Concentrations Of Other Nutrients Research Articles

Alternative Use of Black and Navy Beans as Green Shell Beans

Although there is increasing consumer interest in newer foods such as green seeds, green shell bean production in Virginia is nonexistent. We conducted replicated field studies during 2022–23 to characterize production potential of green shell beans and green seeds from black and navy beans. Average green pod and green seed yields were 10,121 and 5186 kg·ha−1, respectively, whereas average seed number per pod was 3.6. As a group, black beans had a higher shelling percent than navy beans, with an average shelling percent of 54%. Green seeds from black and navy bean contained 26% protein, 82 mg·kg−1 Fe, and 38 mg·kg−1 Zn in addition to appreciable concentrations of other nutrients. Our results indicated that black and navy beans have potential as alternative crops to supply green seeds.

Influence of the pyrolysis temperature on fresh and pelletised chicken litter with focus on sustainable production and utilisation of biochar

AbstractThis study focused on determining the influence of temperature (500–700 °C) during pyrolysis of pelletised chicken litter (PCL) and fresh chicken litter (FCL). The composition of all pyrolysis products was analysed, and their potential applications were discussed. An analysis of phosphorus speciation in FCL and PCL along with their derived biochars revealed that the share of water-soluble phosphorus was greatly reduced in the biochar, implying lower risk of eutrophication in agricultural applications of biochar when used as a soil improver. Indeed, water-soluble phosphorus decreased from 60% for PCL to as low as 3% for the biochars. In addition, the concentration of other nutrients and heavy metals in biochar, and its potential for agriculture application was discussed. Heavy metals content was below the upper limits set out in the European Fertilising Products Regulation only for biochars produced at 500 °C, but biochars produced at higher temperatures did not meet the limits for Zn and Ni content. The energy balance analysis showed that pelletisation of chicken litter is not necessary, as the properties of both PCL and FCL allow for energetically sustainable pyrolysis when hot pyrolysis gas is combusted, and biochar recovered for nutrient recycling.

Uptake, transformation, and environmental impact of zinc oxide nanoparticles in a soil-wheat system.

Zinc oxide nanoparticles (ZnO-NPs) are metal-based nanomaterials, but their long-term effects on plant growth and the soil environment in the field remain unclear with most previous studies using short-term laboratory and glasshouse studies. In this study, we used a field experiment to examine the long-term effects of ZnO-NPs in a soil-wheat (Triticum aestivum) system. It was found that although ZnO-NPs had no significant effect on either yield or the concentration of other nutrients within the grain, the application of ZnO-NPs significantly increased Zn concentrations. Indeed, for grain, the application of ZnO-NPs to both the soil and foliage (SFZnO) (average of 33.1 mg/kg) significantly increased grain Zn concentrations compared to the the control treatment (21.7 mg/kg). Using in situ analyses, nutrients were found to accumulate primarily in the crease tissue and the aleurone layer of the grain, regardless of treatment. Specifically, the concentration of Zn in the aleurone layer for the SFZnO treatment was 2-3 times higher than that in the control, being >300 mg/kg, whilst the Zn concentration in the crease tissue was ca. 600 mg/kg in the SFZnO treatment, being two times higher than for the control. Although the application of ZnO-NPs increased the total Zn within the grain, it did not accumulate within the grain as ZnO-NPs with this being important for food safety, but rather mainly as Zn-phytate, with the remainder of the Zn complexed with either cysteine or phosphate. Finally, we also observed that ZnO-NPs caused fewer changes to the soil bacterial community structure and that it had no nano-specific toxicity.

The effects of concurrent increases in supplementation of calcium and phytase on growth performance, balance of Ca and P, and bone mineralization in nursery pigs

