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1.
J Agric Food Chem ; 68(8): 2316-2328, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-31995376

RESUMO

The climate change is already affecting many agricultural systems and human environments, and the implementation of adaptation strategies, especially those related to irrigated agriculture in semiarid regions, is urgent. In this regard, deep knowledge about the effects that irrigation has on the food quality parameters will allow us to estimate the potential benefits of deficit irrigation (DI) strategies. This work presents the effects on the quality parameters of three almond cultivars (Marta, Guara, and Lauranne) subjected to three irrigation doses: (i) full-irrigated treatment (FI) at 100% crop evapotranspiration (ETC), (ii) an overirrigated treatment at 150% ETC (150% ETC), and (iii) regulated deficit irrigation (RDI65) treatment, in which irrigation was done as in FI, expect during the kernel-filling period when this treatment received 65% ETC. According to experimental findings, the cultivar most sensitive to water stress was Marta, having the most significant improvements for RDI65. In general, the effects of the irrigation dose on the morphological and physicochemical parameters were not huge but some improvements were observed in key parameters such as the color and contents of specific sugars, organic acids, and unsaturated fatty acids. Thus, it can be concluded that the irrigation dose did not drastically affect the fruit almond quality, although it is possible to improve several key parameters when a moderate RDI strategy is applied.


Assuntos
Irrigação Agrícola/métodos , Nozes/química , Prunus dulcis/crescimento & desenvolvimento , Cor , Humanos , Nozes/crescimento & desenvolvimento , Nozes/metabolismo , Prunus dulcis/química , Prunus dulcis/metabolismo , Paladar , Água/análise , Água/metabolismo
2.
J Sci Food Agric ; 100(4): 1558-1569, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31769034

RESUMO

BACKGROUND: The increasing demand in Brazil and the world for products derived from the açaí palm (Euterpe oleracea Mart) has generated changes in its production process, principally due to the necessity of maintaining yield in situations of seasonality and climate fluctuation. The objective of this study was to estimate açaí fruit yield in irrigated system (IRRS) and rainfed system or unirrigated (RAINF) using agrometeorological models in response to climate conditions in the eastern Amazon. Modeling was done using multiple linear regression using the 'stepwise forward' method of variable selection. Monthly air temperature (T) values, solar radiation (SR), vapor pressure deficit (VPD), precipitation + irrigation (P + I), and potential evapotranspiration (PET) in six phenological phases were correlated with yield. The thermal necessity value was calculated through the sum of accumulated degree days (ADD) up to the formation of fruit bunch, as well as the time necessary for initial leaf development, using a base temperature of 10 °C. RESULTS: The most important meteorological variables were T, SR, and VPD for IRRS, and for RAINF water stress had the greatest effect. The accuracy of the agrometeorological models, using maximum values for mean absolute percent error (MAPE), was 0.01 in the IRRS and 1.12 in the RAINF. CONCLUSION: Using these models yield was predicted approximately 6 to 9 months before the harvest, in April, May, November, and December in the IRRS, and January, May, June, August, September, and November for the RAINF. © 2019 Society of Chemical Industry.


Assuntos
Irrigação Agrícola/métodos , Euterpe/crescimento & desenvolvimento , Brasil , Clima , Euterpe/química , Euterpe/metabolismo , Euterpe/efeitos da radiação , Frutas/química , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Frutas/efeitos da radiação , Conceitos Meteorológicos , Modelos Estatísticos , Estações do Ano , Luz Solar , Temperatura Ambiente , Água/análise , Água/metabolismo
3.
J Sci Food Agric ; 100(3): 1350-1357, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31617215

