The Experts below are selected from a list of 40209 Experts worldwide ranked by ideXlab platform
Klaus Butterbachbahl - One of the best experts on this subject based on the ideXlab platform.
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nitrous oxide and methane fluxes from a rice wheat crop rotation under wheat residue incorporation and no tillage practices
Atmospheric Environment, 2013Co-Authors: Xunhua Zheng, Rui Wang, Klaus ButterbachbahlAbstract:Abstract Crop residue incorporation and no-tillage are recommended as management practices and are being increasingly adopted in the agricultural sector. However, few studies have assessed the extent to which these practices integrate annual carbon and Nitrogen trace gas fluxes and grain yield. We investigated the effect of wheat straw incorporation and no-tillage on nitrous oxide (N2O) and methane (CH4) fluxes from a rice–wheat system in southeast China, using year-round field measurements. Compared to the treatment with synthetic Nitrogen Fertilizers alone, the wheat straw incorporation reduced the N2O emissions by 38% (P
Eric A Davidson - One of the best experts on this subject based on the ideXlab platform.
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the contribution of manure and fertilizer Nitrogen to atmospheric nitrous oxide since 1860
Nature Geoscience, 2009Co-Authors: Eric A DavidsonAbstract:Atmospheric nitrous oxide concentrations have been increasing since the industrial revolution and currently account for 6% of total anthropogenic radiative forcing. Microbial production in soils is the dominant nitrous oxide source; this has increased with increasing use of Nitrogen Fertilizers. However, fertilizer use alone cannot account for the historical trends of atmospheric concentrations of nitrous oxide. Here, I analyse atmospheric concentrations, industrial sources of nitrous oxide, and fertilizer and manure production since 1860. Before 1960, agricultural expansion, including livestock production, may have caused globally significant mining of soil Nitrogen, fuelling a steady increase in atmospheric nitrous oxide. After 1960, the rate of the increase rose, due to accelerating use of synthetic Nitrogen Fertilizers. Using a regression model, I show that 2.0% of manure Nitrogen and 2.5% of fertilizer Nitrogen was converted to nitrous oxide between 1860 and 2005; these percentage contributions explain the entire pattern of increasing nitrous oxide concentrations over this period. Consideration of processes that re-concentrate soil Nitrogen, such as manure production by livestock, improved ‘hind-casting’ of nitrous oxide emissions. As animal protein consumption in human diets increases globally, management of manure will be an important component of future efforts to reduce anthropogenic nitrous oxide sources. Atmospheric concentrations of nitrous oxide, a greenhouse gas, have increased since 1860. A regression model indicates that conversion of 2% of manure Nitrogen and 2.5% of fertilizer Nitrogen could explain the pattern of increasing nitrous oxide concentrations between 1860 and 2005, including a rise in the rate of increase around 1960.
X X Zhang - One of the best experts on this subject based on the ideXlab platform.
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deep placement of Nitrogen Fertilizers reduces ammonia volatilization and increases Nitrogen utilization efficiency in no tillage paddy fields in central china
Field Crops Research, 2015Co-Authors: T Q Liu, X X Zhang, J Chen, D J Fan, Cougui CaoAbstract:Abstract Deep placement of Nitrogen fertilizer affects the fate of fertilizer Nitrogen through influencing Nitrogen transformation. Few studies have examined ammonia (NH3) volatilization and Nitrogen-utilization efficiency under deep placement of Nitrogen Fertilizers in no-tillage (NT) paddy fields. Therefore, a field experiment was conducted to investigate the different application methods of Nitrogen Fertilizers [no fertilizer, traditional Nitrogen broadcasting (S), and point deep placed at 5 cm, 10 cm and 20 cm depths as basal fertilizer + Nitrogen broadcasting as topdressing (e.g., 5D, 10D and 20D)] on NH3 volatilization, Nitrogen recovery efficiency (NRE), Nitrogen partial factor productivity (NPFP), Nitrogen agronomic efficiency (NAE), and grain yield in NT paddy fields during the 2012–2013 rice growing seasons in central China. Nitrogen deep placement significantly decreased mean floodwater pH by 2–4% and mean floodwater NH4+–N concentration by 29–98% compared with Nitrogen broadcasting. Nitrogen deep placement treatments significantly decreased cumulative NH3 volatilization by 20–45% in 2012 and by 15–40% in 2013 compared with S treatment. On average, Nitrogen deep placement treatments significantly increased NRE by 26–93%, NPFP by 10–16%, NAE by 31–51%, and grain yield by 5–11% in both seasons compared with S treatment. In addition, 10D treatment showed the highest Nitrogen utilization efficiency and grain yield, implying that this measure can be effective in increasing agricultural economic viability and decreasing NH3 volatilization. However, given high labor requirement for manual deep placement, developing mechanical fertilization technology is necessary to overcome this difficulty in future.