Abstract The objective of this study was to investigate the effects of concomitantly increasing supplementation of Ca and phytase on growth performance, balance of Ca and P, and bone mineralization in nursery pigs. There were eight experimental diets. The positive control (PC) one and two were formulated to contain 0.64% and 0.85% total Ca, respectively, whereas the dietary concentrations of other nutrients were identical and adequate. The negative control (NC) was deficient in total Ca (0.48%) and total P (0.41%). Five combinations of incremental levels of Ca and phytase (0.48% and 1,750 phytase units [FYT]/kg, 0.52% and 2,000 FYT/kg, 0.55% and 2,250 FYT/kg, 0.59% and 2,600 FYT/kg, and 0.63% and 3,000 FYT/kg) were added to the NC to establish the remaining five experimental diets. Each diet was fed to six pens of six pigs (three barrows and three gilts per pen). All diets contained 3 g/kg TiO2, and fecal samples were collected from each pen during the trial. In the end, one pig per pen was euthanized to collect the right tibia and urine in bladder. The results showed that the pigs of NC gained less weight, consumed less feed, and utilized feed less efficiently than their counterparts fed the PC and the treatments with phytase (P < 0.01). With increasing supplementation of Ca and phytase, there was a tendency for gain:feed to decrease (P < 0.10). There was a significant reduction in bone dry weight; and in percentages, as well as weights of bone ash, Ca, and P; in pigs of NC compared with pigs of PC1, PC2, or phytase treatments. In comparison to PC2, PC1 and phytase treatments resulted in a higher percentage of bone P and greater weights of bone ash, Ca, and P (P < 0.05). There was no significant effect of concurrent supplementation of Ca and phytase on bone mineralization. The NC had significantly lower apparent total tract digestibility (ATTD) of Ca and P, lower concentrations of digestible Ca and P, but a higher ATTD Ca/ATTD P ratio than PC1, PC2, or the phytase treatments. The averages of ATTD of Ca and P in treatments with phytase were significantly higher than PC1 or PC2 (P < 0.01). With increasing addition of Ca and phytase, the ATTD of P, digestible Ca and P, and the ATTD Ca/ATTD P ratio increased linearly (P < 0.05), which contrasted with a linear reduction in ATTD of Ca (P < 0.05). Meanwhile, there was a linear (P < 0.01) increase in the concentration of urinary Ca. In conclusion, increasing the dietary supplementation of phytase in conjunction with the increasing dietary Ca level increased the dietary ATTD Ca/ATTD P ratio without damaging the absorption of P in the current study. The higher ATTD Ca/ATTD P ratio did not improve the bone mineralization markedly and thus the extra Ca was voided through urine.

Phosphate drinking water softeners promote Legionella growth.

Phosphate-based drinking water softeners are commonly used to prevent scale formation in drinking water distribution infrastructure. The main reason for drinking water softening is primarily economic (protection of pipes and extension of equipment life), while the health aspect of such treatment is usually neglected. The aim of this work is to investigate the effects of phosphate-based drinking water softeners on growth stimulation of Legionella pneumophila. Bacterial growth was observed at two different phosphate concentrations. On average, an increase in growth of 1.19-1.28 log CFU/mL was observed in selected samples with added phosphates compared with the control. The results of the in vitro experiment confirmed that the added phosphates stimulate the growth of L. pneumophila; growth stimulation could therefore be expected in drinking water distribution systems (DWDS) when phosphates are used as well. The availability of phosphorus in DWDS may be a crucial limiting factor for biofouling control. Consequently, phosphate-based chemicals for drinking water should be avoided or used with prudence, especially in drinking water with high concentrations of other nutrients.

Effect of Se-Enriched Irrigation Water and Soil Texture on Biomass Production and Elemental Composition of Green Pea and Carrot and Their Contribution to Human Se Intake

Selenium (Se)-deficient diets are a problem in large areas of the world and can have serious health consequences, thus, the biofortification of foods with Se has been an important research field for several decades. The effect of Se-enriched irrigation water was investigated regarding the Se concentration in green peas and carrots. A pot experiment was set up in a greenhouse with irrigation water containing 0, 100, and 500 µg Se L−1 with sand, silty sand and silt soil types. Most of the treatments only slightly reduced the biomass, while the 500 µg Se L−1 treatment caused a significant decrease in the dry weight of carrot root. Treatment with irrigation water containing 100 µg Se L−1 increased the Se content in green peas and carrots 76 and 75 times, respectively, producing foodstuffs where 100 g of a fresh product covered 395% and 92% of the recommended dietary allowance, respectively, averaged over the three soil types. The Se concentration was higher for green peas in sand and carrots in silt. The treatments had little effect on the concentrations of other nutrients. The enrichment of irrigation water with Se may thus be a suitable method for the biofortification and production of functional food under certain conditions.

