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

MANIPULATIONS OF STRAW AND ALLELOPATHY IN AGROECOSYSTEMS OF WHEAT (TRITICUM AESTIVUM L. EM. TELL) AND FABABEANS (VICIA FABA. L.).

THE RATE OF DECOMPOSITION AND NUTRIENT RELEASE IN DECOMPOSING WHEAT AND FABABEAN STRAW BURIED IN THE SOIL, WERE STUDIED FOR 2.5 YEARS (JANUARY 1984-JULY 1986). THE RATE OF BIOMASS LOSS OF BOTH SPECIES WAS CONSTANT. THE PROPORTION OF ORGANIC MATTER IN THE UNDECOMPOSED BIOMASS WAS STEADILY REDUCED WITH TIME: TOTAL N AND P WERE REDUCED TOWARDS THE END OF THE EXPERIMENTS BUT NOT SIGNIFICANTLY. THE CIN RATIO OF BIOMASS WAS REDUCED WITH TIME. THE RATE OF K AND MG RELEASE WAS HIGHER DURING THE RAINING PERIOD THAN DURING THE DRY ONES. THE RATE OF CA RELEASE WAS SIGNIFICANT ONLY IN FABABEAN STRAW AND WAS NOT AFFECTED BY RAINFALL. TWOMANIPULATIONS OF STRAW, NAMELY, SOIL INCORPORATION AND BURNING, WERE STUDIED AS REGARDS THEIR EFFECTS ON WHEAT AND FABABEAN GROWTH. EXPERIMENTS WERE CARRIED OUT IN THE FIELD (1983-1986) AND IN THE GLASSHOUSE (1983). FIELD EXPERIMENTS SHOWED THAT STRAW INCORPORATION DID NOT INFLUENCE WHEAT GROWTH, WHILE STRAW BURNING EITHER REDUCED OR TENDED TO REDUCE WHEAT GROWTH. WHEAT GROWTH WAS DECREASED BY ADDITION OF STRAW IN POTS, WHILE STRAW BURNING INCREASED IT. ON GENERAL, FABABEANS WERE NOT AFFECTED BY ANY OF THE TREATMENTS APPLIED. IN LABORATORY AND GLASSHOUSE EXPERIMENTS, THE EFFECT OF EXTRACTS FROM WHEAT AND FABABEAN STRAW, FOLLIAGE, SEEDS, AS WELL AS OF ROOT EXUDATES WAS TESTED ON SEED GERMINATION, SEEDLING AND PLANT GROWTH OF BOTH SPECIES, USING DIFFERENT CULTURE MEDIA. EXTRACTS FROM STRAW AND FOLLIAGE, AS WELL AS ROOT EXUDATES REDUCED SEED GERMINATION, SEEDLING AND PLANT GROWTH. THE EFFECT WAS LESS PRONOUNCED AS THE GROWTH MEDIUM BECAUSE MORE COMPLEX AND ACTIVE.