Nitrate Accumulation In Plants Research Articles

Waste Biopolymers for Eco-Friendly Agriculture and Safe Food Production

This work addresses environmental problems connected with biowaste management, the chemical industry, and agriculture. These sectors of human activity cause greenhouse gas (GHG) emissions in the air, climate change, leaching of excess mineral fertilizers applied to soil into ground water, and eutrophication. To mitigate this problem in agriculture, controlled release fertilizers (CRFs) are made by coating mineral fertilizers granules with synthetic polymers produced from the fossil-based chemical industry. This strategy aggravates GHG emission. In the present work, six formulations containing sunflower protein concentrate (SPC) and a new biopolymer (BP) obtained from sunflower oil cake and by hydrolysis of municipal biowaste, respectively, and commercial urea were tested as CRFs for spinach cultivation against the control growing substrate Evergreen TS and commercial Osmocote®. The results show large differences in plants’ nitrate concentration due to the different treatments, although the same nitrogen amount is added to the substrate in all trials. BP is the key component mitigating nitrate accumulation in plants. The plants grown in the substrates containing BP together with SPC and/or urea, although exhibiting relatively high total N uptake (47–52 g kg−1), have significantly lower nitric to total N ratio (9.6–12.0) than that (15.3–16.5) shown by the plants grown in the substrates containing SPC and/or urea, but no BP. The data confirm that all composites containing BP yield the safest crop coupled with high biomass production. Replication of BP effects for the cultivation of different plants will contribute to the development of a biobased chemical industry exploiting biowastes as feedstock.

Nitrogen Requirement of Italian Rygrass (Lolium multiflorum) : A Review

Nitrogen is an essential nutrient for ryegrass growth and development but excess of it may lead to accumulation of nitrate in plants which may be lethal for ruminants. Irrigation, seed rate, variety, quality, cutting time and frequency, location alittude and fertilizer types are variables in the different articles in this review we selected to see the reaction of Italian rygrass to different nitrogen doses in core. A series of comments were also mentioned in the conclusion part of this article to improve future studies in thes area.

Successful Management of Nitrite Poisoning in Crossbred Dairy Calves

Nitrate/nitrite poisoning in dairy cattle occurs when there is an abrupt change in diet from the introduction of a bulk feed source with high nitrate levels. Over fertilization of fodder with untreated manure and occurrence of drought season followed by a rainy season could result in higher level of accumulation of nitrate in plants. A sudden onset of illness was reported in eight crossbred dairy calves (between 8–11 months of age) at University Livestock Farm and one among the affected calf died after showing symptoms of discomfort, excessive salivation, tympany, dyspnoea, sternal recumbency progressing to lateral recumbency, pedalling movements and, stiffness of the limbs and neck. On clinical examination, the affected animals exhibited sialorrhoea, tympany, increased pulse and respiratory rates, laboured breathing, brownish discoloration of mucous membrane and loss of co-ordination. Microscopical examination of rumen fluid revealed normal protozoan motility. Blood colour was dark chocolate brown in all the affected animals and coagulation time was delayed. Animals had a history of ad libitum feeding with chopped lush green fodder grasses namely hybrid Napier and fodder maize that were harvested from cattle slurry irrigated fodder plots. Based on the history and clinical signs noticed, the case was presumptively diagnosed as nitrate/nitrite poisoning, later confirmed with diphenylamine test. All the animals were treated with intravenous administration of 1 per cent methylene blue @ 1–2 mg/kg BW. Subsequently the dairy calves showed an uneventful recovery from the condition.

Nitrate Accumulation and Expression Patterns of Genes Involved in Nitrate Transport and Assimilation in Spinach.

Excessive accumulation of nitrate in spinach is not only harmful to human beings, but also limits the efficiency of nitrogen usage. However, the underlying mechanism of nitrate accumulation in plants remains unclear. This study analyzed the physiological and molecular characteristics of nitrate uptake and assimilation in the spinach varieties with high or low nitrate accumulation. Our results showed that the variety of spinach with a high nitrate content (So18) had higher nitrate uptake compared to the variety with a low nitrate content (So10). However, the nitrate reductase activities of both varieties were similar, which suggests that the differential capacity to uptake and transport nitrate may account for the differences in nitrate accumulation. The quantitative PCR analysis showed that there was a higher level of expression of spinach nitrate transporter (SoNRT) genes in So18 compared to those in So10. Based on the function of Arabidopsis homologs AtNRTs, the role of spinach SoNRTs in nitrate accumulation is discussed. It is concluded that further work focusing on the expression of SoNRTs (especially for SoNRT1.4, SoNRT1.5 and SoNRT1.3) may help us to elucidate the molecular mechanism of nitrate accumulation in spinach.

