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1.
Ying Yong Sheng Tai Xue Bao ; 31(1): 139-147, 2020 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31957390

RESUMO

To reveal the coupling effect of water and fertilizer on the yield of spring maize under shallow-buried drip irrigation in semi-arid area of western Liaoning, a field experiment was conducted with the quadratic regression orthogonal design of three factors (water, nitrogen and potassium) crossed with five levels in 2017-2018. A quadratic regression model was established with yield (Y) as the dependent variable and irrigation amount (W), nitrogen (N) and potassium (K) application amounts as independent variables to analyze the coupling relationships between Y and W, N and K, respectively. The results showed that the shallow-drip irrigation water-fertilizer coupling had significant impact on yield. The single factor of W, N and K promoted the yield, with their effects ranking as W>N>K. The effect of two-factor interaction on yield increased first and then decreased which ranked as WN>WK>NK. Considering the three-factor coupling effect on yield, the combination of abundant water, nitrogen and potassium was the highest, followed by high water, nitrogen and potassium, and low water, nitrogen and potassium the lowest. As the optimal treatments found by the model, we obtained the suitable water-fertilizer application range of shallow-buried drip irrigation with higher target yield of 8000-8810 kg·hm-2, that was, the irrigation amount was 43-61 mm, nitrogen 138-343 kg·hm-2 and potassium 79-163 kg·hm-2 under the ambient natural rainfall. The results provided a referable basis for application of water-fertilizer integrated cropping pattern under shallow-buried drip irrigation in semi-arid area of northern China.


Assuntos
Fertilizantes , Zea mays , Irrigação Agrícola , Agricultura , Biomassa , China , Nitrogênio , Água
2.
J Environ Manage ; 258: 110040, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31929074

RESUMO

Measures to protect irrigation water supplies for food security continue to receive international attention to address growing water scarcity when faced by increased food demands combined with reduced water supply reliability. Yet, a common problem where water is delivered with earthen canals is delivery inefficiency combined with low economic values per unit of water. In many of the world's arid regions, climate stressed water shortages have raised the importance of discovering measures to improve irrigation delivery efficiency. However, little research grade work to date has presented an integrated analysis of the economic performance of irrigation delivery improvements faced by drought and climate stressed regions. This paper's unique contribution is to investigate the economic performance of water conservation infrastructure combined with dynamically optimized use of saved water. We develop a state-of-the arts empirical dynamic optimization model to discover land and water use patterns that optimize sustained farm income. Results from the upper watershed irrigation region of the Canadian Basin in the southwestern US show that canal and delivery system lining can raise the sustained economic value of water for crop irrigation. The saved water can see immediate use in dry years. It can also be stored in wet years to mitigate the most adverse impacts of future climate water stress. This double dividend is especially important in rain-fed watersheds for which surface water supplies for irrigation are difficult to forecast accurately. Findings light a path for water managers and other stakeholders who bear responsibility of finding economically responsible measures to improve irrigation water productivity in the world's dry regions.


Assuntos
Conservação dos Recursos Hídricos , Irrigação Agrícola , Canadá , Conservação dos Recursos Naturais , Meio Ambiente , Reprodutibilidade dos Testes , Abastecimento de Água
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.
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
5.
Food Chem ; 303: 125402, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31470273

RESUMO

Chickpea is one the most important legumes consumed all around the world because of high protein content. The current study was conducted to investigate the effects of irrigation treatments at different physiological growth stages (before flowering, beginning of flowering, pod-set and pod-fill periods) on nutritional attributes of chickpea. The findings showed that one or two irrigations at different physiological growth stages instead of full irrigation treatment might be sufficient to improve the nutritional attributes of chickpea. Flowering and pod-fill periods were identified as the critical periods for irrigations and affected the nutritional component levels. The greatest protein level (29.52%) was obtained from the samples irrigated before flowering while the greatest total starch (36.30%) was obtained from the samples irrigated at the beginning of flowering. It was concluded based on present findings that physiological growth stages should be taken into consideration in irrigation practices of chickpea farming.


