scholarly journals Nitrogen-use efficiency of organic and conventional arable and dairy farming systems in Germany

Author(s):  
Lucie Chmelíková ◽  
Harald Schmid ◽  
Sandra Anke ◽  
Kurt-Jürgen Hülsbergen

AbstractOptimising nitrogen (N) management improves soil fertility and reduces negative environmental impacts. Mineral N fertilizers are of key importance in intensive conventional farming (CF). In contrast, organic farming (OF) is highly dependent on closed nutrient cycles, biological N fixation and crop rotations. However, both systems need to minimise N balances and maximise nitrogen-use efficiency (NUE). NUE of organic and conventional crop production systems was evaluated in three regions in Germany by analysing N input, N output and N balance of 30 pairs of one OF and one CF farm each from the network of pilot farms for the period 2009–2011; indicators were calculated using the farm management system REPRO. CF had higher N input in all farm pairs. In 90% of the comparisons, N output of CF was higher than OF, in 7% it was the same and in 3% lower. NUE was higher in 60% of the OF, the same in 37% and lower in only 3%. The NUE of crop production in OF was 91% (arable farms: 83%; mixed/dairy farms: 95%) and the NUE in CF was 79% (arable farms: 77%; dairy farms: 80%). N balance was lower in 90% of the OF. The yearly average N balance was four times higher in CF (59 kg N ha−1 a−1) than in OF (15 kg N ha−1 a−1). The results show a huge individual variability within OF and CF. Organic mixed/dairy farms had the lowest N balances and the highest NUE. A further expansion of OF area can help to reduce high N balances and increase the NUE of crop production.

Author(s):  
A.K. Dhaka ◽  
Satish Kumar ◽  
Bhagat Singh ◽  
Karmal Singh ◽  
Amit Kumar ◽  
...  

An experiment was conducted to study nitrogen use efficiency in pigeonpea at Research farm, CCS Haryana Agricultural University, Hisar, India having three nipping treatments (no nipping, nipping at just start of branching and nipping at flower initiation) and five fertility levels (control, 20 kg N + 40 kg P2O5/ha, 30 kg N + 40 kg P2O5 /ha, 40 kg N + 40 kg P2O5/ha and 20 kg N + 40 kg P2O5/ha + foliar spray of 2% N immediately after nipping) replicated thrice in split plot design during growing seasons of 2016 and 2017. Nipping at start of branching reduced the plant height, while increased primary and secondary branches, pods/plant and yield over no nipping. Significantly higher total N uptake, protein content, net return, B: C, agronomical NUE, physiologic NUE, agro-physiologic NUE, apparent recovery efficiency, utilization efficiency of N and partial N balance were improved with nipping at start of branching. Among fertility levels, 40 kg N + 40 kg P2O5 / ha recorded significantly higher yield attributes with 39.7 per cent higher seed yield over control. Significantly higher agronomic NUE, physiologic NUE, agro-physiological NUE, apparent recovery efficiency, utilization efficiency of N, partial N balance and NER were recorded with 20 kg/ha as compared to higher nitrogen doses.


2017 ◽  
Vol 3 (3) ◽  
pp. 413-434 ◽  
Author(s):  
Nilde Antonella Di Benedetto ◽  
◽  
Maria Rosaria Corbo ◽  
Daniela Campaniello ◽  
Mariagrazia Pia Cataldi ◽  
...  

Agronomy ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 304 ◽  
Author(s):  
Jesús Santillano-Cázares ◽  
Fidel Núñez-Ramírez ◽  
Cristina Ruíz-Alvarado ◽  
María Cárdenas-Castañeda ◽  
Iván Ortiz-Monasterio

