Macronutrient Uptake Research Articles

The Response of Weeds and Apple Trees to Beneficial Soil Microorganisms and Mineral Fertilizers Applied in Orchards

The effect of beneficial soil fungi, bacteria and mineral fertilizers containing nitrogen, phosphorus and potassium on the level and species composition of weed infestation, uptake of macronutrients by weeds and the nutritional status of ‘Sampion’ apple trees with nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg) and calcium (Ca) was assessed in three-year studies. In the field experiment, the effect of thirteen treatments was investigated, where fungal or bacterial inocula and mineral fertilizers at a standard dose and a dose reduced by 40% were applied individually or together. The fungal inoculum contained two species: Aspergillus niger and Purpureocillium lilacinum. The bacterial consortium consisted of three Bacillus strains: Bacillus sp., Bacillus amyloliquefaciens and Paenibacillus polymyxa. The weight of weeds and the uptake of macronutrients by weeds in the apple orchard increased significantly more after the application of mineral fertilization than after the application of beneficial organisms. The increased uptake of macronutrients by weeds did not significantly change the mineral nutritional status of apple trees expressed as the content of N, P, K Mg and Ca in apple leaves. After the use of NPK mineral fertilization, also with the addition of beneficial organisms, the uptake of N by both weeds and apple trees increased. P and K were more efficiently absorbed by weeds and they achieved greater benefits from fertilization with these two macroelements than trees.

Efficacy of endophytic SB10 and glycine betaine duo in alleviating phytotoxic impact of combined heat and salinity in Glycine max L. via regulation of redox homeostasis and physiological and molecular responses

Adverse environmental stresses occurring simultaneously exhibit a lethal effect on crop productivity at the global level. Here, we investigated the individual and synergistic effects of endophytic T. virens SB10 and glycine betaine (GB) on the physiological and biochemical responses of Glycine max L. to alleviate the devastating effects of combined heat and salinity (HS) stress. Screening against HS stress tolerance showed that SB10 has significant tolerance against heat stress and produces hormones such as gibberellins and indole-3-acetic acid upon GB amendment of the growth medium under HS stress. Moreover, the current findings illustrated that the synergistic application of SB10 and GB was effective in alleviating the negative effects of HS stress on plant growth and physiology. The findings revealed that SB10 + GB led to a reduction in proline accumulation and Na+ uptake. It also maintained a high K+/Na + ratio by regulating GmHKT1 and GmSOS1 expression and enhanced macronutrient uptake (N, Ca, K) in plants. In turn, plants exhibited a higher growth rate and gaseous exchange attributes coupled with the upregulation of APX, SOD, POD, and GSH antioxidant activities and transcript accumulation of GmSOD1 and GmAPX1 to overcome HS-induced oxidative damage. Furthermore, SB10 + GB downregulated DREB2, DREB1B, and GmNCED3 expression and resulted in the reduced accumulation of endogenous ABA while enhancing endogenous SA accumulation via upregulation of PAL genes. In addition, enhanced accumulation of bioactive gibberellins (GA1, GA3, GA4, and GA7) was detected under HS stress in the SB10 + GB treatment group. Moreover, SB10 + GB also significantly regulated GmHsp90A2 and GmHsfA2 expression in tolerance against HS stress. The combination of SB10 and GB was shown to be an effective and alternative approach for growing G. max at high temperature coupled with saline conditions for sustainable agriculture.

Overexpression of a Plasma Membrane H+-ATPase Gene OSA1 Stimulates the Uptake of Primary Macronutrients in Rice Roots.

