The Impact of Variable Rate N Application on N Use Efficiency of Furrow Irrigated Corn

Author(s):  
G.W. Hergert ◽  
R.B. Ferguson ◽  
C.A. Gotway ◽  
T.A. Peterson
2009 ◽  
Vol 45 (3) ◽  
pp. 275-286 ◽  
Author(s):  
LIMEI ZHAO ◽  
LIANGHUAN WU ◽  
YONGSHAN LI ◽  
XINGHUA LU ◽  
DEFENG ZHU ◽  
...  

SUMMARYField experiments were conducted in 2005 and 2006 to investigate the impacts of alternative rice cultivation systems on grain yield, water productivity, N uptake and N use efficiency (ANUE, agronomic N use efficiency; PFP, partial factor productivity of applied N). The trials compared the practices used with the system of rice intensification (SRI) and traditional flooding (TF). The effects of different N application rates (0, 80, 160 and 240 kg ha−1) and of N rates interacting with the cultivation system were also evaluated. Resulting grain yields with SRI ranged from 5.6 to 7.3 t ha−1, and from 4.1 to 6.4 t ha−1 under TF management. On average, grain yields under SRI were 21% higher in 2005 and 22% higher in 2006 than with TF. Compared with TF, SRI plots had higher harvest index across four fertilizer N rates in both years. However, there was no significance difference in above-ground biomass between two cultivation systems in either year. ANUE was increased significantly under SRI at 80 kg N ha−1 compared with TF, while at higher N application rates, ANUE with SRI was significantly lower than TF. Compared with TF, PFP under SRI was higher across all four N rates in both years, although the difference at 240 kg N ha−1 was not significant. As N rate increased, the ANUE and PFP under both SRI and TF significantly decreased. Reduction in irrigation water use with SRI was 40% in 2005 and 47% in 2006, and water use efficiency, both total and from irrigation, were significantly increased compared to TF. With both SRI and TF, the highest N application was associated with decreases in grain yield, N use efficiency and water use efficiency. This is an important finding given current debates whether N application rates in China are above the optimum, especially considering consequences for soil and water resources. Cultivation system, N rates and their interactions all produced significant differences in this study. Results confirmed that optimizing fertilizer N application rates under SRI is important to increase yield, N use efficiency and water use efficiency.


2016 ◽  
Vol 55 (2) ◽  
pp. 136-144 ◽  
Author(s):  
R. Hackett

Abstract A range of cultivar types, including two-row and six-row types as well as line and hybrid types, are used for winter barley production in Ireland. There is little information available on the fertiliser nitrogen (N) requirements or the N use efficiency of these different types, particularly under Irish conditions. The objectives of the work presented here were to compare the response to fertiliser N of a two-row line cultivar, a six-row line cultivar and a six-row hybrid cultivar in terms of grain yield and aspects of N use efficiency. Experiments were carried out over three growing seasons, in the period 2012-2014, on a light-textured soil comparing the response of the three cultivars of winter barley to fertiliser N application rates ranging from 0 to 260 kg N/ha. There was no evidence that cultivar type, regardless of whether it was a two-row or six-row line cultivar or a six-row hybrid cultivar, influenced the response to fertiliser N of winter barley. There were some indications that six-row cultivars were less efficient at recovering soil N but used accumulated N more efficiently than the two-row cultivar. This work provided no evidence to support adjustment of fertiliser N inputs to winter barley based on cultivar type.


AoB Plants ◽  
2019 ◽  
Author(s):  
M A Míguez-Montero ◽  
A Valentine ◽  
M A Pérez-Fernández

Abstract The impact of phosphorus (P) nutrition on plant growth, symbiotic N2 fixation, and phosphorus and nitrogen use and their assimilation was investigated in four leguminous plants of the genus Cytisus. Plants inoculated with Rhizobium strains isolated from plants of the four species growing in the wild were crop under controlled conditions in soils with either low P (5 µM) or high P (500 µM). The experiment was replicated in the presence and absence of plant irrigation to test for the effects of drought stress of inoculated and non-inoculated plants under the two P levels of fertilization. P-low treatments increased nodule production while plant biomass and shoot and root P and N contents were maximum at sufficient P. The reduction of P in the soil clearly induced biological nitrogen fixation and greater phosphorus and nitrogen uptake efficiencies, as shown by the total N and P accumulated in plants. Similarly, distinct tolerances to drought support this idea. Cytisus balansae had the lowest tolerance to water scarcity. Cytisus multiflorus and Cytisus scoparius were the most resistant species to drought, with this resistance enhanced in the inoculated plants. In the four species, the inoculation treatment clearly enhanced N-use efficiency, whereas P-use efficiency was greater in the non-inoculated plants in the irrigated treatment. With a P-induced demand for N, the plants nodulated prolifically and increased N supply from biological fixation. The physiological basis for N2-fixing C. scoparius and C. striatus maintaining growth at low P supply and responding to greater P supply is through balanced acquisition of P and N for plant demand. Native shrubby legumes are key species in natural ecosystems due to their capability to increase the net N budget in plants and soils and because they modulate the phosphorus availability. Four legumes in the genus Cytisus either native to or commonly represented in the Iberian Peninsula proved to be able shift their N use depending on the soil P availability and on the interactions established with their Bradyrhizobium symbionts. In the four species the inoculation treatment clearly enhanced N-use efficiency and drought tolerance, whereas P-use efficiency was greater in the non-inoculated plants in the irrigated treatment.


