Influence of biochar and microorganisms co-application on the remediation and maize productivity in cadmium-contaminated soil.

Author(s):  
Fasih Ullah Haider ◽  
Muhammad Farooq ◽  
Muhammad Naveed ◽  
Sardar Alam Cheema ◽  
Noor ul Ain ◽  
...  

Abstract The synergistic effects of biochar and microorganisms on the adsorption of Cd and on cereal plant physiology remained unclear. Therefore, this experiment was performed to evaluate the combined effects of biochar pyrolyzed from (maize-straw (BC1), cow-manure (BC2), and poultry-manure (BC3), and microorganisms including (T. harzianum L. and B. subtilis L.), to evaluate, how incorporation of biochar positively influences microorganisms growth and nutrients uptake in plant, and how it mitigates under various Cd-stress levels (0, 10, and 30ppm). Cd2 (30 ppm) had the highest reduction in the intercellular CO2, SPAD value, transpiration rate, water use efficiency, stomatal conductance, and photosynthesis rate, which were 22.36, 34.50, 40.45, 20.66, 29.07, and 22.41% respectively lower than control Cd0 (0 ppm). Sole application BC, resulted in enhanced intercellular CO2, SPAD value, transpiration rate, water use efficiency, stomatal conductance, and photosynthesis rate were recorded in BC2, which were 7.27, 20.54, 23.80, 5.96, 13.37, and 13.50% respectively greater as compared to control and decreased the Cd-concentration in root and shoot of maize by 34.07 and 32.53%, respectively as compared to control. Similarly, among sole microorganism’s inoculation, minimized the Cd-concentration in shoot, root, and soil by 23.77, 20.15, and 10.35% respectively than control. These results suggested that integrated application of cow manure biochar BC2 and inoculation of microorganisms MI3 as soil amendments had synergistic effects in improving the adsorption of nutrients and decreasing the Cd-uptake in maize, and enhancing the physiology of plant grown in Cd-polluted soils as opposed to using either biochar or inoculating microorganisms alone.

2017 ◽  
Vol 47 (5) ◽  
Author(s):  
Márcia Vitória Santos ◽  
Evander Alves Ferreira ◽  
Daniel Valadão ◽  
Fabiana Lopes Ramos de Oliveira ◽  
Vitor Diniz Machado ◽  
...  

ABSTRACT: This study aimed to assess the effects of Eucalyptus and maize shading on characteristics related to water use by Brachiaria in agroforestry systems. Treatments were arranged in a split-split-plot design, with plots consisting of different spacing between Eucalyptus plants (12.0×2.0m and 12.0×4.0m), split-plots of different distances between Brachiaria and Eucalyptus (6.0, 4.0, and 2.0m), and split-split-plots of Brachiaria sowing sites (maize row and inter-row). One treatment with Brachiaria under full sunlight was included. Bread grass intercropping in maize inter-rows associated with the densest Eucalyptus spacing and bread grass proximity to Eucalyptus tree crowns adversely affected the stomatal conductance, internal carbon, and transpiration rate of bread grass. Water use efficiency of bread grass intercropped in maize rows decreased, regardless of the Eucalyptus plot design and distance between forages and trees.


2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Jae Hoon Park ◽  
Sang Bum Kim ◽  
Eung Pill Lee ◽  
Seung Yeon Lee ◽  
Eui Joo Kim ◽  
...  

Abstract Background The sunfleck is an important light environmental factor for plants that live under the shade of trees. Currently, the smartfarm has a system that can artificially create these sunfleks. Therefore, it was intended to find optimal light conditions by measuring and analyzing photosynthetic responses of Eutrema japonica (Miq.) Koidz., a plant living in shade with high economic value under artificial sunflecks. Results For this purpose, we used LED pulsed light as the simulated sunflecks and set the light frequency levels of six chambers to 20 Hz, 60 Hz, 180 Hz, 540 Hz, 1620 Hz, and 4860 Hz of a pulsed LED grow system in a plant factory and the duty ratio of the all chambers was set to 30%, 50%, and 70% every 2 weeks. We measured the photosynthetic rate, transpiration rate, stomatal conductance, and substomatal CO2 partial pressure of E. japonica under each light condition. We also calculated the results of measurement, A/Ci, and water use efficiency. According to our results, the photosynthetic rate was not different among different duty ratios, the transpiration rate was higher at the duty ratio of 70% than 30% and 50%, and stomatal conductance was higher at 50% and 70% than at 30%. In addition, the substomatal CO2 partial pressure was higher at the duty ratio of 50% than 30% and 70%, and A/Ci was higher at 30% than 50% and 70%. Water use efficiency was higher at 30% and 50% than at 70%. While the transpiration rate and stomatal conductance generally tended to become higher as the frequency level decreased, other physiological items did not change with different frequency levels. Conclusions Our results showed that 30% and 50% duty ratios could be better in the cultivation of E. japonica due to suffering from water stress as well as light stress in environments with the 70% duty ratio by decreasing water use efficiency. These results suggest that E. japonica is adapted under the light environment with nature sunflecks around 30–50% duty ratio and low light frequency around 20 Hz.


