Rhizosphere Area Research Articles

Potential of rhizobacterial consortium in increasing area and weight of mulberry leaves (Morus indica)

Abstract. Mustaka Z, Patandjengi B, Alam G, Melina. 2022. Potential of rhizobacterial consortium in increasing area and weight of mulberry leaves (Morus indica). Biodiversitas 23: 1369-1374. Rhizobacteria are a group of bacteria that live saprophytically in the rhizosphere area. Some of them can act as plant growth promoters and as biocontrol agents against diseases to increase crop yields. This study was conducted to find potential of the rhizobacteria consortium in various treatments to increase the area and weight of mulberry (Morus indica L.) leaves. Results showed that the rhizobacteria consortium formulation had a significant effect on increasing leaf area and weight. The percentage increase in leaf area in the treatment using the MKR15 rhizobacteria consortium was better at 39.28% (2,800 mm2) when compared to the control MK0t (1,700 mm2), and the percentage increase in MKR15 leaf weight (74.80 g) was 54.54% higher compared to control MK0t (34 g). With these results, it is clear that the rhizobacteria consortium as PGPR affects plant growth and nutrition in a very specific way involving bacterial components that induce plant responses. Molecules of PGPR can affect plants in complex mechanisms, sometimes affecting plant growth and nutrition, and resistance simultaneously.

Identification of Phosphorus Stress Related Proteins in the Seedlings of Dongxiang Wild Rice (Oryza Rufipogon Griff.) Using Label-Free Quantitative Proteomic Analysis.

Phosphorus (P) deficiency tolerance in rice is a complex character controlled by polygenes. Through proteomics analysis, we could find more low P tolerance related proteins in unique P-deficiency tolerance germplasm Dongxiang wild rice (Oryza Rufipogon, DXWR), which will provide the basis for the research of its regulation mechanism. In this study, a proteomic approach as well as joint analysis with transcriptome data were conducted to identify potential unique low P response genes in DXWR during seedlings. The results showed that 3589 significant differential accumulation proteins were identified between the low P and the normal P treated root samples of DXWR. The degree of change was more than 1.5 times, including 60 up-regulated and 15 downregulated proteins, 24 of which also detected expression changes of more than 1.5-fold in the transcriptome data. Through quantitative trait locus (QTLs) matching analysis, seven genes corresponding to the significantly different expression proteins identified in this study were found to be uncharacterized and distributed in the QTLs interval related to low P tolerance, two of which (LOC_Os12g09620 and LOC_Os03g40670) were detected at both transcriptome and proteome levels. Based on the comprehensive analysis, it was found that DXWR could increase the expression of purple acid phosphatases (PAPs), membrane location of P transporters (PTs), rhizosphere area, and alternative splicing, and it could decrease reactive oxygen species (ROS) activity to deal with low P stress. This study would provide some useful insights in cloning the P-deficiency tolerance genes from wild rice, as well as elucidating the molecular mechanism of low P resistance in DXWR.

The effects of long-term application of organic and inorganic fertilizers on soil and plant Nitrogen-Carbon contents

Soil and crop management such as chemical fertilizer applications hurt the soil’s biological quality and productivity. The most well-known organic fertilizer such as animal manure, compost and mycorrhizal fungi are significantly contributing to soil organic carbon sink and consequently, organic fertilizers have a positive effect on the soil biological diversity and productivity. To increase soil carbon content, long-term organic fertilizer applications increase soil carbon budget hypothesis was tested under field conditions. The aim is to investigate the effects of different organic and inorganic fertilizer applications on the soil and wheat plant carbon and nitrogen content. A long-term field experiment was established in 1996 until the present time. In 2018, before cultivation control, Mineral fertilizer (NPK), Animal manure (25 ton ha-1), Compost (25 ton ha-1) and Compost+Mycorrhiza (10 ton ha-1) were applied. Adana-99 varieties of wheat seeds were sown. After harvest, soil and plant samples were taken and soil-plant carbon-nitrogen analyses were made. Results show that C % and N % contents of the plant seed, shoot, and root have higher concentrations than that of the control treatment. When the TC %, OC %, and N % contents of the soil at different depths (0-15 cm and 15-30 cm) and in the rhizosphere (R) and no rhizosphere (NR) area were examined, compost and animal manure treatments have higher content. At the rhizosphere area 0-15 cm depth the soil % OC, and % IC contents were statistically significant. The highest values of soil OC %, C: N and IC % contents at Rhizosphere 0-15 cm depth were obtained in animal manure with 2.94 %, 10.06, and 3.90 % respectively. Organic fertilizers application increased soil TC %, OC % and N% contents as well as contribute to the carbon and nitrogen budget. The results found support our hypothesis.

