Benomyl Effects on Plant Productivity through Arbuscular Mycorrhiza Restriction in a Greek Upland Grassland

Interactions between plants and microbes are important for plant community structure. Many plants establish symbioses with arbuscular mycorrhizal (AM) fungi, which play a central role in soil fertility, plant nutrition and the maintenance of stability and biodiversity within plant communities by improving uptake of nutrients and water. AM fungi can improve growth/performance in a variety of plant species by influencing intra- and interspecific competition of neighbouring plants and thus regulate coexistence and diversity in mixed communities. The aim was to study AMF effects on plant productivity and diversity in Greek upland grasslands

Could energy equilibrium and greenhouse gas emissions in agroecosystems play a key role in crop replacement? A case study in orange and kiwi orchards

The development of agriculture is linked to energy resources. Consequently, energy analysis in agroecosystems could be a useful tool for monitoring some measures in the agricultural sector to mitigate greenhouse gas emissions. The objectives of this study were to (a) evaluate differences of energy indices in orange and kiwi orchards, and (b) point out whether inputs, outputs, efficiency, productivity, and carbon footprint can play a key role in crop replacement. Proportional stratified random sampling was used to select 26 orchards (10 oranges, 16 kiwis) from the Prefecture of Arta, western Greece, during 2015 and 2016. Univariate statistical methods were combined with multivariate ones. Nitrogen, Mg, Zn, herbicides, insecticides, fungicides, renewable energy inputs, fruit production, total outputs, and energy efficiency and productivity were statistically significantly high in the orange orchards. Phosphorus, Ca, irrigation, machinery, total inputs, intensity, non-renewable energy consumption, and carbon footprint were statistically significantly high in the kiwi orchards. The most important energy inputs for both fruit crops were fertilizers, fuels, irrigation, machinery, and herbicides. The orange orchards seem to be more friendly to the environment than the kiwi orchards by having low total energy inputs 32,210.3 MJ ha−1, intensity 1.4, consumption of non-renewable energy 0.7 MJ kg−1 and CO2 equivalent/fruit production 0.08 kg kg−1, and high energy outputs 105,120.0 MJ ha−1 and fruit production 53,648.0 kg ha−1. The findings of the present study show a relation between climate change and the production of farming systems, which can be a tool for decision makers. The correlation of the above-mentioned parameters ensure higher profits and could help in achieving the best possible sustainable management of the agricultural ecosystems

Belowground DNA-based techniques: untangling the network of plant root interactions

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Carbon dioxide exchange above a Mediterranean C3/C4 grassland during two climatologically contrasting years

Eddy-covariance measurements of net ecosystem carbon exchange (NEE) were carried out above a grazed Mediterranean C3/C4 grassland in southern Portugal, during two hydrological years, 2004–2005 and 2005–2006, of contrasting rainfall. Here, we examine the seasonal and interannual variation in NEE and its major components, gross primary production (GPP) and ecosystem respiration (Reco), in terms of the relevant biophysical controls. The first hydrological year was dry, with total precipitation 45% below the longterm mean (669mm) and the second was normal, with total precipitation only 12% above the long-term mean. The drought conditions during the winter and early spring of the dry year limited grass production and the leaf area index (LAI) was very low. Hence, during the peak of the growth period, the maximum daily rate of NEE and the light-use and water-use efficiencies were approximately half of those observed in the normal year. In the summer of 2006, the warm-season C4 grass, Cynodon dactylon L., exerted an evident positive effect on NEE by converting the ecosystem into a carbon sink after strong rain events and extending the carbon sequestration for several days, after the end of senescence of the C3 grasses. On an annual basis, the GPP and NEE were 524 and 49 gCm 2, respectively, for the dry year, and 1261 and 190 gCm 2 for the normal year. Therefore, the grassland was a moderate net source of carbon to the atmosphere, in the dry year, and a considerable net carbon sink, in the normal year. In these 2 years of experiment the total amount of precipitation was the main factor determining the interannual variation in NEE. In terms of relevant controls, GPP and NEE were strongly related to incident photosynthetic photon flux density on short-term time scales. Changes in LAI explained 84% and 77% of the variation found in GPP and NEE, respectively. Variations in Reco were mainly controlled by canopy photosynthesis. After each grazing event, the reduction in LAI affected negatively the NEE

