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1.
PLoS One ; 15(7): e0235665, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645041

RESUMO

Quantification of seasonal dynamics of soil C and N pools is crucial to understand the land management practices for enhancing agricultural sustainability. In a cover crop (CC) experiment established in 2007 and repeated at an adjacent site in 2008, we evaluated the medium-term impact of CC (no cover crop control (no-CC), oat (Avena sativa L.), oilseed radish (OSR, Raphanus sativus L. var. oleoferus Metzg. Stokes), winter cereal rye (rye, Secale cereale L.), and a mixture of OSR+Rye) and crop residue management (residue removed (-R) and residue retained (+R)) on soil C and N dynamics and sequestration. Labile and stable fractions of C and N were determined at seven different time points from 0-15 cm depth during tomato (Solanum lycopersicum L.) growing season in 2015 and 2016 (referred to as site-years). As expected, over the tomato growing season in both site-years, organic C (OC) and total N did not change while the labile C and N fractions changed with greater concentrations observed at 2 weeks after tillage (WAT) and greater treatment differences observed for seven out of eleven soil attributes at tomato harvest. Therefore, 2WAT (early June) and tomato harvest (early September) are reasonably optimum sampling times for soil C and N attributes. Seasonal variation of labile fractions suggested the potential impact of substrate availability from crop residues on soil C and N cycling. Medium-term CC usage enhanced the surface soil C and N storage. Overall, this study highlights the positive and synergistic influences of CCs and maintaining crop residues in increasing both labile and stable fractions of C and N and enhancing soil quality in a temperate humid climate.


Assuntos
Carbono/análise , Produtos Agrícolas/química , Nitrogênio/análise , Solo/química , Avena , Clima , Umidade , Lycopersicon esculentum , Raphanus , Estações do Ano , Secale
2.
J Chromatogr A ; 1625: 461271, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709323

RESUMO

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous in the environment. However, only a limited number of predominantly persistent perfluoroalkyl acids (PFAAs) have been analyzed in edible plants so far. We present a generic trace analytical method that allows for quantification of 16 intermediate fluorotelomer alcohol (FTOH)- or perfluoroalkane sulfonamidoethanol (FASE)-based transformation products as well as 18 PFAAs in plants. Additionally, 36 suspected intermediate PFAS transformation products were qualitatively analyzed. The ultrasound-assisted solid-liquid extraction of wheat and maize grain, maize leaves, Jerusalem artichoke and ryegrass (1-5 g plant sample intake) was followed by a clean-up with dispersive solid-phase extraction using graphitized carbon adsorbent (5-10 mg per sample) and chemical analysis by reversed phase liquid chromatography-tandem mass spectrometry. The method was based on matrix matched and extracted calibration and displayed good precision with relative standard deviations in triplicate analyses typically below 15% for all quantified analytes and matrices. An average deviation of 12% between quantified concentrations obtained by matrix matched and extracted calibration and a method based on isotopically labelled internal standards underlines the good trueness of the method. The method quantification limits for the majority of analytes in all plant samples were in the low ng/kg concentration range on a dry weight basis. Plant matrices were analyzed from crops grown on agricultural fields that have been contaminated with PFASs. FTOH- and/or FASE-based intermediate transformation products were detected in all samples with N-ethyl perfluorooctane sulfonamidoacetic acid (EtFOSAA) and perfluorooctane sulfonamide (FOSA) as the prevailing compounds in concentrations up to several hundred ng/kg in maize leaves. The 9:3 Acid (a transformation product of 10:2 FTOH) was tentatively identified. In accordance with these findings, the final degradation products perfluorooctane sulfonic acid (PFOS) and perfluorodecanoic acid (PFDA) were frequently detected. For perfluoroalkyl carboxylic acids (PFCAs), according to earlier findings, short chain homologues generally displayed the highest levels (up to 98 µg/kg for perfluorobutanoic acid (PFBA) in maize leaves). However, maize grain was an exception showing the highest concentrations for long chain PFCAs, whereas PFBA was not detected. The uptake of high levels of PFASs into plants is of concern since these may be used as animal feed or represent a direct exposure medium for humans.