Safety Disposal of Rice Straw by Biodegradation Using Streptomyces Tendae

Rice straw is a byproduct formed during rice cultivation. Disposal of rice straw may happen via unhygienic methods such as burning, which is happening in Malaysia and other countries. This study aims to rid rice straw via an eco-friendly biodegradation technique. Biodegradation of rice straw depended on actinobacteria, which were isolated from the cultivated soil of rice and rhizosphere areas in Tabuk region. Out of thirty actinobacterial isolates, only three isolates (S-5, S-12, S-20) biodegraded starch, cellulose, lignin and rice straw powder. The most potent actinobacterial isolate (S-5) was identified as Streptomyces tendae, which effectively biodegraded all polysaccharides of rice straw. Biodegradation of rice straw was associated with a significant reduction in C/N ratio, where the latter fell from 30.4% to 17.2% within 42 d.

Perbanyakan Agen Hayati Trichoderma Sp. Menggunakan Media Beras di Laboratorium Pengamatan Hama dan Penyakit Tanaman Banyumas

The rhizosphere area of a plant is an area rich in microbes, one of which is a group of fungi. This practical work aims to multiply Trichoderma sp. in the rhizosphere of bamboo plants in the Jatilawang area using rice as a medium. This practical work uses rice and coconut media in conducting exploration. The results of practical work obtained spore density of Trichoderma sp. meet the standards for application in plants. Obstacles in exploring Trichoderma sp. is takes a long time.

Comparative Analysis of Rhizospheric Bacteria Associated with Four Medicinal Plants

Rhizosphere microbes contribute greatly to the growth, development and functioning of plants and trees. Microbes living in the rhizospheric area depend on the soil conditions and the products released by the plants. The objective of this work is to study microbes present in the rhizospheric region of Amla (Phyllanthus emblica L.) soil. A comparative study was also conducted among Amla (Phyllanthus emblica L.), Guava (Psidium guajava L.), Jamun (Syzygium cumini (L.) Skeels) and Neem (Azadirachta indica A. Juss.) growing on the same soil. The work indicates that the plant and its rhizosphere may have some effect on microbial diversity. The study on the rhizosphere of amla plant soil was undertaken to have a better understanding of the microbes present on the rhizosphere. Different microbes present in the Phyllanthus emblica (Amla) rhizospheric region. A large variation can be found in many other bacterial species. Details study in this regard will bring many interesting facts about plant-microbe interaction.

Isolation and identification of fungi associated with natural forest land and post-mining areas of PT. Vale Indonesia: Preliminary study

This study aimed to determine the types of fungi that can provide information on microbes associated with the post-mining forest land area of PT. Vale Indonesia. This study used a descriptive method by recording and describing the phenomena obtained. Sampling in the field was done by taking 500 g of soil/point (with three replications). Soil samples were taken around the roots or rhizosphere areas with 10 - 30 cm depth in natural and reclamation forest areas. Isolation of microbial growth was conducted by using the dilution technique. The purification of the obtained isolates was carried out by inoculation in PDA media with the point method, then incubated for ± 5 days at 27°C, and their growth was observed. Characterization of microscopic fungi isolates was identified based on the characteristics of the morphological structures. Based on preliminary research results of fungi soil samples originating from reclamation and natural forest areas, 11 rhizosphere fungi isolates were obtained. The fungi colonies’ color at the top and bottom had various colors and different textures. Greenish and whitish colors dominated the colony color, but some isolates had white, brown, cream, gray, yellowish, whitish, greenish colors, and some had spots. Colony texture was dominated by velvet, but some isolates had the texture of fine cotton and coarse cotton, presumably Aspergillus niger, Aspergillus sp, Fusarium oxysporum, Pénicillium sp., Trichoderma harzianum, and Trichoderma viride. This research will be continued to ascertain the type and function of each isolate.

The rhizosphere of Salix viminalis plants after a phytostabilization process assisted by biochar, compost, and iron grit: chemical and (micro)-biological analyses.

