates ranging from 0 to 246 kg N ha(-1) during the 2005 and 2006 growing seasons. Cropping systems included conventional-till (CT) continuous corn (Zea mays L.), no-till (NT) continuous corn, NT corn...
A mathematical programming model is proposed for optimal cropping patterns under water de®cits in dry regions. Crops may be deliberately under-irrigated in order to increase the total irrigated area and possibly the pro®t. An operating policy will identify both the total area and the irrigation level allocated to a given selected crop taking into account the possible successors and predecessors...
Nitrogen fertilization is essential for optimizing crop yields and economic returns in irrigated cropping systems in the Central Great Plains area of the USA. However, N application generally increases the emissions of the potent greenhouse gas, N 2 O, from these systems. Nitrous oxide is produced through nitrifi cation and denitrifi cation processes in the soil. Agriculture contributes approxi...
Potato productivity in the northeastern US has been relatively constant for over 50 years, raising questions about what factors are limiting productivity. Research was initiated in 2004 to identify key constraints to potato productivity by evaluating Status Quo (SQ), Soil Conserving (SC), and Soil Improving (SI) cropping systems under both rainfed and irrigated management, and it was found that...
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