Assuntos
Cicer/química , Cicer/crescimento & desenvolvimento , Irrigação Agrícola , Cicer/metabolismo , Grão Comestível/química , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Valor Nutritivo , Proteínas de Plantas/análise , Proteínas de Plantas/metabolismo , Amido/análise , Amido/metabolismo , Água/metabolismo
6.
Chemosphere ; 240: 124791, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31546189

RESUMO

Produced water (PW) is a mixture of formation water and injected water from oil and gas reservoirs, which contain a complex composition of dissolved and particulate organic and inorganic chemicals. High quantities of PW are extracted with the oil, which can be discharged into the environment, re-injected into the wells or treated for reuse. The present study aimed to evaluate the soil ecotoxicity under an irrigation system using treated PW (water-oil separation, sand filter, activated charcoal filter, reverse osmosis) for sunflower production, predicting conditions for PW reuse in the semi-arid region of Brazil. The experiment was conducted in a greenhouse using natural soil in vessels. Water from public water supply was used as control. Soil samples from two production cycles of sunflowers were assessed using ecotoxicity tests with soil invertebrate's species representing macro and mesofaunal groups: Eisenia andrei (earthworms), Folsomia candida (collembolans) and Enchytraeus crypticus (enchytraeids). Leachates samples were evaluated with aquatic ecotoxicity tests to assess the soil retention function. Results showed impact of irrigation with PW in all treatments except reverse osmosis. Significant negative correlations were found among reproduction of soil invertebrates, high Na+ concentrations and electrical conductivity. The effects of other contaminants not analyses should not be discarded. It is important to highlight that salinity is not usually included in target values of soil quality. This study reinforces the importance of ecotoxicity tests in predictive and retrospective risk assessment, joining effects of contaminant mixtures or even that contaminants not considered in chemical scope of analysis or legislation.


Assuntos
Irrigação Agrícola , Organismos Aquáticos , Poluentes do Solo/toxicidade , Eliminação de Resíduos Líquidos , Animais , Artrópodes/efeitos dos fármacos , Brasil , Monitoramento Ambiental , Campos de Petróleo e Gás , Oligoquetos/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Estudos Retrospectivos , Solo/química , Poluentes do Solo/análise , Água/análise
7.
Chemosphere ; 239: 124725, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31499300

RESUMO

Use of wastewater is known to provide nutrients for crop plants, but its potential to improve phosphorus (P) availability in semi-arid regions is poorly understood. In this study, seasonal changes in soil P availability as well as associated phyiscochemical and biochemical indicators were investigated from the wastewater irrigated urban soils of Faisalabad, Pakistan. Soil sampling was carried out during summer and winter season from four wastewater irrigated sites of varied stream flow i.e. upstream wastewater (UWW), midstream wastewater (MWW), lowerstream wastewater (LWW) and downstream wastewater (DWW), and canal water irrigation (CWI) as a reference site. Across seasons, MWW site had significantly higher soil organic carbon (SOC), water extractable organic carbon (WEOC), microbial biomass carbon (MBC), microbial biomass phosphorus (MBP) as well as the availability of phosphorus i.e. NaHCO3-P and H2O-P compared to CWI site. In both sampling seasons, MWW site also recorded significantly higher soil enzyme activities compared to the rest of wastewater sites. Moreover, significantly higher total P and electrical conductivity (EC) of soil was noticed at DWW site across both summer and winter seasons. Biplot principle component analysis also indicated seasonally a stronger shift in soil total P and EC at DWW site. On the other hand, availability of P was closely related to soil active carbon pools at MWW site. However, buildup of soil salinity particularly at DWW site along with lower P availability and associated changes in other soil properties, call for careful assessment of wastewater use in these urban soils.


Assuntos
Irrigação Agrícola , Fósforo/análise , Solo/química , Águas Residuárias , Biomassa , Carbono/análise , Cidades , Paquistão , Fósforo/farmacocinética , Salinidade , Estações do Ano , Microbiologia do Solo , Águas Residuárias/química
8.
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
9.
Sci Total Environ ; 698: 134201, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505362