Amendments, such as biochar, compost, and iron grit, used in phytostabilization studies, showed positive effects on soil physico-chemical properties, plant growth, and the microbial community. However, assisted phytostabilization studies do not always focus on the rhizosphere area where soil, plants, and microorganisms are affected by the amendments and plants and microorganisms can also interact with each other. The aims of this study were to evaluate the effects of amendment application on the exudation of organic acids by Salix viminalis plant roots, as well as the effects of amendments and plant development on the soil CHNS contents and the microbial community activity and diversity, assessed by measuring enzyme activities and using Biolog EcoPlatesTM tests and next-generation sequencing analyses. The results of the mesocosm experiment showed that soil C, H, and N contents were increased by amendment application, especially biochar and compost, while the one of S decreased. Enzyme activities, microbial activity, and diversity were also increased by the addition of amendments, except iron grit alone. Finally, the quantity of organic acids exuded by roots were little affected by amendments, which could in part explain the reduced effect of plant development on soil chemical and microbiological parameters. In conclusion, this study showed in particular that biochar and compost were beneficial for the soil CHN contents and the microbial community while affecting poorly Salix viminalis root exudates.

Drought alters the carbon footprint of trees in soils-tracking the spatio-temporal fate of 13 C-labelled assimilates in the soil of an old-growth pine forest.

Above and belowground compartments in ecosystems are closely coupled on daily to annual timescales. In mature forests, this interlinkage and how it is impacted by drought is still poorly understood. Here, we pulse‐labelled 100‐year‐old trees with 13CO2 within a 15‐year‐long irrigation experiment in a naturally dry pine forest to quantify how drought regime affects the transfer and use of assimilates from trees to the rhizosphere and associated microbial communities. It took 4 days until new 13C‐labelled assimilates were allocated to the rhizosphere. One year later, the 13C signal of the 3‐h long pulse labelling was still detectable in stem and soil respiration, which provides evidence that parts of the assimilates are stored in trees before they are used for metabolic processes in the rhizosphere. Irrigation removing the natural water stress reduced the mean C residence time from canopy uptake until soil respiration from 89 to 40 days. Moreover, irrigation increased the amount of assimilates transferred to and respired in the soil within the first 10 days by 370%. A small precipitation event rewetting surface soils altered this pattern rapidly and reduced the effect size to +35%. Microbial biomass incorporated 46 ± 5% and 31 ± 7% of the C used in the rhizosphere in the dry control and irrigation treatment respectively. Mapping the spatial distribution of soil‐respired 13CO2 around the 10 pulse‐labelled trees showed that tree rhizospheres extended laterally 2.8 times beyond tree canopies, implying that there is a strong overlap of the rhizosphere among adjacent trees. Irrigation increased the rhizosphere area by 60%, which gives evidence of a long‐term acclimation of trees and their rhizosphere to the drought regime. The moisture‐sensitive transfer and use of C in the rhizosphere has consequences for C allocation within trees, soil microbial communities and soil carbon storage.

Potential phosphate solubilizing bacteria from the rhizosphere of Cotylelobium melanoxylon tree

Microorganism have important roles in soil cycles and plant living activities. Phosphate solubilizing bacteria is one of the microorganisms in the soil that plays a role in helping provide phosphorus nutrients that are not available to plants. The purpose of this study was to obtain potential phosphate solubilizing bacteria from the rhizosphere Cotylelobium melanoxylon plants. Soil samples were taken in a composite at a depth of 0-20 cm from the rhizosphere area of C. melanoxylon plants in the village of Bona Lumban, Tukka District, Tapanuli Tengah Regency, North Sumatra. Isolation of phosphate solubilizing bacteria using the dilution plate technique with Pikovskaya medium. Phosphate solubilizing bacterial isolates were selected qualitatively by measuring the ratio of the clear zone. Selected isolates are identified up to species molecularly. The isolation results obtained were 16 isolates of phosphate solubilizing bacteria with a clear zone ratio varying between 1.03 to 1.68. Four isolates were selected with the highest clear zone ratio. Based on molecular identification, the four isolates included Pseudomonas aeruginosa species.

Interaction between type of plant growth promoting rhizobacteria and patchouli varieties on growth and yield of patchouli (Pogostemon cablin Benth.)