RESUMO

BACKGROUND: 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). Nevertheless, juice quality standards were satisfied. Regardless of the irrigation treatment (FI or RDI), a trend towards increasing fruit weight was also detected with RW. In grapefruit, its rootstock (Citrus macrophylla) enhanced salinity resilience with respect to the rootstock of mandarin ('Carrizo' citrange) and, hence, MI was not affected by RW. The RDI strategy, without saline stress (TW-RDI), increased, to a similar degree, both SSC and TA in mandarin fruit, not affecting the MI. In grapefruit, the water stress of RDI did improve the MI due to the TA did not change and SSC increased significantly, the TA did not change. The combination of both strategies, RW-RDI, decreased the MI only in some years because TA increased proportionally more than SSC in mandarin. CONCLUSIONS: The medium- and long-term feasibility of using RW and RDI to irrigate citrus was demonstrated. However, they must be performed cautiously and with appropriate management to avoid damaging fruit quality as a result of phytotoxic elements. © 2019 Society of Chemical Industry.


Assuntos
Irrigação Agrícola/métodos , Citrus/crescimento & desenvolvimento , Frutas/química , Água/metabolismo , Citrus/química , Citrus/metabolismo , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Águas Salinas/análise , Águas Salinas/metabolismo , Água/análise
4.
J Sci Food Agric ; 100(4): 1515-1523, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31756770

RESUMO

BACKGROUND: The effects of cluster thinning (TH) on Verdejo wine composition were studied. Cluster thinning was applied in three water regimes (WR) (R0, rainfed control; R25, drip-irrigated at 25% ETo, and R50, drip-irrigated at 50% ETo) during the 2012-2014 seasons. RESULTS: Cluster thinning advanced grape maturity, although this was only significant in 2012. A significant effect of TH on R0 was observed in 2013, the wettest season, increasing the concentration of alcohols, esters, acetates, and lactones. The same trend was shown in 2012 for all groups of volatile compounds in R0. In contrast, for all volatile families to increase was observed in 2014, the driest season, when TH was applied to R50. WR*TH interactions were found in most wine chemical parameters. CONCLUSION: The variation in wine volatile composition among the vintages that were observed shows that the capacity of TH to exert an influence depends not only on the water regime but also on annual conditions. © 2019 Society of Chemical Industry.


Assuntos
Irrigação Agrícola/métodos , Vitis/fisiologia , Água/metabolismo , Vinho/análise , Frutas/química , Frutas/crescimento & desenvolvimento , Frutas/fisiologia , Estações do Ano , Estresse Fisiológico , Vitis/química , Vitis/crescimento & desenvolvimento , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/metabolismo , Água/análise
5.
Chemosphere ; 240: 124911, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726614

RESUMO

The reuse of treated municipal wastewater (herein referred to as reclaimed water) in agricultural irrigation (RWAI) as a means to alleviate water scarcity is gaining increasing policy attention, particularly in areas where water demand mitigation measures have proved insufficient. However, reclaimed water reuse in practice is lagging behind policy ambition, with <2.5% of it reused in a European context. A key barrier identified as limiting its full valorisation is concern over its impact on human and environmental health. To address this concern, and to meet further objectives including achieving parity between current reclaimed water reuse guidelines operational in various Member States, the European Commission has proposed a regulation which identifies minimum quality requirements (MQR) for a range of microbiological and physico-chemical parameters but the inclusion of compounds of emerging concern (CECs) in terms of the determination of quality standards (QS) is missing. This paper reviews the existing pertinent EU legislation in terms of identifying the need for CEC QS for RWAI, considering the scope and remit of on-going pan-European chemicals prioritisation schemes. It also evaluates opportunities to link in with the existing EQS derivation methodology under the EU WFD to address all protection targets in the environmental compartments exposed via potential pathways of RWAI. Finally, it identifies the main data gaps and research needs for terrestrial ecosystems, the removal efficiency of CECs by WWTPs and transformation products generated during the wastewater reuse cycle.