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deep placement of Nitrogen Fertilizers reduces ammonia volatilization and increases Nitrogen utilization efficiency in no tillage paddy fields in central china
Field Crops Research, 2015Co-Authors: X X Zhang, J Chen, Chengfang LiAbstract:Abstract Deep placement of Nitrogen fertilizer affects the fate of fertilizer Nitrogen through influencing Nitrogen transformation. Few studies have examined ammonia (NH3) volatilization and Nitrogen-utilization efficiency under deep placement of Nitrogen Fertilizers in no-tillage (NT) paddy fields. Therefore, a field experiment was conducted to investigate the different application methods of Nitrogen Fertilizers [no fertilizer, traditional Nitrogen broadcasting (S), and point deep placed at 5 cm, 10 cm and 20 cm depths as basal fertilizer + Nitrogen broadcasting as topdressing (e.g., 5D, 10D and 20D)] on NH3 volatilization, Nitrogen recovery efficiency (NRE), Nitrogen partial factor productivity (NPFP), Nitrogen agronomic efficiency (NAE), and grain yield in NT paddy fields during the 2012–2013 rice growing seasons in central China. Nitrogen deep placement significantly decreased mean floodwater pH by 2–4% and mean floodwater NH4+–N concentration by 29–98% compared with Nitrogen broadcasting. Nitrogen deep placement treatments significantly decreased cumulative NH3 volatilization by 20–45% in 2012 and by 15–40% in 2013 compared with S treatment. On average, Nitrogen deep placement treatments significantly increased NRE by 26–93%, NPFP by 10–16%, NAE by 31–51%, and grain yield by 5–11% in both seasons compared with S treatment. In addition, 10D treatment showed the highest Nitrogen utilization efficiency and grain yield, implying that this measure can be effective in increasing agricultural economic viability and decreasing NH3 volatilization. However, given high labor requirement for manual deep placement, developing mechanical fertilization technology is necessary to overcome this difficulty in future.
Kees Jan Van Groenigen - One of the best experts on this subject based on the ideXlab platform.
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enhanced efficiency Nitrogen Fertilizers for rice systems meta analysis of yield and Nitrogen uptake
Field Crops Research, 2013Co-Authors: Bruce A Linquist, Chris Van Kessel, Kees Jan Van GroenigenAbstract:Abstract Nitrogen is deficient in most soils and is applied in the greatest quantities of all nutrients. Given its high potential for loss, efficient fertilizer N management has both economic and environmental consequences. Enhanced efficiency Nitrogen Fertilizers (EENF) have been developed to decrease N losses and improve N use efficiency. However, studies evaluating the effectiveness of EENF products in rice systems show mixed results. The objective of this meta-analysis was to quantify the benefits of EENF (i.e. nitrification and urease inhibitors, neem, and slow release Fertilizers) in terms of yield and N uptake and to determine under what conditions EENF are most effective. The analysis included 32 field studies (178 observations) for the effects of EENF on crop yield and 14 studies (82 observations) on N uptake. Overall, the use of EENF led to a 5.7% (95% CI = 3.9–7.7%) increase in yield and an 8.0% (95% CI = 5.2–10.7%) increase in N uptake. Soil pH (pH of dry soil) had a significant impact on EENF effectiveness. In acidic soils (pH ≤ 6.0) the application of EENF did not significantly affect yield or N uptake; however the yield response to EENF increased to 10.2% (95% CI = 5.3–16.6%) in alkaline soils (pH ≥ 8.0). There was no difference among the classes of EENF when separated by their mode of action (i.e. urease inhibitors, nitrification inhibitors or slow release). When EENF products were analyzed separately, NBPT [N-(n-butyl) phosphoric triamide] and neem proved effective in increasing yield, while PPD (phenyl phosphorodiamidate) and DCD (dicyandiamide) were not effective. The EENF effectiveness was not dependent on N rate, method of first N application (incorporated, surface applied, or applied into water), timing of first N application in relation to a permanent flood being established, and how water was managed during the season (permanent flood vs. intermittent wet and dry). Overall, this meta-analysis suggests that certain EENF products can increase yield and N uptake but the average increase is modest.
Chengfang Li - One of the best experts on this subject based on the ideXlab platform.
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deep placement of Nitrogen Fertilizers reduces ammonia volatilization and increases Nitrogen utilization efficiency in no tillage paddy fields in central china
Field Crops Research, 2015Co-Authors: X X Zhang, J Chen, Chengfang LiAbstract:Abstract Deep placement of Nitrogen fertilizer affects the fate of fertilizer Nitrogen through influencing Nitrogen transformation. Few studies have examined ammonia (NH3) volatilization and Nitrogen-utilization efficiency under deep placement of Nitrogen Fertilizers in no-tillage (NT) paddy fields. Therefore, a field experiment was conducted to investigate the different application methods of Nitrogen Fertilizers [no fertilizer, traditional Nitrogen broadcasting (S), and point deep placed at 5 cm, 10 cm and 20 cm depths as basal fertilizer + Nitrogen broadcasting as topdressing (e.g., 5D, 10D and 20D)] on NH3 volatilization, Nitrogen recovery efficiency (NRE), Nitrogen partial factor productivity (NPFP), Nitrogen agronomic efficiency (NAE), and grain yield in NT paddy fields during the 2012–2013 rice growing seasons in central China. Nitrogen deep placement significantly decreased mean floodwater pH by 2–4% and mean floodwater NH4+–N concentration by 29–98% compared with Nitrogen broadcasting. Nitrogen deep placement treatments significantly decreased cumulative NH3 volatilization by 20–45% in 2012 and by 15–40% in 2013 compared with S treatment. On average, Nitrogen deep placement treatments significantly increased NRE by 26–93%, NPFP by 10–16%, NAE by 31–51%, and grain yield by 5–11% in both seasons compared with S treatment. In addition, 10D treatment showed the highest Nitrogen utilization efficiency and grain yield, implying that this measure can be effective in increasing agricultural economic viability and decreasing NH3 volatilization. However, given high labor requirement for manual deep placement, developing mechanical fertilization technology is necessary to overcome this difficulty in future.