RESUMO

A study was conducted to investigate the impact of raw wastewater use for irrigation on dissemination of bacterial resistance in urban agriculture in African cities. The pollution of agricultural fields by selected antibiotic residues was assessed. The structure and functions of the soil microbial communities, presence of antibiotic resistance genes of human clinical importance and Enterobacteriaceae plasmid replicons were analysed using high throughput metagenomic sequencing. In irrigated fields, the richness of Bacteroidetes and Firmicutes phyla increased by 65% and 15.7%, respectively; functions allocated to microbial communities' adaptation and development increased by 3%. Abundance of antibiotic resistance genes of medical interest was 27% greater in irrigated fields. Extended spectrum ß-lactamase genes identified in irrigated fields included blaCARB-3, blaOXA-347, blaOXA-5 and blaRm3. The presence of ARGs encoding resistance to amphenicols, ß-lactams, and tetracyclines were associated with the higher concentrations of ciprofloxacin, enrofloxacin and sulfamethoxazole in irrigated fields. Ten Enterobacteriaceae plasmid amplicon groups involved in the wide distribution of ARGs were identified in the fields. IncQ2, ColE, IncFIC, IncQ1, and IncFII were found in both farming systems; IncW and IncP1 in irrigated fields; and IncY, IncFIB and IncFIA in non-irrigated fields. In conclusion, raw wastewater irrigated soils in African cities could represent a vector for the spread of antibiotic resistance, thus threatening human and animal health. Consumers of products from these farms and farmers could be at risk of acquiring infections due to drug-resistant bacteria.


Assuntos
Irrigação Agrícola , Resistência Microbiana a Medicamentos/genética , Microbiologia do Solo , Águas Residuárias/microbiologia , África , Agricultura , Cidades , Monitoramento Ambiental , Poluentes do Solo/análise , beta-Lactamas
10.
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
11.
Sci Total Environ ; 698: 134154, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505342

RESUMO

Water scarcity, nutrient-depleted soils and pollution continue to be a major challenge worldwide and these are likely to worsen with increasing global populations particularly, in urban areas. As a result, environmental and public health problems may arise from the insufficient provision of sanitation and wastewater disposal facilities. Because of this, a paradigm shifts with regard to the sustainable management of waste disposal in a manner that could protect the environment at the same time benefits society by allowing nutrient recovery and reuse for food production is required. Hence, the use of urban wastewater for agricultural irrigation has more potential, especially when incorporating the reuse of nutrients like nitrogen and phosphorous, which are essential for crop production. Among the current treatment technologies applied in urban wastewater reuse for agriculture, hydroponic system is identified as one of the alternative technology that can be integrated with wastewater treatment. The integration of hydroponic system with municipal wastewater treatment has the advantage of reducing costs in terms of pollutants removal while reducing maintenance and energy costs required for conventional wastewater treatment. The efficiency of a hydroponic system with regard to municipal wastewater reuse is mainly linked to its capacity to allow continuous use of wastewater through the production of agricultural crops and the removal of pollutants/nutrients (nitrogen and phosphorus), resulting to increased food security and environmental protection. Moreover, the suitability of hydroponic system for wastewater treatment is derived from its capacity to minimize associated health risks to farmers, harvested crop and consumers, that may arise through contact with wastewater.


Assuntos
Agricultura/métodos , Hidroponia , Verduras/crescimento & desenvolvimento , Eliminação de Resíduos Líquidos , Irrigação Agrícola , Conservação dos Recursos Naturais , Produtos Agrícolas , Fazendeiros , Nitrogênio , Fósforo , Saneamento , Tecnologia , Águas Residuárias , Água , Purificação da Água
12.
Huan Jing Ke Xue ; 41(1): 420-429, 2020 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854945