Performance of Transmit of Some Macronutrients from Soil to Leaves in Selected Prunus Rootstocks

This study was carried out to investigate the intake of macro plant nutrients from the soil of rootstocks that are considered promising in the wild plum rootstock breeding project carried out in Malatya and Elazığ provinces. The study was completed in 2020 on the land of the Malatya Apricot Research Institute and the laboratories of the Kahramanmaraş East Mediterranean Transitional Zone Agricultural Research of Institute. According to the analysis results of the soil samples taken from 0-30 cm and 30-60 cm depths of the experimental area, it was determined that the concentrations of other nutrients except available phosphorus were in very good condition. As a result of the analysis of leaf samples taken from 69 rootstocks selected in June, scoring was made by applying measured grading to the amounts obtained. This method has been applied for the first time in the world with this study. At the end of the study, it was determined that phosphorus varied between 0.16-0.55%, potassium 0.80-2.40%, calcium 0.41-3.48% and magnesium 0.15-0.49% in leaf contents. These values compared to other literature data, it was observed that phosphorus and potassium were high and calcium and magnesium were low.

Ion-specific Limitations of Sodium Chloride and Calcium Chloride on Growth, Nutrient Uptake, and Mycorrhizal Colonization in Northern and Southern Highbush Blueberry

Excess salinity is becoming a prevalent problem for production of highbush blueberry (Vaccinium L. section Cyanococcus Gray), but information on how and when it affects the plants is needed. Two experiments, including one on the northern highbush (Vaccinium corymbosum L.) cultivar, Bluecrop, and another on the southern highbush (V. corymbosum interspecific hybrid) cultivar, Springhigh, were conducted to investigate their response to salinity and assess whether any suppression in growth was ion specific or due primarily to osmotic stress. In both cases, the plants were grown in soilless media (calcined clay) and fertigated using a complete nutrient solution containing four levels of salinity [none (control), low (0.7–1.3 mmol·d−1), medium (1.4–3.4 mmol·d−1), and high (2.8–6.7 mmol·d−1)] from either NaCl or CaCl2. Drainage was minimized in each treatment except for periodic determination of electrical conductivity (EC) using the pour-through method, which, depending on the experiment, reached levels as high as 3.2 to 6.3 dS·m−1 with NaCl and 7.8 to 9.5 dS·m−1 with CaCl2. Total dry weight of the plants was negatively correlated to EC and, depending on source and duration of the salinity treatment, decreased linearly at a rate of 1.6 to 7.4 g·dS−1·m−1 in ‘Bluecrop’ and 0.4 to 12.5 g·dS−1·m−1 in ‘Springhigh’. Reductions in total dry weight were initially similar between the two salinity sources; however, by the end of the study, which occurred at 125 days in ‘Bluecrop’ and at 111 days in ‘Springhigh’, dry weight declined more so with NaCl than with CaCl2 in each part of the plant, including in the leaves, stems, and roots. The percentage of root length colonized by mycorrhizal fungi also declined with increasing levels of salinity in Bluecrop and was lower in both cultivars when the plants were treated with NaCl than with CaCl2. However, leaf damage, which included tip burn and marginal necrosis, was greater with CaCl2 than with NaCl. In general, CaCl2 had no effect on uptake or concentration of Na in the plant tissues, whereas NaCl reduced Ca uptake in both cultivars and reduced the concentration of Ca in the leaves and stems of Bluecrop and in each part of the plant in Springhigh. Salinity from NaCl also resulted in higher concentrations of Cl and lower concentrations of K in the plant tissues than CaCl2 in both cultivars. The concentration of other nutrients in the plants, including N, P, Mg, S, B, Cu, Fe, Mn, and Zn, was also affected by salinity, but in most cases, the response was similar between the two salts. These results point to ion-specific effects of different salts on the plants and indicate that source is an important consideration when managing salinity in highbush blueberry.

Zinc allocation to and within Arabidopsis halleri seeds: Different strategies of metal homeostasis in accessions under divergent selection pressure.