Foliar elemental composition of European forest tree species associated with evolutionary traits and present environmental and competitive conditions

Aim Plant elemental composition and stoichiometry is crucial for plant structure and function. We studied to what extent plant stoichiometry might be caused by environmental drivers and competition from coexisting species. Location Europe. Methods We analyzed foliar N, P, K, Ca and Mg concentrations and their ratios among 50 species of European forest trees sampled in 5284 plots across Europe and their relationships with phylogeny, forest type, current climate and N deposition. Results Phylogeny is strongly related to overall foliar elemental composition in European tree species. Species identity explained the 56.7 percent of the overall foliar elemental composition and stoichiometry. Forest type and current climatic conditions also partially explained the differences in foliar elemental composition among species. In the same genus co-occuring species had overall higher differences in foliar elemental composition and stoichiometry than the non co-occuring species. Main conclusions The different foliar elemental compositions among species are related to phylogenetic distances, but they are also related to current climatic conditions, forest types, global change drivers such as atmospheric N deposition, and to differences among co-occurring species as a probable consequence of niche specialization to reduce direct competition for the same resources. Different species have singular "fixed" foliar elemental compositions but retain some degree of plasticity to the current climatic and competitive conditions. A wider set of elements beyond N and P better represents the biogeochemical niche and is highly sensitive to plant function. Foliar elemental composition can thus be useful for representing important aspects of plant species niche