Plasma membrane (PM) H+-ATPase is a master enzyme involved in various plant physiological processes, such as stomatal movements in leaves and nutrient uptake and transport in roots. Overexpression of Oryza sativa PM H+-ATPase 1 (OSA1) has been known to increase NH4+ uptake in rice roots. Although electrophysiological and pharmacological experiments have shown that the transport of many substances is dependent on the proton motive force provided by PM H+-ATPase, the exact role of PM H+-ATPase on the uptake of nutrients in plant roots, especially for the primary macronutrients N, P, and K, is still largely unknown. Here, we used OSA1 overexpression lines (OSA1-oxs) and gene-knockout osa1 mutants to investigate the effect of modulation of PM H+-ATPase on the absorption of N, P, and K nutrients through the use of a nutrient-exhaustive method and noninvasive microtest technology (NMT) in rice roots. Our results showed that under different concentrations of P and K, the uptake rates of P and K were enhanced in OSA1-oxs; by contrast, the uptake rates of P and K were significantly reduced in roots of osa1 mutants when compared with wild-type. In addition, the net influx rates of NH4+ and K+, as well as the efflux rate of H+, were enhanced in OSA1-oxs and suppressed in osa1 mutants under low concentration conditions. In summary, this study indicated that overexpression of OSA1 stimulated the uptake rate of N, P, and K and promoted flux rates of cations (i.e., H+, NH4+, and K+) in rice roots. These results may provide a novel insight into improving the coordinated utilization of macronutrients in crop plants.

Lead tolerance, accumulation and translocation in two Asteraceae plants: Limbarda crithmoides and Helianthus annuus

• Limbarda crithmoides L. and helianthus annuus L. plants morphology has not been affected under effect of lead (Pb) with the exception of height reduction in some Pb applied concentrations. • According to the metal tolerance index, limbarda crithmoides was more tolerant to Pb induced stress than helianthus annuus . • High levels of Pb were detected in the above-ground parts. • The concentrations of the accumulated Pb were higher in the roots of limbarda crithmoides and helianthus than in the shoots of these species. Lead (Pb) is known as a toxic metal and a non-essential element for plant metabolism and growth. This work investigated the phytotoxicity of Pb induced stress and assessed the accumulation potential of Pb in two Asteraceae plants; Limbarda crithmoides and Helianthus annuus. The experiments were performed for 45 days using different concentrations of Pb (0, 100, 200, 300 and 500 µmol.L –1 ). The dry biomass production in shoots and roots of Limbarda crithmoides were significantly enhanced with the increase of Pb doses in the growth medium, Helianthus annuus plants showed a modest variation in shoot and root dry weights, but without any significant difference as compared to the untreated plants. In addition, metal tolerance index values determined in the shoots and roots of these two species followed a similar trend as the dry weight contents. Both phenolic compounds and flavonoids were significantly increased in the two Pb treated species in comparison to the untreated plants (except flavonoid content of Limbarda crithmoides roots). Total inorganic nitrogen and macronutrient uptake were also assessed, and the two species showed different behaviour when varying Pb concentrations. Moreover, the two species accumulated Pb in their roots more than in the shoots (less than 1000 µg.g –1 DW) with a low translocation from roots into shoots (translocation factor < 1). Our findings demonstrated that both Limbarda crithmoides and Helianthus annuus were tolerant to Pb stress; nonetheless, the two species could not be classified as Pb hyperaccumulators.

Effects of elevated ozone on the uptake and allocation of macronutrients in poplar saplings above- and belowground

Ground-level ozone (O3) is a secondary air pollutant and affects the roots and soil processes of trees. Therefore, O3 can affect the uptake and allocation of nutrients in trees, which merits further clarification. A fumigation experiment with five O3 levels was conducted in 15 open top chambers for two poplar clones, and the concentrations of six macronutrients (N, P, K, S, Ca, Mg) in different organs and leaf positions were determined. Under all O3 levels, the concentration of mobile nutrients (N and P) was higher in upper leaves than in lower leaves, while the non-mobile nutrients (Ca and S) concentration was the opposite. Relative to charcoal filtered ambient air (CF), high O3 treatment (NF60) significantly increased the concentration of mobile nutrients K and Mg in upper leaves by 38 % and 33 %, in lower leaves by 142 % and 65 %, respectively, which suggested the effect of O3 on their concentrations was greater at the lower leaf position than at the upper leaf position. Elevated O3 significantly increased the macronutrient concentrations in most organs. The effects of O3 on nutrient concentrations were attributed using graphical vector analysis, suggested that the increase of nutrient concentration in the shoots was attributed to excessive nutrient stocks, while their increase in root was attributed to the “concentration” effect. Compared to CF, NF60 also reduced the root-to-shoot ratio of N, P, S, K, Ca and Mg stocks by 34 %, 39 %, 37 %, 64 %, 46 % and 42 %, respectively, indicating the allocation of increased nutrients to shoots in response to O3 stress. Changes in the allocation pattern of nutrients in different leaf positions and organs of poplar were primarily in response to O3 stress since these nutrients play important roles in some physiological processes. These results will help improve the plantation nutrient utilization by optimizing fertilizer management regimes under O3 pollution.