RESUMO

A five year field experiment was conducted to evaluate the effect of continually returning cotton straw or biochar on microbial metabolic function and bacterial community composition of soil in a cotton field under drip irrigation conditions. The experiment involved three treatments:control (single application of chemical fertilizer, CK), cotton straw (returning of cotton straw plus chemical fertilizer application, ST), and biochar (returning of cotton straw biochar plus chemical fertilizer application, BC). The returning of cotton straw and biochar both significantly increased soil organic matter, total nitrogen, and available nutrients, but the effect of returning biochar was more significant. The carbon source metabolic activities of the soil in the ST treatment was the highest, followed by the BC treatment, which was significantly higher than of that in the CK treatment. The returning of cotton straw promoted the metabolism of carbohydrate and amine carbon sources, while biochar significantly increased the metabolism of polymer carbon sources. Compared with the CK treatment, the ST treatment significantly increased the phylum of Proteobacteria, Actinobacteria, Bacteroides, and the family of Xanthomonadaceae, Acidobacteriaceae, Microbacteriaceae, and Cytophagaceae. The BC treatment significantly increased the phylum of Acidobacteria, Gemmatimonadetes, Nitrospirae, and the family of Blastocatellaceae (subgroup 4), Gemmatimonadaceae, and Nitrosomonadaceae. The correlation analysis showed that there were significant positive correlations between the relative abundances of Xanthomonadaceae and Acidobacteriaceae and the carbon source metabolic activities of carbohydrates, amino acids, carboxylic acids, and amines. The relative abundances of Microbacteriaceae and Cytophagaceae were positively correlated with carbohydrates and amines. There was a significant positive correlation between the relative abundance of Blastocatellaceae (subgroup 4), Gemmatimonadaceae, Nitrosomonadaceae and the carbon metabolism of polymers. These results suggest that the continual returning of biochar increased soil nutrients, change bacterial community composition, and promoted the metabolic activity of polymer carbon sources in the drip-irrigated cotton field.


Assuntos
Bactérias/metabolismo , Carvão Vegetal , Microbiologia do Solo , Irrigação Agrícola , Bactérias/classificação , Fertilizantes , Gossypium/crescimento & desenvolvimento
13.
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
14.
J Sci Food Agric ; 100(2): 595-606, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31591721

RESUMO

BACKGROUND: Climate change has posed great challenges to rice production. Temperature and solar radiation show significant variations in central China. This study aims to analyze the responses of different rice genotypes to the variations of temperature and solar radiation in central China, and to find the way of identifying the optimal sowing date to improve and stabilize rice production. For this end, four rice genotypes (two Indica and two Japonica cultivars) were cultivated at two locations under irrigation conditions in 2 years with six sowing dates. RESULTS: We investigated variations of rice grain yield, resource use efficiency, average daily temperature and solar radiation during different phenological stages. Rice grain yield could increase by about 2-17% in central China. Compared with solar radiation, temperature was a more important factor affecting rice grain yield in central China. The grain yield showed great correlation with the means temperature during different phenological stages, especially during the first 20 days after heading (GT20). Besides our results demonstrated that the grain yield displayed slender variations when the GT20 was within 24.9-26.4 °C. However, GT20 was higher than 26.4 °C in most cases, which became more frequent due to climate changes. Analysis of climate change during the last 25 years revealed that the frequency of GT20 within 24.9-26.4 °C was increased by the delay of sowing date. CONCLUSION: We propose that delaying sowing date to achieve the optimal GT20 (24.9 °C-26.4 °C) can be an effective strategy to stabilize and improve rice grain yield and resource use efficiency in central China. © 2019 Society of Chemical Industry.


Assuntos
Produção Agrícola/métodos , Oryza/crescimento & desenvolvimento , Irrigação Agrícola , China , Mudança Climática , Genótipo , Oryza/genética , Oryza/metabolismo , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Temperatura Ambiente , Água/análise , Água/metabolismo
15.
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
16.
J Sci Food Agric ; 100(4): 1764-1774, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31849058

RESUMO

BACKGROUND: Water productivity improvement is fundamental to agricultural water use control, and the water footprint provides a new and comprehensive method for identifying the crop-water relationship. This study is intended to explore the spatiotemporal pattern and driving forces underlying the rice water footprint productivity (WFP) in China during the years 1996-2015 based on calculations of the provincial blue, green, gray, and white water footprints. RESULTS: The national water footprint in paddy rice cultivation was 240.97 Gm3 , and green water accounted for 43.9% of the total. The WFP was 0.795 kg m-3 and increased over time in all 30 provinces for which it was calculated. The growth rate in the northern provinces was greater than that in the southern part of the country. The WFP clustered geographically in all years observed. High-value provinces were concentrated to the south of the Yangtze River, whereas most of the provinces that showed a low WFP were distributed in the north China and northwest subregions. Precipitation and sunshine hours were the most obvious driving factors of rice WFP. The effects of agricultural input, e.g., agricultural machinery power, pesticides, and irrigation efficiency, on WFP also could not be ignored. CONCLUSION: The WFP is a comprehensive and useful index of the crop-water relationship and water-use efficiency. Improving agricultural input and irrigation technology are reliable approaches for WFP promotion. Areas in northeast China showed the most urgent need for improving the rice WFP, and the inclusion of the main grain producing areas in the Yangtze River Basin will further reduce ineffective water occupancy to improve water-use efficiency. © 2019 Society of Chemical Industry.