Vegetative tissues of metal(loid)-hyperaccumulating plants are widely used to study plant metal homeostasis and adaptation to metalliferous soils, but little is known about these mechanisms in their seeds. We explored essential element allocation to Arabidopsis halleri seeds, a species that faces a particular trade-off between meeting nutrient requirements and minimizing toxicity risks.Combining advanced elemental mapping (micro-particle induced X-ray emission) with chemical analyses of plant and soil material, we investigated natural variation in Zn allocation to A. halleri seeds from non-metalliferous and metalliferous locations. We also assessed the tissue-level distribution and concentration of other nutrients to identify possible disorders in seed homeostasis.Unexpectedly, the highest Zn concentration was found in seeds of a non-metalliferous lowland location, whereas concentrations were relatively low in all other seed samples-including metallicolous ones. The abundance of other nutrients in seeds was unaffected by metalliferous site conditions.Our findings depict contrasting strategies of Zn allocation to A. halleri seeds: increased delivery at lowland non-metalliferous locations (a likely natural selection toward enhanced Zn-hyperaccumulation in vegetative tissues) versus limited translocation at metalliferous sites where external Zn concentrations are toxic for non-tolerant plants. Both strategies are worth exploring further to resolve metal homeostasis mechanisms and their effects on seed development and nutrition.

Investigation of Different Selenium Sources and Supplying Methods for Selenium Enrichment of Basil Vegetable (A Case Study under Calcareous and Non-calcareous Soil Systems).

Selenium (Se) is a crucial component of selenoaminoacids and selenoproteins. Therefore, Se-enriched agricultural products can reduce health complications induced by Se deficiency. This research was carried out to investigate the effects of Se bio-enrichment on Basil grown in calcareous and non-calcareous soil systems and also to evaluate the changes in Se concentration in the soil after harvesting. The experiment executed in two calcareous and one non-calcareous soil systems, and different Se application methods (control, soil application, seed inoculation, foliar application, and soil + foliar application) were administered. Selenobacteria, a plant growth-promoting rhizobacteria (PGPR), derived from the soil was used as a biofertilizer, compared to the other Se sources. The results showed that both soil types and the methods of Se application had significant effects (P ˂ 0.01) on root and shoot dry weights and concentrations of P, K, Zn, Fe, and Se in both of the root and shoot. Shoot dry weight of plants treated with foliar Se was maximum in the calcareous soil. Compared to the control treatment, foliar application of Se increased shoot Se content in both calcareous and non-calcareous soils by 242% and 204%, respectively. Furthermore, the increase in shoot Se concentration in calcareous soil induced by Se application increased the concentration of other nutrients in the shoot and root. Plant growth parameters and concentrations of nutrients were significantly increased by using selenobacter inoculum. The application of Se-containing compounds can improve vegetable quality. Considering the daily requirement of the human body for minerals and nutrients, enriching basil with Se can play an important role in community health. Moreover, some patents have reported the effectiveness of endophyte bacteria.

The effect of stage of regrowth on the physical composition and nutritive value of the various vertical strata of kikuyu (<i>Cenchrus clandestinus</i>) pastures

A plot study was conducted at the Gatton Research Dairy, Queensland, Australia, to quantify the effects of 5 regrowth periods (9, 11, 14, 16 and 18 days) and 4 vertical strata on the composition and nutritive value of kikuyu (Cenchrus clandestinus) pastures using a block factorial design with 4 replicates. Pasture samples were analyzed for crude protein (CP), ethanol-soluble carbohydrates (ESC), acid detergent fiber (ADF), neutral detergent fiber (aNDFom), in vitro indigestible neutral detergent fibre (iNDF240) and minerals. Metabolizable energy (ME) was then calculated from the concentrations of other nutrients. Regardless of the stage of regrowth, stems were located mainly in the bottom 1 or 2 strata, while leaves were present mainly in the top 2 or 3 strata. CP, ESC and ME declined, but aNDFom, ADF and iNDF240 increased with stage of regrowth and from top to bottom of the swards (P<0.05). While herbage quality variables were affected by both factors, vertical stratum had a much larger impact on quality than stage of regrowth. These results indicate that grazing management of kikuyu pastures should be based not only on stage of regrowth but also on level of defoliation, as both have strong impacts on the nutritive value of the consumed forage.