2009 ◽  
Vol 57 (3) ◽  
pp. 285-296 ◽  
Author(s):  
U. Sangakkara ◽  
P. Stamp

Green manuring is considered an important agronomic practice for smallholder farming systems in the tropics. Different species of legumes and non-legumes are applied either as ex situ or in situ green manures. Thus a field study conducted under rainfed conditions in Sri Lanka compared the effect of in situ and ex situ green manuring using two popular green manures ( Crotolaria juncea — a legume and Tithonia diversifolia — a non-legume) on the growth, seed yield and N use pattern of maize ( Zea mays ), the most popular upland cereal in the Asian tropics, grown with high and low N rates, in the two seasons that correspond to the monsoonal rains. In situ green manuring, especially with crotolaria, increased the growth, seed yield and N use efficiency of maize when compared to the ex situ addition of similar quantities of the green manure. The impact was also greater in the minor season, when the crop was subjected to moisture stress conditions. The benefits of in situ green manuring with tithonia were lower than those due to crotolaria. In situ green manuring with tithonia also led to a greater increase in growth, seed yield and N use efficiency in maize compared to ex situ green manuring with this species. The green manures, especially in situ application, also increased the benefits of enhanced rates of N fertilizer to the crops in both seasons, with greater use efficiency in the major season. The study showed the benefits of green manuring (both in and ex situ ) for obtaining higher yields of maize in the growing seasons of the Asian tropics, especially the in situ application of legume species.


2019 ◽  
Vol 56 (Special Issue) ◽  
pp. 125-135
Author(s):  
D Panda ◽  
AK Nayak ◽  
S Mohanty

Nitrogen is the one of most limiting nutrient for rice production, and in India rice cultivation alone accounts approximately 37% of the total fertilizer-N consumption in the year 1917-18. However, 60-70% of applied N is lost from the rice ecosystem system in the form of reactive N species such as ammonia (NH3), nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2) and nitrate (NO3) through various processes. Hence enhancing N use efficiency through improved N management is of greater importance for ensuring food security and environmental sustainability. The decisions on optimum level, time, form and method of N application are crucial to an efficient N management strategy. Earlier studies suggested blanket fertilizer recommendations for different rice ecosystems and soil test based fertilizer applications. Subsequently, innovative methods of N application including deep placement of urea super granule in reduced zone, subsurface incorporation of urea through farmer friendly methods were also recommended Recently several advancements have been made in N management practices for rice crop such as site specific N management, real time N management using leaf colour chart (LCC) and customised LCC, enhanced efficiency N fertilizers (EENF) using N transformation regulators and GIS and remote sensing (RS) - based N application technologies. The objective of this paper is to comprehensively discuss about the established and emerging N management options for improving yield, N use efficiency and environmental sustainability of rice.


2013 ◽  
Vol 64 (10) ◽  
pp. 1020 ◽  
Author(s):  
V. O. Snow ◽  
P. N. Smale ◽  
M. B. Dodd

Ecological studies often suggest that natural grasslands with high species diversity will grow more biomass and leach less nitrogen (N). If this diversity effect also applies to fertilised and irrigated pastures with controlled removal of herbage, it might be exploited to design pastures that can assist the dairy industry to maintain production while reducing N leaching losses. The purpose of this study was to test whether pasture mixtures with a high functional diversity in ryegrass traits will confer on the system higher water- and N-use efficiency. The hypothesis was tested using a process-based model in which pasture mixtures were created with varying levels of diversity in ryegrass traits likely to affect pasture growth. Those traits were: the winter- or summer-dominance of growth, the ability of the plant to intercept radiation at low pasture mass, and rooting depth. Pasture production, leaching and water- and N-use efficiency were simulated for management typical of a dairy pasture. We found that the performance of the diverse ryegrass–clover mixtures was more strongly associated with the performance of the individual components than with the diversity across the components. Diverse pasture mixtures may confer other benefits, e.g. pest or disease resistance and pasture persistence. The testing here was within a selection of ryegrasses, and the greater possible diversity across species may produce different effects. However, these results suggest that highly performing pastures under fertilised and irrigated grazed conditions are best constructed by selecting components that perform well individually than by deliberately introducing diversity between components.


2019 ◽  
Vol 56 (Special) ◽  
pp. 125-135
Author(s):  
D Panda ◽  
AK Nayak ◽  
S Mohanty

Nitrogen is the one of most limiting nutrient for rice production, and in India rice cultivation alone accounts approximately 37% of the total fertilizer-N consumption in the year 1917-18. However, 60-70% of applied N is lost from the rice ecosystem system in the form of reactive N species such as ammonia (NH3), nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2) and nitrate (NO3) through various processes. Hence enhancing N use efficiency through improved N management is of greater importance for ensuring food security and environmental sustainability. The decisions on optimum level, time, form and method of N application are crucial to an efficient N management strategy. Earlier studies suggested blanket fertilizer recommendations for different rice ecosystems and soil test based fertilizer applications. Subsequently, innovative methods of N application including deep placement of urea super granule in reduced zone, subsurface incorporation of urea through farmer friendly methods were also recommended Recently several advancements have been made in N management practices for rice crop such as site specific N management, real time N management using leaf colour chart (LCC) and customised LCC, enhanced efficiency N fertilizers (EENF) using N transformation regulators and GIS and remote sensing (RS) - based N application technologies. The objective of this paper is to comprehensively discuss about the established and emerging N management options for improving yield, N use efficiency and environmental sustainability of rice.


2019 ◽  
Vol 21 (3) ◽  
pp. 695-712 ◽  
Author(s):  
S. Stamatiadis ◽  
J. S. Schepers ◽  
E. Evangelou ◽  
A. Glampedakis ◽  
M. Glampedakis ◽  
...  

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