Assuntos
Irrigação Agrícola/normas , Eliminação de Resíduos Líquidos/normas , Águas Residuárias/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/normas , Irrigação Agrícola/métodos , Ecossistema , Humanos , Eliminação de Resíduos Líquidos/métodos
6.
Sci Total Environ ; 698: 134025, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31493571

RESUMO

Contaminants in freshwater environments, as well as the associated negative impacts on agricultural produce, have emerged as a critical theme of the water-energy-food nexus affecting food safety and irrigation management. Agricultural produce exposed to irrigation with questionable freshwater can internalize and concentrate pollutants. However, the potential risks posed by the ubiquitous presence of biofilms within irrigation water distribution systems (IWDS) remains overlooked, even though such biofilms may harbor and spread pathogenic, chemical, and other environmental pollutants. Our limited knowledge about the role and functional attributes of IWDS biofilms can be blamed mostly to experimental challenges encountered during attempted studies of these biofilms in their natural environments. Hence, a laboratory-based experimental system designed to simulate a freshwater environment was combined with a biofilm reactor capable of recreating the piping environments in water distribution systems. This experimental system was then tested to assess the robustness and repeatability of experimental early-stage biofilms with respect to physical structure and microbial community, using state-of-the-art confocal microscopy and next-generation sequencing, respectively. The results demonstrated the suitability of this laboratory-based experimental system for studying the impacts of selected pollutants on irrigation water distribution systems.


Assuntos
Irrigação Agrícola/métodos , Biofilmes , Fazendas , Água Doce , Microbiologia da Água , Qualidade da Água
7.
Chemosphere ; 239: 124741, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31518921

RESUMO

In many parts of the world, wastewater irrigation has become a common practice because of freshwater scarcity and to increase resource reuse efficiency. Wastewater irrigation has positive impacts on livelihoods and at the same time, it has adverse impacts related to environmental pollution. Hydrochemical processes and groundwater behaviour need to be analyzed for a thorough understanding of the geochemical evolution in the wastewater irrigated systems. The current study focuses on a micro-watershed in the peri-urban Hyderabad of India, where farmers practice intensive wastewater irrigation. To evaluate the major factors that control groundwater geochemical processes, we analyzed the chemical composition of the wastewater used for irrigation and groundwater samples on a monthly basis for one hydrological year. The groundwater samples were collected in three settings of the watershed: wastewater irrigated area, groundwater irrigated area and upstream peri-urban area. The collected groundwater and wastewater samples were analyzed for major anions, cations and nutrients. We systematically investigated the anthropogenic influences and hydrogeochemical processes such as cation exchange, precipitation and dissolution of minerals using saturated indices, and freshwater-wastewater mixtures at the aquifer interface. Saturation indices of halite, gypsum and fluorite are exhibiting mineral dissolution and calcite and dolomite display mineral precipitation. Overall, the results suggest that the groundwater geochemistry of the watershed is largely controlled by long-term wastewater irrigation, local rainfall patterns and water-rock interactions. The study results can provide the basis for local decision-makers to develop sustainable groundwater management strategies and to control the aquifer pollution influenced by wastewater irrigation.


Assuntos
Irrigação Agrícola/métodos , Água Subterrânea/química , Águas Residuárias , Ânions/análise , Carbonato de Cálcio/química , Sulfato de Cálcio/química , Cátions/análise , Meio Ambiente , Monitoramento Ambiental/métodos , Água Doce/química , Água Subterrânea/análise , Hidrologia/métodos , Índia , Magnésio/química , Salinidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Qualidade da Água
8.
J Sci Food Agric ; 100(2): 682-694, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31583702