2005 ◽  
Vol 32 (10) ◽  
pp. 945 ◽  
Author(s):  
Thomas R. Sinclair ◽  
Graeme L. Hammer ◽  
Erik J. van Oosterom

Limitations on maximum transpiration rates, which are commonly observed as midday stomatal closure, have been observed even under well-watered conditions. Such limitations may be caused by restricted hydraulic conductance in the plant or by limited supply of water to the plant from uptake by the roots. This behaviour would have the consequences of limiting photosynthetic rate, increasing transpiration efficiency, and conserving soil water. A key question is whether the conservation of water will be rewarded by sustained growth during seed fill and increased grain yield. This simulation analysis was undertaken to examine consequences on sorghum yield over several years when maximum transpiration rate was imposed in a model. Yields were simulated at four locations in the sorghum-growing area of Australia for 115 seasons at each location. Mean yield was increased slightly (5–7%) by setting maximum transpiration rate at 0.4 mm h–1. However, the yield increase was mainly in the dry, low-yielding years in which growers may be more economically vulnerable. In years with yield less than ∼450 g m–2, the maximum transpiration rate trait resulted in yield increases of 9–13%. At higher yield levels, decreased yields were simulated. The yield responses to restricted maximum transpiration rate were associated with an increase in efficiency of water use. This arose because transpiration was reduced at times of the day when atmospheric demand was greatest. Depending on the risk attitude of growers, incorporation of a maximum transpiration rate trait in sorghum cultivars could be desirable to increase yields in dry years and improve water use efficiency and crop yield stability.


2016 ◽  
Vol 44 (1) ◽  
pp. 250-256 ◽  
Author(s):  
Bianca do Carmo SILVA ◽  
Pêola Reis de SOUZA ◽  
Daihany Moraes CALLEGARI ◽  
Vanessa Ferreira ALVES ◽  
Allan Klynger da Silva LOBATO ◽  
...  

Boron (B) is a very important nutrient required by forest plants; when supplied in adequate amounts, plants can ameliorate the negative effects of abiotic stresses. The objective of this study was to (i) investigate gas exchange, (ii) measure oxidant and antioxidant compounds, and (iii) respond how B supply acts on tolerance mechanism to water deficit in young Schizolobium parahyba plants. The experiment employed a factorial that was entirely randomised, with two boron levels (25 and 250 µmol L-1, simulating conditions of sufficient B and high B, respectively) and two water conditions (control and water deficit). Water deficit induced negative modifications on net photosynthetic rate, stomatal conductance and water use efficiency, while B high promoted intensification of the effects on stomatal conductance and water use efficiency. Hydrogen peroxide and electrolyte leakage of both tissues suffered non-significant increases after B high and when applied water deficit. Ascorbate levels presented increases after water deficit and B high to leaf and root. Our results suggested that the tolerance mechanism to water deficit in young Schizolobium parahyba plants is coupled to increases in total glutathione and ascorbate aiming to control the overproduction of hydrogen peroxide and alleviates the negative consequences on electrolyte leakage and gas exchange. In relation to B supply, this study proved that sufficient level promoted better responses under control and water deficit conditions.


2018 ◽  
Vol 36 (1) ◽  
pp. 7-13
Author(s):  
Melissa C. Smith ◽  
Richard N. Mack

Abstract Suitable plant water dynamics and the ability to withstand periods of low moisture input facilitate plant establishment in seasonally arid regions. Temperate bamboos are a major constituent of mixed evergreen and deciduous forests throughout temperate East Asia but play only an incidental role in North American forests and are altogether absent in the Pacific Northwest forest. Many bamboo species are classified as mesic or riparian, but none are considered drought tolerant. To assess their ability to withstand low water, we subjected five Asian temperate and one North American temperate bamboo species to three irrigation treatments: 100%, 50%, and 10% replacement of water lost through evapotranspiration. Plants were irrigated every four days over a 31-day period. Plant response to treatments was measured with stomatal conductance, leaf xylem water potentials, and intrinsic water use efficiency (iWUE). Pleioblastus distichus and Pseudosasa japonica showed significant reductions in conductance between high and low irrigation treatments. Sasa palmata had significantly lower stomatal conductance in all treatments. Pleioblastus chino displayed significantly higher iWUE in the mid irrigation treatment and Arunindaria gigantea displayed significantly lower iWUE than P. chino and S. palmata in the low irrigation treatment. The Asian bamboo species examined here tolerate low water availability and readily acclimate to different soil moisture conditions. Index words: Temperate bamboos, irrigation response, stomatal conductance, intrinsic water use efficiency. Species used in this study: Giant Cane [Arundinaria gigantea (Walt.) Muhl.]; Pleioblastus chino (Franchet & Savatier) Makino; Pleioblastus distichus (Mitford) Nakai; Pseudosasa japonica (Makino); Sasa palmata (Bean) Nakai.


1991 ◽  
Vol 71 (3) ◽  
pp. 695-702 ◽  
Author(s):  
J. M. Clarke ◽  
R. A. Richards ◽  
A. G. Condon

Increasing the water use efficiency (WUE) of wheat (Triticum spp.) has long been a goal in semiarid areas. Low rates of residual (cuticular) transpiration are thought to improve yield potential of wheat under dry conditions, although the linkage is tenuous. The objective of this work was to investigate the association of residual transpiration with water use, WUE, and leaf water status in hexaploid (T. aestivum L.) and tetraploid (T. turgidum L. var. durum) genotypes grown under two watering regimes in two glasshouse experiments. Single plants were grown in 0.1-m × 1-m (0.1-m × 0.5-m in exp. 2 low-stress treatment) PVC tubes filled with soil. The watering regimes consisted of weekly replenishment of water used (low stress), or addition of sufficient water to ensure plant survival (high stress). At anthesis, flag leaf residual transpiration (rate of water loss from excised leaves), stomatal conductance, relative water content (RWC), and osmotic potential (exp. 1 only) were measured. Water use was not correlated with residual transpiration rate in either experiment. Residual transpiration rate did not differ for the two stress treatments in exp. 1, but there were significant (P < 0.01) genotype by stress treatment interactions. Residual transpiration rate was not related to plant water status (leaf RWC or osmotic potential) as had been reported in other studies. Key words: Cuticular transpiration, water use efficiency, Triticum aestivum L., Triticum turgidum L. var. durum


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.


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