Assuntos
Produtos Agrícolas/química , Monitoramento Ambiental/métodos , Fluorcarbonetos/análise , Animais , Humanos , Limite de Detecção , Folhas de Planta/química , Padrões de Referência , Reprodutibilidade dos Testes
3.
Ecotoxicol Environ Saf ; 203: 111012, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32684522

RESUMO

Planting sweet potato (Ipomoea batatas (L.) Lam.) instead of rice in the area contaminated with heavy metals is one of the measures to ensure people's health and agricultural economy. Therefore, it is important to screen the low accumulation cultivars of sweet potato and to find out the concentration rule of cadmium (Cd) and lead (Pb) in edible parts along with the associated health risks to humans. A field experiment was performed with fourteen of three main types (starch, purple, and edible-type) of sweet potato cultivars grown on farmland polluted with Cd and Pb in eastern Hunan Province, China. The Cd and Pb concentrations in the sweet potato tissues as well as the yield were measured. The yield of the shoot and tuberous root of the fourteen sweet potato cultivars ranged from 14.59 to 68.57 and 26.35-50.76 t ha-1 with mean values of 33.09 and 33.46 t ha-1, respectively. Compared with purple and edible-type cultivars, the starch-type cultivar had lower Cd and Pb concentrations in the flesh, but higher in the shoot. The Cd and Pb concentrations in the flesh of cultivars Shangshu 19, Sushu 24, Yushu 98, and Xiangshu 98 were lower than MCL provided in Chinese National Food Safety Standards GB2762-2017. Based on the hazard index (HI), the consumption of sweet potato flesh is lower health risk, while shoots pose a greater health risk to local people and Cd is the main cause of the risk. As a result, sweet potato cultivars Shangshu 19, Sushu 24, Yushu 98 and Xiangshu 98 can be plant in serve Cd and Pb contaminated soils with the advantages of easy cultivation, high yield and economic benefits without stopping agricultural production.


Assuntos
Cádmio/análise , Exposição Dietética/análise , Ipomoea batatas/química , Chumbo/análise , Poluentes do Solo/análise , China , Produtos Agrícolas/química , Produtos Agrícolas/genética , Exposição Dietética/normas , Inocuidade dos Alimentos , Humanos , Ipomoea batatas/genética , Medição de Risco
4.
PLoS One ; 15(7): e0234611, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32649667

RESUMO

Perennial vegetables are a neglected and underutilized class of crops with potential to address 21st century challenges. They represent 33-56% of cultivated vegetable species, and occupy 6% of world vegetable cropland. Despite their distinct relevance to climate change mitigation and nutritional security, perennial vegetables receive little attention in the scientific literature. Compared to widely grown and marketed vegetable crops, many perennial vegetables show higher levels of key nutrients needed to address deficiencies. Trees with edible leaves are the group of vegetables with the highest levels of these key nutrients. Individual "multi-nutrient" species are identified with very high levels of multiple nutrients for addressing deficiencies. This paper reports on the synthesis and meta-analysis of a heretofore fragmented global literature on 613 cultivated perennial vegetables, representing 107 botanical families from every inhabited continent, in order to characterize the extent and potential of this class of crops. Carbon sequestration potential from new adoption of perennial vegetables is estimated at 22.7-280.6 MMT CO2-eq/yr on 4.6-26.4 Mha by 2050.


Assuntos
Agricultura/métodos , Sequestro de Carbono/fisiologia , Verduras/metabolismo , Biodiversidade , Carbono/metabolismo , Mudança Climática , Produtos Agrícolas/química , Produtos Agrícolas/metabolismo , Abastecimento de Alimentos , Nutrientes/análise , Nutrientes/metabolismo , Estado Nutricional/fisiologia
5.
PLoS One ; 15(7): e0234770, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645004

RESUMO

BACKGROUND: Zinc (Zn) deficiency is one of the most common micronutrient deficiencies worldwide. Accurate estimates of Zn intake would facilitate the design and implementation of effective nutritional interventions. OBJECTIVE: We sought to improve estimates of dietary Zn intake by evaluating staple crop Zn content and dietary Zn consumption by children under the age of 5 in 9 rural districts of Uganda. METHODS: We measured the Zn content of 581 crop samples from household farms and 167 crop samples from nearby markets, and administered food frequency questionnaires to the primary caretakers of 237 children. We estimated Zn consumption using 3 sources of crop Zn content: (i) the HarvestPlus food composition table (FCT) for Uganda, (ii) measurements from household crops, and (iii) measurements from market crops. RESULTS: The Zn content of staple crops varied widely, resulting in significantly different estimates of dietary Zn intake. 41% of children appeared to be at risk when estimates were based on market-sampled crops, 23% appeared at risk when estimates were based on the HarvestPlus FCT, and 16% appeared at risk when estimates were based on samples from household farms. CONCLUSION: The use of FCTs to calculate Zn intake overestimated the risk of dietary inadequacy for children who primarily consumed staple crops that were produced on household farms, but underestimated the risk for children who primarily consumed staple crops that were purchased at market. More information on the Zn content of staple crops in developing countries could lead to more accurate estimates of dietary intake and associated deficiencies.