RESUMO

BACKGROUND: Cropping practices focusing on agronomic water use efficiency and their impact on quality parameters must be investigated to overcome constraints affecting olive groves. We evaluated the response of olive trees (Olea europaea, cv. 'Cobrançosa') to different water regimes: full irrigation (FI, 100% crop evapotranspiration (ETc )), and three deficit irrigation strategies (DIS) (regulated (RDI, irrigated with 80% of crop evapotranspiration (ETc ) in phases I and III of fruit growth and 10% of ETc in the pit hardening stage), and two continuous sustained strategies (SDI) - a conventional SDI (27.5% of ETc ), and low-frequency irrigation adopted by the farmer (SDIAF, 21.2% of ETc ). RESULTS: The effects of water regimes on the plant water status, photosynthetic performance, metabolite fluctuations and fruit quality parameters were evaluated. All DIS treatments enhanced leaf tissue density; RDI and SDI generally did not affect leaf water status and maintained photosynthetic machinery working properly, and the SDIAF treatment impaired olive tree physiological indicators. The DIS treatments maintained the levels of primary metabolites in leaves, but SDIAF plants showed signs of oxidative stress. Moreover, DIS treatments led to changes in the secondary metabolism, both in leaves and in fruits, with increased total phenolic compounds, ortho-diphenols, and flavonoid concentration, and higher total antioxidant capacity, as well higher oil content. Phenolic profiles showed the relevance of an early harvest in order to obtain higher oleuropein levels with associated higher health benefits. CONCLUSION: Adequate DIS are essential for sustainable olive growing, as they enhance the competitiveness of the sector in terms of olive production and associated quality parameters. © 2019 Society of Chemical Industry.


Assuntos
Irrigação Agrícola/métodos , Frutas/química , Olea/crescimento & desenvolvimento , Extratos Vegetais/química , Água/metabolismo , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Olea/química , Olea/metabolismo , Estresse Oxidativo , Fenóis/química , Fenóis/metabolismo , Fotossíntese , Extratos Vegetais/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Água/análise
9.
Chemosphere ; 238: 124988, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31645266

RESUMO

Over the past three decades, the occurrence of high concentrations of arsenic (As) in drinking-water and its subsequent poisoning in rice has been recognized as a major public-health concern globally, especially in Ganga Delta Plain with more than 80 million peoples in serious As exposure far beyond than its allowable limit. An extensive field study was conducted for consecutive four years viz. 2013 to 2016, introducing a process of intermittent irrigation pattern comparing to the conventional practice of rice cultivation in India. The practice provides a combination of aerobic and anaerobic irrigation resulting better rice productivity with lesser arsenic mobility and accumulation in rice grains. This present research finding clearly points out to the marked reduction of arsenic load from average 1.6 mg/kg to 0.5 mg/kg in rice grain, much closer to FAO/WHO prescribed safe limit and in the continuous practice of proposed agricultural strategy resulting in a gradual decrease of 15% bioavailable arsenic in each year. Total productivity (in kg/hectare) also increased by 540 kg/year in boro and 340 kg/year in amon subsequently achieving the prescribed safe limit of As in grain.


Assuntos
Arsênico/análise , Água Potável/química , Grão Comestível/química , Oryza/química , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Irrigação Agrícola/métodos , Índia , Abastecimento de Água
10.
Molecules ; 24(19)2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31590381

RESUMO

Three factors for the extraction of extra virgin olive oil (EVOO) were evaluated: diameter of the grid holes of the hammer-crusher, malaxation temperature, and malaxation time. A Box-Behnken design was used to obtain a total of 289 olive oil samples. Twelve responses were analyzed and 204 mathematical models were obtained. Olives from super-intensive rainfed or irrigated crops of the Arbequina, Koroneiki, and Arbosana cultivars at different stages of ripening were used. Malaxation temperature was found to be the factor with the most influence on the total content of lipoxygenase pathway volatile compounds; as the temperature increased, the content of volatile compounds decreased. On the contrary, pigments increased when the malaxation temperature was increased. EVOO from irrigated crops and from the Arbequina cultivar had the highest content of volatile compounds. Olive samples with a lower ripening degree, from the Koroneiki cultivar and from rainfed crops, had the highest content of pigments.


