Nitrogen use efficiency and soil chemical composition in small-scale dairy systems

Ruminant livestock are generally considered inefficient converters of dietary nitrogen (N) into animal product. Animal nitrogen use efficiency (NUE) is a measure of the relative transformation of feed N into product and in dairy systems this is often expressed as milk N per unit of N intake (g milk N/100 g N intake). This study was a theoretical exercise to explore the relative potential efficacy and value proposition of breeding versus feeding to improve NUE, reduce urinary N excretion and associated environmental impact in pasture-based dairy systems. The biophysical whole farm systems model DairyMod was used across three dairying regions of south-eastern Australia representing a high-rainfall cool temperate climate (HRCT), a high-rainfall temperate climate (HRT) and a medium-rainfall temperate climate (MRT) to examine the two theoretical approaches of (1) maintaining the same amount of N exported in milk from a reduced N intake; and (2) increasing the amount of N exported in milk for the same amount of dietary N intake. Sixteen scenarios were explored for each site; these include four supplementary feed N (SN) concentrations (ranging from 1% to 4% N) combined with four milk N (MN) concentrations (ranging from 0.50% to 0.65% N). Reducing the SN concentration from 4% to 1% increased the 30-year mean model-predicted NUEs from ~16 g milk N/100 g N intake at all three sites to between 23 and 28 g milk N/100 g N intake, with the least and greatest improvements in NUE occurring for the HRCT and MRT sites, respectively. Corresponding to this improved NUE through reduced SN concentrations, model-predicted N2O emissions declined from 3.0 to 1.3 t carbon dioxide equivalents (CO2-e)/ha.annum for the HRCT site, from 4.2 to 2.1 t CO2-e/ha.annum for the HRT site and from 4.4 to 2.1 t CO2-e/ha.annum for the MRT site, representing a decline of between 50% and 57%. In contrast, increasing the MN concentration from 0.50% to 0.65% increased the 30-year mean model-predicted NUEs from 17 to 22 g milk N/100 g N intake for the HRCT site, from 18 to 23 g milk N/100 g N intake for the HRT site and from 18 to 24 g milk N/100 g N intake for the MRT site. Corresponding to the improved NUE through increased MN concentrations, model-predicted N2O emissions declined from 2.3 to 2.0 t CO2-e/ha.annum for the HRCT site, from 3.3 to 3.1 t CO2-e/ha.annum for the HRT site and from 3.4 to 3.2 t CO2-e/ha.annum for the MRT site; representing a decline of between 7% and 11%. These results suggest that improving animal NUE to reduce associated N2O losses holds much more promise if achieved through a reduction in the amount of N in supplementary feed than through increasing N exported in milk. This is an important finding for the Australian dairy industry, since manipulation of dietary N to better balance the energy to protein ratio would be much easier to implement than manipulation of N concentration in milk through genetics.

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Yielding, chemical composition and nitrogen use efficiency determined for white cabbage (Brassica oleracea L. var. capitata L.) supplied organo-mineral fertilizers from spent mushroom substrate

Journal of Elementology ◽

10.5601/jelem.2019.24.1.1778 ◽

2019 ◽

Author(s):

Beata Rutkowska ◽

Ewa Spychaj-Fabisiak ◽

Beata Rutkowska ◽

Wiesław Szulc ◽

Ewa Kuśmirek ◽

...

Keyword(s):

Chemical Composition ◽

Brassica Oleracea ◽

Nitrogen Use Efficiency ◽

Mineral Fertilizers ◽

Spent Mushroom Substrate ◽

Nitrogen Use ◽

White Cabbage ◽

Use Efficiency ◽

Brassica Oleracea L

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Agricultural answers and chemical composition of Massai grass under different nitrogen doses and urea sources

Semina Ciências Agrárias ◽

10.5433/1679-0359.2018v39n3p1225 ◽

2018 ◽

Vol 39 (3) ◽

pp. 1225

Author(s):

Aline Barros da Silva ◽

Carlos Augusto Brandão de Carvalho ◽

Danilo Antonio Morenz ◽

Pedro Henrique Ferreira da Silva ◽

Alex Junio dos Santos ◽

...

Keyword(s):

Chemical Composition ◽

Nitrogen Use Efficiency ◽

Nitrogen Fertilization ◽

Structural Characteristics ◽

Block Design ◽

Dry Mass ◽

Panicum Maximum ◽

Nitrogen Use ◽

Coated Urea ◽

Use Efficiency

Under the hypothesis that modifying nitrogen sources and doses could increase nitrogen fertilization efficiency and productivity and improve forage quality, this study aimed to evaluate the morphological composition, structural characteristics and chemical composition of Panicum maximum cv. Massai forage cultivated under different urea sources (common and coated with Policote®) and nitrogen doses (200, 400 and 600 kg ha-1 year-1) during the autumn, winter and spring of 2014 and the summer and autumn of 2015. The experiment was carried out in Seropédica, RJ, under a randomized complete block design in a factorial arrangement (3x2) + 1 with four replications. High nitrogen rates promoted higher percentages of leaf blade dry mass and lower percentages of dead material dry mass in the forage mass and provided higher tiller population density and forage accumulation rate of Massai grass during the studied seasons. The use of coated urea promoted higher levels of crude protein in the forage than did the use of common urea in all seasons. The intensification of nitrogen fertilization reduced the nitrogen use efficiency but benefitted the structural characteristics, forage accumulation and chemical composition of Massai grass forage. The use of coated urea promoted greater of nitrogen use efficiency during all seasons of the year.