A win-win scenario for photosynthesis and the plasma membrane H+ pump.

In plants, cytosolic and extracellular pH homeostasis are crucial for various physiological processes, including the uptake of macronutrients and micronutrients, cell elongation, cell expansion, and enzyme activity. Proton (H+) gradients and the membrane potential are generated by a H+ pump consisting of an active primary transporter. Plasma membrane (PM) H+-ATPase, a PM-localized H+ pump, plays a pivotal role in maintaining pH homeostasis in plant cells and extracellular regions. PM H+-ATPase activity is regulated by protein abundance and by post-translational modifications. Several stimuli have been found to activate the PM H+-ATPase through phosphorylation of the penultimate threonine (Thr) of the carboxy terminus. Light- and photosynthesis-induced phosphorylation of PM H+-ATPase are conserved phenomena among various plant species. In this work, we review recent findings related to PM H+-ATPase regulation in the photosynthetic tissues of plants, focusing on its mechanisms and physiological roles. The physiological roles of photosynthesis-dependent PM H+-ATPase activation are discussed in the context of nitrate uptake and cytoplasmic streaming in leaves.

Cocoa Clones Reveal Variation in Plant Biomass, Root Nitrogen Uptake, and Apparent Nitrogen Recovery at the Seedling Stage

We aimed to investigate variation in growth, biomass, macro-nutrient uptake, and nitrogen (N) use efficiency indices of cocoa (Theobroma cocoa L.) scion clones under two different nitrogen conditions. Ten clones were top-grafted onto 4-month-old rootstocks clone MCC 02. Each seedling received either 0 or 4.6 g of nitrogen applied as urea fertilizer. The design was arranged as a two-factor experiment with four replicates in a factorial randomized block design. We measured stem diameter, biomass, nutrient concentration, and calculated nutrient uptake, nitrogen use efficiency (NUE), agronomic efficiency (AE), apparent nitrogen recovery (ANR), and physiological efficiency (PE). We found that clones significantly affected stem diameter and shoot biomass of both rootstocks and scions. Clones differed in root magnesium (Mg) and shoot calcium (Ca) concentration, root N, and shoot Mg uptake. Furthermore, a significant clone effect was observed on ANR, with local clones showing higher ANR than introduced clones. Nitrogen application significantly improved stem diameter and biomass. Compared to unfertilized plants, a significantly higher N concentration was observed in roots, resulting in higher N uptake in both roots and shoots. Nitrogen application increased shoot Ca concentration and uptake but decreased shoot phosphorus (P) and Mg concentrations. Our results suggest genotypic variability in nitrogen uptake efficiency in clonal cocoa. Clones with high nitrogen uptake efficiency are valuable genetic resources for breeding cocoa clones that efficiently use available N and, therefore, grow better under N-deficient conditions.

Concentration and mobility of trace elements (Li, Ba, Sr, Ag, Hg, B) and macronutrients (Ca, Mg, K) in soil-orchid system on different bedrock types.

The mobility of chemical elements in the soil-orchid system has been poorly studied. The aim of this study is to evaluate the uptake and mobility of several trace (Li, Ba, Sr, Ag, Hg, and B) and macronutrients (Ca, Mg, and K) in the orchid Anacamptis morio (L.) R.M.Bateman, Pridgeon & M.W.Chase from soils in western Serbia. The sampling sites are characterized by three different bedrock types-cherts, limestones, and serpentines, which are the source of the significant chemical differences in the elemental status of the soil and plant tissues. The four-step Community Bureau of Reference sequential extraction procedure was used to determine the distribution of fractions and predict their potential phytoavailability. The orchid and soil samples were analyzed for total elemental content analysis using ICP-OES. The greatest potential for plant availability was determined for Ba and Sr, representing about 80% of the total soil content. More than 40% of Li in the soils was found to be potentially phytoavailable. Significant correlations were found between the total content of Li, B, and Sr in soils. Between 38 and 60% of Li content and more than 80% of Ba and Sr content were determined to be potentially phytoavailable by sequential analysis. The highest bioconcentration factor (> 1) was determined in the case of B and Sr for all orchid organs, while translocation factor for Li was highest in tubers and leaves. The studied elements were mainly stored in tubers and roots, indicating the exclusion strategy of A. morio as a metal tolerance mechanism. The data obtained showed significant differences in metal content in soils and plants originating from sites with different parent materials, suggesting that bedrock type and associated soil properties are important factors that determine chemical element mobility and uptake.