Assuntos
Oryza/metabolismo , Água/análise , Irrigação Agrícola , China , Oryza/crescimento & desenvolvimento , Água/metabolismo
17.
Ying Yong Sheng Tai Xue Bao ; 30(12): 4159-4168, 2019 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-31840461

RESUMO

Reasonable irrigation is still lacking for potato production in the sandy areas of Yulin, northern Shaanxi Province. To solve this problem, field drip fertigation was conducted to examine the growth, yield and quality of potato during the whole growing season. We further analyzed the responses of these indices to different irrigation frequencies and amounts. There were three irrigation frequencies (d), i.e. 4 (D1), 8 (D2) and 10 (D3), and three irrigation amounts, i.e. 60%ETc (W1), 80%ETc(W2) and 100%ETc(W3), where ETc was the crop water requirement, resulting in a total of nine treatments. Under the same irrigation frequency, plant height, leaf area index, dry matter, tuber yield and economic benefits of W3 were higher than those of W1 and W2. W1 had the highest irrigation water use efficiency (IWUE), while water use efficiency was not significantly affected by irrigation amount. The average tuber yield of W3 was 43442 kg·hm-2, which was 23.3% and 11.6% higher than that of W1 and W2, respectively. The net income of W3 was 23492 yuan·hm-2, which was 40.4% and 18.7% higher than that of W1 and W2, respectively. Tubers from W3 had the highest starch and vitamin C contents but the lowest reducing sugar content, which were 14.4%, 18.54 mg·(100 g)-1 FW and 0.7%, respectively. At the same irrigation amount, tuber yield, IWUE, starch and vitamin C contents of D1 were the highest, but the reducing sugar content was the lowest at the low and medium irrigation amounts. At the high irrigation amount, D2 had the highest tuber yield, IWUE, net income, starch and vitamin C contents but the lowest reducing sugar content, which were 46572 kg·hm-2, 23.04 kg·m-3, 26,622 yuan·hm-2,14.6%, 19.53 mg·(100 g)-1 FW and 0.7%, respectively. Based on the interacting effects of drip irrigation frequency and amount, both yield and quality of D2W3 reached the maximum. Results from the principal component analysis showed that D2W3 had the highest score. D2W3(8 d, 100%ETc) had the greatest yield and quality and relatively higher water use efficiency, which was thus considered as the optimal combination of drip irrigation frequency and amount. The results could provide a scientific basis for the drip irrigation scheduling design for high-yield, high-efficiency and high-quality potato production in the sandy areas of Yulin, northern Shaanxi.


Assuntos
Solo , Solanum tuberosum , Irrigação Agrícola , Biomassa , China , Areia , Triticum , Água
18.
Ying Yong Sheng Tai Xue Bao ; 30(12): 4169-4176, 2019 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-31840462

RESUMO

We investigated the effects of different drip irrigation quotas on leaf area index (LAI), diffuse non-interceptance (DIFN), light interception rate (LIR), canopy apparent photosynthetic rate (CAP), and cotton yield of Xinluzao 45 in field of north Xinjiang. There were five drip irrigation treatments, i.e. W1: 600 m3·hm-2, W2: 540 m3·hm-2, W3: 480 m3·hm-2, W4: 420 m3·hm-2, W5: 360 m3·hm-2. The results showed that with the decrease in drip irrigation quota, LAI, LIR and CAP of cotton substantially decreased, with the difference between W1 and W2 being not statistically significant from the full squaring to boll opening stage. Moreover, DIFN was enhanced with the reduction in drip irrigation quota. Highest seed and lint yield (6549 kg·hm-2 and 2677 kg·hm-2, respectively) presented in W1. W2 got a 6.5% reduction of seed cotton yield compared with W1, but the irrigation water use efficiency was enhanced by 3.9%. LAI, LIR and CAP were positively correlated with seed cotton yield from full flowering stage to full boll stage. Therefore, drip irrigation quota at 540 m3·hm-2 could increase irrigation water use efficiency, maintain higher leaf area index, increase diffuse non-interceptance, and ensure light interception rate from full flowering stage to full boll stage, which could enhance canopy apparent photosynthetic rate and water use efficiency without sacrificing yield.


