scholarly journals Alternate partial root-zone N-fertigation increases water use efficiency and N uptake of barley at elevated CO2

2021 ◽  
Vol 258 ◽  
pp. 107168
Author(s):  
Li Li ◽  
Yaosheng Wang ◽  
Fulai Liu
Soil Research ◽  
2004 ◽  
Vol 42 (3) ◽  
pp. 345 ◽  
Author(s):  
C. Kütük ◽  
G. Çaycı ◽  
L. K. Heng

A greenhouse experiment was conducted to investigate the response of tomato plants (Lycopersicon lycopersicum L.) to salinity and to determine the interactive effects of salinity and nitrogen fertilisation on yield, nitrogen uptake, water use efficiency (WUE), and root-zone salinity during early plant growth. Furthermore, the effects of salinity and N fertilisation were evaluated by measurement of carbon isotope discrimination (Δ). Tomato plants were grown in pots filled with 8 kg (dry weight equivalent) of Krumbach sandy loam. Salinity treatments were imposed by irrigation water containing Na, Ca, and Mg salts and having electrical conductivity of 0, 3, 6, 9, and 12 dS/m at 25�C. 15N-labelled urea (10 atom % excess) was also applied at 0, 80, 160, and 240 mg N/kg soil. Increasing salinity reduced plant growth; fresh and dry weights of shoots and roots decreased significantly, except for the non-fertilised plants. The maximum growth reduction in shoots occurred due to salinity–N fertilisation relationships at 12 dS/m (59.4% reduction compared with 0 dS/m in 160 mg N/kg). Root growth was less affected than shoots. Vegetative growth and N content increased with increasing nitrogen treatment. However, salinity generally reduced N uptake by plants. Δ was negatively correlated with WUE at all salinity levels in young tomato plants. Similar correlations were also obtained between WUE and Δ at various N treatments; the result suggests that Δ is a useful tool for assessing stress conditions. Smaller Δ values were obtained when salinity or N level increased. Increasing N fertiliser increased WUE in plants, whereas increasing salinity increased WUE at 3 dS/m and decreased WUE to some extent at other salinity levels. Electrical conductivity of the root-zone increased due to increasing salinity and time, whereas pH decreased. It was concluded that the early stage of development was a salt sensitive period for tomato plants.


2008 ◽  
Vol 95 (6) ◽  
pp. 659-668 ◽  
Author(s):  
Taisheng Du ◽  
Shaozhong Kang ◽  
Jianhua Zhang ◽  
Fusheng Li ◽  
Boyuan Yan

2013 ◽  
Vol 726-731 ◽  
pp. 3035-3039 ◽  
Author(s):  
Xue Bin Qi ◽  
Zong Dong Huang ◽  
Dong Mei Qiao ◽  
Ping Li ◽  
Zhi Juan Zhao ◽  
...  

Agriculture is a big consumer of fresh water in competition with other sectors of the society. The agricultural sector continues to have a negative impact on the ecological status of the environment. The worlds interest in high quality food is increasing. Field experiments were conducted to investigate the effect of subsurface drip irrigation on physiological responses, yield and water use efficiency, Soil nitrogen, Root weight density of potato in the semi-humid region of middle China using subsurface drip irrigation. The experiment used second-stage treated wastewater with and without addition of chloride, and both subsurface drip and furrow irrigations were investigated. Results indicated that the alternate partial root-zone irrigation is a practicable water-saving strategy for potato. The drip with chlorinated and non-chlorinated water improved water use efficiency by 21.48% and 39.1%, respectively, and 44.1% in the furrow irrigation. Partial root zone drying irrigation stimulates potato root growth and enhances root density. The content of the heavy metal in the potato tubers is no more than the National Food Requirements, and it is consistent with National Food Hygiene Stands.


2005 ◽  
Vol 277-279 ◽  
pp. 528-535
Author(s):  
Oh Hyun Kyung ◽  
Yeonsook Choung

The response of Quercus mongolica, one of the major tree species in Northeast Asia and the most dominant deciduous tree in Korea, was studied in relation to elevated CO2 and the addition of nitrogen to soil in terms of its physiology and growth over two years. Plants were grown from seed at two CO2 conditions (ambient and 700 µL L-1) and with two levels of soil nitrogen supply (1.5 mM and 6.5 mM). Elevated CO2 was found to significantly enhance the photosynthesis rate and water use efficiency by 2.3-2.7 times and by 1.3-1.8 times, respectively. Over time within a growing season, there was a decreasing trend in the photosynthesis rate. However, the decrease was slower especially in two-year-old seedlings grown in elevated CO2 and high nitrogen conditions, suggesting that their physiological activity lasted relatively longer. Improved photosynthesis and water use efficiency as well as prolonged physiological activity under high CO2 condition resulted in an increase in biomass accumulation. That is, in elevated CO2, total biomass increased by 1.7 and 1.2 times, respectively, for one- and two-year-old seedlings with low nitrogen conditions, and by 1.8 and 2.6 times with high nitrogen conditions. This result indicates that the effect of CO2 on biomass is more marked in high nitrogen conditions. This, therefore, shows that the effect of CO2 is accelerated by the addition of nitrogen. With the increase in total biomass, the number of leaves and stem diameter increased significantly, and more biomass was allocated in roots, resulting in structural change. Overall, the elevated CO2 markedly stimulated the physiology and growth of Q. mongolica. This demonstrates that Q. mongolica is capable of exploiting an elevated CO2 environment. Therefore, it will remain a dominant species and continue to be a major CO2 sink in the future, even though other resources such as nitrogen can modify the CO2 effect.


2021 ◽  
Vol 243 ◽  
pp. 106421
Author(s):  
Dionei Lima Santos ◽  
Eugênio Ferreira Coelho ◽  
Fernando França da Cunha ◽  
Sérgio Luiz Rodrigues Donato ◽  
Wallace de Paula Bernado ◽  
...  

2013 ◽  
Vol 40 (2) ◽  
pp. 201 ◽  
Author(s):  
Gyro L. Sherwin ◽  
Laurel George ◽  
Kamali Kannangara ◽  
David T. Tissue ◽  
Oula Ghannoum

This study explored reductions in tissue nitrogen concentration ([N]) at elevated CO2 concentrations ([CO2]), and changes in plant water and N uptake. Eucalyptus saligna Sm. seedlings were grown under three [CO2] levels (preindustrial (280 μL L–1), current (400 μL L–1) or projected (640 μL L–1)) and two air temperatures (current, (current + 4°C)). Gravimetric water use, leaf gas exchange and tissue dry mass and %N were determined. Solid-state 15N-NMR spectroscopy was used for determining the partitioning of N chemical groups in the dry matter fractions. Water use efficiency (WUE) improved with increasing [CO2] at ambient temperature, but strong leaf area and weak reductions in transpiration rates led to greater water use at elevated [CO2]. High temperature increased plant water use, such that WUE was not significantly stimulated by increasing [CO2] at high temperature. Total N uptake increased with increasing [CO2] but not temperature, less than the increase recorded for plant biomass. Tissue [N] decreased with rising [CO2] and at high temperature, but N use efficiency increased with rising [CO2]. Total N uptake was positively correlated with total water use and root biomass under all treatments. Growth [CO2] and temperature did not affect the partitioning of 15N among the N chemical groups. The reductions of tissue [N] with [CO2] and temperature were generic, not specific to particular N compounds. The results suggest that reductions in tissue [N] are caused by changes in root N uptake by mass flow due to altered transpiration rates at elevated [CO2] and temperature.


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