Assuntos
Olea/crescimento & desenvolvimento , Azeite de Oliva/análise , Compostos Orgânicos Voláteis/análise , Irrigação Agrícola/métodos , Manipulação de Alimentos , Lipoxigenase/metabolismo , Modelos Teóricos , Odorantes/análise , Olea/química , Olea/classificação , Olea/metabolismo , Azeite de Oliva/classificação , Fenóis/análise , Proteínas de Plantas/metabolismo , Temperatura Ambiente
11.
Ecotoxicol Environ Saf ; 185: 109711, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31574369

RESUMO

There have been no controlled systematic studies on the dynamic variation of As in soil - soil porewater - root surface (Fe plaques) - rice plant system under alternate wetting and drying (AWD) irrigation. Therefore, effects of continuous flooding (CF) and AWD treatments (2F2D: 2-day flooding followed by 2-day drying; 7F2D: 7-day flooding followed by 2-day drying) on the migration of As from soil to brown rice were studied. Results indicated that As contents in brown rice of AWD treatments (0.03-0.17 mg/kg) were 43.3%-85.0% lower than CF (0.20-0.30 mg/kg). AWD irrigation promoted the transformation of Fe and associated As in rhizosphere soil from highly active forms (H2O and HCl-extracted Fe-bound As) to stable states (oxalate and DCB-extracted Fe-bound As), which decreased the release of As from rhizosphere soil. The dynamic variation of As contents in porewater was described by a dissolution factor (DF) which decreased significantly in AWD treatments and had a significant positive correlation (R2 = 0.83; P < 0.05) with As contents in brown rice. In addition, contents of Fe and associated As on the root surface were about 17.1% and 11.0% higher in AWD treatments than in CF treatment, respectively, and the transfer factor (TF) of As from root surface into root was 22.7% lower in AWD treatments than in CF. In summary, AWD irrigation reduced As contents in porewater through decreasing availability of As in rhizosphere soil; and AWD also reduced the transfer of As into rice roots through promoting As sequestration by Fe plaques on root surface.


Assuntos
Irrigação Agrícola/métodos , Arsênico/análise , Oryza/crescimento & desenvolvimento , Rizosfera , Poluentes do Solo/análise , Solo/química , Arsênico/metabolismo , Oryza/metabolismo , Poluentes do Solo/metabolismo
12.
Nature ; 574(7776): 90-94, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31578485

RESUMO

Groundwater is the world's largest freshwater resource and is critically important for irrigation, and hence for global food security1-3. Already, unsustainable groundwater pumping exceeds recharge from precipitation and rivers4, leading to substantial drops in the levels of groundwater and losses of groundwater from its storage, especially in intensively irrigated regions5-7. When groundwater levels drop, discharges from groundwater to streams decline, reverse in direction or even stop completely, thereby decreasing streamflow, with potentially devastating effects on aquatic ecosystems. Here we link declines in the levels of groundwater that result from groundwater pumping to decreases in streamflow globally, and estimate where and when environmentally critical streamflows-which are required to maintain healthy ecosystems-will no longer be sustained. We estimate that, by 2050, environmental flow limits will be reached for approximately 42 to 79 per cent of the watersheds in which there is groundwater pumping worldwide, and that this will generally occur before substantial losses in groundwater storage are experienced. Only a small decline in groundwater level is needed to affect streamflow, making our estimates uncertain for streams near a transition to reversed groundwater discharge. However, for many areas, groundwater pumping rates are high and environmental flow limits are known to be severely exceeded. Compared to surface-water use, the effects of groundwater pumping are markedly delayed. Our results thus reveal the current and future environmental legacy of groundwater use.


Assuntos
Mapeamento Geográfico , Água Subterrânea/análise , Chuva , Rios/química , Movimentos da Água , Abastecimento de Água/métodos , Irrigação Agrícola/métodos , Organismos Aquáticos , Mudança Climática , Dessecação , Secas/estatística & dados numéricos , Ecossistema , Água Doce/análise , Internacionalidade , Modelos Teóricos
13.
Environ Sci Pollut Res Int ; 26(33): 34499-34509, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31646419

