Plant Tissue Nutrient Concentrations Research Articles

Fertilizer Value of Nutrient-Enriched Biochar and Response of Canola Crop

Excessive use of chemical fertilizers (CFs) can result in a decrease of soil organic matter, lowering soil fertility and agricultural productivity. Biochar application could be a promising approach to reduce these issues and increase soil fertility. In this study, the effects of nutrient-enriched biochar (NEBC) on soil properties and canola (Brassica napus L.) plant growth were investigated. A pot experiment was conducted following a completely randomized design with three replications. Two contrasting Australian soils were amended with three doses (i.e., control, 1%, and 5% w/w) of three NEBCs, one biosolid biochar (BSBC), and CF. The canola plant growth experiment spanned over eight weeks assessing the effects of the amendments. Soil properties were examined after plant harvesting. NEBC and BSBC lowered soil pH (up to 1.38 units) and increased soil EC (up to 378 µS cm−1). They also increased P (up to 19-fold) and K (up to 0.67 g kg−1) availability, improving canola growth compared to CF. Biochar increased dehydrogenase enzyme activity (up to twofold), but NEBC reduced seed germination due to high nutrient content. Nutrient concentration in plant tissues increased with NEBC and BSBC application. Application of NEBC and BSBC improved soil properties, resulting in increased growth of canola. The application rate of NEBC fertilizer requires further optimization to improve soil fertility and crop productivity.

Nutrient uptake efficiency and stoichiometry for different plant functional groups on spoil heap after hard coal mining in Upper Silesia, Poland

Various plant functional groups (PFGs) used in the reclamation of post-mining heaps may differ in their nutrient uptake efficiency and thus in their effect on the ecosystem development. The effect of PFGs may be additionally modified by the applied reclamation measures such as e.g. topsoiling. In this study we compared the nutrient uptake efficiencies and plant stoichiometry for two PFGs (grasses and forbs) growing on the sites reclaimed by applying topsoil (TS) and unreclaimed sites on carboniferous bare rock (BR) in hard coal spoil heap in Upper Silesia (southern Poland). Basic soil parameters, including pH, texture, soil organic carbon, and nutrients (N, P, K, Ca, and Mg), were measured, and the aboveground plant biomass and nutrient content in plant tissue were determined. Forbs were characterized by a larger biomass and higher nutrient concentrations (except for P) than grasses. The TS treatment supported higher concentrations of N and P in plant tissues but not to the level ensuring more significant primary biomass production. The nutrient concentration and elemental stoichiometry in plant tissue indicated that N was the primary limiting element. However, the major growth limitation for N-fixing forbs was from P. Forbs were much more efficient in nutrient uptake than grasses, independent of the reclamation treatment. Therefore, they stimulate nutrient cycling in the restored ecosystems more than grasses.

Status of crop fertility management and plant tissue nutrient concentration of blackberry in the southeastern United States

Status of crop fertility management and plant tissue nutrient concentration of blackberry in the southeastern United States

Detection of calcium, magnesium, and chlorophyll variations of wheat genotypes on sodic soils using hyperspectral red edge parameters

Plants grown on sodic soils can suffer from macronutrient deficiencies, such as calcium (Ca), magnesium (Mg), and potassium (K), reducing health and growth. Nutrient concentrations in plant tissue could potentially provide a signal to identify cultivars tolerant to sodic conditions. However, conventional approaches to diagnosing crop nutrient and chlorophyll status involve determining total elemental content in plant tissues. These methods are time-consuming, tedious, and expensive, requiring destructive sampling of plant parts and complex laboratory analyses. Here, we propose a novel approach using hyperspectral sensing to determine macronutrient and chlorophyll variations/deficiencies of 18 different wheat genotypes grown in moderately sodic (MS) and highly sodic (HS) soil conditions in north-eastern Australia. Canopy reflectance was measured using a handheld spectroradiometer close to flowering to compute red edge spectral indices, such as normalized difference red edge index (NDRE), red edge inflection point (REIP), and red edge chlorophyll index (Cl rededge). Plant Ca, Mg, and K concentrations were also measured by destructive sampling of young mature leaves followed by laboratory analysis. The maximum first derivative of reflectance spectra for 18 wheat genotypes were observed at 722–728 nm and 719–725 nm for the MS and HS site, respectively and was used to determine REIP for the genotypes using a four-point linear interpolation method. Ca and Mg had a significant positive association with both REIP and NDRE, with Ca more closely correlated than either Mg or K. REIP was more closely associated with Ca (R2=0.72; RMSE=0.02 for the MS site and R 2=0.57; RMSE=0.02 for the HS site) than NDRE. This suggests that REIP has a great potential to detect structural variations of wheat genotypes in sodic soil environment. Furthermore, Ca was also significantly (p<0.0001) and positively correlated with Cl rededge at both sites with R2=0.53 and 0.51 for the MS and HS site. This suggests that plant structural variations in sodic soil can regulate leaf chlorophyll concentration and, in turn, photosynthetic activities. Overall, results demonstrate that hyperspectral sensing can be efficiently used to detect plant Ca, Mg, and chlorophyll concentrations. The study improves understanding of genotypic nutrient variation for tolerance to different levels of sodic soil conditions using optical properties of plant structure and can be beneficial to the plant science community for developing new approaches to study plant physiology.