Self-Selection of Feeding Substrates by Tenebrio molitor Larvae of Different Ages to Determine Optimal Macronutrient Intake and the Influence on Larval Growth and Protein Content.

Simple SummaryInsects are widely discussed as being an alternative source of protein and a substitute for soy- and fishmeal. However, mass production is still expensive, so means are being sought to reduce production costs. One way is to keep the costs for insect diets low. One such possibility could be the use of food industry side streams or agricultural by-products to formulate an insect diet. This study tested different substrates as feed for mealworm larvae. These included by-products from grain processing such as husks or bran, pomace and other plant components. In many studies, feed is often tested individually, during which insect larvae are given a defined substrate as a single feed or in a two-component mixture, which they either eat or reject. It is often difficult to define the right nutrient composition for creating an insect diet. Therefore, the method of self-selection was used, in order to draw conclusions about the necessary nutrient requirements, especially depending on the age of the larvae. The results showed that the most suitable substrates for rearing mealworm larvae were mainly wheat bran and flour, maize hulls, oat bran and flakes, rice flour, lupine flour and potato flakes. Irrespective of their age, the larvae required a high content of carbohydrates and proteins and a low amount of fats and minerals. Indeed, protein and fat requirements grow with increasing age. These findings contribute towards formulating diet mixtures for Tenebrio molitor larvae of different ages.Nutrient self-selection was used to determine the optimal uptake of macronutrients by the yellow mealworm (Tenebrio molitor) larvae. The selection study consisted of four combinations of eight pelleted substrates from a total choice of 25, available to the larvae in a multiple-choice arena. In order to be able to determine the nutrient requirements as a function of the larvae age, six, eight and tenweekold larvae were used for the experiment. The larvae were free to choose between the different feeds for a period of two weeks. Rearing took place at 27 °C, 75% relative humidity and under dark conditions. The optimal ratios of macronutrients were 67.3 to 71.5% for carbohydrates, 19.9 to 22.8% for proteins and 8.6 to 10.0% for lipids to ensure the best results. Biomass growth, food intake and conversion were positively influenced to a significant extent by carbohydrate intake. The protein content, too, varied according to the macronutrient intake and substrate composition; a higher protein consumption increased the larval protein content. Wheat bran and flour, oat bran and flakes, maize hulls, lupine flour and potato flakes, in particular, were considered suitable substrates for the feeding and rearing of Tenebrio molitor larvae and highlighted that these larvae preferred a grain-based diet.

Response of Common Ice Plant (Mesembryanthemum crystallinum L.) to Photoperiod/Daily Light Integral in Vertical Hydroponic Production

Common ice plant (Mesembryanthemum crystallinum L.) is a novel edible plant with a succulent and savory flavor emerging as new crop for greenhouse and plant factory growers. Currently very limited information is available on the response of ice plant to photoperiod and to daily light integral (DLI). The objective of this study was to determine the impact of photoperiod/DLI on the growth of ice plant for indoor vertical production. Four-week old seedlings of ice plant were transplanted into vertical hydroponic systems and given five photoperiod/DLI treatments: 8/6.3, 12/9.5, 16/12.7, 20/15.8, and 24/19.0 h/mol·m−2·d−1. Sequential destructive harvests to determine plant growth occurred 14, 21, and 28 days after lighting treatments began. Plants performed better with increasing photoperiod/DLI from 8 h/6.3 mol·m−2·d−1 to 20 h/15.8 mol·m−2·d−1. By day 28, shoot fresh weight increased from 160 g to 639 g as the photoperiod/DLI increased from 8 h/6.3 mol·m−2·d−1 to 20 h/15.8 mol·m−2·d−1. The continuous lighting treatment, 24 h/19 mol·m−2·d−1, showed a negative effect on the plant fresh weight (FW) and dry weight (DW). Light treatment did not have obvious effects on shoot:root ratio and macronutrient uptake except that potassium (K) uptake decreased slightly with increased photoperiod/DLI. Plants receiving higher photoperiod/DLI showed the same number of leaves (indicating the same development stage) but had smaller, thicker, and darker green leaves compared to lower photoperiod/DLI treatments. Leaf water content was not affected by light treatment up to 20 h/15.8 mol·m−2·d−1 but decreased at 24 h/19 mol·m−2·d−1. Further research is needed to separate the physiological response of increasing/continuous photoperiod from the response of increasing DLI.