Effect of molybdenum treatment on molybdenum concentration and nitrate reduction in maize seedlings

Since 1940 molybdenum has been known as an essential trace element in plant nutrition and physiology. It has a central role in nitrogen metabolism, and its deficiency leads to nitrate accumulation in plants. In this study, we cultivated maize seedlings (Zea mays L. cv. Norma SC) in nutrient solution and soil (rhizoboxes) to investigate the effect of molybdenum treatment on the absorption of molybdenum, sulfur and iron. These elements have been previously shown to play important roles in nitrate reduction, because they are necessary for the function of the nitrate reductase enzyme. We also investigated the relationship between molybdenum treatments and different nitrogen forms in maize. Molybdenum treatments were 0, 0.96, 9.6 and 96 μg kg−1 in the nutrition solution experiments, and 0, 30, 90, 270 mg kg−1 in the rhizobox experiments.On the basis of our results, the increased Mo level produced higher plant available Mo concentration in nutrient solution and in soil, which resulted increased concentration of Mo in shoots and roots of maize seedlings.In addition it was observed that maize seedlings accumulated more molybdenum in their roots than in their shoots at all treatments. In contrast, molybdenum treatments did not affect significantly either iron or sulfur concentrations in the plant, even if these elements (Mo, S and Fe) play alike important roles in nitrogen metabolism. Furthermore, the physiological molybdenum level (1× Mo = 0.01 μM) reduced NO3–N and enhanced the NH4–N concentrations in seedlings, suggesting that nitrate reduction was more intense under a well-balanced molybdenum supply.

Effects of Nitrogen and Cycocel Application on Soil Nitrate Pollution and Agronomic Characters of Rice (Oryza sativa L.)

Nowadays, due to the effective role of nitrogen fertilizer in growth, yield and crop quality, farmers apply large amount of chemical fertilizers. High application of nitrogen fertilizers has caused soil and water pollution and environmental dangers, higher nitrate accumulation in plant, and different disease risks in human and livestock. In order to investigate the effects of nitrogen and cycocel application effects on soil nitrate pollution and agronomic traits of rice, an experiment was arranged in split plot based on a completely randomized block design with three replicates at Sari region (north of Iran) in 2010. The main factor was nitrogen in four levels and cycocel was considered as a sub factor in three levels. Results showed that maximum and minimum plant height and fourth internodes bending moment were obtained in 0 and 150 kg N ha, respectively. Higher filled spikelet percentage per panicle, grain yield and harvest index were obtained in 100 kg N ha application. Application of N up to 150 kg N ha increased soil nitrate by 44.7 percent. As cycocel application decreased, the plant height and panicle length were reduced, but tiller number per plant, filled spikelet percentage per panicle, and grain yield were increased.

Накопление нитратов в растениях и качество озимой пшеницы при систематическом применении удобрений (в условиях Топчихинского района Алтайского края)

Накопление нитратов в растениях и качество озимой пшеницы при систематическом применении удобрений (в условиях Топчихинского района Алтайского края)

Accumulation of Nitrate in the Roots of Carrot in Conditions of Transylvania and Correlation Between the Amount of Soluble Dry Matter and of Nitrites

Nitrate accumulation in plants is a natural phenomenon resulting from uptake of nitrate ion in excess of its reduction and subsequent assimilation. The problem of nitrate (V) accumulation in vegetable plants is very important to a potential consumer, due to the reported negative impact of nitrates on human health. T he aim of this study was to determine the nitrate contents in edible parts of 2 varieties of carrot, before clamping and after uncovering, in fresh carrot and dry matter. Achievement of a rational system of supplementary fertilization requires setting of the most appropriate combination of fertilizers, the ratio between these epochs and the doses of administration and knowledge of how each variety or hybrid reacts to fertilizers used. Also, if you use organic carrots then the organic fertilizer has natural nitrates unlike chemical fertilizer which can create a higher concentration of nitrates. Normal 0 21 false false false RO X-NONE X-NONE

Histopathological Changes in the Liver of Rabbits Exposed to High Nitrate Ingestion in Drinking Water