ΜΕΛΕΤΗΘΗΚΕ Ο ΡΥΘΜΟΣ ΑΠΟΚΟΔΟΜΗΣΗΣ ΤΟΥ ΑΧΥΡΟΥ ΔΥΟ ΦΥΤΙΚΩΝ ΕΙΔΩΝ, (ΣΙΤΑΡΙΟΥ ΚΑΙ ΚΟΥΚΙΩΝ) ΚΑΘΩΣ ΚΑΙ Ο ΡΥΘΜΟΣ ΕΛΕΥΘΕΡΩΣΗΣ ΘΡΕΠΤΙΚΩΝ ΣΤΟΙΧΕΙΩΝ ΟΤΑΝ ΑΥΤΟ ΑΝΑΜΙΓΝΥΕΤΑΙ ΜΕ ΤΟ ΕΔΑΦΟΣ. Ο ΠΕΙΡΑΜΑΤΙΣΜΟΣ ΕΓΙΝΕ ΣΤΟ ΧΩΡΑΦΙ ΚΑΙ ΔΙΗΡΚΕΣΕ 2,5 ΕΤΗ (ΙΑΝΟΥΑΡΙΟΣ 1984-ΙΟΥΛΙΟΣ 1986). ΤΟ ΞΗΡΟ ΒΑΡΟΣ ΤΟΥ ΑΧΥΡΟΥ ΤΩΝ ΔΥΟ ΦΥΤΙΚΩΝ ΕΙΔΩΝ ΜΕΙΩΝΟΤΑΝΣΤΑΘΕΡΑ ΜΕ ΤΟ ΧΡΟΝΟ. ΣΤΑΘΕΡΟΣ ΗΤΑΝ ΚΑΙ Ο ΡΥΘΜΟΣ ΜΕΙΩΣΗΣ ΤΗΣ ΟΡΓΑΝΙΚΗΣ ΟΥΣΙΑΣ ΩΣ ΠΟΣΟΣΤΟΥ ΤΗΣ ΜΗ ΑΠΟΙΚΟΔΟΜΟΥΜΕΝΗΣ ΒΙΟΜΑΖΑΣ. ΤΟ ΟΛΙΚΟ Ν ΚΑΙ Ο Ρ ΔΕΝ ΕΠΗΡΕΑΣΘΗΚΑΝ ΑΠΟ ΤΟ ΧΡΟΝΟ. Ο ΛΟΓΟΣ 4Ν ΜΕΙΩΝΟΤΑΝ ΜΕ ΤΟ ΧΡΟΝΟ. ΣΤΟ Κ ΚΑΙ MG Ο ΡΥΘΜΟΣ ΕΛΕΥΘΕΡΩΣΗΣ ΠΟΙΚΙΛΛΕ . ΗΤΑΝ ΥΨΗΛΟΤΕΡΟΣ ΣΤΙΣ ΠΕΡΙΟΔΟΥΣ ΒΡΟΧΟΠΤΩΣΕΩΝ. ΣΤΟ ΟΛΙΚΟ CA Η ΜΕΙΩΣΗ ΗΤΑΝ ΣΗΜΑΝΤΙΚΗ ΜΟΝΟ ΣΤΟ ΑΧΥΡΟ ΤΩΝ ΚΟΥΚΙΩΝ. ΜΕΛΕΤΗΘΗΚΕ Η ΕΠΙΔΡΑΣΗ ΤΩΝ ΔΥΟ ΧΕΙΡΙΣΜΩΝ ΤΟΥ ΑΧΥΡΟΥ (ΕΝΣΩΜΑΤΩΣΗ ΣΤΟ ΕΔΑΦΟΣ ΚΑΨΙΜΟ) ΣΤΙΣ ΚΑΛΛΙΕΡΓΕΙΕΣ ΠΟΥ ΑΚΟΛΟΥΘΟΥΝ. Ο ΠΕΙΡΑΜΑΤΙΣΜΟΣ ΕΓΙΝΕ ΣΤΟ ΧΩΡΑΦΙ (1983-1986) ΚΑΙ ΣΤΟ ΘΕΡΜΟΚΗΠΙΟ (1983). ΟΙΠΟΣΟΤΗΤΕΣ ΤΟΥ ΑΧΥΡΟΥ ΠΟΥ ΕΝΣΩΜΑΤΩΘΗΚΑΝ ΑΚΑΦΤΕΣ ΜΕ ΤΟ ΕΔΑΦΟΣ ΜΕΙΩΣΑΝ ΤΙΣ ΑΠΟΔΟΣΕΙΣ ΤΟΥ ΣΙΤΑΡΙΟΥ ΣΤΙΣ ΓΛΑΣΤΡΕΣ, ΕΝΩ ΟΤΑΝ ΚΑΙΓΟΝΤΑΝ ΟΙ ΑΠΟΔΟΣΕΙΣ ΑΥΞΑΝΟΥΝ. ΤΑ ΚΤΗΝΟΤΡΟΦΙΚΑ ΚΟΥΚΙΑ ΔΕΝ ΕΠΗΡΕΑΣΤΗΚΑΝ ΑΠΟ ΚΑΜΙΑ ΑΠΟ ΤΙΣ ΕΠΕΜΒΑΣΕΙΣ ΠΟΥ ΔΟΚΙΜΑΣΘΗΚΑΝ. ΤΕΛΟΣ, ΜΕΛΕΤΗΘΗΚΕ Η ΑΛΛΗΛΟΠΑΘΕΙΑ ΜΕΤΑΞΥ ΤΩΝ ΔΥΟ ΦΥΤΙΚΩΝ ΕΙΔΩΝ ΟΠΩΣ ΕΚΔΗΛΩΝΕΤΑΙ ΜΕ ΤΙΣ ΑΝΑΣΤΑΛΤΙΚΕΣ ΕΠΙΔΡΑΣΕΙΣ ΣΤΟ ΦΥΤΡΩΜΑ ΤΩΝ ΣΠΟΡΩΝ ΚΑΙ ΤΗΝ ΑΥΞΗΣΗ ΤΩΝ ΑΡΤΙΒΛΑΣΤΩΝ. Ο ΠΕΙΡΑΜΑΤΙΣΜΟΣ ΕΓΙΝΕ ΥΠΟ ΕΛΕΓΧΟΜΕΝΕΣ ΣΥΝΘΗΚΕΣ (1983) ΤΑ ΕΚΧΥΛΙΣΜΑΤΑ ΑΠΟ ΤΑ ΔΙΑΦΟΡΕΤΙΚΑ ΜΕΡΗ ΤΩΝ ΔΥΟ ΦΥΤΙΚΩΝ ΕΙΔΩΝ ΕΠΗΡΕΑΣΑΝ ΤΟ ΠΟΣΟΣΤΟ ΦΥΤΡΩΤΙΚΟΤΗΤΑΣ ΚΑΙ ΤΗΝ ΑΥΞΗΣΗ ΤΩΝ ΑΡΤΙΒΛΑΣΤΩΝ. Η ΔΡΑΣΗ ΤΩΝ ΕΚΧΥΛΙΣΜΑΤΩΝ ΗΤΑΝ ΕΝΤΟΝΟΤΕΡΑ ΣΤΑΑΔΡΑΝΗ ΜΕΣΑ ΣΤΗΡΙΞΗΣ