Plant Tissue Nutrient Concentration and Major Soil Nutrients Influenced by NPSB Fertilizer Rates and Plant Population of Maize (Zea Mays L.) at Bako, Oromia National Regional State

Plant nutrients such as nitrogen, phosphorus, potassium and sulfur are the nutrients frequently limit the yields of maize over the world. Nutrient recommendation should be based on the optimum yield and environmental save that can be through plant tissue analysis and soil test. This experiment was conducted at Bako Agricultural Research Center west region of Ethiopia Gobu Sayo using split plot desighn with three levels of plant population 53.333,66,666 and 76,923 plants per hectare on main plot and five level 0,100,150,200,250 kg/ha of NPSB fertilizer rates on sub-plots. Soil sample was taken from the plots pre-harvesting for composite sample and post-harvest from each plot and analyzed at Bako soil laboratory and Ethiopia water work design Addis Ababa for soil fertility management. Nutrient in plant tissue was analyzed at Holota Agricultural Research Center soil laboratory. Collected data was analyzed using Genstat computer statistical soft-ware package. The result of pre planting soil analysis showed soil of the study area was categorized as clay soil with medium and stable organic matter and low organic carbon and low total nitrogen that shows low soil fertility. The ANOVA result showed addition of fertilizer reduced soil pH from 5.7 to 5.47 and bellow. 150 kg/ha of NPSB which gave economically feasible yield 9460kg/ha moderately acidified the soil. This soil analysis result showed that the level at which fertilizer boost yield of maize. Only percent of phosphorus was changed due to plant population density. Plant tissue concentration at silking was significantly influenced by fertilizer rates. Potassium is at sufficiency range for all level of supplied fertilizer. Sufficient range nitrogen at silkin was recorded from the plot received 100-150 kg/ha which gave economically feasible yield. It is better to use fertilizer rate of 150kg/ha which shows sufficiency range for nutrient concentration of soil and plant tissue in leaf at silking stage. This finding is not the end for the area and further research should be carried out for feature. Keywords: plant tissue, soil, Zea mays L., Nitrogen, Phosphorus, Sulfur, potassium DOI: 10.7176/JBAH/12-13-04 Publication date: July 31 st 2022

Defoliation-induced changes in foliage quality may trigger broad-scale insect outbreaks

Top-down effects, like predation, are drivers of insect outbreaks, but bottom-up effects, like host nutritional quality, also influence outbreaks and could in turn be altered by insect-caused defoliation. We evaluated the prediction that herbivory leads to a positive feedback on outbreak severity as nutrient concentration in plant tissues increases through improved soil nutrient availability from frass and litter deposition. Over seven years of a spruce budworm outbreak, we quantified litter nutrient fluxes, soil nitrogen availability, and host tree foliar nutrient status along a forest susceptibility gradient. As the outbreak progressed, both soil nutrient fluxes and availability increased which, in turn, improved foliage quality in surviving host trees. This is consistent with boosted insect fitness and increased population density and defoliation as outbreaks grow. Our results suggest that a positive bottom-up feedback to forest ecosystems from defoliation may result in conditions favorable to self-amplifying population dynamics in insect herbivores that can contribute to driving broad-scale outbreaks.