PLANT SPECIES CO-EXISTENCE IN HERBACEOUS COMMUNITIES OF LATE SUCCESSIONAL STAGES

THIS WORK WAS AIMED TO INVESTIGATE WHETHER THE PLANT SPECIES OF INFERTILE GRASSLANDS (I) HAVE RELATIVE ABUNDANCE'S WHICH ARE RELATED TO TISSUE CONCENTRATIONS IN THE LIMITING NUTRIENTS, (II) DIFFER IN DISTRIBUTION OF THE ACTIVE ROOTS WITH THE DEPTH OF THE SOIL, AND IF THEIR DISTRIBUTION IS AFFECTED BY THE ADDITIONS OF THE LIMITING NUTRIENTS. ALSO, (III) IF THE DIFFERENCES IN PHENOLOGY AMONG THE PLANT SPECIES ARE RELATED TO SPECIES' TOLERANCE TO DROUGHT. IN A SPECIES RICH LOWLAND GRASSLAND, DEVELOPED ON MODERATELY ACID SOIL, N ADDITION FAVOURED MOSTLY THE EARLY GROWING ANNUAL OR BIENNIAL GRASSES WHILE P ADDITION FAVOURED THE LEGUME SPECIES. THESE EFFECTS WERE MORE PRONOUNCED WHEN RAINFALL DURINGTHE GROWTH PERIOD WAS ADEQUATE. THE SPECIES' RELATIVE ABUNDANCE WAS NEGATIVELY RELATED TO SPECIES N OR P CONCENTRATIONS. THE ADDITION OF N OR P PROPORTIONALLY FAVOURED MORE THE SPECIES WITH HIGHER N OR P TISSUE CONCENTRATIONS. THE PHENOLOGY OF THE 5 MOST ABUNDANT SPECIES WAS FOUND TO BE RELATED WITH THE SPECIES' TOLERANCE TO DROUGHT. THE ROOT ACTIVITY OF CO-EXISTING PLANT SPECIES WAS ASSESSED FOR TWO YEARS BY INJECTING LITHIUM, STRONTIUM AND CAESIUM AT THE DEPTHSOF 5 AND 15 CM IN THE SOIL OF AN UPLAND GRASSLAND IN WHICH FOUR TREATMENTS OFN AND P ADDITIONS WERE APPLIED. SR AND CS GAVE QUITE SIMILAR RESULTS, WHICH IN SOME CASES WERE QUITE DIFFERENT FROM THOSE OF LI. THE DEPTH UP TO WHICH THE ROOTS WERE ACTIVE DIFFERED IN THE VARIOUS CO-EXISTING SPECIES, AND FOR SOME OFTHEM IT WAS DIFFERENTIATED IN THE VARIOUS NUTRIENT TREATMENT. (ABSTRACT TRUNCATED)Η ΕΡΓΑΣΙΑ ΑΥΤΗ ΑΠΟΣΚΟΠΟΥΣΕ ΣΤΟ ΝΑ ΔΙΕΡΕΥΝΗΣΕΙ ΕΑΝ (I) ΤΑ ΕΙΔΗ ΦΥΤΩΝ ΣΕ ΑΓΟΝΑ ΦΥΣΙΚΑ ΠΟΟΛΙΒΑΔΑ ΕΧΟΥΝ ΣΧΕΤΙΚΕΣ ΑΦΘΟΝΙΕΣ ΠΟΥ ΣΧΕΤΙΖΟΝΤΑΙ ΜΕ ΤΙΣ ΣΥΓΚΕΝΤΡΩΣΕΙΣ ΤΩΝ ΠΕΡΙΟΡΙΣΤΙΚΩΝ ΘΡΕΠΤΙΚΩΝ ΣΤΟΙΧΕΙΩΝ ΣΤΟΥΣ ΙΣΤΟΥΣ ΤΟΥΣ, (II) ΔΙΑΦΕΡΟΥΝ ΣΤΗΝ ΚΑΤΑΝΟΜΗ ΤΟΥ ΕΝΕΡΓΟΥ ΡΙΖΙΚΟΥ ΣΥΣΤΗΜΑΤΟΣ ΜΕ ΤΟ ΒΑΘΟΣ ΤΟΥ ΕΔΑΦΟΥΣ ΚΑΙ ΑΝ ΑΥΤΗ Η ΚΑΤΑΝΟΜΗ ΕΠΗΡΕΑΖΕΤΑΙ ΑΠΟ ΤΗΝ ΠΡΟΣΘΗΚΗ ΤΩΝ ΠΕΡΙΟΡΙΣΤΙΚΩΝ ΘΡΕΠΤΙΚΩΝ ΣΤΟΙΧΕΙΩΝ ΚΑΙ(III) ΕΚΔΗΛΩΝΟΥΝ ΤΗΝ ΦΑΙΝΟΛΟΓΙΑ ΤΟΥΣ ΣΥΜΦΩΝΑ ΜΕ ΤΑ ΟΡΙΑ ΑΝΟΧΗΣ ΤΟΥΣ ΣΤΗΝ ΞΗΡΑΣΙΑ. ΣΕ ΠΕΔΙΝΟ ΟΞΙΝΟ ΚΑΙ ΑΓΟΝΟ ΠΟΟΛΙΒΑΔΟ ΜΕ ΜΕΓΑΛΟ ΑΡΙΘΜΟ ΕΙΔΩΝ ΤΟ Ν ΕΥΝΟΗΣΕ ΤΑ ΠΡΩΙΜΩΣ ΑΝΑΠΤΥΣΣΟΜΕΝΑ ΕΤΗΣΙΑ Η ΔΙΕΤΗ ΑΓΡΩΣΤΩΔΗ ΚΑΙ Ο Ρ ΤΑ ΨΥΧΑΝΘΗ. ΟΙ ΕΠΙΔΡΑΣΕΙΣ ΗΤΑΝ ΕΝΤΟΝΟΤΕΡΕΣ ΟΤΑΝ ΟΙ ΒΡΟΧΕΣ ΣΤΗ ΠΕΡΙΟΔΟ ΑΥΞΗΣΕΩΣ ΤΩΝ ΦΥΤΩΝ ΗΤΑΝ ΕΠΑΡΚΕΙΣ. Η ΣΧΕΤΙΚΗ ΑΦΘΟΝΙΑ ΤΩΝ ΕΙΔΩΝ ΒΡΕΘΗΚΕ ΝΑ ΕΙΝΑΙ ΑΡΝΗΤΙΚΗ ΜΕ ΤΙΣ ΣΥΓΚΕΝΤΡΩΣΕΙΣ ΤΩΝ ΕΙΔΩΝ ΣΕ Ν ΚΑΙ Ρ. Η ΠΡΟΣΘΗΚΗ ΤΟΥ Ν ΚΑΙ Ρ ΕΥΝΟΗΣΕ ΑΝΑΛΟΓΙΚΑ ΠΕΡΙΣΣΟΤΕΡΟΤΑ ΕΙΔΗ ΜΕ ΤΙΣ ΥΨΗΛΟΤΕΡΕΣ ΣΥΓΚΕΝΤΡΩΣΕΙΣ Ν ΚΑΙ Ρ, ΑΝΤΙΣΤΟΙΧΑ. Η ΕΚΔΗΛΩΣΗ ΤΗΣ ΦΑΙΝΟΛΟΓΙΑΣ ΣΕ ΠΕΝΤΕ ΑΠΟ ΤΑ ΑΦΘΟΝΟΤΕΡΑ ΕΙΔΗ ΣΤΗΝ ΠΕΡΙΟΧΗ ΣΧΕΤΙΖΟΝΤΑΝ ΜΕ ΤΗΝ ΑΝΟΧΗ ΤΟΥΣ ΣΤΗ ΞΗΡΑΣΙΑ. Η ΔΡΑΣΤΗΡΙΟΤΗΤΑ ΤΩΝ ΡΙΖΩΝ ΣΥΝΥΠΑΡΧΟΝΤΩΝ ΕΙΔΩΝ ΕΚΤΙΜΗΘΗΚΕ ΜΕ ΠΡΟΣΘΗΚΕΣ SR, CS ΚΑΙ LI ΣΕ ΒΑΘΗ 5 ΚΑΙ 15 CM ΣΕ ΟΡΕΙΝΟ ΠΟΟΛΙΒΑΔΟ ΣΕ ΤΕΣΣΕΡΙΣ ΜΕΤΑΧΕΙΡΙΣΕΙΣ ΠΡΟΣΘΗΚΗΣ Ν ΚΑΙ Ρ ΕΠΙ ΔΥΟ ΕΤΗ. ΟΙ ΕΚΤΙΜΗΣΕΙΣ ΤΗΣ ΔΡΑΣΤΗΡΙΟΤΗΤΑΣ ΤΟΥ ΡΙΖΙΚΟΥ ΣΥΣΤΗΜΑΤΟΣ ΜΕ SR ΚΑΙ CS ΕΔΩΣΑΝ ΠΑΡΟΜΟΙΑ ΑΠΟΤΕΛΕΣΜΑΤΑ ΤΑ ΟΠΟΙΑ ΔΙΕΦΕΡΑΝ ΣΕ ΚΑΠΟΙΟ ΒΑΘΜΟ ΑΠΟ ΤΑ ΑΝΤΙΣΤΟΙΧΑ ΤΟΥ LI. ΤΟ ΒΑΘΟΣ ΜΕΧΡΙ ΤΟΥ ΟΠΟΙΟΥ ΔΡΑΣΤΗΡΙΟΠΟΙΟΥΝΤΑΝ ΟΙ ΡΙΖΕΣ ΔΙΕΦΕΡΕ ΣΤΑ ΣΥΝΥΠΑΡΧΟΝΤΑ ΕΙΔΗ ΚΑΙ ΓΙΑ ΟΡΙΣΜΕΝΑ ΕΙΔΗ ΔΙΑΦΟΡΟΠΟΙΗΘΗΚΕ ΣΤΙΣ ΔΙΑΦΟΡΕΣ ΜΕΤΑΧΕΙΡΙΣΕΙΣ ΠΡΟΣΘΗΚΗΣ Ν ΚΑΙ Ρ. (ΠΕΡΙΚΟΠΗ ΠΕΡΙΛΗΨΗΣ

The Use of Crop Yield Autocorrelation Data as a Sustainable Approach to Adjust Agronomic Inputs

Agricultural fields have natural within-field soil variations that can be extensive, are usually contiguous, and are not always traceable. As a result, in many cases, site-specific attention is required to adjust inputs and optimize crop performance. Researchers, such as agronomists, agricultural engineers, or economists and other scientists, have shown increased interest in performing yield monitor data analysis to improve farmers’ decision-making concerning the better management of the agronomic inputs in the fields, while following a much more sustainable approach. In this case, spatial analysis of crop yield data with the form of spatial autocorrelation analysis can be used as a practical sustainable approach to locate statistically significant low-production areas. The resulted insights can be used as prescription maps on the tractors to reduce overall inputs and farming costs. This aim of this work is to present the benefits of conducting spatial analysis of yield crop data as a sustainable approach. Current work proves that the implementation of this process is costless, easy to perform and provides a better understanding of the current agronomic needs for better decision-making within a short time, adopting a sustainable approach