A group of bacteria living in the rhizosphere area and capable to actively colonize the plant's root system called Plant Growth Promoting Rhizobacteria (PGPR). These bacteria can improve plant growth and yield. We determine the interaction between types of PGPR and patchouli varieties on growth and yield. This research was conducted at the Laboratory of Seed Science and Technology and Experimental Farm, Faculty of Agriculture, Syiah Kuala University, between January to June 2020. The collecting data from experiment were analyzed by factorial randomized block design with three replications. Seven type of rhizobacteria consist used without rhizobacteria, Necercia sp., Pseudomonas capacia, Bacillus firmus, Bacillus bodius, Bacillus alvei, Bacillus stearothermophillus. The varieties consist of three levels Tapak Tuan, Lhokseumawe, and Sidikalang. There was very significant interaction between rhizobacteria and varieties on the parameters of fresh weight and dry weight and significant interactions on plant height at 60 and 120 DAP, number of branches at 90 and 120 DAP, and leaf area. Variety of Sidikalang combination with P. capacia have very high wet weight (73.43 g), dry weight (18.05 g), and leaf area (84.00 cm2).

KARAKTERISTIK MORFOLOGI DAN FISIOLOGI BAKTERI ENDOFIT DAN RIZOBAKTERI DARI TANAMAN CENGKEH SEHAT

One of the determining factors in disease control is the use of superior seeds which have good quality and quantity. The use of biological control agents that form a symbiotic mutualism in their host plants can be used as an effort to obtain quality clove seeds. Endophytic bacteria and rhizobacteria have been reported as potential biological control agents for many plant diseases because of their safety in humans and non-target organisms. The purpose of this study was to identify the physiological and morphological characteristics of endophytic and rhizobacterial isolates obtained from clove plants. A total of 46 endophytic bacterial isolates were isolated from healthy clove roots, stems, leaves and flowers. Also, 66 isolates were isolated from the soil around the rhizosphere area. Based on the results of the identification of physiological and morphological characteristics, it is evident that the endophytic and rhizobacterial bacteria tested have the same character as Bacillus spp.

IMPACT OF ENRICHED HUMIC ACID WITH BENEFICIAL MICROORGANISM IN REDUCING MINERAL FERTILIZERS ON JERUSALEM ARTICHOKE PLANTS UNDER SANDY SOIL CONDITION

A field experiment was carried out at experimental farm at El-Kassasin, Horticulture Station, Agricultural Research Center (ARC), Ismallia Governorate, Egypt during summer season of 2016 and 2017 to evaluate the potentiality effect of humic acid and/or biofertilizers combined with different rates from mineral fertilization to reduce dependence on mineral fertilizers,and improve growth and productivity of Jerusalem artichoke plants (Helianthus tuberosus L. cv. Fuseau). The highest values of growth parameters i.e., plant height, number of main stems, number of branches, fresh and dry weight of shoots were exhibited with humic acid + biofertilizers treatment combined with 75% NPK in both seasons. This treatment also indicated the maximum NPK percentage values and uptake of these elements in shoots in both seasons. Still this treatment 75% NPK + H + BF was superior in tubers yield as it gave 25.001 and 25.429 ton/fed and the relative increase over control reached to 2.57 and 1.69% in both seasons, respectively. Concerning the tubers quality represented by total carbohydrates and inulin, the application of humic acid with biological fertilization combined with 75% NPK increased the tubers 'content of inulin, which reached 2.77 and 2.798 ton/ fed in both seasons, respectively, the relutive increase over the control by 4.33 and 4.47 %, respectively. While the tubers contentof carbohydrate was not affected by addition H and BF with 75% NPK compared with control. The obtained results revealed that the total microbial count and yeast count in the rhizospheric area were higher with the treatment 75% NPK + H + BF compared to control, while the maximum count of Azotobacter sp. was attained with treatment 50% NPK + H + BF in both seasons. The mixture treatment (75% NPK + H + BF) was still the superior one where it gave the highest enzymes activity represented in nitrogenase (µmole C2H4/g rhizosphere/h), Dehydrogenase (µg TPF/g dry soil/day) and acid and alkaline phosphatase (µg/g dry soil). Generally, these results undoubtedly confirm that humic acid dual with bio-fertilizers could saving the use of chemical fertilizers and consequently improve the quality and quantity of plants and produce more save foods at the same time.