Spatial approach for diagnosis of yield-limiting nutrients in smallholder agroecosystem landscape using population-based farm survey data.

Adept use of fertilizers is critical if sustainable development goal two of zero hunger and agroecosystem resilience are to be achieved for African smallholder agroecosystems. These heterogeneous systems are characterized by poor soil health mainly attributed to soil nutrient depletion. However, conventional methods do not take into account spatial patterns across geographies within agroecosystems, which poses great challenges for targeted interventions of nutrient management. This study aimed to develop a novel population-based farm survey approach for diagnosing soil nutrient deficiencies. The approach embraces principles of land health surveillance of problem definition and rigorous sampling scheme. The advent of rapid soil testing techniques, like infrared spectroscopy, offers opportune avenues for high-density soil and plant characterization. A farm survey was conducted on 64 maize fields, to collect data on soil and plant tissue nutrient concentration and grain yield (GY) for maize crops, using hierarchical and purposive sampling. Correlations between soil test values with GY and biomass were established. The relationship between GY, soil NPK, and the tissue nutrient concentrations was evaluated to guide the setting up of localized critical soil test values. Diagnosis Recommendation Integrated System (DRIS) indices for total nitrogen (N), total phosphorus (P), and total potassium (K) were used to rank and map the prevalence of nutrient limitations. A positive correlation existed between plant tissue nutrient concentration with GY with R2 values of 0.089, 0.033, and 0.001 for NPK, respectively. Soil test cut-off values were 0.01%, 12 mg kg-1, 4.5 cmolc kg-1 for NPK, respectively, which varied slightly from established soil critical values for soil nutrient diagnostics. N and K were the most limiting nutrients for maize production in 67% of sampled fields. The study demonstrates that a population-based farm survey of crop fields can be a useful tool in nutrient diagnostics and setting priorities for site-specific fertilizer recommendations. A larger-scale application of the approach is warranted.

Serratia plymuthica MBSA-MJ1 Increases Shoot Growth and Tissue Nutrient Concentration in Containerized Ornamentals Grown Under Low-Nutrient Conditions

High fertilizer rates are often applied to horticulture crop production systems to produce high quality crops with minimal time in production. Much of the nutrients applied in fertilizers are not taken up by the plant and are leached out of the containers during regular irrigation. The application of plant growth promoting rhizobacteria (PGPR) can increase the availability and uptake of essential nutrients by plants, thereby reducing nutrient leaching and environmental contamination. Identification of PGPR can contribute to the formulation of biostimulant products for use in commercial greenhouse production. Here, we have identified Serratia plymuthica MBSA-MJ1 as a PGPR that can promote the growth of containerized horticulture crops grown with low fertilizer inputs. MBSA-MJ1 was applied weekly as a media drench to Petunia×hybrida (petunia), Impatiens walleriana (impatiens), and Viola×wittrockiana (pansy). Plant growth, quality, and tissue nutrient concentration were evaluated 8weeks after transplant. Application of MBSA-MJ1 increased the shoot biomass of all three species and increased the flower number of impatiens. Bacteria application also increased the concentration of certain essential nutrients in the shoots of different plant species. In vitro and genomic characterization identified multiple putative mechanisms that are likely contributing to the strain’s ability to increase the availability and uptake of these nutrients by plants. This work provides insight into the interconnectedness of beneficial PGPR mechanisms and how these bacteria can be utilized as potential biostimulants for sustainable crop production with reduced chemical fertilizer inputs.

Plant Functional Types Differ in Their Long-term Nutrient Response to eCO2 in an Extensive Grassland

Increasing atmospheric CO2 enhances plant biomass production and may thereby change nutrient concentrations in plant tissues. The objective of this study was to identify the effect of elevated atmospheric CO2 concentrations on nutrient concentrations of grassland biomass that have been grown for 16 years (1998–2013). The grassland biomass grown at the extensively managed Giessen FACE experiment, fumigated with ambient and elevated CO2 (aCO2; eCO2; +20%) was harvested twice annually. Concentrations of C, N, P, K, Ca, Mg, Mn, Fe, Cu and Zn were determined separately for grasses, forbs and legumes. Under eCO2, the concentration of N was reduced in grasses, Ca was reduced in grasses and forbs, P was reduced in grasses but increased in legumes, Mg concentration was reduced in grasses, forbs and legumes and K was reduced in grasses but increased in forbs. The nutrient yield (in g nutrient yield of an element per m−2) of most elements indicated negative yield responses at a zero biomass response to eCO2 for grasses. K and Zn nutrient yields responded positively to eCO2 in forbs and Mn and Fe responded positively in forbs and legumes. The results suggest that under eCO2 the nutrient concentrations were not diluted by the CO2 fertilization effect. Rather, altered plant nutrient acquisitions via changed physiological mechanisms prevail for increased C assimilation under eCO2. Furthermore, other factors such as water or nutrient availability affected plant nutrient concentrations under eCO2.

