Budgeting nitrogen flows and the food nitrogen footprint of Egypt during the past half century: Challenges and opportunities

Elrys, Ahmed S.; Raza, Sajjad; Abdo, Ahmed I.; Liu, Zhanjun; Chen, Zhujun; Zhou, Jianbin

doi:10.1016/j.envint.2019.06.005

Cited by 45 publications

(27 citation statements)

References 42 publications

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“…As a result, N surplus has increased significantly in Egypt from −7.0 kg N ha −1 yr −1 (N mining) to 181 kg N ha −1 yr −1 during the last five decades (figure 2) due the prominent decline in NUE from 102% to 45% ( figure 4). This decrease can be attributed to excessive N application and a shift from a dependence on soil N mining to external N input (Elrys et al 2019a). Further, highest estimated gaseous emissions were recorded in Botswana, Egypt, Mauritius, South Africa, and Zambia reaching 48, 138, 43, 25, and 46 kg N ha −1 yr −1 , respectively, during 2011-2016.…”

Section: Spatial Trends Of the N Budget And Nue In Africamentioning

confidence: 99%

“…We calculated the cultivated area per year for each African country over the past 56 years by combining the area of all cropland in each country using the FAO database (Elrys et al 2019a). We calculated the total annual N uptake by crop production using the annual yield of each crop harvested and its N content (Lassaletta et al 2014).…”

Section: Nitrogen Budget and Nuementioning

confidence: 99%

“…Farmers are typically wealthier in these countries, and N fertilizers are generally more affordable due to government subsidies (Ciceri and Allanore 2019). High N application in these countries are predominantly due to increasing cropland area, low soil fertility, and the high N demand of cereals (Masso et al 2017, Elrys et al 2019a. In particular, 37% of the total SNF use in Africa occurs in Egypt (Elrys et al 2019a).…”

Section: Spatial Trends Of the N Budget And Nue In Africamentioning

confidence: 99%

“…High N application in these countries are predominantly due to increasing cropland area, low soil fertility, and the high N demand of cereals (Masso et al 2017, Elrys et al 2019a. In particular, 37% of the total SNF use in Africa occurs in Egypt (Elrys et al 2019a).…”

Section: Spatial Trends Of the N Budget And Nue In Africamentioning

confidence: 99%

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Spatial trends in the nitrogen budget of the African agro-food system over the past five decades

Elrys

Abdel-Fattah

Raza

et al. 2019

Environ. Res. Lett.

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Low nitrogen (N) fertilization is a dominant cause of malnutrition in Africa, but the spatial and temporal variability of N cycling patterns in Africa remain unclear. This study is the first to perform a detailed analysis of the N cycling patterns of 52 African countries from 1961 to 2016. We calculated the N use efficiency (NUE) in crop production, country-specific N fertilization trends, and the impacts of N fertilization on human protein demand and the environment. Over the past five decades, total N input to African croplands increased from 20 to 35 kg N ha −1 yr −1 , while the application of synthetic N fertilizers (SNF) increased from 4.0 to 15 kg N ha −1 yr −1 . N contributions from animal manure and biological N fixation remained lower than 10 kg N ha −1 yr −1 and 20 kg N ha −1 yr −1 , respectively. The total N crop production increased from 15 to 22 kg N ha −1 yr −1 from 1961 to 2016. Total N surplus in Africa increased from 5 to 13 kg N ha −1 yr −1 , while estimated gaseous losses increased from 4.0 to 11 kg N ha −1 yr −1 . However, NUE declined from 74% to 63% during the past five decades, and protein consumption increased from 2.99 to 3.78 kg N capita −1 yr −1 . These results suggest that Africa suffers from extremely low N input and that N loss is increasing in agricultural land. We recommend the implementation of an effective N management strategy incorporating the use of locally available organic material along with the balanced application of SNF. Such measures will require effective policy development and cooperation between all stakeholders. Acronyms and abbreviationsOPEN ACCESS RECEIVED

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Section: Spatial Trends Of the N Budget And Nue In Africamentioning

confidence: 99%

Section: Nitrogen Budget and Nuementioning

confidence: 99%

Section: Spatial Trends Of the N Budget And Nue In Africamentioning

confidence: 99%

Section: Spatial Trends Of the N Budget And Nue In Africamentioning

confidence: 99%

See 2 more Smart Citations

Spatial trends in the nitrogen budget of the African agro-food system over the past five decades

Elrys

Abdel-Fattah

Raza

et al. 2019

Environ. Res. Lett.