Maternal and Cord Blood Folate Concentrations Are Inversely Associated with Fetal DNA Hydroxymethylation, but Not DNA Methylation, in a Cohort of Pregnant Canadian Women

Aberrancies in fetal DNA methylation programming may modify disease susceptibility of the offspring. Maternal folate status has potential to alter fetal DNA methylation. We examined the association of maternal and cord blood concentrations of folate and unmetabolized folic acid (UMFA), vitamin B-12, vitamin B-6, and choline with fetal DNA methylation and hydroxymethylation and assessed potential modifying effects of 38 fetal genetic variants in 22 genes. Nutrient blood concentrations were measured in 368 pregnant women in early pregnancy (12-16 wk of gestation) and at delivery (37-42 wk of gestation) and in cord blood. DNA methylation and hydroxymethylation in cord blood mononuclear cells were quantified by LC-MS/MS. Pearson partial correlations were used to determine the association between individual nutrients and DNA methylation and hydroxymethylation. Serum and RBC folate and plasma UMFA concentrations (primary outcomes) in early pregnancy, at delivery, and in cord blood were not significantly associated with fetal DNA methylation. In contrast, maternal RBC folate in early pregnancy (r=-0.16, P=0.04) and cord plasma UMFA (r=-0.23, P=0.004) were inversely correlated with fetal DNA hydroxymethylation. Neither maternal and cord blood concentrations of other nutrients nor fetal genotypes (secondary outcomes) were significantly associated with fetal DNA methylation or hydroxymethylation. Infants born to mothers with RBC folate concentrations in the highest quartile and serum vitamin B-12 concentrations in the lowest quartile in early pregnancy had significantly lower fetal DNA methylation and higher birth weight compared with those born to mothers with lower RBC folate and higher serum vitamin B-12 concentrations (P=0.01). Maternal and cord blood folate concentrations are associated with fetal DNA hydroxymethylation, but not DNA methylation, in a cohort of pregnant Canadian women. The observation that high folate and low vitamin B-12 maternal status in early pregnancy may be associated with decreased fetal DNA methylation and higher birth weight warrants further investigation. This trial was registered at clinicaltrials.gov as NCT02244684.

Effects of incorporation of vermiculite on carbon and nitrogen retention and concentration of other nutrients during composting of cattle manure

A study was carried out to determine the effects of vermiculite inclusion into cattle manure on compost performance and nutrient retention during composting. All compost mixtures passed through the major composting phases and inclusion of vermiculite increased retention of total nitrogen with treatments recording N losses of 27.8, 25.3, 21 and 14.5% for the 0, 10, 20 and 30% vermiculite treatments. Vermiculite inclusion also reduced mineral N (as a percentage of initial nitrogen), NH4+:NO3− ratio and C:N ratio and enhanced the Ca and Mg concentrations of the final cattle manure composts but lowered K concentration. Incorporation of vermiculite in composting of cattle manure reduced the Ca: Mg ratio of final compost to <1. Further work is recommended to determine the availability of nutrients, particularly N, K, Ca and Mg when these co-composts are applied as organic fertilisers.

High fibre selection by roe deer (Capreolus capreolus): evidence of ruminal microbiome adaption to seasonal and geographical differences in nutrient composition

Context. The European roe deer owes its ability to digest fibre to its microbiome. This is made up of many different species at different levels of abundance and with different differentiations. In Europe, the roe deer is often classified as a so-called ‘concentrate selector’. This term has often been interpreted by different researchers to mean a selector of either protein- or energy-rich food. According to various studies, this selection behaviour is due to the low abundance of fibre-degrading microorganisms. Aims. The aim of the present study was to determine the concentration of crude nutrients in the rumen of roe deer, with the focus on the fibre fractions, and to show changes among seasons and between habitats. Furthermore, the aim was to find out how far the composition of the ruminal microbiota adapts to these changes. Methods. From 2011 to 2014, we collected the rumens of 245 roe deer in two Bavarian habitat types, a forest and an agricultural habitat. The crude nutrient contents and the size of the total microbiome and the proportions of individual genera were determined in the rumen content. Key results. The average annual concentration of crude fibre in the ingested food is 26–30% and this rises to 38% in certain months. The forest roe deer had the highest proportions of crude fibre in their food and the concentrations of other nutrients were also highly dependent on the season and habitat. Furthermore, the animals also have far less protein in their rumen content than often assumed. The total number of microorganisms in the rumens of the forest deer is significantly higher than in animals living in the agricultural area. The number of microorganisms was highest in the forest roe deer in winter, and in the roe deer from the agricultural area in summer. Clear connections can also be seen between individual groups of microorganisms and particular crude nutrients. The high crude-fibre concentration leads to a high number of fibre-degrading microorganisms, such as, for example, anaerobic fungi or the Ruminococcus flavefaciens. Conclusions. The results showed a high adaptability of the animals to a fibre-rich diet. The microbiome adapts very well to the respective nutrient availabilities. This, in turn, is what allows the roe deer to adapt so readily to diverse habitats and environmental conditions. Implications. Due to the generally high concentrations of fibre, combined with the high numbers of fibre-degraders in the rumen, we suggest that, from now on, we should talk of a roe deer as being a ‘selector’ or ‘browser’ rather than a ‘concentrate selector’.

