Current trends in agriculture are focused on implementing sustainable practices that avoid the use of chemical compounds. It is important to propose environmentally friendly methods, which may enhance plant growth physiology and yield without affecting soil microbial community as much. In this context, irrigation with ozonated water could be a potential strategy to reduce some chemical compounds in soils due to the degradative power of ozone.
View Article and Find Full Text PDFIrrigation with desalinated seawater (DSW) is a potential solution for addressing water scarcity in semiarid regions across the globe. However, this strategy may compromise the health of agricultural ecosystems due to the high content of phytotoxic elements (mainly boron, B) in this water. Here, a three-year experiment was carried to evaluate the response of the soil's physicochemical and microbiological properties, and plant physiology, to three irrigation water treatments (DSW; fresh water, FW; and their blend (1:1), BW) in the presence or not of organic amendments.
View Article and Find Full Text PDFOzone has been applied in many processes (drinking water disinfection and wastewater treatment, among others) based on its high degree of effectiveness as a wide-spectrum disinfectant and its potential for the degradation of pollutants and pesticides. Nevertheless, the effects of irrigation with ozonated water on the soil microbial community and plant physiology and productivity at the field scale are largely unknown. Here, we assessed the impact of irrigation with ozonated water on the microbial community of a Mediterranean soil and on Solanum lycopersicum L.
View Article and Find Full Text PDFspecies can form ectomycorrhizae and arbuscular mycorrhizal fungus that can bring benefits when plants are under water stress conditions. However, the application of some ectomycorrhizae on the water uptake under drought through physiological traits and hormonal regulation is less known. The experiment was performed during three months in a growth chamber with plants in which the combined effect of the ectomycorrhiza inoculation and two irrigation treatments (control and water-stressed plants) were applied.
View Article and Find Full Text PDFClimate change is one of the main challenges facing the agricultural sector as it strives to meet global food needs. In arid and semiarid areas, the scarcity of water imposes the use of alternative sources - such as reclaimed water (RW) or desalinated water (DW) - and of deficit irrigation strategies, such as regulated deficit irrigation (RDI), in order to maintain productivity. The impact of both alternative water sources and RDI strategies on soil microbial communities in conjunction with the crop response has been little studied, and far less in fruit trees.
View Article and Find Full Text PDFPesticides have been used extensively in agriculture to control pests and soil-borne diseases. Most of these pesticides can persist in soil in harmful concentrations due to their intrinsic characteristics and their interactions with soil. Soil solarization has been demonstrated to enhance pesticide degradation under field conditions.
View Article and Find Full Text PDFThe 70% worldwide surface of olive orchards is irrigated. The evaluation of non-conventional water resources and water-saving techniques has gained importance during the last decades in arid and semiarid environments. This study evaluated the effects of irrigation with two water sources: low-cost water DEsalination and SEnsoR Technology (DESERT) desalinated water (DW) EC ∼1 dS m) and reclaimed water (RW) (EC ∼ 3 dS m) combined with two irrigation strategies: full irrigation (FI) (100% of ET) and regulated deficit irrigation (RDI, 50% of ET) on fruit yield, ripening indices, and oil yield and quality of olive trees cv Arbosana planted in Mediterranean conditions.
View Article and Find Full Text PDFBackground: Non-conventional water sources and water-saving techniques can be valuable in semi-arid regions, although their long-term effects on citrus quality are little known. This study evaluated the effects of irrigation with two sources, transfer water (TW) and reclaimed water (RW), combined with two irrigation strategies, full irrigation (FI) and regulated deficit irrigation (RDI), on fruit quality of mandarins and grapefruits during eight growth seasons.
Results: Reclaimed water irrigation in mandarin, without water restriction, influenced maturity index (MI) less than TW-FI, because titratable acidity (TA) increased to a greater degree than soluble solid contents (SSC).
Warmer and drier conditions associated with ongoing climate change will increase abiotic stress for plants and mycorrhizal fungi in drylands worldwide, thereby potentially reducing vegetation cover and productivity and increasing the risk of land degradation and desertification. Rhizosphere microbial interactions and feedbacks are critical processes that could either mitigate or aggravate the vulnerability of dryland vegetation to forecasted climate change.We conducted a four-year manipulative study in a semiarid shrubland in the Iberian Peninsula to assess the effects of warming (~2.
View Article and Find Full Text PDFClimate change models point to a decrease in water availability in semiarid areas that would compromise the maintenance of sustainable agriculture. Here, we used a grapefruit agroecosystem model to evaluate the responses of the active soil microbial community - as a microbial subset directly involved in soil functionality- undergoing strategies to cope with the low water availability in south-east Spain. For this purpose, we tested the impacts of: (i) water quality: transfer-water from a river (TW) or reclaimed-water from a wastewater-treatment plant (RW); and (ii) water quantity: continuous optimal amount of water or reduced irrigation (RDI) in the temporal frame when the crop is less sensitive; and their interactions.