RESUMO

The effective water management in the North China Plain (NCP) needs a tool to predict winter wheat production due to water quality. A large quantity of brackish water is stored underground in this region, and whether this water can be used properly in agriculture is becoming a crucial issue that is about to be resolved. The SALTMED model is a generic modeling tool for efficient irrigation management strategies, especially for cyclic use of saline and fresh water as well as different water qualities, and it still needs further investigation for alternate irrigation using saline and fresh water at different growth stages of winter wheat. Therefore, the aim of this investigation was to evaluate the performance of SALTMED model and simulate the production of winter wheat grown under different irrigation strategies. Irrigation strategies comprised rain-fed cultivation (NI), fresh and saline water irrigation (FS), saline and fresh water irrigation (SF), saline water irrigation (SS), and fresh water irrigation (FF). Three-year observed data were used for the validations of SALTMED model. The values of evaluation indices of relative error, RMSE, NRMSE, index of agreement (D-index), and R2 between simulated and observed grain yield were 6.8%, 0.8, 10.7, 0.9, and 0.9, respectively. The model results supported and matched the observed data and indicated similar differences among the irrigated and rain-fed treatments. It is concluded that the SALTMED model is able to predict grain yield of winter wheat and its productivity under the alternate irrigation using saline and fresh water and their interaction in the climate condition of the NCP.


Assuntos
Agricultura/métodos , Triticum/metabolismo , Irrigação Agrícola/métodos , Biomassa , China , Grão Comestível/crescimento & desenvolvimento , Água Doce , Chuva , Estações do Ano , Triticum/crescimento & desenvolvimento , Água
14.
Ying Yong Sheng Tai Xue Bao ; 30(9): 3137-3144, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31529889

RESUMO

The objective of this study was to evaluate the effects and underlying physiological mecha-nisms of partial root zone irrigation (PRI) and rational close planting, as well as their interaction on yield and water productivity (WP) of cotton and to explore new alternatives of water-saving irrigation in dry land areas. A factorial field experiment with irrigation mode (normal irrigation, partial root-zone irrigation and deficient irrigation) and plant population density (135000, 180000 and 225000 plants·hm-2) was conducted in the west of Inner Mongolia to examine their effects on cotton growth, yield, water productivity and related physiological characters. The results showed that the irrigation mode and plant density as well as their interaction significantly affected the biomass, yield, yield components and harvest index. Under normal irrigation, the biomass and the number of bolls per unit area increased with the increasing of plant density, but the harvest index and boll weight significantly reduced. The yield of high plant density was comparable to that of medium plant density, both of which were increased significantly compared with that of low plant density. The content of abscisic acid (ABA) significantly increased and that of auxin (IAA) significantly reduced in cotton leaves under partial root-zone irrigation, which significantly increased the harvest index by improving the partitioning of assimilates to reproductive organs under partial root-zone irrigation. The number of bolls per unit area increased and boll mass remained unchanged with the increasing of density under partial root-zone irrigation. The yield of high density increased by 6.7% and 11.5% compared with that of medium and low density under partial root zone irrigation. The pre-frost seed cotton increased by 22.5%, the amount of irrigation reduced by 30%, and water productivity increased by 49.3% under partial root zone irrigation compared with that under normal irrigation at high plant density. Plant density did not affect photosynthetic rate (Pn) of functional leaves, but irrigation mode significantly affected Pn. Deficient irrigation significantly reduced the Pn of the main-stem functional leaves, but the Pn under partial root-zone irrigation was comparable to that of normal irrigation. The jasmonate (JA) content and the expression level of plasma membrane intrinsic protein (PIP) gene were significantly increased in the hydrated root under partial root-zone irrigation compared with those under normal irrigation. The results suggested that the increased JA content, as a signal molecule, up-regulated the expression level of PIP gene in dehydrated root and increased water uptake capacity of roots and guaranteed water balance of leaves, and then contributed to a relatively high Pn. Partial root-zone irrigation combined with relatively high plant density (225000 plants·hm-2) is an important agronomic alternative for water saving in cotton plantation in the dry land areas.