Assuntos
Produtos Agrícolas/química , Zinco/análise , Zinco/deficiência , Pré-Escolar , Dieta , Feminino , Humanos , Lactente , Masculino , Micronutrientes/deficiência , Minerais , Avaliação Nutricional , Estado Nutricional , Valor Nutritivo , Uganda , Zinco/metabolismo
6.
Isotopes Environ Health Stud ; 56(4): 335-345, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32508160

RESUMO

For many years after the discovery of the two stable isotopes of boron (10B,11B) in 1920 they were not used as tracers in the soil-plant system due to analytical constraints. However, with the advent of inductively coupled plasma mass spectrometry in the early 1980s, it became possible to measure precisely the natural variations of the B isotopes in biological systems. Nevertheless, up to the present time there is very little information in the literature on δ 11B variations in soils, plants, fertilizers and foodstuffs. Therefore, information on the potential of δ 11B as a tracer of B dynamics in natural- and agro-ecosystems remains limited. The relative abundance of the boron isotope (δ 11B) in soils, plants and nutrient sources, and applications of variations in the natural abundance of 11B as a tracer of anthropogenic sources of nitrate contamination of water and the provenance of agricultural products are reviewed.


Assuntos
Boro/análise , Poluentes Ambientais/análise , Isótopos/análise , Nitratos/análise , Produtos Agrícolas/química , Ecossistema , Fertilizantes/análise , Plantas/química , Solo/química
7.
PLoS One ; 15(6): e0234395, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32525930

RESUMO

As rice is an important staple food globally, research for development and enhancement of its nutritional value it is an imperative task. Identification of nutrient enriched rice germplasm and exploiting them for breeding programme is the easiest way to develop better quality rice. In this study, we analyzed 113 aromatic rice germplasm in order to identify quantitative trait loci (QTL) underpinning nutrition components and determined by measuring the normal frequency distribution for Fe, Zn, amylose, and protein content in those rice germplasm. Comparatively, the germplasm Radhuni pagal, Kalobakri, Thakurbhog (26.6 ppm) and Hatisail exhibited the highest mean values for Fe (16.9 ppm), Zn (34.1 ppm), amylose (26.6 ppm) and protein content (11.0 ppm), respectively. Moreover, a significant linear relationship (R2 = 0.693) was observed between Fe and Zn contents. Cluster analysis based on Mahalanobis D2 distances revealed four major clusters of 113 rice germplasm, with cluster III containing a maximum 37 germplasm and a maximum inter-cluster distance between clusters III and IV. The 45 polymorphic SSRs and four trait associations exhibited eight significant quantitative trait loci (QTL) located on eight different chromosomes using composite interval mapping (CIM). The highly significant QTL (variance 7.89%, LOD 2.02) for protein content (QTL.pro.1) was observed on chromosome 1 at 94.9cM position. Also, four QTLs for amylose content were observed with the highly significant QTL.amy.8 located on chromosome 8 exhibiting 7.2% variance with LOD 1.83. Only one QTL (QTL.Fe.9) for Fe content was located on chromosome 9 (LOD 1.24), and two (QTL.Zn.4 and QTL.Zn.5) for Zn on chromosome 4 (LOD 1.71) and 5 (LOD 1.18), respectively. Overall, germplasm from clusters III and IV might offer higher heterotic response with the identified QTLs playing a significant role in any rice biofortification breeding program and released with development of new varieties.


Assuntos
Oryza/genética , Locos de Características Quantitativas , Amilose/análise , Biofortificação/métodos , Produtos Agrícolas/química , Produtos Agrícolas/classificação , Produtos Agrícolas/genética , Alimentos Fortificados/análise , Genes de Plantas , Marcadores Genéticos , Ferro/análise , Valor Nutritivo , Oryza/química , Oryza/classificação , Fenótipo , Melhoramento Vegetal/métodos , Proteínas de Vegetais Comestíveis/análise , Análise de Regressão , Sementes/química , Sementes/genética , Zinco/análise
8.
J Environ Sci Health B ; 55(7): 630-645, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32338140

RESUMO

Effect of the wheat straw ash (WSA) on pretilachlor and the rice straw ash (RSA) on sulfosulfuron kinetics and adsorption behavior was studied. Kinetics study suggested that adsorption of herbicides in soil/soil + 0.2% ash mixture was best explained by the pseudo second order model. Ashes at 0.1%-0.5% levels increased adsorption of respective herbicide; but, effect varied with ash content and soil type. Effect of ash (0.2%) on herbicide's adsorption was more in the sandy loam soil (144%-188%) than in the clay loam soil (112%-122%) suggesting masking of ash particles. The Freundlich adsorption isotherm explained the adsorption of herbicides in the soils/soil + ash mixtures and sorption was highly nonlinear as 1/n (slope) values varied between 0.57 and 1.25 for pretilachlor and 0.32 and 0.77 for sulfosulfuron. Adsorption increased with increase in temperature. High surface area unburnt carbon in ashes was responsible for increase in adsorption and decrease in desorption of herbicides in ash mixed soils. The pH of soil/soil + ash mixtures affected herbicide adsorption, but effect was significant for pretilachlor. The negative free energy change (ΔG) values suggested that the sorption process was exothermic and spontaneous in nature. This study has implications in identifying the role of crop residue burning on fate of herbicides applied in succeeding crop.


