The effect of grazing season length on nitrogen utilization efficiency and nitrogen balance in spring-calving dairy production systems

2012 ◽  
Vol 150 (5) ◽  
pp. 630-643 ◽  
Author(s):  
W. RYAN ◽  
D. HENNESSY ◽  
T. M. BOLAND ◽  
L. SHALLOO

SUMMARYThere is a continual requirement for grass-based production systems to optimize economic and environmental sustainability through increased efficiency in the use of all inputs, especially nitrogen (N). An N balance model was used to assess N use efficiency and N surplus, and to predict N losses from grass-based dairy production systems differing in the length of the grazing season (GS). Data from a 3-year grazing study with a 3×3 factorial design, with three turnout dates (1 February, 21 February and 15 March) and three housing dates (25 October, 10 November and 25 November) were used to generate estimates of N use efficiency and N losses. As the length of the GS increased by a mean of 30 days, milk production, milk solids production and milk N output increased by 3, 6 and 6%, respectively. The increase in milk production as the length of the GS increased resulted in a 2% decline in N surplus and a 5% increase in N use efficiency. Increasing GS length increased the proportion of grazed grass in the diet, which increased N cycling within the system, resulting in an 8% increase in milk solids/ha produced/kg of surplus N. The increased cycling of N reduced the quantity of N partitioned for loss to the environment by 8%. Reducing fertilizer N input by 20% increased N use efficiency by 22% and reduced total N losses by 16%. The environmental and production consequences of increased length of the GS and reduced N loss are favourable as the costs associated with N inputs increase.

Soil Research ◽  
2017 ◽  
Vol 55 (6) ◽  
pp. 479 ◽  
Author(s):  
Cecile A. M. de Klein ◽  
Ross M. Monaghan ◽  
Marta Alfaro ◽  
Cameron J. P. Gourley ◽  
Oene Oenema ◽  
...  

Nitrogen (N) is invaluable for maintaining agricultural production, but its use, and particularly inefficient use, can lead to environmental losses. This paper reviews N use efficiency (NUE) and N surplus indicators for dairy production systems to assess their utility for optimising N use outcomes and minimising environmental N losses. Using case-study examples, we also assess realistic goals for these indicators and discuss key issues associated with their use. Published whole-farm NUE and whole-farm N surplus values ranged within 10–65% and 40–700 kg N ha–1 year–1 respectively. In a study of five catchments across New Zealand, whole-farm NUE was more strongly affected by catchment differences in soil and climatic conditions than by differences in management. In contrast, whole-farm N surplus differed both between- and within-catchments and was a good indicator of N losses to water. Realistic goals for both NUE and N surplus thus depend on the agro-climatic context of the dairy system and on its economic and environmental goals. Crop and animal NUE values can be valuable indicators for optimising fertiliser and feed use and minimising N losses. However, global or national whole-farm NUE values appear of limited value if the ultimate goal for setting targets is to reduce the environmental impact of N use; whole-farm level targets based on N surplus would be a more useful indicator for this purpose. Our review also reinforces the importance of standardising the variables that should be used to estimate NUE and N surplus values, to ensure equitable comparisons between different systems. Finally, NUE and N surplus targets should also be set in the context of other agro-environmental considerations.


2021 ◽  
Vol 5 ◽  
Author(s):  
Pauline Chivenge ◽  
Sheetal Sharma ◽  
Michelle Anne Bunquin ◽  
Jon Hellin

Fertilizer use and genetic improvement of cereal crops contributed to increased yields and greater food security in the last six decades. For rice, however, fertilizer use has outpaced improvement in yield. Excess application of nutrients beyond crop needs, especially nitrogen (N), is associated with losses to the environment. Environmental pollution can be mitigated by addressing fertilizer overuse, improving N use efficiency, while maintaining or improving rice productivity and farmers' income. A promising approach is the site-specific nutrient management (SSNM), developed in the 1990s to optimize supply to meet demand of nutrients, initially for rice, but now extended to other crops. The SSNM approach has been further refined with the development of digital decision support tools such as Rice Crop Manager, Nutrient Expert, and RiceAdvice. This enables more farmers to benefit from SSNM recommendations. In this mini-review, we show how SSNM can foster sustainability in rice production systems through improved rice yields, profit, and N use efficiency while reducing N losses. Farmer adoption of SSNM, however, remains low. National policies and incentives, financial investments, and strengthened extension systems are needed to enhance scaling of SSNM-based decision support tools.


2020 ◽  
Vol 12 (3) ◽  
pp. 1055
Author(s):  
Nyncke Hoekstra ◽  
Gertjan Holshof ◽  
Ronald Zom ◽  
Bert Philipsen ◽  
René Schils ◽  
...  

The aim of the study was to assess the effect of two contrasting grazing systems, strip-grazing and kurzrasen, at a high stocking rate on herbage intake and milk production and quality on a peat meadow. Additionally, we assessed the effect of the level of crude protein (CP) fed in concentrate on milk production and N use efficiency. Even at the relatively high stocking rates, cows still achieved substantial fresh grass intake (on average >6 kg dry matter cow−1 day−1) from both systems. Despite the lower level of gross grass production under kurzrasen management, the difference in milk production between kurzrasen and strip-grazing was small and non-significant. Feeding concentrate with a lower CP level, had no negative impact on milk yield, provided that the CP content of the total ration remained above ~150 g kg−1 DM and milk urea content was above ~18 mg 100 g−1 milk. Reducing the CP content in the concentrate significantly increased the N use efficiency, and both were strongly related to the milk urea content. Therefore, optimising the use of milk urea as a management tool on dairy farms, also during the grazing season, could reduce N losses to the environment, while maintaining productivity.


2017 ◽  
Vol 209 ◽  
pp. 39-46 ◽  
Author(s):  
Meng Wang ◽  
Lichun Wang ◽  
Zhenling Cui ◽  
Xinping Chen ◽  
Jiagui Xie ◽  
...  

2001 ◽  
Vol 1 ◽  
pp. 114-121 ◽  
Author(s):  
Lenz Haderlein ◽  
T.L. Jensen ◽  
R.E. Dowbenko ◽  
A.D. Blaylock

Controlled release nitrogen (N) fertilizers have been commonly used in horticultural applications such as turf grasses and container-grown woody perennials. Agrium, a major N manufacturer in North and South America, is developing a low-cost controlled release urea (CRU) product for use in field crops such as grain corn, canola, wheat, and other small grain cereals. From 1998 to 2000, 11 field trials were conducted across western Canada to determine if seed-placed CRU could maintain crop yields and increase grain N and N use efficiency when compared to the practice of side-banding of urea N fertilizer. CRU was designed to release timely and adequate, but not excessive, amounts of N to the crop. Crop uptake of N from seed-placed CRU was sufficient to provide yields similar to those of side-banded urea N. Grain N concentrations of the CRU treatments were higher, on average, than those from side-banded urea, resulting in 4.2% higher N use efficiency across the entire N application range from 25 to 100 kg ha-1. Higher levels of removal of N in grain from CRU compared to side-banded urea can result in less residual N remaining in the soil, and limit the possibility of N losses due to denitrification and leaching.


2021 ◽  
Vol 319 ◽  
pp. 107546
Author(s):  
Guillermo Guardia ◽  
Sandra García-Gutiérrez ◽  
Rocío Rodríguez-Pérez ◽  
Jaime Recio ◽  
Antonio Vallejo

Agriculture ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 541
Author(s):  
Gerhard Moitzi ◽  
Reinhard W. Neugschwandtner ◽  
Hans-Peter Kaul ◽  
Helmut Wagentristl

Improvements in nitrogen (N) use efficiency in crop production are important for addressing the triple challenges of food security, environmental degradation and climate change. The three fertilizers, calcium ammonium nitrate (CAN), urea (Urea) and stabilized urea (Ureastab), were applied at a rate of 160 kg N ha−1 with two or three splits to winter wheat (Triticum aestivum L.) in the Pannonian climate region of eastern Austria. On average, over all fertilization treatments, the grain yield (GY) increased by about a quarter and the grain N concentration (GNC) doubled compared to the control without fertilization. Consequently, the grain N yield (NYGRAIN) was increased with N fertilization by 154%. The GY increased due to a higher grain density with no differences between N fertilizers but with a tendency of a higher grain yield with three compared to two splits. Three splits also slightly increased the GNC and consequently the NYGRAIN of CAN and Ureastab in one year. The removal of N fertilizer with the NYGRAIN (N surplus) was higher than the amount of applied fertilizer. Fertilization decreased the N use efficiency (NUE), the N uptake efficiency (NUpE) and the N utilization efficiency (NUtE) but increased the soil mineral nitrate (NO3-N) at harvest and the apparent N loss (ANL). Three compared to two applications resulted in a higher NO3-N at harvest but also a lower N surplus due to partly higher NYGRAIN. Consequently, the ANL was lower with three compared to two splits. Also, the NUpE and the apparent N recovery efficiency (ANRE) were higher with three splits. The best N treatment regarding highest above-ground biomass yield with lowest N surplus, N balance and ANL was the three-split treatment (50 CAN, 50 CAN, 60 liquid urea ammonium nitrate). Three splits can, under semi-arid conditions, be beneficial when aiming high-quality wheat for bread-making and also for reducing the N loss. Whereas, two splits are recommended when aiming only at high GY, e.g., for ethanol-wheat production.


Author(s):  
Chen Erying ◽  
Qin Ling ◽  
Yang Yanbing ◽  
Zhang Huawen ◽  
Wang Hailian ◽  
...  

Abstract: The objective of this work was to identify the genetic variation of foxtail millet (Setaria italica) cultivars, from three ecogeographic origins in China, regarding the uptake and utilization of N by the genotypes at the seedling stage, aiming at the genetic improvement of this crop. Seedlings of 79 cultivars were fertilized with a nutrient solution, on a sand substrate, and evaluated under low-N (LN, 0.2 mmol L-1) and high-N (HN, 6.0 mmol L-1) concentrations. A large variation was observed between cultivars, among the three ecogeographic regions, for shoot biomass, shoot N content and concentration, and N use efficiency (NUE), uptake efficiency (NupE), and utilization efficiency (NutE), especially under HN conditions. Cultivars of Northwest China showed the highest variation for shoot biomass, N content, NUE, and NupE. A strong positive correlation was observed between NUE and NupE, and NUE and NutE, but there was no correlation between NupE and NutE. NupE accounted for 77.6% of the total variation of NUE, and NutE for the rest. The uptake and utilization of N show a large variation among the foxtail millet cultivars at the seedling stage, and the variation of N uptake contributes more than that of N utilization to the variation of N use efficiency.


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