Assuntos
Irrigação Agrícola/métodos , Gossypium/crescimento & desenvolvimento , Água , Biomassa , China , Fotossíntese
15.
J Appl Microbiol ; 127(6): 1889-1900, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31489745

RESUMO

AIMS: Effect of ground water (GW), secondary-treated wastewater (STWW) and roof-harvested rainwater (RHW) irrigation on microbiological quality of spinach in field was investigated. METHODS AND RESULTS: Spinach grown at the Fulton farm (Chambersburg, PA) was spray-irrigated with GW, STWW or RHW once a week for 2 weeks in summer and fall seasons. Four replicate spinach and soil samples collected from two plots for each group were analysed for indicator and pathogenic bacteria on 0, 1, 2 and 4 days postirrigation (dpi). While total coliforms remained unchanged on spinach regardless of the treatment waters and growing seasons, populations of faecal coliform significantly decreased on RHW- and STWW-irrigated spinach as compared to spinach irrigated with GW at 4 dpi of each week in fall. Irrigation with STWW that contained Escherichia coli population <1·0 log CFU per 100 ml resulted in the lowest E. coli recovery on spinach in fall. Bacterial pathogens were not detected in any sample. CONCLUSIONS: The transference of indicator micro-organisms from irrigation waters to plants was influenced by the type of water and growing season. SIGNIFICANCE AND IMPACT OF THE STUDY: Alternative water sources such as STWW and RHW containing low indicator bacterial populations may be suitable for spinach irrigation in the mid-Atlantic region. However, microbiological quality of these waters must be determined prior to their use for irrigation.


Assuntos
Irrigação Agrícola/métodos , Escherichia coli/isolamento & purificação , Microbiologia de Alimentos , Spinacia oleracea/microbiologia , Microbiologia da Água , Abastecimento de Água/métodos , Contagem de Colônia Microbiana , Escherichia coli/classificação , Fezes/microbiologia
16.
J Agric Food Chem ; 67(38): 10577-10586, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31490682

RESUMO

Root and rhizosphere is important for phosphorus (P) uptake in rice plants. However, little is known about the detailed regulation of irrigation regimes, especially frequently alternate wetting and drying (FAWD), on P usage of rice plants. Here, we found that compared with normal water and P dose, FAWD with a reduced P dose maintained the grain yield in two rice varieties. Compared to rice variety Gaoshan1, rice variety WufengyouT025 displayed a higher grain yield, shoot P content, rhizosphere acid phosphatase activity, abundance of bacteria, and bacterial acid phosphatase gene of rhizosphere. Moreover, the FAWD regime may increase the abundance of bacteria with acid phosphatase activity to release available phosphorus in the rhizosphere, which is associated with rice varieties. Our results suggest that an optimized management of irrigation and phosphorous application can enhance both water and phosphorus use efficiency without sacrificing the yield, which may contribute significantly to sustainable agriculture production.


Assuntos
Irrigação Agrícola/métodos , Produção Agrícola/métodos , Oryza/crescimento & desenvolvimento , Fósforo/metabolismo , Microbiologia do Solo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Produção Agrícola/instrumentação , Fertilizantes/análise , Microbiota , Oryza/classificação , Oryza/metabolismo , Oryza/microbiologia , Rizosfera , Água/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-31484337

RESUMO

Wastewater irrigation is widely practiced and may cause serious environmental problems. However, current knowledge on the effects of long-term irrigation with wastewater from different sources on the biouptake of trace metals (TMs) in the rhizosphere zone by plants in farmlands is limited. Here, we analyzed wheat rhizosphere soil and wheat roots collected from a typical wastewater irrigation area in North China to evaluate the influence of wastewater irrigation from different sources on the bioavailability of trace metals in soils. Results showed that irrigation with tanning and domestic wastewater helped enhance the bioavailability of trace metals in rhizosphere soil by increasing the active organic carbon content, soil redox potential, and catalase activity, thus enhancing the proportion of the potentially bioavailable part of trace metal speciation. Conversely, irrigation with pharmaceutical wastewater can reduce the bioavailability of trace metals in rhizosphere soil by increasing total soil antibiotics and thus decreasing the proportions of bioavailable and potentially bioavailable parts of trace metal speciation. These findings can provide insights into the migration and transformation of trace metal speciation in soil rhizosphere microenvironments under the context of wastewater irrigation.