Response of a Pioneering Species (Leptospermum scoparium J.R.Forst. & G.Forst.) to Heterogeneity in a Low-Fertility Soil.

Root foraging may increase plant nutrient acquisition at the cost of reducing the total volume of soil explored, thereby reducing the chance of the roots encountering additional patches. Patches in soil seldom contain just one nutrient: the patch may also have distinct textural, hydrological, and toxicological characteristics. We sought to determine the characteristics of root foraging by a pioneering species, Leptospermum scoparium, using pot trials and rhizobox experiments with patches of biosolids. The growth of L. scoparium was increased by <50 t/ha equiv. of biosolids but higher doses were inhibitory. Roots foraged patches of biosolids in a low-fertility soil. There was no evidence of chemotaxis, rather, the roots proliferated toward the patch of biosolids, following chemical gradients of nitrate. While the biosolids also contained high concentrations of other nutrients (P, K, and S), only significant chemical gradients of nitrate were found. Once the roots encountered a patch of biosolids, the growth of the plant increased to a level similar to plants growing in soil homogeneously mixed with biosolids or surface-applied biosolids. Our results indicate that roots forage nitrate, which is mobile in soil, and that gradients of nitrate may lead to patches containing other less mobile nutrients, such as phosphate or potassium.

Plant-soil-nutrient status of vegetables and wheat grown on calcareous soil

Calcareous soil is extremely important in determining nutrient status and availability when applying different fertilizers to different crops associated with or without irrigation. The objective of this study was to investigate the nutritional status (nutrient availability) of different plants grown in two different ecosystems dominated with calcareous soil: Ghor Alsafi (eggplants, tomato and beans) as an example of irrigated area and the Karak Mountain Area (wheat) as an example for non-irrigated area. Physiochemical properties in soils and nutrients concentrations (C, Fe, Mn, Zn, available P, available and non-available K) in soil and plant leaves were analyzed. This study showed that N concentration in soil from both Ghor Alsafi (ranged from 4.4–5.1 mg/g) and the Karak Mountain Area (1.9–3.2 mg/g) was relatively low. This study showed that Fe content in vegetables grown in Ghor Alsafi was about 3 to 5 fold higher than the recommended maximum Fe concentration. The concentration of other nutrients (N, K, Zn and Mn) in investigated vegetables fell within the recommended concentrations range (38.3–39.7 mg/g, 36.6–39.5 mg/g, 21.7–27.3 ppm and 49.2–102.6 ppm, respectively). Phosphorus content in vegetables grown in Ghor Alsafi and in wheat grown in different locations in the Karak Mountain Area was about 5?6 fold higher than the recommended P concentration. Our results indicated that the high levels of P (ranged from 3.28–3.43 mg/g) and Fe (ranged from 340.4–551.3 ppm) in vegetables grown in Ghor Alsafi and high levels of P (ranged from 2.2–2.52 mg/g) in wheat in the Karak Mountain Area can be attributed to high levels of fertilizer application.

Influence of nitrogen supply on macro- and micronutrient accumulation during growth of winter wheat

The understanding of the dynamics of nutrient accumulation in crops is essential to obtain optimal yield and high quality food products. Modern crop production is characterized by high nitrogen (N) rates, which can influence the uptake and concentrations of other nutrients. The aim of this study was to investigate the influence of N fertilization on the temporal accumulation pattern and concentrations of nutrients during the life cycle of a winter wheat crop grown in a cool temperate climate. Seven field trials involving four N treatments (0–240kgNha−1) in southern and central Sweden were sampled over one growing cycle. Above-ground plant parts were sampled at tillering, stem elongation, flowering and full maturity; and the samples were analyzed for macronutrients (N, S, P, K, Ca, and Mg) and micronutrients (Fe, Zn, Mn, Cu, and B). Temporal accumulation pattern of some elements (P, Mg, Zn, Cu, Mn and B) followed biomass accumulation, while other elements (K, Ca, N, S and Fe) accumulated faster than biomass, especially at the early developmental stages and at high N fertilization rates. Low uptake early in the growing season could, at least partly, be compensated by late season uptake with possible implications for nutrient management. In vegetative tissues, the total amounts and concentrations of most macro- and micronutrients (except P, Mn and B) increased with N uptake. In grains, high N rate resulted in increased concentrations of S and Fe, but decreased concentration of K. Enhanced N supply did not generally result in the dilution of other elements in the grain. Results suggest that the high N accumulation rates in high-yielding crops (here winter wheat) are associated with increased demands also of other nutrients, in terms of both increased amounts and tissue concentrations. Nutrient management plans for these crops should accommodate not only the enhanced demand for N, but also other nutrients. Critical threshold concentrations for the avoidance of nutrient deficiencies should be considered in relation to the crop N concentrations.

