Genotypic variation in nitrogen utilization efficiency in oilseed rape is related to the coordination of leaf senescence and root N uptake during reproductive stage

Abstract Foliar sprays application is an important crop management strategy, which could help to maximize yield and other beneficial substances. Therefore, a field experiment was conducted at Kafrelsheikh University research farm, Egypt, to study the effect of stimulating compounds (control, salicylic acid and ascobien) and nitrogen levels (0, 57.5, 115, 172.5 and 230 kg N ha-1) on yield and nitrogen utilization efficiency of wheat. Results indicated that spraying of ascobien and increasing nitrogen level had significant effect on yield traits. Interaction between stimulating compounds and nitrogen were achieved progressive increases in all yield traits, furthermore, the magnitude of increments was much more pronounced in response to salicylic acid and control treatments in both seasons. It was observed no statistically significant difference between 172.5 and 230 kg N ha-1 in both seasons. A significant interactive effect were observed on grain N uptake, whole plant N uptake, nitrogen harvest index (NHI), nitrogen utilization efficiency (NUtE) and nitrogen use efficiency (NUE) by using foliar spraying combined with N fertilizer. Grain N uptake and whole plant N uptake were closely correlated with nitrogen under stimulating compounds, whereas ascobien with 172.5 kg N ha-1 was more effective than salicylic acid in both seasons. Interestingly, foliar spraying of ascobien and N level of 172.5 kg ha-1 was the optimal and could be a useful to improve the efficiency of N-fertilizer and it can be saved 57.5 kg N ha-1. Consequently, could be the key to reduce the need for chemical fertilizers and decrease the cost of production.

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Dynamics of Growth and Nitrogen Capture in Winter Oilseed Rape Hybrid and Line Cultivars under Contrasting N Supply

Agronomy ◽

10.3390/agronomy10081183 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1183 ◽

Cited By ~ 1

Author(s):

Yangyang Zhang ◽

Piaopiao Lu ◽

Tao Ren ◽

Jianwei Lu ◽

Li Wang

Keyword(s):

Oilseed Rape ◽

Seed Yield ◽

Field Experiments ◽

N Uptake ◽

Genotypic Variation ◽

Utilization Efficiency ◽

Winter Oilseed Rape ◽

N Accumulation ◽

N Supply ◽

Parental Lines

Cultivation of winter oilseed rape hybrids has been introduced as a promising solution to improve the nitrogen use efficiency (NUE) and to reduce the large N balance surpluses in this crop. To achieve a better understanding of the underlying physiological mechanisms, field experiments were conducted over two years to investigate the dynamics of growth and N capture in an oilseed rape hybrid and its parental lines under both low (0 kg ha−1) and high (180 kg ha−1) N supply. The results showed that the dynamic trajectories of crop growth and N capture could be accurately characterized by logistic equation using growing degree days as the independent variable. At both N rates, the oilseed rape hybrid outperformed the parental lines in seed yield and aboveground biomass accumulation, which was more closely associated with the longer duration (td) of the rapid growth period (RGP), than with the higher maximum growth rate (vm). N uptake was the main factor driving genotypic variation in seed yield, with an increasing importance of N utilization efficiency at high N supply. The hybrid had significantly higher N uptake than the parental lines at both low and high N supply, because of larger vm for N accumulation during the RGP, which may present a scope for genetically improving NUE in oilseed rape. High N application enhanced crop biomass production and N accumulation, as a result of prolonged td and larger vm during the RGP. The initiation of RGP for N accumulation occurred after overwinter period, which could not be accelerated by high N supply, suggesting rational distribution of N fertilizer with reduced basal dose. However, larger amounts in spring would be beneficial for a better synchronization to crop N demand with lower environmental risks.

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Application of Bag-Controlled Release Fertilizer Facilitated New Root Formation, Delayed Leaf, and Root Senescence in Peach Trees and Improved Nitrogen Utilization Efficiency

Frontiers in Plant Science ◽

10.3389/fpls.2021.627313 ◽

2021 ◽

Vol 12 ◽

Author(s):

Yafei Zhang ◽

Jingjing Luo ◽

Futian Peng ◽

Yuansong Xiao ◽

Anqi Du

Keyword(s):

Controlled Release ◽

Leaf Senescence ◽

Fine Roots ◽

Turnover Rate ◽

Ammonia Volatilization ◽

Nitrogen Utilization ◽

Utilization Efficiency ◽

Nitrogen Utilization Efficiency ◽

Peach Trees ◽

Annual Turnover

It is very important to promote root growth and delay root and leaf senescence, to improve nitrogen absorption and utilization efficiency, and to improve the storage nutrition level of the tree, so as to improve the fruit quality and yield of peach. In this experiment, we compared and analyzed the effects of traditional fertilization and bag-controlled release fertilizer (BCRF) on the growth of shoots and roots, senescence of leaves and roots, and fruit yield and quality. Moreover, the impacts of BCRF on ammonia volatilization, nitrogen utilization rate, fine root turnover, and plant storage nutrients were also investigated. Compared with conventional fertilizer use, the application of BCRF significantly promoted the shoot growth of young peach trees. Additionally, BCRF delayed leaf senescence and increased root activity in autumn. This increased the storage nutrients of the peach tree. Compared with traditional fertilizer, ammonia volatilization reduced to 54.36% under BCRF application situation. BCRF also promoted the occurrence of fine roots and decreased the annual turnover rate. A 15N tracer test showed that, compared with traditional fertilizer, BCRF nitrogen utilization efficiency increased by 37.73% in peach trees under BCRF treatment significantly. The results from 3 consecutive years showed that the application of BCRF increased the yield of individual plants by 21.35% on average compared to the yield from plants receiving equal amounts of fertilizer applied by spreading (FSA). Thus, BCRF can promote the occurrence of fine roots and decrease the root annual turnover rate in peach trees, and it also improves the utilization efficiency of fertilizer, reduces ammonia volatilization, delays leaf senescence, and enhances storage nutrition, fruit yield, and fruit quality in peach trees.

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