Using Constructed Floating Wetlands to Remove Nutrients from a Waste Stabilization Pond

This study reports the biomass accumulation, plant nutrient concentration, and nutrient uptake rates of plants in a constructed floating wetland (CFW) installed for a sewage treatment application in Australia. Plant biomass accumulation was estimated based on field samplings throughout the duration of the study. Analysis of samples of each plant species was also completed to estimate the mean plant tissue nutrient content. The plant biomass accumulation estimate and the mean plant tissue nutrient concentration were then used to estimate the total nutrient uptake for each species. Each of the species were found to differ in biomass accumulation and plant tissue nutrient concentration and the distribution of biomass and nutrients between the shoots and roots. The nutrient uptake rates varied between the species, with B. articulata having the greatest nutrient uptake rates (shoots: N, 104 ± 31.5 g/m2, P, 12.9 ± 3.87 g/m2; roots: N, 23.9 ± 7.23 g/m2, P, 5.54 ± 1.67 g/m2). Harvesting of the four CFW islands after 375 days of growth removed an estimated 23.2 kg of N and 2.97 kg of P. The results of this study indicate that the use of CFWs with carefully selected plant species can successfully remove significant amounts of nutrients from domestic wastewater.

Motorway age is linked to larger body size, but not song carrier frequency, in male grasshoppers from roadside populations

Producing calls with increased minimum carrier frequency is well documented in sound communicating species confronted with noise pollution, possibly helping them to avoid acoustic masking of low-frequency signals. However, the lack of studies on invertebrates limits our understanding of the potentially adverse effects of anthropogenic noise on natural populations. While males of the grasshopper Chorthippus biguttulus are known to produce courtship signals with elevated low-frequency local maxima (LFLM) in roadside populations, previous studies provided no insight into morphological traits underlying LFLM shifts. Although developmental plasticity was identified as one main factor accounting for elevated LFLM, an additional role for a more hard-wired trait architecture was proposed, possibly as a result of adaptation to traffic noise. Our current study therefore aims to assess (1) whether the position of LFLM is related to male body size, (2) whether body size is correlated with motorway age, and (3) whether the position of LFLM is correlated with motorway age in C. biguttulus males from roadside populations. In addition to substantial variation in LFLM among C. biguttulus males, we found that larger males produced signals with lower LFLM, suggesting a potential role in female choice as a predictor of male quality. While we found no significant correlation between LFLM and motorway age, C. biguttulus males were larger near older motorway sections. This positive correlation may be due to several reasons, including: (1) higher nutrient concentration and availability in plant tissues due to eutrophication of roadside habitats; (2) temporal succession of male size phenotypes during colonization processes; and/or (3) selection for larger body size in roadside populations. Our results highlight the multifaceted and often complex nature of the relationships between morphology, signal traits and anthropogenic pressures on sound communication in invertebrates.

Low phosphorus supply constrains plant responses to elevated CO2 : A meta-analysis.