The Ubiquitin Proteasome System and Nutrient Stress Response.

Plants utilize different molecular mechanisms, including the Ubiquitin Proteasome System (UPS) that facilitates changes to the proteome, to mitigate the impact of abiotic stresses on growth and development. The UPS encompasses the ubiquitination of selected substrates followed by the proteasomal degradation of the modified proteins. Ubiquitin ligases, or E3s, are central to the UPS as they govern specificity and facilitate the attachment of one or more ubiquitin molecules to the substrate protein. From recent studies, the UPS has emerged as an important regulator of the uptake and translocation of essential macronutrients and micronutrients. In this review, we discuss select E3s that are involved in regulating nutrient uptake and responses to stress conditions, including limited or excess levels of nitrogen, phosphorus, iron, and copper.

Biodiversity of Photosynthetic Pigments, Macronutrients Uptake and Fruit Quality of Tomato Genotypes

Biodiversity of Photosynthetic Pigments, Macronutrients Uptake and Fruit Quality of Tomato Genotypes

Long Term Effect of Fertilizers and Amendments on Macronutrients Uptake by Maize and Relationship with Soil Organic Carbon in Maize-Wheat System in Acid Alfisol f North-oWestern Himalayas

Present study was carried out during 2018 in the ongoing long-term fertilizer experiment, initiated in 1972 at the experimental kharif farm of the Department of Soil Science, Chaudhary Sarwan Kumar Himachal Pradesh Agriculture University, Palampur, to study the effect of chemical fertilizers, farmyard manure and lime application on yield and nutrient uptake by maize and their relationship with soil organic C in an acid Alfisol. The experiment consisted of three replications of eleven treatments in a randomized block design. The results revealed that the continuous use of NPK fertilizers along with FYM or lime increased the maize yield by 46.7 and 38.5%, whereas omission of S and K from the fertilization schedule declined the yield by 54.8 and 52.2% over the sole use of NPK fertilizers, respectively. The uptake of N, P, K, S, Ca and Mg by maize grain and stover was significantly higher in 100% NPK+FYM and 100% NPK+lime than rest of the treatments. Soil organic C recorded a positive and significant relation with uptake of macronutrients by maize, the highest being with P uptake by maize grain (r = 0.918**).

Arbuscular Mycorrhiza mediated mineral biofortification and arsenic toxicity mitigation in Triticum aestivum L.

The potential of arbuscular mycorrhizal fungi in augmenting arsenic (As) tolerance in wheat is well recognized; however, its effect on mineral profile of grains under As stress is not known. The study was performed to assess the effectiveness of Rhizophagus intraradices on acquisition, translocation, and accumulation of minerals in grains of wheat grown in three As levels (0, 25, and 50 mg As kg−1 soil). Inoculation of R. intraradices decreased As accumulation, increased macronutrients uptake, and ensured higher accumulation of N, P, K, Ca, and Mg in grains. However, its influence was non-significant on S concentration in grains. Presence of As in soil reduced Zn, Ni, and Se and augmented Fe, Na, and Mn concentrations in wheat roots. Conversely, translocation of Fe, Na, and Mn to grains declined significantly and concentrations of Fe, Na, Zn, Mn, Ni, and Se reduced in grains with increasing As level in soil. Regardless of lower concentration of Fe and Mn in roots, mycorrhizal (M)-plants maintained higher concentrations of Zn, Mn, Fe, Ni, Se, and Mo in grains than non-inoculated (NI)-plants. Although, mycorrhizal status of plant had non-significant effect on grain phytic acid concentration, R. intraradices significantly increased the bioavailability of Fe and Zn in grains, which was primarily due to enhanced accumulation of Fe and Zn. While bioavailability of Zn improved from poor to moderate, bioavailability of Fe in M-plants, although higher than NI-plants, remained below the desired level.Overall, the study advocates that in addition to limiting As accumulation in grains, AMF could also provide augmented levels of P, N, K, Mg, Ca, Fe, Zn, Mn, Ni, and Se in grains, thus can aid in overcoming the mineral deficiencies for populations consuming wheat-based diets especially in As contaminated areas.