Assuntos
Produtos Agrícolas/química , Herbicidas/química , Poluentes do Solo/química , Acetanilidas/química , Adsorção , Carbono , Argila , Índia , Cinética , Oryza/química , Pirimidinas/química , Solo/química , Sulfonamidas/química , Triticum/química
9.
Ecotoxicol Environ Saf ; 197: 110627, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32302856

RESUMO

Pesticides are part of a large group of organic compounds with different physicochemical characteristics, designed to control and prevent pests in various crops and plantations, improving productivity. This works provides a perspective on pesticide use in current agriculture with the aim of identifying the influence of pesticides on food production and their impact on the environment. Therefore, it is necessary to highlight the importance of determining pesticide residues in food, aiming to ensure food safety, since these compounds can represent risks to human health and the environment. The effects of pesticides on humans range from headaches, nausea and skin and eye irritation to chronic problems such as cancer and neurological disorders, and extend to other non-target organisms such as birds, fish and bees, contaminating water, soil, and plants, as opposed to the benefits of increased production, consequently other measures for pesticide consumption need to be evaluate to ensure human health, food safety and environmental protection. It is important to note that chromatographic techniques and mass spectrometry assist in the determination of pesticide residues and evaluate the quality of the food that reaches the consumer, and together with the Maximum Residue Limits (MRLs), established by the legislation of each country, these instrumentation act to control the exposure of population to pesticides. Although the MRL is used as a parameter for food quality, the global differences in pesticide legislation do not guarantee the consumer safety. In this sense, a brief analysis of MRL inefficiency is also present in this paper.


Assuntos
Produtos Agrícolas/normas , Poluentes Ambientais/análise , Contaminação de Alimentos/análise , Inocuidade dos Alimentos/métodos , Resíduos de Praguicidas/análise , Animais , Produtos Agrícolas/química , Produtos Agrícolas/crescimento & desenvolvimento , Poluentes Ambientais/toxicidade , Qualidade dos Alimentos , Humanos , Resíduos de Praguicidas/toxicidade , Medição de Risco , Fatores Socioeconômicos
10.
PLoS One ; 15(4): e0230954, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32267854

RESUMO

Alternative management practices are needed to minimize the need for chemical fertilizer use in non-leguminous cropping systems. The use of biological agents that can fix atmospheric N has shown potential to improve nutrient availability in grass crops. This research was developed to investigate if inoculation with Azospirillum brasilense in combination with silicon (Si) can enhance N use efficiency (NUE) in maize. The study was set up in a Rhodic Hapludox under a no-till system, in a completely randomized block design with four replicates. Treatments were tested in a full factorial design and included: i) five side dress N rates (0 to 200 kg ha-1); ii) two liming sources (Ca and Mg silicate and dolomitic limestone); and iii) with and without seed inoculation with A. brasilense. Inoculation with A. brasilense was found to increase grain yield by 15% when N was omitted and up to 10% when N was applied. Inoculation also increased N accumulation in plant tissue. Inoculation and limestone application were found to increase leaf chlorophyll index, number of grains per ear, harvest index, and NUE. Inoculation increased harvest index and NUE by 9.5 and 19.3%, respectively, compared with non-inoculated plots. Silicon application increased leaf chlorophyll index and N-leaf concentration. The combination of Si and inoculation provided greater Si-shoot accumulation. This study showed positive improvements in maize growth production parameters as a result of inoculation, but the potential benefits of Si use were less evident. Further research should be conducted under growing conditions that provide some level of biotic or abiotic stress to study the true potential of Si application.


Assuntos
Azospirillum brasilense/fisiologia , Nitrogênio/química , Silício/química , Solo/química , Zea mays/crescimento & desenvolvimento , Produtos Agrícolas/química , Fertilizantes , Folhas de Planta/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Estresse Fisiológico/fisiologia
11.
J Chromatogr A ; 1621: 461038, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32199674