Rhizobacteria and their metabolites as a promising green approach for the treatment of pesticide contaminated agricultural soils

Pesticides are employed to control and manage pest populations at tolerable levels. Pesticides are classified especially according to their chemical structure, toxicity, environmental persistence and target organisms. The massive use of these pollutants in addition to their toxic potential seriously threatens ecosystems and humans. For this reason, the development of green bioremediation processes is necessary. The ability of several microorganisms to bioremediate pesticides is mainly based on their biodegradation activity. Though bacteria have been proved to be efficient biodegraders and bioremediators, some fungi and archae could biodegrade recalcitrant pesticides too. The bioremediation of pesticide-contaminated agricultural sites may be optimized by considering the prevalent environmental conditions, the microorganisms that solubilize and degrade the pesticides most effectively, the variables that affect the biodegradation rate and the chemical structure of pesticides. This chapter explores the importance of pesticides as persistent organic pollutants in agricultural soils, particularly in the plants rhizospheric area and further illustrates the recent advances in pesticide microbial bioremediation, with emphasis on the metabolic potential of pseudomonads as a representative model of pesticide-degrading microorganisms.

Importance of fungi in a 63 years old long-term field experiment with 20 years of maize growth

Microbial diversity and their activity in the rhizosphere and bulk soil areas were measured in a long-term field trial (started in 1956), where maize has been grown for the last 20 years with and without N fertilisation. Various microbial groups and their substrate feeding strategies (i.e. demonstrating activities) were identified through phospholipid fatty acids (PLFAs) analysis and their δ13C values. Microbial abundance (esp. fungi) remained unaffected by long-term N fertilisation. However, fungi dominated over bacteria with 2–3 times higher biomass in the rhizosphere than bulk soil. The δ13C of PLFAs showed that fungi had the highest values, particularly in fertilised rhizosphere areas, indicating that this was the most active group (than any other microbial group) for assimilation of maize rhizodeposits.

Geochemical fractions of trace metals in surface and core sections of aggregates in agricultural soils

Agrochemicals containing trace metals such as pesticides and fertilizer are intensively used in apple production systems in many countries. There is a risk of accumulation of trace metals, particularly in the sensitive root rhizosphere area. In this study, the trace metal concentrations of soils were determined in macroaggregates at the “mm scale” sampled from apple orchards. Soil samples were taken from five different locations at 0–20 cm soil depths in an apple orchard. Pseudo-total trace metal (Cd, Cr, Cu, Ni, Pb, and Zn) concentrations of soil samples separated from the surface and core sections of the soil aggregate were determined by digestion with Aqua regia. The modified BCR sequential extraction method was used to determine four operationally defined geochemical trace metal fractions in soil samples. The pseudo-total concentrations of Cd and Cu were significantly higher, and Zn was lower at the surface than in the core sections (paired-t test, p < 0.05) of soil aggregates. The concentrations of all trace metals in the acid-soluble fraction and reducible fractions were significantly higher at the surface of soil aggregates than those in the core section. The same was true for the sum of trace metal concentrations in the extracts of the three fractions considered potentially mobilizable, except for Cr. Our results demonstrated that Cd and Cu originated probably from agrochemicals accumulating significantly on aggregate surfaces, where they were in close contact with plant roots. The generally higher extractability of all trace metals on the surface of aggregates can be attributed to the preferential accumulation of newly-added trace metals in comparatively weakly bound chemical forms.

Allelopathy Effect of Trichoderma spp. and Some Plant Extracts against Pythium aphanidermatum (In-vitro)

Background: Serious seed-borne and soil-borne pathogens are existing at the rhizosphere area, many species of Pythium can cause seed rot and damping-off disease. The application of plant extracts and biological agents as alternative ways for the management of plant diseases has recently become an important variable component for Integrated Pest Management, so plant metabolites regarded as eco-friendly where plants play an important role in the control of diseases. The current study amid to evaluate the allelopathy effect of two species of biological agents particularly Trichoderma spp. and some plant extracts against the soil-borne pathogen P. aphanidermatum on cucumber seedlings under laboratory conditions. Methods: In this study laboratory investigation during 2018, used the allelopathy effect of two species of Trichoderma (T. harzianum and T. hamatum) and five plant extracts, in Three conc. 10.000, 20.000 and 30.000 ppm, to control damping-off disease in cucumber caused by Pythium aphanidermatum instead of using chemicals fungicides. Result: Our study observed that Trichoderma spp., have a high inhibitory effect on the tested pathogen, but in the assay of plant extracts, only some with different concentrations had a significant effect against P. aphanidermatum (in-vitro). Cinnamomum cassia, Syzygium aromaticum and Eucalyptus globulus were most affective from all other five tested plant extracts, where the concentration of 30.000 ppm gave the highest inhibitory effect against P. aphanidermatum, while Psidium guajava and Lawsonia inermis extracts showed a lower inhibitory effect on radial growth of P. aphanidermatum.