Phosphorus (P) is an essential macro-nutrient required for plant metabolism and growth. Low P availability could potentially limit plant responses to elevated carbon dioxide (eCO2 ), but consensus has yet to be reached on the extent of this limitation. Here, based on data from experiments that manipulated both CO2 and P for young individuals of woody and non-woody species, we present a meta-analysis of P limitation impacts on plant growth, physiological, and morphological response to eCO2 . We show that low P availability attenuated plant photosynthetic response to eCO2 by approximately one-quarter, leading to a reduced, but still positive photosynthetic response to eCO2 compared to those under high P availability. Furthermore, low P limited plant aboveground, belowground, and total biomass responses to eCO2 , by 14.7%, 14.3%, and 12.4%, respectively, equivalent to an approximate halving of the eCO2 responses observed under high P availability. In comparison, low P availability did not significantly alter the eCO2 -induced changes in plant tissue nutrient concentration, suggesting tissue nutrient flexibility is an important mechanism allowing biomass response to eCO2 under low P availability. Low P significantly reduced the eCO2 -induced increase in leaf area by 14.3%, mirroring the aboveground biomass response, but low P did not affect the eCO2 -induced increase in root length. Woody plants exhibited stronger attenuation effect of low P on aboveground biomass response to eCO2 than non-woody plants, while plants with different mycorrhizal associations showed similar responses to low P and eCO2 interaction. This meta-analysis highlights crucial data gaps in capturing plant responses to eCO2 and low P availability. Field-based experiments with longer-term exposure of both CO2 and P manipulations are critically needed to provide ecosystem-scale understanding. Taken together, our results provide a quantitative baseline to constrain model-based hypotheses of plant responses to eCO2 under P limitation, thereby improving projections of future global change impacts.

Do soil test levels and fertilization with phosphorus and potassium impact field crop tissue concentrations?

AbstractSoil testing and plant tissue nutrient concentrations form the basis for fertilizer recommendations in Ohio. The response of crop phosphorus (P) and potassium (K) nutrient concentrations to soil test levels and fertilizer applications influences fertilizer recommendations but have not been rigorously evaluated in this region. The objective of our study was to determine the effects of (a) soil test P and K levels and (b) P and K fertilization on mid‐season leaf and grain P and K concentrations of corn (Zea mays L.), soybean [Glycine max (L.) Merr.], and wheat (Triticum aestivum L.). From 2014–2018, we conducted 186 on‐farm trials (99 P, 87 K trials) over a diversity of soil types, crop genetics, and management histories in 39 counties throughout Ohio. Soil test P and K levels, mid‐season leaf P and K concentrations, and grain P and K concentrations were measured on randomized and replicated plots. Both leaf and grain nutrient concentrations generally increased with the soil test levels, but the relationships were weak in all three crops. Fertilization of P and K marginally but consistently increased leaf tissue concentrations in all crops but had a lesser effect on grain P and K concentrations. Our data suggest that current sufficiency ranges for corn, soybean, and wheat are too high and need revision. Collectively, our results show that crop P and K tissue concentrations are positively, but weakly related to soil test levels and fertilization, and this information has important implications for future development of nutrient management frameworks in Ohio.

Effect of foliar applications of phosphites on growth, nutritional status and defense responses in tomato plants

The use of phosphite (Phi)-containing products as foliar fertilizers is a common practice in food production systems, yet their actual contribution as a source of phosphorus (P) for plant nutrition has been object of debate. In this study, we aim to determine, not only the potential impact of foliar Phi applications on tomato plants nutritional status and biomass production, but also their effect on the expression of genes related to plant phosphate (Pi)-starvation and defense responses. The effect of Phi was evaluated on hydroponic tomato plants growing under low (0.1 mM) and optimal (1.0 mM) Pi conditions. Phi-treatments consisted of foliar sprayings of KPhi, CaPhi, AlPhi or H3PO3. Gene expression analysis was carried out 24 h, 48 h and 7 days after the last Phi application, while biomass production and nutrient concentration in the plant tissues were determined seven days after the last Phi application. Regardless the Pi concentration in the hydroponic solution, foliar application of Phi influenced neither net biomass production and partitioning nor photosynthesis-related parameters nor nutrient concentration in plant tissues. Phi applications activated the plant-defense mechanisms but suppressed the Pi-starvation response of tomato plants. Foliar applications of Phi on tomato plants can be used to activate plant-defense responses, but they would not contribute to improve growth and nutritional status of tomato plants, indicating that Phi is not a relevant source of nutrients. Phi-containing products might suppress the response mechanism to Pi-starvation in plants growing under low Pi conditions.

Effect of Groundwater Quality on Yield Index and Nutrient Concentration in Stem Plant Tissue of Winter Wheat (Triticum turgidum L.)