RESUMO

A QuEChERS method was optimized and validated for the LC-MS/MS analysis of perfluoro-n-pentanoic acid (PFPeA), perfluoro-1-butanesulfonic acid (PFBuS), perfluoro-n-hexanoic acid (PFHxA), perfluoro-n-heptanoic acid (PFHpA), perfluoro-1-hexanesulfonic acid (PFHxS), perfluoro-n-octanoic acid (PFOA), perfluoro-n-nonanoic acid (PFNA), perfluoro-1-octanesulfonic acid (PFOS) and perfluoro-n-decanoic acid (PFDA) in freeze-dried strawberry and olive, as model fruits characterized by very different chemical compositions. The method was evaluated for apparent recovery, intra-day and inter-day precision, matrix effect and recovery. The method optimized for strawberry provided for most compounds absolute values of matrix effect (|ME%|) ≤ 11%, except for PFHxA, which showed a signal suppression of 22%. The extraction efficiency was tested at the spike levels 500-5000 pg/g d.w. for PFPeA, PFBuS, and PFHxA, and 100-1000 pg/g d.w. for the other target analytes, evidencing as a whole recoveries in the range of 65-89%. For olive fruits, due to their high fat content, an ultrasound-assisted extraction was necessary to obtain an efficient sample disgregation so as to increase the extraction yield and its precision. Moreover, a d-SPE clean-up with GCB allowed to achieve |ME%| ≤ 8% (except for PFBuS, which showed a signal enhancement of 19%) and recoveries calculated at the aforementioned spike levels were in the range 75-97%. The two methods provided very good linearity (R2 ≥ 0.9984) from 10,000 pg/g down to compound specific quantification limits, which were included in the ranges of 2.9-393 pg/g and 2.6-127 pg/g for strawberry and olive fruit, respectively. The methods were applied to the analysis of PFAAs in strawberry and olive fruits commercially available in two Italian supermarkets, as well as obtained under irrigation with various treated wastewaters (TWWs), evidencing in both cases a higher PFAAs occurrence in olives than in strawberry. However, PFAAs concentrations determined in the investigated fruit matrixes were quite low, being their sum 1.9 ng/g d.w. in the worst case (i.e. olive fruits grown under irrigation with TWWs).


Assuntos
Cromatografia Líquida/métodos , Fluorcarbonetos/análise , Fragaria/química , Frutas/química , Olea/química , Espectrometria de Massas em Tandem/métodos , Irrigação Agrícola , Produtos Agrícolas/química , Águas Residuárias
12.
Food Chem ; 319: 126544, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32151901

RESUMO

Colorimetric biosensors have been widely applied to mycotoxins testing. However, the colorimetric assay previously reported used a single color to detect one mycotoxin, and there were few reports on the simultaneous detection of multiple mycotoxins. In this work, a colorimetric biosensor for dual mycotoxins detection was developed. A Fe3O4/GO based platform for aflatoxins B1 (AFB1) detection and a Fe3O4@Au based platform for ochratoxin A (OTA) detection were fabricated. The quantification of OTA and AFB1 was respectively achieved by the release of thymolphthalein under alkaline conditions and 3,3',5,5'-tetramethylbenzidine was catalyzed by Au NPs under acidic conditions. Because of different conditions, two sensing methods didn't interfere with each other but could provide a higher detection efficiency. The detection range of AFB1 is 5-250 ng·ml-1 and that of OTA is 0.5-80 ng·ml-1. This biosensor has been successfully applied in real sample detection, which has a broad application prospect in fields of food safety.


Assuntos
Aflatoxina B1/análise , Produtos Agrícolas/química , Contaminação de Alimentos/análise , Ocratoxinas/análise , Técnicas Biossensoriais , Colorimetria
13.
PLoS One ; 15(3): e0230178, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32187213

RESUMO

The Olsen phosphorus (Olsen-P) concentration of soil is generally a good indicator for estimating the bioavailability of P and environmental risk in soils. To maintain soil Olsen-P at adequate levels for crop growth and environmental sustainability, the relationship between soil Olsen-P and the P budget (the P input minus the output) as well as the variations of soil Olsen-P and P budget were investigated from three long-term (22 years) experiments in China. Five treatments were selected: (1) unfertilized control (CK); (2) nitrogen and potassium (NK); (3) nitrogen, phosphorous, and potassium (NPK); (4) nitrogen, phosphorous, potassium and straw; (5) nitrogen, phosphorous, potassium and manure. The results showed that without P fertilizers (CK, NK), there was a soil P deficit of 75-640 kg ha-1, and the lowest P deficit (mean of CK and NK) was in Eutric Cambisol. Soil Olsen-P decreased by 0.11-0.39 mg kg-1 year-1 in the order of Luvic Phaeozems > Eutric Cambisol > Calcaric Cambisol. Soil Olsen-P and the P deficit had a significantly (P<0.01) positive linear relationship. For every 100 kg of P ha-1 of deficit, soil Olsen-P decreased by 0.44-9.19 mg kg-1 in the order of Eutric Cambisol > Luvic Phaeozems > Calcaric Cambisol. Under the P fertilizer treatments (NPK, NPKS, and NPKM), soil Olsen-P showed an obvious surplus (except the NPK and NPKS in Luvic Phaeozems) of 122-2190 kg ha-1, and the largest P surplus was found under the NPKM treatment at each site. The relation between soil Olsen-P and the experimental years could be simulated using quadratic equation of one unknown in Calcaric Cambisol for the lower P input after 14 years of fertilization. And soil Olsen-P increased by 1.30-7.69 mg kg-1 year-1 in the order of Luvic Phaeozems > Eutric Cambisol. The relation between soil Olsen-P and the P surplus could be simulated by a simple linear equation except under NPK and NPKS in Luvic Phaeozems. With 100 kg ha-1 P surplus, soil Olsen-P increased by 3.24-7.27 mg kg-1 in the order of Calcaric Cambisol (6.42 mg kg-1) > Eutric Cambisol (3.24 mg kg-1). In addition, the change in soil Olsen-P with a 100 kg P ha-1 surplus (soil Olsen-P efficiency) was affected by the soil organic matter (SOM), pH, and CaCO3 content, etc. In the practice of fertilization, it's not necessary to increase the amount of P fertilizers, farmers should take measure to solve the local problem, for adjust the soil pH of Eutric Cambisol and Calcaric Cambisol, and apply more nitrogen in Luvic Phaeozems. In the area of serious soil P surplus, it is encouraged to stop applying P fertilizers for a few years to take advantage of soil accumulated P and make the high Olsen-P content decrease to a reasonable level.