Growth dynamics and nutrient uptake of panicum maximum under nitrogen fertilisation

ABSTRACT We investigated the effects of nitrogen (N) fertilisation levels on structural, productive and morphogenetic traits, chlorophyll content, tiller number (TN) and macronutrient uptake capacity of three Panicum maximum cultivars (BRS Zuri, BRS Quênia and BRS Tamani). The experiment was laid out in a completely randomised design with five N doses (0, 50, 100, 200, and 400 mg dm−3). The concentration of chlorophyll increase linearly with increasing N doses in BRS Zuri. There was a significant interaction effect between cultivars and N doses on forage mass (FM), forage yield (FY), TN and the uptakes of nitrogen, potassium, phosphorus, calcium, magnesium and sulfur. The BRS Zuri had the highest FY and FM independent of the applied N dose. In the dose range of 200 and 400 mg dm−3 of N, there was no increase in the productive performance of BRS Tamani and BRS Quênia, which were similar to each other. N fertilisation increased TN. Higher N doses in the soil translated into greater N uptake by the grasses. Nitrogen application to the soil can increase the production and structural indices of Panicum maximum cultivars and increases grass growth, but its concentration must consider the productive capacity of the plant for this nutrient.

Clonal differences in nitrogen use efficiency and macro-nutrient uptake in young clonal cocoa (Theobroma cacao L.) seedlings from Indonesia

Nitrogen (N) is one of the most required nutrients in cocoa production. Unlike in many other crops, there is limited knowledge on genotypic variation in nitrogen use efficiency (NUE) in clonal cocoa. We therefore evaluated the effect of nitrogen application on cocoa NUE in 10 clonal cocoa scions that were top-grafted on 4-month old rootstock seedlings of cocoa clone MCC 02. Grafted seedlings received either 0 or 2.3 g/plant of N at the beginning of the experiment, which lasted for five months and was arranged in a nursery of the Indonesian Coffee and Cocoa Research Institute (ICCRI) in Jember, Indonesia. A factorial randomized block design was used with four replications. We found that clones significantly affected rootstock stem diameter and dry biomass both in roots and shoots. Nitrogen application decreased rootstock stem diameter and root biomass but increased shoot-root ratio. Following the N application, we observed significantly higher N concentration and uptake both in roots and shoots. This higher N concentration and uptake contributed to significantly lower NUE in both roots and shoots. We did not observe clonal differences in N concentration, uptake, NUE in either roots or shoots and ANR (Apparent Nitrogen Recovery). Nitrogen application influenced P, K, Mg, and Ca uptake in both roots and shoots. There was a clonal effect on P, K and Mg uptake and on P and Mg use efficiency in both roots and shoots. This implies that the studied clones vary in their P and Mg nutrient use efficiency but not in NUE.

Influence of Clomazone on Weeds, Macronutrients Uptake, Yield of Transplanted Rice Crop in Lowland of Egypt

Influence of Clomazone on Weeds, Macronutrients Uptake, Yield of Transplanted Rice Crop in Lowland of Egypt

Agronomic fortification in finger millet (Eleusine coracana) for yield and quality improvement in red sandy loam soils