In India, especially in Rajasthan, people drink water which contains high level of nitrates and the possibility of finding concentrations of up to 500 mg of nitrate ions per litre of water is not unusual. Excessive use of nitrate fertilisers and herbicides results in accumulation of nitrate in plants and methemoglobinaemia in cattle as consequences of nitrate poisoning. The ingested nitrate is converted to nitrite in the digestive system and it is absorbed in blood, thus causing methemoglobinaemia. Methaemoglobinaemia is not restricted to infants alone, but it is prevalent in higher age groups also. Therefore, an experimental study was conducted on 10 rabbits which were between three and a half months to four months of age, which had weights which ranged from 1.310 kg to 1.720 kg. Five groups A, B, C,D and E were formed, with two rabbits in each group. The control Group A was given water orally, which had 45 mg/litres of nitrate. Groups B to E (experimental groups) were administered water orally, which had concentrations of 100mg/litre, 200mg/litre, 400mg/litre and 500mg/litre of nitrate respectively, for 120 days. During experimental period, the differences in general behaviour of rabbits were noted. After this, rabbits were anaesthetised and sacrificed according to guidelines of ICMR and their livers were removed and processed for making paraffin sections,.Hematoxyllin and eosin staining was done for microscopic observations. During experimental period, the animals were found to be lethargic on 75(th) day. Quantity of intake of food and water was not altered in the rabbits which were undergoing experiments in different groups. Rabbits of all groups i.e. A to E showed a continuous increase in heart rate (up to 218/minute in Group E) and respiration rate (up to 84/minute in Group E) respectively. The microscopic study showed mild necrosis of hepatocytes, with infiltration of inflammatory cells in between hepatocytes. In higher groups, the liver showed bridging necrosis and portal triditis. Dilatations of central vein with eosinophilic degeneration were observed in Group E only.

Denitrification in soil amended with thermophile-fermented compost suppresses nitrate accumulation in plants

NO (3) (-) is a major nitrogen source for plant nutrition, and plant cells store NO (3) (-) in their vacuoles. Here, we report that a unique compost made from marine animal resources by thermophiles represses NO (3) (-) accumulation in plants. A decrease in the leaf NO (3) (-) content occurred in parallel with a decrease in the soil NO (3) (-) level, and the degree of the soil NO (3) (-) decrease was proportional to the compost concentration in the soil. The compost-induced reduction of the soil NO (3) (-) level was blocked by incubation with chloramphenicol, indicating that the soil NO (3) (-) was reduced by chloramphenicol-sensitive microbes. The compost-induced denitrification activity was assessed by the acetylene block method. To eliminate denitrification by the soil bacterial habitants, soil was sterilized with γ irradiation and then compost was amended. After the 24-h incubation, the N(2)O level in the compost soil with presence of acetylene was approximately fourfold higher than that in the compost soil with absence of acetylene. These results indicate that the low NO (3) (-) levels that are often found in the leaves of organic vegetables can be explained by compost-mediated denitrification in the soil.

The effect of nitrogen fertilization on production and qualitative properties of sown grasslands in the system of sustainable production

Nitrogen fixation in grass-leguminous mixtures is not sufficient to satisfy the nitrogen requirements of plants, therefore it is necessary to compensate this deficiency by nitrogen from mineral fertilizers. Objective of this study is to present the effect of N application in grass-leguminous mixtures on their production and qualitative properties, i.e. to give an answer to the question if application of nitrogen fertilizers results in the increase or decrease of yield, quality and changes in the structural composition of the grassland. N from mineral fertilizers, especially considerable amounts of nitrogen, changes the structural composition of grasslands - the share of leguminous plants decreases and share of grasses increases. Yield of dry matter increases with added nitrogen fertilizers. The amounts of nitrogen fertilizer which exceed the requirements of plants reduce the economical justification of fertilization and sometimes can have even opposite effect. Nitrogen fertilization increases the content of crude proteins and protein yield, whereas other quality parameters decrease or remain unchanged. Too much nitrogen in crops leads to nitrate accumulation in plants which is undesirable quality parameter.

Studies on the Effect of Urea Application on Nitrate Toxicity in Forages

ObjectiveUnder certain adverse conditions nitrate can accumulate to potentially toxic concentrations in forages like oats (Avena sativa), barley (Hordeum vulgare), maize (Zea mays), sarson (Brassica juncea) and berseem (Trifolium alexandrinum). The conditions under which plants accumulate excessive amounts of nitrates are not fully understood. We hypothesized that excessive use of nitrogenous fertilizers may be responsible for accumulation of nitrate in plants and decided to determine the effect of excess urea application on nitrate accumulation in berseem, berseem+ rye grass (Lolium perenne) (B+RG), breseem + sarson (B+S) and berseem + oats (B+O).MethodsThe crop was sown on the experimental area in the plot sizes of 5X4 m2 in three replications. The crop was sprayed with 5 different concentrations of urea ranging from 1 to 5% and subsequently analyzed for nitrate content.ResultsThe results indicate that the crude protein and nitrate content of berseem, B+RG, B+S and B+O increases with increasing concentrations of urea. The maximum nitrate concentration in B+S was observed at 4% of urea concentration while in B+RG and B+O at 5% of urea.ConclusionThe excessive nitrogen application appears to be responsible for the nitrate accumulation in the forage crops which may lead to large scale livestock losses.