Assuntos
Fósforo/química , Potássio/química , Agricultura/métodos , China , Produtos Agrícolas/química , Fazendeiros , Fertilizantes , Esterco/análise , Nitrogênio/química , Solo
14.
PLoS One ; 15(3): e0230458, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32168339

RESUMO

Gradients in the elemental composition of a potato leaf tissue (i.e. its ionome) can be linked to crop potential. Because the ionome is a function of genetics and environmental conditions, practitioners aim at fine-tuning fertilization to obtain an optimal ionome based on the needs of potato cultivars. Our objective was to assess the validity of cultivar grouping and predict potato tuber yields using foliar ionomes. The dataset comprised 3382 observations in Québec (Canada) from 1970 to 2017. The first mature leaves from top were sampled at the beginning of flowering for total N, P, K, Ca, and Mg analysis. We preprocessed nutrient concentrations (ionomes) by centering each nutrient to the geometric mean of all nutrients and to a filling value, a transformation known as row-centered log ratios (clr). A density-based clustering algorithm (dbscan) on these preprocessed ionomes failed to delineate groups of high-yield cultivars. We also used the preprocessed ionomes to assess their effects on tuber yield classes (high- and low-yields) on a cultivar basis using k-nearest neighbors, random forest and support vector machines classification algorithms. Our machine learning models returned an average accuracy of 70%, a fair diagnostic potential to detect in-season nutrient imbalance of potato cultivars using clr variables considering potential confounding factors. Optimal ionomic regions of new cultivars could be assigned to the one of the closest documented cultivar.


Assuntos
Produtos Agrícolas/química , Estado Nutricional , Folhas de Planta/química , Solanum tuberosum/química , Algoritmos , Canadá , Produtos Agrícolas/metabolismo , Humanos , Aprendizado de Máquina , Folhas de Planta/metabolismo , Quebeque , Solanum tuberosum/metabolismo
15.
Am J Primatol ; 82(3): e23102, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32003053

RESUMO

Agricultural expansion encroaches on tropical forests and primates in such landscapes frequently incorporate crops into their diet. Understanding the nutritional drivers behind crop-foraging can help inform conservation efforts to improve human-primate coexistence. This study builds on existing knowledge of primate diets in anthropogenic landscapes by estimating the macronutrient content of 24 wild and 11 cultivated foods (90.5% of food intake) consumed by chimpanzees (Pan troglodytes verus) at Bossou, Guinea, West Africa. We also compared the macronutrient composition of Bossou crops to published macronutrient measures of crops from Bulindi, Uganda, East Africa. The composition of wild fruits, leaves, and pith were consistent with previous reports for primate diets. Cultivated fruits were higher in carbohydrates and lower in insoluble fiber than wild fruits, while wild fruits were higher in protein. Macronutrient content of cultivated pith fell within the ranges of consumed wild pith. Oil palm food parts were relatively rich in carbohydrates, protein, lipids, and/or fermentable fiber, adding support for the nutritional importance of the oil palm for West African chimpanzees. We found no differences in the composition of cultivated fruits between Bossou and Bulindi, suggesting that macronutrient content alone does not explain differences in crop selection. Our results build on the current understanding of chimpanzee feeding ecology within forest-agricultural mosaics and provide additional support for the assumption that crops offer primates energetic benefits over wild foods.