A field experiment was conducted during kharif 2015–18 to study the yield responses of finger millet [Eleusine coracana (L.) Gaertn.] to graded doses of macronutrient fertilizers (100% and 150% RDF) in combination with soil and foliar application of Zn and Fe, which are important for early establishment of finger millet. The experimental results indicated that significantly higher grain and straw yields of finger millet were recorded with 150% RDF+ZnSO4 0.5% foliar spray+FeSO4 0.2% foliar spray compared to 100% RDF. Soil available N, P2O5, K2O and plant macronutrient uptake were also found highest in the same treatment. Whereas the highest available Zn in the soil was recorded in the treatment 150% RDF+ZnSO4 soil application+FeSO4 0.2% foliar spray, and the highest available Fe was evidenced in the treatment 150% RDF+FeSO4 0.2% foliar spray. The grain zinc content was found highest with the treatment 150% RDF+ZnSO4 0.5% foliar spray, iron content in the grain was found highest with the treatment 150% RDF+ZnSO4 0.5 % foliar spray + FeSO4 0.2% foliar spray. The uptake of Zn and Fe were found highest with the treatment 150% RDF+ZnSO4 0.5 % foliar spray+FeSO4 0.2 % foliar spray. Hence, the treatment with 150% RDF+ZnSO4 0.5% foliar spray + FeSO4 0.2% foliar spray was considered to be the best treatment which was at par with 150% RDF+ZnSO4 @50 kg/ha soil application+FeSO4 0.2% foliar spray.

Poultry Litter and Inorganic Fertilization: Effects on Biomass Yield, Metal and Nutrient Concentration of Three Mixed-Season Perennial Forages

Poultry litter and fertilizers are normally added as soil amendments. The effects of poultry litter and inorganic fertilizers on three mixed-season perennial forages were studied for two years in the field to understand growth dynamics, metals, and nutrient uptake. The primary objective was to investigate the heavy metal and nutrient concentrations, biomass yield and forage potential of a cool-season forage, stinging nettle (Urtica dioica L.), relative to warm-season forages, bermudagrass (Cynodon dactylon (L.) Pers.) and switchgrass (Panicum virgatum L.). Forage cuttings and soil samples were analyzed for heavy metals and nutrients using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Total biomass yield was higher by 66% and 50% in switchgrass and bermudagrass, respectively, compared with stinging nettle for the first year. While the warm-season forages yielded more biomass over the cool-season forage, metal concentrations were significantly higher for all elements in the cool-season forage. Stinging nettle showed greater macro-nutrient uptake with 103.20 kg ha−1, 0.87 kg ha−1, 27.49 kg ha−1 and 32.08 kg ha−1 for Ca, Fe, Mg, and P, except for K with 223.51 kg ha−1 compared with 267.29 kg ha−1 and 283.96 kg ha−1 for switchgrass and bermudagrass, respectively. Heavy metals were also higher in stinging nettle but were within the allowable limits for forages, indicating its potential as a resource for forages and nutrient cycling, particularly when double-cropped with warm-season forages.

Application of Synthetic Peptide CEP1 Increases Nutrient Uptake Rates Along Plant Roots.

The root system of a plant provides vital functions including resource uptake, storage, and anchorage in soil. The uptake of macro-nutrients like nitrogen (N), phosphorus (P), potassium (K), and sulphur (S) from the soil is critical for plant growth and development. Small signaling peptide (SSP) hormones are best known as potent regulators of plant growth and development with a few also known to have specialized roles in macronutrient utilization. Here we describe a high throughput phenotyping platform for testing SSP effects on root uptake of multiple nutrients. The SSP, CEP1 (C-TERMINALLY ENCODED PEPTIDE) enhanced nitrate uptake rate per unit root length in Medicago truncatula plants deprived of N in the high-affinity transport range. Single structural variants of M. truncatula and Arabidopsis thaliana specific CEP1 peptides, MtCEP1D1:hyp4,11 and AtCEP1:hyp4,11, enhanced uptake not only of nitrate, but also phosphate and sulfate in both model plant species. Transcriptome analysis of Medicago roots treated with different MtCEP1 encoded peptide domains revealed that hundreds of genes respond to these peptides, including several nitrate transporters and a sulfate transporter that may mediate the uptake of these macronutrients downstream of CEP1 signaling. Likewise, several putative signaling pathway genes including LEUCINE-RICH REPEAT RECPTOR-LIKE KINASES and Myb domain containing transcription factors, were induced in roots by CEP1 treatment. Thus, a scalable method has been developed for screening synthetic peptides of potential use in agriculture, with CEP1 shown to be one such peptide.