The Field experiment was conducted at private land in Grdarasha southern Erbil-Iraq to study the effect of 7 water qualities having electrical conductivity of (0.42, 0.50, 1.43, 2.20, 2.60, 5.40 and 5.70) dS m-1 on chemical characteristics and growth of plant and protein percent in wheat grains in winter season of 2015-2016. The crop was cultivated on 11.12.2015 and continued growing to 30.5.2016. The experiment land was equally divided into three plots spaced 75 cm between them. The results showed that weights and lengths of straw and spike were reduced by W.q5 (67.49, 100.01) g and (51.87, 6.30) cm increased with W.q3 treatment (96.58, 139.17) g and (91.08, 10.57) cm respectively; and wheat grains protein percentage was also increased by W.q6 (13.70) treatment comparing with minimum percent of protein by W.q5 (7.26). The data of Irrigation by saline water of W.q7 resulted concentration increasing of Ca2+, Mg2+ and Na+ (7.39, 2.22 and 4.52) mg g-1; while the concentrations of the same elements were 1.54, 0.61 and 1.81 mg g-1 by W.q2 watering respectively. Potassium concentration was the highest (0.16) mg g-1 by W.q2 water compared to minimum level (0.06) mg g-1 with W.q5 irrigation. The watering by W.q5 (0.29) mg g-1 resulted was lower concentration of phosphorus in the plant compared to minimal saline water W.q3 and W.q4 (0.34) mg g-1.

Relatively rare root endophytic bacteria drive plant resource allocation patterns and tissue nutrient concentration in unpredictable ways.

Plant endophytic bacterial strains can influence plant traits such as leaf area and root length. Yet, the influence of more complex bacterial communities in regulating overall plant phenotype is less explored. Here, in two complementary experiments, we tested whether we can predict plant phenotype response to changes in microbial community composition. In the first study, we inoculated a single genotype of Populus deltoides with individual root endophytic bacteria and measured plant phenotype. Next, data from this single inoculation were used to predict phenotypic traits after mixed three-strain community inoculations, which we tested in the second experiment. By itself, each bacterial endophyte significantly but weakly altered plant phenotype relative to noninoculated plants. In a mixture, bacterial strain Burkholderia BT03, constituted at least 98% of community relative abundance. Yet, plant resource allocation and tissue nutrient concentrations were disproportionately influenced by Pseudomonas sp. GM17, GM30, and GM41. We found a 10% increase in leaf mass fraction and an 11% decrease in root mass fraction when replacing Pseudomonas GM17 with GM41 in communities containing both Pseudomonas GM30 and Burkholderia BT03. Our results indicate that interactions among endophytic bacteria may drive plant phenotype over the contribution of each strain individually. Additionally, we have shown that low-abundance strains contribute to plant phenotype challenging the assumption that the dominant strains will drive plant function.

Tropical Tree Branch-Leaf Nutrient Scaling Relationships Vary With Sampling Location.

Bivariate relationships between plant tissue nutrient concentration have largely been studied across broad environmental scales regardless of their covariation with soil and climate. Comparing leaf and branch wood concentrations of C, Ca, K, Mg, N, Na, and P for trees growing in tropical forests in Amazonia and Australia we found that the concentrations of most elements varied with sampling location, but with foliar and branch woody tissues varying from site to site in different ways. Using a Mixed Effect Model (MEM) approach it was further found that relationships between branch and leaf concentrations within individual plots differed in terms of both slope and/or significance to the ordinary least squares (OLS) estimates for most elements. Specifically, using MEM we found that within plots only K and Mg were correlated across organs, but with the K cross-organ intercept estimates varying significantly between sites. MEM analyses further showed that within-plot wood density variations were also negatively related to wood K and Na, suggesting a potentially important role for these cations in water transport and/or storage in woody tissues. The OLS method could not detect significant correlations in any of the above cases. By contrast, although Ca, N, and P leaf and wood tissue concentrations showed similar patterns when individual elements were compared across sites, MEM analyses suggested no consistent association within sites. Thus, for all these three elements, strong within-tree scaling relationships were inferred when data were analyzed across sites using OLS, even though there was no relationship within individual sites. Thus (as for Ca, N, and P) not only can a pooling of data across sites result in trait (co)variations attributable to the environment potentially being incorrectly attributed solely to the species and/or individual (the so-called “ecological fallacy”), but in some cases (as was found here for K and Na) the opposite can also sometimes occur with significant within-site covariations being obscured by large site-site variations. We refer to the latter phenomenon as “environmental obfuscation.”