The responses of phytoplankton communities to elevated CO2 show seasonal variations in the highly eutrophic Lake Taihu

From April 2012 to January 2013 (over four seasons), in situ microcosm experiments were conducted in Lake Taihu, perturbed over a range of pCO2 scenarios (270, 380, and 750 μatm; 1 atm = 101.325 kPa). The influence of CO2 level on microcosms was greatest during the spring because of the high growth rate of phytoplankton. In this season, rising CO2 levels caused a pH reduction, and the maximum reduction was 0.6 units when CO2 level was enhanced from the present level to 750 μatm. The doubling of CO2 level could increase the net primary production (NPP) by 65% during spring when the concentrations of other nutrients were maintained. The rise of NPP could cause a decline of dissolved inorganic carbon (DIC) concentration, and CO2 enrichment might mitigate the extent of this decline. Meanwhile, higher CO2 may slow or prevent a loss of diversity of phytoplankton in microcosms in this season. During the other three seasons, Microcystis predominated, and the percentage of cyanobacteria did not alter with the change of CO2. We did not observe a significant increase in the abundance of any taxa with the rise of CO2 during the in situ microcosm experiments.

The Change in Patterns and Conditions of Algal Blooms Resulting from Construction of Weirs in the Youngsan River: Long-term Data Analysis

The effect of weir construction (2009~2011) was investigated on algal bloom dynamics and surrounding conditions in the Youngsan River by analyzing the long-term (2001~2014) data provided by the Water Information System, Ministry of Environment. The data include chlorophyll a and water properties such as total suspended solids (TSS), ammonium (NH4 +), nitrate (NO3-), orthophosphate (PO43-), total nitrogen (TN), total phosphorus (TP) and DIN/DIP molar ratio collected from 12 stations along the channel of the river. Temporal variations were examined using data collected monthly from 2001~2014 and Box-Whisker plot was used to examine the difference in algal bloom dynamics between before (2006~2008) and after (2012~2014) the weir construction. Pearson’s correlation analysis was also used to analyze the correlation of parameters. The results showed that TSS affecting water turbidity increased during the construction but decreased especially at the stations located in the upper and middle regions of the river after the construction. Ammonium concentrations increased whereas the concentrations of other nutrients decreased after the construction inducing an increase in N:P molar ratio. Chlorophyll a decreased suddenly during the construction but increased clearly after the construction at the stations where TSS decreased. This indicates that algal blooms can develop in the Youngsan River due to a decrease in turbidity that increases light penetration in water column although the concentrations of nutrients such as orthophosphate were reduced after the weir construction.

Boron fertilisation of organically managed grass-clover swards on coarse-textured soils: effects on botanical and element composition

Three trials were performed on two organic farms with dairy and suckler cows and using home-produced forage and feed crops, predominantly grass-clover ley, in order to determine whether boron (B) is a limiting factor for legumes on coarse-textured soils in an area predisposed to low B soil concentrations. The effects of B fertilisation (applied as sprayed liquid) on biomass yield, botanical composition and plant macro- and micronutrient concentrations relative to soil concentrations and livestock requirements were investigated. Boron fertilisation (i) did not affect any yield, (ii) increased the white clover percentage significantly in forage on one farm and (iii) increased B concentrations in plants and soil on both farms, and (iv) did not affect concentrations of other nutrients in forage on either farm. Thus, B was not an obvious limiting factor on these farms. Effects of management practices on interactions and ratios between B, calcium (Ca), potassium (K), magnesium (Mg) and sodium (Na) and their implications are discussed.