Effects of sericea lespedeza residues on warm-season grasses

Soil incorporation of sericea lespedeza [Lespedeza cuneata (Dum. de Cours) G. Don.] residues has been reported to inhibit growth of some forage grasses. No information is available on the performance of sericea lespedeza grown in association with warm-season perennial grasses. Laboratory and greenhouse experiments were conducted to determine if sericea lespedeza residues affect seed germination and seedling growth of bermudagrass [Cynodon dactylon (L.) Pers.] and bahiagrass (Paspalum notatum Flugge); if any such response was cultivar dependent; and if the response was subject to manipulation by N fertilization. Sericea lespedeza residues inhibited bermudagrass and bahiagrass growth, but did not affect their seed germination and emergence. No differences among cultivars of bermudagrass and bahiagrass in response to sericea lespedeza residues were found in the greenhouse. Nevertheless, differences among bermudagrass cultivars for tolerance to sericea lespedeza residues were observed in the laboratory. The harmful effects of sericea lespedeza residues were small (17 and 16% reduction of dry weight for bermudagrass and bahiagrass, respectively) compared to the positive effects of N fertilization.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Effects of sericea lespedeza root exudates on some perennial grasses

Root exudates are substances released into the surrounding medium by healthy and intact plant roots. Research on root exudates has shown that root exudates can reduce seed germination and plant growth. There is no information on the effect of sericea lespedeza [Lespedeza cuneata (Dum. de Cours) G. Don.] root exudates on other plants. In a series of greenhouse experiments we studied (1) if sericea root exudates affect seed germination and seedling growth of the perennial grasses tall fescue (Festuca arundinacea Schreb.), bermudagrass [Cynodon dactylon (L.) Pers.], and bahiagrass (Paspalum notatum Flugge); and (2) if any such responses were cultivar dependent. The effects of the root exudates were measured in 2 experiments. In the first one, coarse perlite was used as a medium to measure seed germination and radicle and coleoptile growth. In the second experiment, soil was used as a medium to measure emergence and biomass. Root exudates from sericea lespedeza had no effect on germination and emergence of tall fescue and bahiagrass but reduced their radicle and coleoptile length and biomass. Germination, radicle, and coleoptile length, and emergence of bermudagrass decreased when exposed to the root exudates; however, biomass was not affected. Cultivars of the grass species differed in their response to the root exudates of sericea lespedeza. Thus, establishment of tall fescue in mixture with sericea lespedeza is not likely to be affected; however, its growth is likely to be decreased. Therefore, tall fescue contribution to total yield will be reduced. Conversely, establishment of bermudagrass is likely to be affected, but once established, its growth is expected to be similar to its grown alone.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Effects of sericea lespedeza residues on cool-season grasses