View Article and Find Full Text PDFWhereas warming enhances plant nutrient status and photosynthesis in most terrestrial ecosystems, dryland vegetation is vulnerable to the likely increases in evapotranspiration and reductions in soil moisture caused by elevated temperatures. Any warming-induced declines in plant primary production and cover in drylands would increase erosion, land degradation, and desertification. We conducted a four-year manipulative experiment in a semi-arid Mediterranean ecosystem to evaluate the impacts of a ~2°C warming on the photosynthesis, transpiration, leaf nutrient status, chlorophyll content, isotopic composition, biomass growth, and postsummer survival of the native shrub Helianthemum squamatum.
View Article and Find Full Text PDFBackground And Aims: Water deficit is the most serious environmental factor limiting agricultural production. In this work, the tolerance to water stress (WS) of transgenic plum lines harbouring transgenes encoding cytosolic antioxidant enzymes was studied, with the aim of achieving the durable resistance of commercial plum trees.
Methods: The acclimatization process was successful for two transgenic lines: line C3-1, co-expressing superoxide dismutase (two copies) and ascorbate peroxidase (one copy) transgenes simultaneously; and line J8-1, harbouring four copies of the cytosolic ascorbate peroxidase gene (cytapx).
We have performed the isolation, functional characterization, and expression analysis of aquaporins in roots and leaves of Helianthemum almeriense, in order to evaluate their roles in tolerance to water deficit. Five cDNAs, named HaPIP1;1, HaPIP1;2, HaPIP2;1, HaPIP2;2, and HaTIP1;1, were isolated from H. almeriense.
View Article and Find Full Text PDFVariation in the stable carbon and oxygen isotope composition (δ13C, Δ18O) of co-occurring plant species may reflect the functional diversity of water use strategies present in natural plant communities. We investigated the patterns of water use among 10 coexisting plant species representing diverse taxonomic groups and life forms in semiarid southeast Spain by measuring their leaf δ13C and Δ18O, the oxygen isotope ratio of stem water and leaf gas exchange rates. Across species, Δ18O was tightly negatively correlated with stomatal conductance (gs), whereas δ13C was positively correlated with intrinsic water use efficiency (WUEi).
View Article and Find Full Text PDFWe investigated whether stand structure modulates the long-term physiological performance and growth of Pinus halepensis Mill. in a semiarid Mediterranean ecosystem. Tree radial growth and carbon and oxygen stable isotope composition of latewood (δ(13)C(LW) and δ(18)O(LW), respectively) from 1967 to 2007 were measured in P.
View Article and Find Full Text PDFSilvicultural thinning usually improves the water status of remaining trees in water-limited forests. We evaluated the usefulness of a dual stable isotope approach (δ¹³C, δ¹⁸O) for comparing the physiological performance of remaining trees between forest stands subjected to two different thinning intensities (moderate versus heavy) in a 60-year-old Pinus halepensis Mill. plantation in semiarid southeastern Spain.
View Article and Find Full Text PDFThe use of regulated deficit irrigation (RDI) strategies is becoming a common practice in areas with low water availability. Little information is available about the effects of RDI on the antioxidant content of fruits. In this study, the influence of RDI on the content of vitamin C, phenolic compounds and carotenoids was investigated.
View Article and Find Full Text PDFSeedlings of Lycopersicon esculentum Mill. var. Amalia were grown in a growth chamber under a photoperiod of 16 h light at 25 degrees C and 8 h dark at 20 degrees C.
View Article and Find Full Text PDFThis study tests the hypothesis that diffusional limitation of photosynthesis, rather than light, determines the distribution of photosynthetic capacity in olive leaves under drought conditions. The crowns of four olive trees growing in an orchard were divided into two sectors: one sector absorbed most of the radiation early in the morning (MS) while the other absorbed most in the afternoon (AS). When the peak of radiation absorption was higher in MS, air vapour pressure deficit (VPD) was not high enough to provoke stomatal closure.
View Article and Find Full Text PDFThe experiment was carried out in a research field near Murcia, Spain, over a 3-week period between September 26 and October 16, 2000. Sixteen trees were used in the experiment, eight of which were placed under a rectangular shading net, while the other eight were maintained in the open air. Trees were irrigated once per day and, after October 5th, water was witheld from eight trees (four shaded and four unprotected for 5 days).
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