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Small-Scale Variation in Nitrogen Use Efficiency Parameters in Winter Wheat as Affected by N Fertilization and Tillage Intensity

Sustainability ◽

10.3390/su12093621 ◽

2020 ◽

Vol 12 (9) ◽

pp. 3621

Author(s):

Ruth-Maria Hausherr Lüder ◽

Ruijun Qin ◽

Walter Richner ◽

Peter Stamp ◽

Bernhard Streit ◽

...

Keyword(s):

Winter Wheat ◽

Nitrogen Use Efficiency ◽

Block Design ◽

N Fertilization ◽

Small Scale ◽

Limited Information ◽

Nitrogen Use ◽

Use Efficiency ◽

N Rates ◽

Scale Variation

Limited information exists on how tillage and nitrogen (N) fertilization affects small-scale variation in nitrogen use efficiency (NUE) and crop performance. In a two-year field study under temperate conditions, we investigated how tillage (NT, no-tillage; CT, conventional tillage) and N fertilization affected the small-scale variation in NUE and winter wheat performance (grain yield, Gw; grain protein concentration, GPC). A randomized complete block design with three replications was used. Within each tillage plot (12 × 35 m2), N rates (0, 50, 100, 150, 200, 250 kg N ha−1) were completely randomized within each of four groups of microplots (1.5 × 1.5 m2). Early-season soil mineral N (Nmin) was also monitored in both years. At rates < 150 kg N ha−1, NT was not competitive with CT in terms of Gw and NUE. Gw and aboveground plant N were not correlated with Nmin prior to application of N fertilizer. NT usually led to larger spatial heterogeneity of Nmin, Gw, and NUE. The small-scale variability of Gw, GPC, NUE, and N supply decreased with increasing N fertilization rates under both tillage systems. Significant increases in Gw and GPC were observed with increasing N rates, whereas NUE decreased slightly with increasing N rates in both NT and CT. The overall moderate spatial variation in Nmin, Gw, and NUE did not justify site-specific N fertilization in these small fields, with the exception of the stony within-plot positions, which were not responsive to rates of N > 50 kg N ha−1.

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Faculty Opinions recommendation of Leaf-level nitrogen use efficiency: definition and importance.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717964300.793465842 ◽

2012 ◽

Author(s):

Christian Körner

Keyword(s):

Nitrogen Use Efficiency ◽

Nitrogen Use ◽

Leaf Level ◽

Use Efficiency

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Faculty Opinions recommendation of PvNAC1 and PvNAC2 Are Associated with Leaf Senescence and Nitrogen Use Efficiency in Switchgrass.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726131278.793514339 ◽

2016 ◽

Author(s):

Elizabeth Hood

Keyword(s):

Leaf Senescence ◽

Nitrogen Use Efficiency ◽

Nitrogen Use ◽

Use Efficiency

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ROLE OF CONSERVATION AGRICULTURE IN IMPROVING PRODUCTION WATER AND NITROGEN EFFICIENCY OF WHEAT UNDER RAINFED CONDITIONS

IRAQI JOURNAL OF AGRICULTURAL SCIENCES ◽

10.36103/ijas.v51i4.1093 ◽

2020 ◽

Vol 51 (4) ◽

pp. 1139-1148

Author(s):

Othman & et al.

Keyword(s):

Crop Rotation ◽

Nitrogen Use Efficiency ◽

Agricultural Research ◽

Research Work ◽

Conservation Agriculture ◽

Nitrogen Efficiency ◽

Research Station ◽

Wheat Varieties ◽

Nitrogen Use ◽

Use Efficiency

The research work was conducted in Izra’a Research station, which affiliated to the General Commission for Scientific Agricultural Research (GCSAR), during the growing seasons (2016 – 2017; 2017 – 2018), in order to evaluate the response of two durum wheat verities (Douma3 and Cham5) and two bread wheat varieties (Douma4 and Cham6) to Conservation Agriculture (CA) as a full package compared with Conventional Tillage system (CT) under rainfed condition using lentils (Variety Edleb3) in the applied crop rotation. The experiment was laid according to split-split RCBD with three replications. The average of biological yield, grain yield, rainwater use efficiency and nitrogen use efficiency was significantly higher during the first growing season, under conservation agriculture in the presence of crop rotation, in the variety Douma3 (7466 kg. ha-1, and 4162kg. ha-1, 19.006 kg ha-1 mm-1, 39.62 kg N m-2respectively). The two varieties Douma3 and Cham6 are considered more responsive to conservation agriculture system in the southern region of Syria, because they recorded the highest grain yields (2561, 2385 kg ha-1 respectively) compared with the other studied varieties (Cham5 and Douma4) (1951 and 1724 kg ha-1 respectively). They also exhibited the highest values of both rainwater and nitrogen use efficiency.

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