Drought soil legacy overrides maternal effects on plant growth.

Maternal effects (i.e. trans‐generational plasticity) and soil legacies generated by drought and plant diversity can affect plant performance and alter nutrient cycling and plant community dynamics. However, the relative importance and combined effects of these factors on plant growth dynamics remain poorly understood.We used soil and seeds from an existing plant diversity and drought manipulation field experiment in temperate grassland to test maternal, soil drought and diversity legacy effects, and their interactions, on offspring plant performance of two grassland species (Alopecurus pratensis and Holcus lanatus) under contrasting glasshouse conditions.Our results showed that drought soil legacy effects eclipsed maternal effects on plant biomass. Drought soil legacy effects were attributed to changes in both abiotic (i.e. nutrient availability) and biotic soil properties (i.e. microbial carbon and enzyme activity), as well as plant root and shoot atom 15N excess. Further, plant tissue nutrient concentrations and soil microbial C:N responses to drought legacies varied between the two plant species and soils from high and low plant diversity treatments. However, these diversity effects did not affect plant root or shoot biomass.These findings demonstrate that while maternal effects resulting from drought occur in grasslands, their impacts on plant performance are likely minor relative to drought legacy effects on soil abiotic and biotic properties. This suggests that soil drought legacy effects could become increasingly important drivers of plant community dynamics and ecosystem functioning as extreme weather events become more frequent and intense with climate change. A plain language summary is available for this article.

Lime Rate Affects Substrate pH and Container-grown Birch Trees

ABSTRACTNursery production of birch (Betula nigra L.) trees commonly occurs in containers using a soilless substrate such as pine bark or peat moss. Birch trees have been reported to suffer from pH-induced micronutrient deficiencies in landscapes; thus, they are recommended to be planted in low-pH soils (<6.5). Little research has addressed the influence of substrate pH on birch trees during container production. Therefore, the objective of this research was to determine if substrate pH influences birch tree growth and development. Birch (Betula nigra ‘NBMTF’) liners were transplanted into 11.4 L plastic nursery containers filled with an 80 pine bark: 20 sphagnum peat moss (v:v) amended with either 0.6 kg.m−3 of elemental sulfur (S) or 0, 1.8, 3.5, or 7.1 kg.m−3 dolomitic lime. Substrate pH ranged from 4.8 to 7.3. There were only a few and minor differences in leaf chlorophyll content and no differences in plant growth. Differences in leachate and plant tissue nutrient concentration occurred for some elements, although these differences were not enough to affect plant growth. Container-grown birch trees can be grown over a wide range of substrate pH (4.8 to 7.3) with little or no effect on their growth.

Ameliorative Effect of Ammonium Sulfate on Salt Tolerance and Ion Homeostasis in Lemon (C. limon) Seedlings

To investigate interaction effects of salinity and nitrogen on growth, mineral composition and salinity tolerance of lemon seedlings, a greenhouse experiment with four sodium chloride concentrations (0, 250, 500 and 1000 mg kg-1 soil) and four nitrogen levels (0, 50, 100, and 200 mg kg-1 soil ammonium sulfate) was carried out. Experiment was conducted in a completely randomized design with three replications. Sodium and chloride ions in plant tissues were increased to toxic levels with increase in salinity which resulted in a significant reduction of plant dry weight. Nitrogen consumption up to 100 mg kg-1 soil increased plant dry weight. As the concentration of sodium chloride was increased, the improvement effect of nitrogen on plant growth was decreased. Although nitrogen had no considerable effect on sodium concentration in root and shoot, it made a decrease in chloride concentration in shoot and an increase in root concentration of this element. Salinity decreased essential nutrients concentration in plant shoot. Therefore, it can be concluded that adverse effect of salinity is to some extent due to reduction of required elements to suboptimal ranges in plant tissues. Nitrogen improved the adverse effects of salinity on plant nutrients by increasing their concentration in plant tissues. Therefore it can be inferred that part of the ameliorative effects of nitrogen on salinity adverse effects is related to the maintenance of essential nutrient concentrations in plant tissues. The results of the present study indicate that nitrogen can be applied in amounts higher than optimal level to reduce the harmful effects of salinity.