Self Cite

View full text Add to dashboard Cite

show abstract

“…For example, the consumer-oriented N-Calculator model by Leach et al (2012) estimates the reactive N released to the environment on a per capita basis related to food production and consumption, household utilities, transportation, and the purchase of goods and services. National per capita N footprints have been calculated for more than 10 countries and vary between 15 and 47 kg N capita −1 yr −1 (Pierer et al 2014, Shibata et al 2014, Stevens et al 2014, Liang et al 2016, Shibata et al 2017, Guo et al 2017, Elrys et al 2019. Typically, these studies have emphasized the role of food production (e.g.…”

Section: Introductionmentioning

confidence: 99%

Geographic versus institutional drivers of nitrogen footprints: a comparison of two urban universities

MacDonald

Talbot

Moore

et al. 2020

Environ. Res. Lett.

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Excess reactive nitrogen (N) is linked to a myriad of environmental problems that carry large social costs. Nitrogen footprint tools can help institutions understand how their direct and indirect activities are associated with N release to the environment through energy use, food, and transportation. However, little is known about how geographic context shapes the environmental footprints of institutions. Defining the system boundaries over which institutions are responsible and able to control individual drivers of N footprints is also a challenge. Here, we compare and contrast the circa 2017 N footprints for two research intensive universities located in Montréal, Canada, with a combined full-time equivalent campus population of ∼83 000. Our estimate of McGill University's N footprint (121.2 t N yr −1 ) is 48% greater than Université de Montréal's (74.1 t N yr −1 ), which is also reflected on a per capita basis (3.3 and 1.6 kg N capita −1 yr −1 , respectively). Key institutional factors that explain the differences include McGill's larger residential and international student populations, research farm, and characteristics of its on-campus fuel use. We use a series of counterfactual scenarios to test how shared urban geographic context factors lead to an effective reduction of the N footprints at both universities: the relatively small direct role of both institutions in food intake on campus (29%-68% reduction compared to a counterfactual scenario), energy from hydroelectricity (17%-21% reduction), and minimal car commuting by students (2%-3% reduction). In contrast, the nearzero N removal from the municipal wastewater system effectively increases the N footprints (11%-13% increase compared to a modest N removal and offset scenario). Our findings suggest that a shared geographic context of a dense city with plentiful off-campus housing, food options, and access to hydroelectricity shapes the absolute N footprints of Montréal's two main universities more than the divergent institutional characteristics that influence their relative N footprints.

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Effect of drought and nutrient availability on invaded plant communities in a semi‐arid ecosystem

Ali

Bucher

2022

Ecology and Evolution

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Ecosystem functions are heavily dependent on the functional composition of the plant community, i.e., the functional traits of plants forming the community. This, on the one hand, depends on plant occurrence, but on the other hand, depends on the intraspecific variability of functional traits of the species, which are influenced by climate and nutrient availability and affected by plant–plant interactions. To illustrate that, we studied the effects of drought and nitrogen addition (+ N), two important abiotic variables which are changing with ongoing global change, as well as their combined effect on the functional responses of grassland communities in semi‐arid environments of Northern Africa comprising of natural and invasive species. We conducted an experiment where we planted three native species and one invasive plant species in artificial communities of five individuals per species per plot. We exposed these communities to four different treatments: a drought treatment, an N‐addition treatment, the combination between drought and N‐addition, as well as a control. To assess the performance of plants within treatments, we measured selected plant functional traits (plant height, specific leaf area [SLA], leaf dry matter content [LDMC], N content of the leaves [Nmass], specific root length [SRL], and root diameter) for all individuals occurring in our plots, and additionally assessed the above and belowground biomass for each plant individual. We found that the invasive species showed a higher performance (higher biomass accumulation, taller plants, higher SLA, Nmass, SRL, and root diameter as well as lower LDMC) than the native species under drought conditions. The invasive species was especially successful with the combined impact of drought + N, which is a likely scenario in ongoing global change for our research area. Thus, plant functional traits might be a key factor for the invasion success of plant species which will be even more pronounced under ongoing global change.

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Budgeting nitrogen flows and the food nitrogen footprint of Egypt during the past half century: Challenges and opportunities

Cited by 45 publications

References 42 publications

Spatial trends in the nitrogen budget of the African agro-food system over the past five decades

Spatial trends in the nitrogen budget of the African agro-food system over the past five decades

Geographic versus institutional drivers of nitrogen footprints: a comparison of two urban universities

Effect of drought and nutrient availability on invaded plant communities in a semi‐arid ecosystem

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