Assuntos
Irrigação Agrícola/métodos , Metais/metabolismo , Rizosfera , Poluentes do Solo/metabolismo , Triticum/metabolismo , Águas Residuárias , Disponibilidade Biológica , China , Indústria Farmacêutica , Resíduos Industriais , Metais/análise , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Solo/química , Poluentes do Solo/análise , Curtume , Triticum/química , Águas Residuárias/análise
18.
Environ Sci Pollut Res Int ; 26(28): 28829-28841, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31377927

RESUMO

Irrigation with treated waste water (TWW) in combination with plantation of agroforest species was tested in the Kalaât Landelous region for the reclamation of salt affected soils. Five species (Atriplex nummularia, Eucalyptus gomphocephala, Acacia cyanophylla, Casuarina glauca, Pinus halepensis) were cultivated in saline soils that are affected by shallow, saline groundwater and were irrigated with TWW during the summer season. The results after 4 years of experimentation show a distinct decrease in soil pH and salinity accompanied by a decrease in Cl and Na concentrations. Irrigation decreased the heavy metal concentrations in the topsoil but an increase in deeper layers indicate to leaching due to TWW irrigation. The investigated plant species were differently affected in growth performance by salinity and TWW irrigation. Atriplex nummularia appeared to be the most resistant species and Pinus halepensis the most sensitive one to hydro-pedological conditions of the Kalaât Landelous plot. In conclusion, salt-tolerant plant species seem to be good candidates for the reclamation of salt-affected, waterlogged sites in combination with TWW irrigation, as the adaptations of such species seem to operate under different abiotic stress conditions.


Assuntos
Irrigação Agrícola/métodos , Atriplex/química , Metais Pesados/análise , Água Subterrânea , Metais Pesados/química , Salinidade , Plantas Tolerantes a Sal , Solo , Tunísia , Águas Residuárias , Água
19.
Biol Res ; 52(1): 43, 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31405373

RESUMO

BACKGROUND: Drought is one of the main serious problems for agriculture production which its intensity is increasing in many parts of the world, hence, improving water use efficiency is a main goal for sustainable agriculture. RESULTS: Growth indices including relative shoot length growth (SL), relative stem diameter increase (SD) and relative trunk cross sectional area growth (TCSA) measured at the start and end of the season decreased by reducing the irrigation level. Chlorophyll index (CI) was decreased at 70% crop evapotranspiration, however water use efficiency (WUE), leaf and fruit total phenolic content (TPC), and fruit anthocyanin content (AC) were among the traits that showed increment by water deficit stress in both cultivars. Shafi-Abadi cultivar showed to be more sensitive to the water stress than 'Golab'. Kaolin treatment improved SL, SD and CI traits, but this increase was statistically significant only for SD at 5% level. Kaolin had no significant effect on yield and water use efficiency (WUE), however, it had negative effect on yield efficiency (YE). Kaolin treatments also significantly increased fruit and leaf TPC (P < 0.01) but had no effect on leaf and fruit total antioxidant activity (AA), as well as fruit anthocyanin content (AC) and soluble proteins (SP). CONCLUSIONS: Irrigation at 85% ETc showed better results than 100% and 70% ETc levels for yield attributes. It seems that the more pronounced effect of kaolin on vegetative traits but not on the fruits, might be attributed to the early ripening and harvest time of the examined cultivars.


Assuntos
Irrigação Agrícola/métodos , Secas , Frutas/crescimento & desenvolvimento , Caulim/administração & dosagem , Malus/crescimento & desenvolvimento , Frutas/efeitos dos fármacos , Malus/efeitos dos fármacos , Estações do Ano
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