Effect of Soil Water Content on Growth, Photosynthetic Rate, and Stomatal Conductance of Kimchi Cabbage at the Early Growth Stage after Transplanting

Abstract The purpose of this study was to evaluate growth, chlorophyll content, and photosynthesis in Jatropha at different levels of soil moisture. Plants were cultivated in containers and the treatments of the soil water content evaluated were: 0% (without watering), 20, 40, 60, and 80% soil water content. Plant height was statistically similar for all treatments, but the number of leaves differed significantly. Total dry matter and chlorophyll at 40, 60, and 80% soil water content were statistically similar, but different from 0 and 20% soil water content. Leaf area at 40, 60, and 80% soil water content was statistically different from 0 and 20% soil water content. The photosynthetic rate, transpiration and stomatal conductance at 60 and 80% soil water content were statistically similar but different from 0 and 20% soil water content. Water stress affected growth, chlorophyll content, photosynthetic rate, transpiration, and stomatal conductance.

Download Full-text

Effects of Superabsorbent Polymer on Soil Water Content and Sugarcane Germination and Early Growth in Sandy Soil Conditions

Sugar Tech ◽

10.1007/s12355-018-0672-5 ◽

2018 ◽

Vol 21 (3) ◽

pp. 444-450 ◽

Cited By ~ 3

Author(s):

Kenta Watanabe ◽

Samran Saensupo ◽

Yanischa Na-iam ◽

Peeraya Klomsa-ard ◽

Klanarong Sriroth

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Sandy Soil ◽

Early Growth ◽

Soil Conditions ◽

Superabsorbent Polymer

Download Full-text

Physiological and climate controls on foliar mercury uptake by European tree species

10.5194/bg-2021-239 ◽

2021 ◽

Author(s):

Lena Wohlgemuth ◽

Pasi Rautio ◽

Bernd Ahrends ◽

Alexander Russ ◽

Lars Vesterdal ◽

...

Keyword(s):

Stomatal Conductance ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Tree Species ◽

Physiological Activity ◽

Growing Season ◽

Relevant Parameter ◽

Uptake Rates ◽

Mercury Uptake

Abstract. Despite the importance of vegetation uptake of atmospheric gaseous elemental mercury (Hg(0)) within the global Hg cycle, little knowledge exists on the physiological, climatic and geographic factors controlling stomatal uptake of atmospheric Hg(0) by tree foliage. We investigate controls on foliar stomatal Hg(0) uptake by combining Hg measurements of 3,569 foliage samples across Europe with data on tree species traits and environmental conditions. To account for foliar Hg accumulation over time, we normalized foliar Hg concentration over the foliar life period from the simulated start of the growing season to sample harvest. The most relevant parameter impacting daily foliar stomatal Hg uptake was tree functional group (deciduous versus coniferous trees). On average, we measured 3.2 times higher daily foliar stomatal Hg uptake rates in deciduous leaves than in coniferous needles of the same age. Across tree species, for foliage of beech and fir, and at two out of three forest plots with more than 20 samples, we found a significant (p < 0.001) increase in foliar Hg values with respective leaf nitrogen concentrations. We therefore suggest, that foliar stomatal Hg uptake is controlled by tree functional traits with uptake rates increasing from low to high nutrient content representing low to high physiological activity. For pine and spruce needles, we detected a significant linear decrease of daily foliar stomatal Hg uptake with the proportion of time, during which vapor pressure deficit (VPD) exceeded the species-specific threshold values of 1.2 kPa and 3 kPa, respectively. The proportion of time within the growing season, during which surface soil water content (ERA5-Land) in the region of forest plots was low correlated negatively with corresponding foliar Hg uptake rates of beech and pine. These findings suggest that stomatal uptake of atmospheric Hg(0) is inhibited under high VPD conditions and/or low soil water content due the regulation of stomatal conductance to reduce water loss under dry conditions. We therefore propose, that foliar Hg measurements bear the potential to serve as proxy for stomatal conductance. Other parameters associated with forest sampling sites (latitude and altitude), sampled trees (average age and diameter at breast height) or regional satellite observation-based transpiration product (GLEAM) did not significantly correlate with daily foliar Hg uptake rates. We conclude that tree physiological activity and stomatal response to VPD and soil water content should be implemented in a stomatal Hg model, to assess future Hg cycling under different anthropogenic emission scenarios and global warming.