Assuntos
Irrigação Agrícola , Fotossíntese , Biomassa , China , Água
19.
Ying Yong Sheng Tai Xue Bao ; 30(11): 3745-3752, 2019 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-31833687

RESUMO

To clarify the differences in light energy utilization and distribution characteristics of flag leaf 13C assimilate in different spike-type wheat varieties and their responses to supplementary irrigation, we set three water treatments in a field experiment, including no irrigation during growth duration of wheat (W0), water-saving irrigation (W1, irrigating at jointing and anthesis of wheat to keep the relative moisture of 0-40 cm soil to 65% and 70%), full irrigation (W2, irrigating at jointing and anthesis of wheat to keep the relative moisture of 0-40 cm soil to 85% and 90%) with the medium-spike wheat cultivars Jimai 22 and Qingnong 2, large-spike wheat cultivars Shannong 23 and Shannong 30 as test materials. The effects of different water treatments on canopy light energy utilization and 13C assimilate distribution characteristics of two spike-type wheat varieties were examined. The results showed that leaf area index, canopy light interception rate, and light energy utilization rate of the two varieties at 2, 11, 20 and 31 days after anthesis were significantly higher than W0 treatment, but there was no significant change in each index when the irrigation increased to W2 treatment. The distribution of flag leaf 13C assimilates of Jimai 22 and Shannong 23 of W1 in grain was 159.34 and 171.1 g·hm-2 higher than W0, respectively, and the distribution ratio was 6.5% and 6.5%, with no significant difference compared with W2. The grain yields of both varieties under W1 were significantly higher than that under W0, but with no significant difference with W2. Under water-saving irrigation, the medium-spike cultivars had higher canopy photosynthetically active radiation interception and utilization ability at 2 and 11 days after anthesis and large-spike cultivars at 20 and 31 days after anthesis. The distribution amount and ratio of 13C assimilates in the grain of medium-spike variety Jimai 22 flag leaf were 6.8% and 2.7% lower than that of the large-spike variety Shannong 23.


Assuntos
Irrigação Agrícola , Triticum , Biomassa , Folhas de Planta , Solo , Água
20.
Huan Jing Ke Xue ; 40(11): 5151-5163, 2019 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854585

RESUMO

Reclaimed water is considered to be a reasonable and sustainable alternative water resource to improve water resource layout and mitigate the shortage of traditional water resources. Its use in irrigation will cause changes in the microbial community structure and opportunistic pathogen abundance in soils and crops, but few studies have been conducted on this subject. Peppers were used as the research subjects, and the treatments were direct irrigation of reclaimed water, mixed irrigation with freshwater and reclaimed water, rotated irrigation with freshwater and reclaimed water, with potable water irrigation as the control. The effects of different irrigation methods of reclaimed water on the soil physicochemical properties were analyzed through a pot experiment. Furthermore, changes in bacterial community and opportunistic pathogen abundance in pepper fruit and the rhizosphere under reclaimed water irrigation conditions were investigated based on high-throughput sequencing technology and quantitative PCR methods. The results showed that direct irrigation with reclaimed water increased soil EC and decreased soil pH. 16S rDNA high-throughput sequencing showed that Proteobacteria, Bacteroides, Actinobacteria, and Firmicutes were present in both pepper fruit and the rhizosphere at phylum level, and the most dominant genera (Pantoea, Pseudomonas, Sphingomonas, Sphingopyxis, Luteimonas, and Mariniflexile) were greatly affected by reclaimed water irrigation methods. Quantitative PCR results indicated that the influence of reclaimed water irrigation on the distribution and abundance of pathogenic bacteria in the soil-pepper system was different, and the abundance of Legionella spp. in pepper fruit and Pseudomonas syringae in the rhizosphere increased with reclaimed water irrigation. Our results indicated that the reclaimed water was suitable for agricultural irrigation, but different reclaimed water irrigation methods may introduce different degrees of microbial contamination. In addition, attention must be given to some opportunistic pathogens and phytopathogens.


Assuntos
Bactérias , Microbiologia do Solo , Solo , Água , Irrigação Agrícola , Rizosfera
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