scholarly journals Growth Responses of Agropyron Mongolicum Keng to Nitrogen Addition Is Linked to Root Morphological Traits and Nitrogen-Use Efficiency.

2021 ◽  
Author(s):  
Aiyun XU ◽  
Xing Wang ◽  
Xiaojia Wang ◽  
Dongmei Xu ◽  
Bing Cao
Keyword(s):  
Native Species ◽  
Morphological Traits ◽  
Growth Response ◽  
N Deposition ◽  
N Use Efficiency ◽  
N Addition ◽  
Desert Grassland ◽  
Growth Responses ◽  
Use Efficiency ◽  
N Use

Abstract Background and aimsNitrogen (N) is the primary limiting factors for plant growth and development, and increasingly N deposition alters plant composition, consequently affecting ecosystem function have been widely acknowledged. However, the effects of N fertilization on native species in desert grassland ecosystem and underlying mechanisms of these effects are still poorly understood. This study was conducted to examine the growth response of Agropyron mongolicum keng to N addition and potential mechanisms underlying this effect.MethodsA.mongolicum Keng was subjected to five N addition levels (0, 0.8,1.6, 2.4, and 4.0g N m−2 yr−1) for six months under greenhouse conditions. A combination of linear and structural equation modelling was used to examine growth response of A.mongolicum Keng to N addition and test whether its response related to root morphological traits and N-use efficiency.ResultsGrowth responses of A. mongolicum Keng to increasing N addition appeared a unimodal-shaped with a N saturation threshold at 3.2g N m-1 yr-1. Its response closely related to the root surface area, volume, length, and forks number, N uptake and utilization efficiency. Besides, N-induced changes in soil available nutrient have an indirect impaction biomass of A. mongolicum Keng via regulation of root morphological traits and N-use efficiency.ConclusionsThese findings highlight the sensibility of A. mongolicum Keng to N addition and the importance of root morphological traits and N-use efficiency in affecting biomass. Therefore, these can provide important insights into potential changes of native species survival and development in nutrient-limited desert grassland caused by N deposition.

scholarly journals Optimization of Topdressing for Winter Wheat by Accurate Growth Monitoring and Improved Production Estimation

2021 ◽  
Vol 13 (12) ◽  
pp. 2349
Author(s):  
Jingchun Ji ◽  
Jianli Liu ◽  
Jingjing Chen ◽  
Yujie Niu ◽  
Kefan Xuan ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Crop Production ◽  
Optimization Method ◽  
Growth Potential ◽  
N Use Efficiency ◽  
Growth Monitoring ◽  
Aerial Vehicle ◽  
Use Efficiency ◽  
Improved Model ◽  
N Use

Topdressing accounts for approximately 40% of the total nitrogen (N) application of winter wheat on the Huang-Huai-Hai Plain in China. However, N use efficiency of topdressing is low due to the inadaptable topdressing method used by local farmers. To improve the N use efficiency of winter wheat, an optimization method for topdressing (THP) is proposed that uses unmanned aerial vehicle (UAV)-based remote sensing to accurately acquire the growth status and an improved model for growth potential estimation and optimization of N fertilizer amount for topdressing (NFT). The method was validated and compared with three other methods by a field experiment: the conventional local farmer’s method (TLF), a nitrogen fertilization optimization algorithm (NFOA) proposed by Raun and Lukina (TRL) and a simplification introduced by Li and Zhang (TLZ). It shows that when insufficient basal fertilizer was provided, the proposed method provided as much NFT as the TLF method, i.e., 25.05% or 11.88% more than the TRL and TLZ methods and increased the yields by 4.62% or 2.27%, respectively; and when sufficient basal fertilizer was provided, the THP method followed the TRL and TLZ methods to reduce NFT but maintained as much yield as the TLF method with a decrease of NFT by 4.20%. The results prove that THP could enhance crop production under insufficient N preceding conditions by prescribing more fertilizer and increase nitrogen use efficiency (NUE) by lowering the fertilizer amount when enough basal fertilizer is provided.

INFLUENCE OF THE SYSTEM OF RICE INTENSIFICATION ON RICE YIELD AND NITROGEN AND WATER USE EFFICIENCY WITH DIFFERENT N APPLICATION RATES

2009 ◽  
Vol 45 (3) ◽  
pp. 275-286 ◽  
Author(s):  
LIMEI ZHAO ◽  
LIANGHUAN WU ◽  
YONGSHAN LI ◽  
XINGHUA LU ◽  
DEFENG ZHU ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
N Use Efficiency ◽  
System Of Rice Intensification ◽  
N Application ◽  
Application Rates ◽  
Rice Intensification ◽  
Use Efficiency ◽  
N Rates ◽  
N Use

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.

scholarly journals Single and split nitrogen dose in wheat yield indicators

2018 ◽  
Vol 22 (1) ◽  
pp. 16-21 ◽  
Author(s):  
Juliane S. P. Costa ◽  
Rubia D. Mantai ◽  
José A. G. da Silva ◽  
Osmar B. Scremin ◽  
Emilio G. Arenhardt ◽  
...  
Keyword(s):  
Block Design ◽  
Wheat Yield ◽  
N Use Efficiency ◽  
Phenological Stages ◽  
Split Dose ◽  
N Supply ◽  
N Release ◽  
Residual N ◽  
Use Efficiency ◽  
N Use

ABSTRACT Single or split nitrogen (N) supply can maximize the expression of wheat yield indicators. The objective of the study was to evaluate the greater N use efficiency on wheat yield indicators by the single and split N supply under favorable and unfavorable year conditions to the crop in succession system of high and reduced residual N release. The study was conducted in 2014 and 2015, in a randomized complete block design with four replicates in a 4 x 3 factorial, for N-fertilizer doses (0, 30, 60, 120 kg ha-1) and supply forms [full dose (100%) in the phenological stage V3 (third expanded leaf); split dose (70 and 30%) in the phenological stages V3/V6 (third and sixth expanded leaves, respectively) and; split dose (70 and 30%) in the phenological stages V3/R1 (third expanded leaf and early grain filling)], respectively, in soybean/wheat and maize/wheat cultivation systems. The highest N use efficiency for wheat yield was obtained with the single dose supply in favorable year of temperature and rainfall and with the split dose in the V3/V6 stages in unfavorable year, regardless of the succession system of high and reduced residual N release.

Irrigation and N-use Efficiency of Cotton Cultivar MNH554 Under Multan Conditions

2002 ◽  
Vol 2 (1) ◽  
pp. 4-8
Author(s):  
Mahmood-ul-Hassan . ◽  
Taj Muhammad . ◽  
Saeed Ahmad . ◽  
Muhammad Iqbal . ◽  
Abdul Karim . ◽  
...  
Keyword(s):  
N Use Efficiency ◽  
Use Efficiency ◽  
N Use ◽  
Cotton Cultivar
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