Evaluation of short-term pilot reed bed performance for real domestic wastewater treatment

Abstract Domestic wastewater is one of the sources of pollutant for water bodies if not disposed properly. Reed bed system is very potential to be used to treat domestic wastewater as it is good in terms of overall performance, low in operation and maintenance costs, and environmentally friendly. This study examined the overall performance of pilot reed bed system planted with two native Malaysian plants of Scirpus grossus and Lepironia articulata in treating real domestic wastewater under short term batch reactor. Four systems were used in this experiment, in which first system planted with S. grossus, second system planted with L. articulata, third system planted with 50% S. grossus + 50% L. articulata, and the fourth system was left unplanted as control reactor. A total of 5 days of parameters observation and two sampling points (on the top of medium and at the bottom of medium) were chosen to analyse the effect of the treatment period and the contribution of rhizosphere area to the overall reed bed performance. The planted system performed very well in removing pollutant reaching up to 99% for TSS, 99.7% for BOD, 96.6% for COD, 100% for ammonium, and 99.6% for phosphate. The addition of plants significantly increased the DO concentration inside reed bed. Both plants showed no significant difference performance in terms of the removal efficiencies. There was a significant difference in terms of removal between both sampling points (up and down) at day 0 and day 1, indicating that rhizosphere area played a very important role in the treatment of wastewater which provide lower pollutant concentration in shorter period of time. There are no significant differences obtained for measured parameter at day 3 and day 5 in all reactor, indicating that the systems already achieved the steady state at day 3 of the observation.

STUDI KARAKTERISASI FISIOLOGI CENDAWAN ENTOMOPATOGEN Metarhizium spp DARI BERBAGAI RIZOSFER TANAMAN HORTIKULTURA KOTA PADANGSIDIMPUAN

Entomopathogenic fungi are bioinsecticides used to control insect pests. Entomopathogenic fungi can found in the rhizosphere area of plants. This study aims to determine the germination, sporulation, and colonization of Metarhizium spp that are found in the various horticultural plants' rhizosphere of Padangsidimpuan . Metarhizium spp used were MetCP, MetKP, MetMP, MetKPP, MetSP, MetJP, MetTP. This research conducted in the Agrotechnology Laboratory of the Faculty of Agriculture, Universitas Muhmmadiyah Tapanuli Selatan. The study used a completely randomized design (CRD). The results showed that the highest germination rate at 6 hours after inoculation (HAI) founded in MetKPP of 31.05%. MetKPP also had the highest germination rate of 37.43% on 24 HAI. The highest diameter growth founded in MetKP, which was 5.50 cm at 14 HAI. The highest conidia density was 1,821 x 10 6 conidia/ml, found in MetMP, significantly different from MetCP, which had the lowest conidia density that was 1.169 x 10 6 conidia/ml.

Responses of soil-grown Scots pine seedlings to experimental warming, moderate nitrogen addition and bark herbivory in a three-year field experiment

Increased soil nitrogen (N), warming and bark herbivory all are expected to affect boreal forests in the future. We studied the effects of warming (0.5 °C and 4.0 °C above ambient air and soil temperature, respectively), moderate N addition (30 kg N ha−1 y−1) and bark herbivory by large pine weevil (Hylobius abietis L.) on soil-grown Scots pine (Pinus sylvestris L.) seedlings in a three-year (2014–2016) open-air field experiment. Seedling dry mass, root mass fraction (RMF), root morphology, mycorrhizal colonization, mycorrhizal morphotypes, root phenolics and microbial abundance in the rhizosphere area were studied. We observed that both moderate N addition and warming showed interactive effects, and generally improved seedling growth after the three consecutive growing seasons. However, soil dryness was increased due to combined warming and N addition treatment in 2016, and it seemed to limit the shoot growth stimulation as well as increase the dependence of the non-herbivory seedlings on the mycorrhizas. Moderate N addition generally reduced herbivory damage intensity and increased RMF. It also decreased total mycorrhizal colonization rate and increased SRL of the seedlings in 2016, but only in the absence of other factors. In 2016, herbivory affected soil exploration efficiency and mycorrhizal colonization without other factors, and had a tendency to increase root phenolics. There were only minor effects of N addition and herbivory on soil microbial abundances. We conclude that warming and N addition to soil may increase growth in young Scots pine if soil drought or herbivory do not start to limit it; and that in young Scots pine stands moderate bark herbivory are likely to affect roots more than shoots.