Assuntos
Dieta/veterinária , Nutrientes/análise , Pan troglodytes , Animais , Produtos Agrícolas/química , Feminino , Preferências Alimentares , Frutas/química , Guiné , Masculino , Folhas de Planta/química , Caules de Planta/química
16.
BMC Plant Biol ; 20(1): 51, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32005156

RESUMO

BACKGROUND: Soybean oil is a major source of edible oil, and the domestication of wild soybean has resulted in significant changes in oil content and composition. Extensive efforts have been made to identify genetic loci that are related to soybean oil traits. The objective of this study was to identify quantitative trait loci (QTLs) related to soybean seed oil and compare the fatty acid composition between wild and cultivated soybean. RESULTS: Using the specific-locus amplified fragment sequencing (SLAF-seq) method, a total of 181 recombinant inbred lines (RILs) derived from a cross between wild soybean ZYD00463 (Glycine soja) and cultivated soybean WDD01514 (Glycine max) were genotyped. Finally, a high-density genetic linkage map comprising 11,398 single-nucleotide polymorphism (SNP) markers on 20 linkage groups (LGs) was constructed. Twenty-four stable QTLs for seed oil content and composition were identified by model-based composite interval mapping (CIM) across multiple environments. Among these QTLs, 23 overlapped with or were adjacent to previously reported QTLs. One QTL, qPA10_1 (5.94-9.98 Mb) on Chr. Ten is a novel locus for palmitic acid. In the intervals of stable QTLs, some interesting genes involved in lipid metabolism were detected. CONCLUSIONS: We developed 181 RILs from a cross between wild soybean ZYD00463 and cultivated soybean WDD01514 and constructed a high-density genetic map using the SLAF-seq method. We identified 24 stable QTLs for seed oil content and compositions, which includes qPA10_1 on Chr. 10, a novel locus for palmitic acid. Some interesting genes in the QTL regions were also detected. Our study will provide useful information for scientists to learn about genetic variations in lipid metabolism between wild and cultivated soybean.


Assuntos
Ácidos Graxos/análise , Sementes/química , Óleo de Soja/química , Soja/genética , Produtos Agrícolas/química , Produtos Agrícolas/genética , Locos de Características Quantitativas , Sementes/genética , Óleo de Soja/genética , Soja/química
17.
Environ Geochem Health ; 42(9): 2803-2818, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32036508

RESUMO

Selenium (Se) is an essential trace element. However, Se in soil is often accompanied by heavy metals, such as cadmium (Cd), because of geological background. The safe utilization of such Se-rich land resources remains a challenge. A typical Se-rich area located in Enshi County, China, was systematically investigated with geochemical and epidemiological methods. The results show that Se in the topsoil is 0.84 ± 1.39 µg/g, whereas that of Cd is 0.93 ± 1.63 µg/g. And the concentration of Se and Cd in corn is 0.22 ± 0.96 µg/g and 0.15 ± 0.32 µg/g, respectively, which is mainly related to the high concentrations in soil. The benchmark dose limit of urinary Cd for ß2-microglobulin in subjects (n = 160) was calculated as 3.27 µg/g Cr. In view of crop-human dose effect and combining the relationship among the concentrations of crops and human biomarkers and the concentrations of crops and topsoil, this study established the models of land resource safety zoning. With that, the risk screening value of Cd in the soil could be obtained as 0.98 µg/g in this typical area. The proportions of priority utilization, safe utilization, and strict management of agricultural land area were 58.85%, 22.90%, and 18.25%, respectively, in Enshi, China. These results could provide scientific support for local agricultural development and ecological sustainability.


Assuntos
Selênio/análise , Solo/química , Zea mays/química , Cádmio/análise , Cádmio/farmacocinética , Cádmio/toxicidade , China , Produtos Agrícolas/química , Exposição Dietética/efeitos adversos , Exposição Dietética/análise , Monitoramento Ambiental/métodos , Contaminação de Alimentos/análise , Humanos , Metais Pesados/análise , Modelos Teóricos , Medição de Risco , Selênio/farmacocinética , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Zea mays/metabolismo
18.
PLoS One ; 15(2): e0228641, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32053630