Incorporation of crop residues into the soil prior to planting has been shown to reduce the growth of subsequent crops. Information is limited on the allelopathic effect of sericea lespedeza [Lespedeza cuneata (Dum. Cours) G. Don.] residues on multiple cropping and rotational systems. Experiments were conducted to determine (1) if sericea lespedeza residues affected seed germination and plant growth of rye (Secale cereale L.), ryegrass (Lolium multiflorum Lam.), and tall fescue (Festuca arundinacea Schreb.); (2) if cultivars of these species varied in response to phytotoxins from sericea lespedeza residues; and (3) if N fertilization nullified the effects of residues. Germination experiments were conducted by using water extracts from low- or high-tannin sericea lespedeza residues, distilled water (control), and topsoil and subsoil obtained from areas in which low- or high-tannin sericea lespedeza plants had grown for 4 years. Greenhouse experiments showed that germination, emergence, seedling growth, above-ground biomass, and N concentration of rye and tall fescue were reduced by sericea lespedeza residues. Although ryegrass germination was not affected by the residues, biomass and N concentration were reduced. Rye and tall fescue germination were not affected by soils where sericea lespedeza previously had grown, but ryegrass germination and seedling growth of all 3 species were reduced. Immobilized N was the main factor limiting plant growth. Fertilizer-N more than compensated for the negative effects of the residues on all species. Establishment of rye and tall fescue in a sericea lespedeza field is likely to require higher seeding rates than normal to compensate for reduced germination, whereas ryegrass would not be affected. Fertilizer-N may be needed to enhance growth of grasses that otherwise would be curtailed by sericea lespedeza residues.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Effects of Organic Farming on Winter Plant Composition, Cover and Diversity in Olive Grove Ecosystems in Central Greece

The present study aimed to assess the effects of organic farming in comparison with conventional on plant composition, plant cover (%), diversity [species richness, Shannon, Simpson, and evenness (Pielou's) indexes] and investigate and describe the relations among plant species richness, plant cover, indexes, and soil parameters (pH and temperature) in olive grove ecosystems during the winter. Organic olive groves had significantly greater values of cover, species richness, and Shannon and Simpson indexes than the conventional ones. Plant species richness was positively correlated to plant cover and Shannon and Simpson indexes but negatively correlated to evenness index for both farming system. Finally, plant cover was positively correlated to the Shannon and Simpson indexes for both farming systems. According to principal component analysis (PCA), for axis 1, positive correlation was detected among the plant species richness, soil temperature, and Shannon and Simpson diversity indexes, whereas for axis 2, negative correlation was detected between plant cover and soil pH. It can be concluded that the organic management system enhances herbaceous plant cover and diversity (species richness, Shannon and Simpson indexes) in olive grove ecosystems during the winter

Energy budget in organic and conventional olive groves

An energy analysis, combined with an economic one, in conventional and organic olive groves is useful in evaluating present situation and deciding best management strategies. The objective of this study was to evaluate the differences in the energy budget between organic and conventional olive groves in three locations in the island of Thasos and to calculate CO2-emissions based on the used fossil energy. The data were collected through personal interviews with farmers during 2000-2003. Twenty-four farmers, who owned olive groves about I ha each, were randomly selected to participate in this study [(4 conventional and 4 organic) x 3 locations]. The means averaged over all locations for fertilizer application energy was significantly higher in conventional than in organic olive groves, while the opposite occurs for insect trapping energy. Means averaged over the two farming systems for weed control energy were significantly higher in the northeastern part of the island, followed by the northwestern and southern part. The means averaged over all locations for labor and fertilizers energy were significantly higher in conventional than in organic olive groves, while the opposite was observed for tools energy. Means averaged over the two farming systems for labor and tools energy were significantly higher in the northwestern part of the island. Means averaged over the two farming systems for electric and pesticides energy were significantly higher in the northwestern part of the island. Total energy inputs were not affected by any of the studied parameters, while outputs were affected by the location, by the farming system and their interaction. Outputs in the northeastern part of the island and production in all parts of the island were significantly lower in organic than in conventional olive groves. Outputs and production were lower in the southern part of the island than in the other parts, since olive groves in southern Thasos are located in slopes with less productive soils. The results show a clear response of energy inputs to energy outputs that resulted from the farming system and location. Global warming potential and CO2-emissions were not affected by the farming system and location. Organic olive groves tended to have lower CO2-emissions caused by the different uses of fossil energy. (C) 2007 Elsevier B.V. All rights reserved