Download Full-text

Photosynthesis and Stomatal-Conductance Responses of Johnsongrass (Sorghum halepense) to Water Stress

Weed Science ◽

10.1017/s0043174500082990 ◽

1985 ◽

Vol 33 (5) ◽

pp. 635-639 ◽

Cited By ~ 11

Author(s):

Bryan L. Stuart ◽

Daniel R. Krieg ◽

John R. Abernathy

Keyword(s):

Water Stress ◽

Stomatal Conductance ◽

Water Potential ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Osmotic Potential ◽

Grain Filling ◽

Leaf Temperature ◽

Sorghum Halepense

The influence of water stress on johnsongrass [Sorghum halepense(L.) Pers. ♯ SORHA] physiology was evaluated in a semiarid environment. Stomatal conductance of johnsongrass responded to more negative leaf water potential and increasing leaf temperature. The sensitivity of the leaf temperature effect was dependent on the soil water content. At low soil water content, conductance was limited by low water potential, and increasing leaf temperature had little effect. Conductance of CO2was related to net photosynthesis in a curvilinear manner, with conductance levels greater than 0.3 mol·m-2· s-1being in excess of that necessary for maximum photosynthesis. At both high conductance levels and low levels associated with increased water stress, intercellular CO2concentration increased, indicating nonstomatal limitations to photosynthesis. Decreased osmotic potential provided the highest correlation with the linear decline of photosynthetic rate as stress intensified. The expression of osmotic adjustment in johnsongrass is reported during grain filling. Plants in the milkdough stage of grain filling had approximately 0.3 MPa lower osmotic potential at any relative water content than those at anthesis.

Download Full-text

Estimating mesophyll and biochemical limitations to carbon assimilation of potato crop during drought

10.5194/egusphere-egu21-11021 ◽

2021 ◽

Author(s):

Quentin Beauclaire ◽

Bernard Longdoz

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Photosynthetic Rate ◽

Potato Crop ◽

Carbon Assimilation ◽

Development Stage ◽

Rate Variation ◽

Drought Treatment ◽

The Impact

Understanding how plant crops respond to drought is essential for both improving photosynthesis modelling and predicting the impacts of climate change on agricultural production. Over the past years, researches have focused on identifying the stomatal processes that restrict the net photosynthetic rate and quantifying the importance and how different factors limit it. However, the constraints to photosynthesis coming from perturbation in the mechanisms taking place from sub-stomatal cavities to carboxylation sites in chloroplasts are not yet fully understood especially in plant crops. The aim of our study was to investigate the impact of drought on the light-limited photosynthesis rate for potato (Solanum Tubersosum) by measuring the photosynthesis limitations and partitioning them between stomatal, mesophyll and biochemical constrains during a field-experiment that took place in Wallonia during the summer 2020. Gas-exchange and fluorescence techniques were used to quantify mesophyll conductance (gm), stomatal conductance (gs), Rubisco carboxylation rate (Vcmax) and electron transport rate (Jmax) in response to low soil water content during the tuber development stage. We obtained a clear reduction of the leaf assimilation and performed a limitation analysis identifying which factor contributed the most to the light-saturated photosynthetic rate (An) decrease. During the one-month drought treatment, An, gm, Jmax and Vcmax significantly decreased when the relative extractable water (REW) passed below a threshold ranging from 0.5 to 0.7 . On the opposite, g1, the slope of the gs dependence on environmental factors, remained constant. When soil water was not limiting, most of the light-saturated photosynthetic rate variation was explained by VPD while mesophyll and biochemical influence progressively increased when soil water content declined. At the maximum drought intensity, gm and Vcmax reduction explained respectively 40 % and 30% of the light-saturated photosynthetic rate decrease. The coexistence of aerial drought (high VPD) accounted only for 3% of the total limitation. This highlights the importance of mesophyll and biochemical limitations on potato photosynthesis and development.

Download Full-text