Sustainable crop production systems can be attained by using inputs efficiently and nitrogen use efficiency (NUE) parameters are indirect measurements of sustainability of production systems. The objective of this study was to investigate the effect of selected nitrogen (N) management treatments on wheat yields, grain and straw N concentration, and NUE parameters, under conservation agriculture (CA). The present study was conducted at the International Maize and Wheat Improvement Center (CIMMYT), in northwest, Mexico. Seventeen treatments were tested which included urea sources, timing, and methods of fertilizer application. Orthogonal contrasts were used to compare groups of treatments and correlation and regression analyses were used to look at the relationships between wheat yields and NUE parameters. Contrasts run to compare wheat yields or agronomic efficiency of N (AEN) performed similarly. Sources of urea or timing of fertilizer application had a significant effect on yields or AEN (p > 0.050). However, methods of application resulted in a highly significant (p < 0.0001) difference on wheat yields and agronomic efficiency of N. NUE parameters recorded in this study were average but the productivity associated to NUE levels was high. Results in this study indicate that wheat grew under non-critically limiting N supply levels, suggesting that N mineralization and reduced N losses from the soil under CA contributed to this favorable nutritional condition, thus minimizing the importance of N management practices under stable, mature CA systems.


2009 ◽  
Vol 8 (sup3) ◽  
pp. 178-180 ◽  
Author(s):  
Severino Segato ◽  
Giorgio Marchesini ◽  
Igino Andrighetto

2015 ◽  
Vol 15 (24) ◽  
pp. 13849-13893 ◽  
Author(s):  
D. Fowler ◽  
C. E. Steadman ◽  
D. Stevenson ◽  
M. Coyle ◽  
R. M. Rees ◽  
...  

Abstract. The global nitrogen (N) cycle at the beginning of the 21st century has been shown to be strongly influenced by the inputs of reactive nitrogen (Nr) from human activities, including combustion-related NOx, industrial and agricultural N fixation, estimated to be 220 Tg N yr−1 in 2010, which is approximately equal to the sum of biological N fixation in unmanaged terrestrial and marine ecosystems. According to current projections, changes in climate and land use during the 21st century will increase both biological and anthropogenic fixation, bringing the total to approximately 600 Tg N yr−1 by around 2100. The fraction contributed directly by human activities is unlikely to increase substantially if increases in nitrogen use efficiency in agriculture are achieved and control measures on combustion-related emissions implemented. Some N-cycling processes emerge as particularly sensitive to climate change. One of the largest responses to climate in the processing of Nr is the emission to the atmosphere of NH3, which is estimated to increase from 65 Tg N yr−1 in 2008 to 93 Tg N yr−1 in 2100 assuming a change in global surface temperature of 5 °C in the absence of increased anthropogenic activity. With changes in emissions in response to increased demand for animal products the combined effect would be to increase NH3 emissions to 135 Tg N yr−1. Another major change is the effect of climate changes on aerosol composition and specifically the increased sublimation of NH4NO3 close to the ground to form HNO3 and NH3 in a warmer climate, which deposit more rapidly to terrestrial surfaces than aerosols. Inorganic aerosols over the polluted regions especially in Europe and North America were dominated by (NH4)2SO4 in the 1970s to 1980s, and large reductions in emissions of SO2 have removed most of the SO42− from the atmosphere in these regions. Inorganic aerosols from anthropogenic emissions are now dominated by NH4NO3, a volatile aerosol which contributes substantially to PM10 and human health effects globally as well as eutrophication and climate effects. The volatility of NH4NO3 and rapid dry deposition of the vapour phase dissociation products, HNO3 and NH3, is estimated to be reducing the transport distances, deposition footprints and inter-country exchange of Nr in these regions. There have been important policy initiatives on components of the global N cycle. These have been regional or country-based and have delivered substantial reductions of inputs of Nr to sensitive soils, waters and the atmosphere. To date there have been no attempts to develop a global strategy to regulate human inputs to the nitrogen cycle. However, considering the magnitude of global Nr use, potential future increases, and the very large leakage of Nr in many forms to soils, waters and the atmosphere, international action is required. Current legislation will not deliver the scale of reductions globally for recovery from the effects of Nr deposition on sensitive ecosystems, or a decline in N2O emissions to the global atmosphere. Such changes would require substantial improvements in nitrogen use efficiency across the global economy combined with optimization of transport and food consumption patterns. This would allow reductions in Nr use, inputs to the atmosphere and deposition to sensitive ecosystems. Such changes would offer substantial economic and environmental co-benefits which could help motivate the necessary actions.


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