RESUMO

The use of plant tissue analysis as a tool for attaining low cyanogenic glucoside levels in cassava roots, has hardly been investigated. Just as the quality of crops is improved through the use of plant tissue analysis, the same can probably be done to consistently attain the lowest possible cyanogenic glucoside levels in cassava roots. High levels of cyanogenic glucosides in consumed fresh cassava roots or in their products have the potential of causing cyanide intoxication, hence the need to lower them. An experiment was thus conducted to assess the occurrence of meaningful relationships between plant nutritional status and cyanogenic glucoside production in cassava roots. Total hydrogen cyanide (HCN) levels in cassava roots were used to assess cyanogenic glucoside production. Using NPK fertiliser application to induce changes in plant nutritional status, the main objective of the study was investigated using the following sub-objectives; (1) to determine the effects of increased NPK fertiliser application on cassava root HCN levels; (2) and to show the occurrence of relationships between changes in nutrient levels in plant 'indicator tissue' and HCN levels in cassava roots. The study was a field experiment laid out as a split-plot in a randomized complete block design with three replicates. It was repeated in two consecutive years, with soil nutrient deficiencies only being corrected in the second year. The varieties Salanga, Kalinda, Supa and Kiroba were used in the experiment, while the NPK fertiliser treatments included; a control with no fertiliser applied; a moderate NPK treatment (50 kg N + 10 kg P + 50 kg K /ha); and a high NPK treatment (100 kg N + 25 kg P + 100 kg K /ha). A potassium only treatment (50 kg K/ha) was also included, but mainly for comparison. The root HCN levels of Salanga, Kalinda and Kiroba were significantly influenced by NPK fertiliser application in at least one of the two field experiments, while those of Supa remained uninfluenced. Changes in plant nutritional status in response to fertiliser application were thus shown to influence cyanogenic glucoside production. The results of the multiple linear regression analysis for the first field experiment, generally showed that the root HCN levels of some cassava varieties could have been 'reduced' by decreasing concentrations of nitrogen, potassium and magnesium in plants, or by improving plant calcium concentrations along with NPK fertiliser application. However, in the second field experiment (with corrected soil nutrient deficiencies) the regression analysis generally showed that the root HCN levels of some cassava varieties could have been 'reduced' by improving either one or a combination of the nutrients phosphorous, zinc and potassium in plants along with NPK fertiliser application. Although the results obtained in the two experiments had been contradicting due to slight differences in how they were conducted, the study had nonetheless demonstrated the occurrence of meaningful relationships between plant nutritional status and cyanogenic glucoside production; confirming the possible use of plant tissue analysis in predicting fertiliser needs for the consistent attainment of low cyanogenic glucosides in cassava roots.


Assuntos
Fertilizantes , Glucosídeos/análise , Cianeto de Hidrogênio/análise , Manihot/química , Nitrilos/análise , Raízes de Plantas/química , Agricultura , Produtos Agrícolas/química , Cianetos/análise , Glicosídeos/análise , Concentração de Íons de Hidrogênio , Modelos Lineares , Nitrogênio/análise , Fósforo/análise , Potássio/análise , Solo
19.
Food Chem ; 316: 126213, 2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32045811

RESUMO

Heavy metal contamination is one of the most pressing concerns for food security and human health. Understanding the risk to human health posed by soil pollution that enters the food chain is paramount. Here, we systematically assessed potential risks due to heavy metal (Cd, Cr, Pb, Hg, and As) contamination in soil and crops (2241 pairs of soil and crop (78 species) samples) in the Pearl River Delta urban agglomeration of China. Cadmium was the most common pollutant among all the heavy metals identified in soil and crops. The greatest risk of Cd ingestion from leaf and root vegetable consumption was concentrated within Huizhou. The highest risks to human health from heavy metals were found in rice and maize. This is the first time that the risk to human health from heavy metal contamination in soil and crops, and their associated spatial risk pattern, in China have been assessed systematically.


Assuntos
Produtos Agrícolas/química , Rios/química , Solo/química , China , Poluição Ambiental , Humanos , Metais Pesados/análise , Oryza/química , Folhas de Planta/química , Medição de Risco , Poluentes do Solo/análise , Verduras/química , Zea mays/química
20.
Sensors (Basel) ; 20(2)2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31963226

RESUMO

Optical sensors can be used to assess crop N status to assist with N fertilizer management. Differences between cultivars may affect optical sensor measurement. Cultivar effects on measurements made with the SPAD-502 (Soil Plant Analysis Development) meter and the MC-100 (Chlorophyll Concentration Meter), and of several vegetation indices measured with the Crop Circle ACS470 canopy reflectance sensor, were assessed. A cucumber (Cucumis sativus L.) crop was grown in a greenhouse, with three cultivars. Each cultivar received three N treatments, of increasing N concentration, being deficient (N1), sufficient (N2) and excessive (N3). There were significant differences between cultivars in the measurements made with both chlorophyll meters, particularly when N supply was sufficient and excessive (N2 and N3 treatments, respectively). There were no consistent differences between cultivars in vegetation indices. Optical sensor measurements were strongly linearly related to leaf N content in each of the three cultivars. The lack of a consistent effect of cultivar on the relationship with leaf N content suggests that a unique equation to estimate leaf N content from vegetation indices can be applied to all three cultivars. Results of chlorophyll meter measurements suggest that care should be taken when using sufficiency values, determined for a particular cultivar.


Assuntos
Clorofila/análise , Produtos Agrícolas/química , Cucumis sativus/química , Imagem Óptica/métodos , Fertilizantes , Nitrogênio/análise , Fenótipo , Folhas de Planta/química
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