Nitrate accumulation in plants, factors affecting the process, and human health implications. A review

Leafy vegetables occupy a very important place in the human diet, but unfortunately constitute a group of foods which contributes maximally to nitrate consumption by living beings. Under excessive application of nitrogen fertilizer, these vegetables can accumulate high levels of nitrate and, upon being consumed by living beings, pose serious health hazards. Therefore, efforts are warranted to minimize the accumulation of nitrate in leafy vegetables and its ingestion by human beings. This review focuses on (i) the contribution of vegetables towards dietary nitrate intake by humans, (ii) the nutritional, environmental and physiological factors affecting nitrate accumulation in plants, (iii) the harmful and beneficial effects of nitrate on human health, and (iv) the strategies that may be followed to minimize the nitrate content in plants and its subsequent consumption by human beings. The risk to human health due to nitrate consumption may be minimized by harvesting vegetables at noon, removal of organs rich in nitrate content and cooking of vegetables in water with a low nitrate content. The European Commission Regulation No. 1822/2005 needs to be followed in order to ensure safe levels of nitrate in plants for human consumption.

Characterization of red beet and carrot with special emphasis on nitrate accumulation

Nitrate accumulation in plants is a natural phenomenon resulting from uptake of nitrate ion in excess of its reduction and subsequent assimilation. The water soluble nitrate content of various carrot and red beet varieties was measured as a function of irrigation and mineral supplement in three years. In the first year, the nitrate content increased in both roots (significant differences were found for three carrot and at three red beet cultivars) following the irrigation. The activity of nitrate-reductase in the leaves was also significantly higher after irrigation in three red beet varieties in 1998. The mineral supplement in most of the carrot varieties increased the nitrate content. In the third year, the impact of water supply showed various tendencies in nitrate accumulation in both vegetables. On the basis of results for three years, the conclusion was that the seasonal and varietal differences were also remarkable.

APPLICATION OF ANAEROBIC DIGESTED RESIDUES ON SAFE FOOD PRODUCTION

ABSTRACT Experiments were conducted in pot culture and field plots to study the effects of Anaerobic Digested Residues (ADR) on nitrate accumulation in leaf vegetables, which is critical for the safety of food. The results showed that compared to chemical fertilizer, ADR could decrease the nitrate accumulation in rape and spinach. Furthermore, nitrate content in plant tissue was increased with the increase of percentage of chemical nitrogen in the mixture of chemical fertilizer and ADR. A comparison of spraying digested slurry with irrigation showed that spraying method could reduce the nitrate content of rape, however, a reverse result was found in spinach. The nitrate accumulation in rape affected by ADR was more apparent in high fertility soil than that in low fertility one. To regulate the nitrate accumulation in plant, it was more apparent in rape under greenhouse cultivation, while more apparent in spinach under open-air cultivation. The results demonstrated that the ADR was effective in the safe food production and it may convert the technology to be more profitable.

Ecoagrochemical Approaches to the Problem of Nitrate Pollution in Agroecosystems

On the basis of long-term studies, the role of agricultural chemicals in enhancing the production process and the rate of nitrate accumulation in plants is shown. Their influence on the state of plants is evaluated from physiological and agrochemical standpoints. The possibility of improving the resistance of agroecosystems to various adverse factors is considered.

Growth-limiting phosphate nutrition suppresses nitrate accumulation in greenhouse lettuce

Two contrasting explanations of the seasonal- or light eVect on the nitrate level can be found in the literature. Lettuce was grown in aerated nutrient solutions con- There can be no question that the nitrate concentration taining all necessary plant nutrients except phosphate. in the plant is the result of the combined eVects of net Phosphate was supplied at four different exponentially influx and the rate of nitrate reduction, the latter being increasing rates of daily dosage. In addition, two levels proportional to net photosynthesis and growth (Scaife, of light and atmospheric CO 2 were imposed. The four 1989; Scaife and Schloemer, 1994; Cardenas-Navarro phosphate addition treatments resulted in different, et al., 1998). The diVerence is focused on the role of the fairly constant relative growth rates, whereas little internal nitrate concentration in the regulation of its effect was observed from light or CO 2 levels. Growth own state. reduction associated with limiting phosphate nutrition One interpretation, which will be referred to as the resulted in increases in root/shoot ratio, dry matter nitrate homeostasis concept, assumes that the nitrate content and concentrations of sugars and organic influx is adjusted to the reduction flux by means of acids. By contrast, the concentration of nitrate in the negative feedback control, which is proportional to the shoots was decreased. The concentrations of nitrate internal concentration (Cardenas-Navarro et al., 1998). and the sum of sugars and organic acids in the shoot A similar model, advocated by Scaife (1989) and Scaife showed a strong negative correlation. Two opposing and Schloemer (1994), assumes a concentration- mechanistic models concerning the effects of environ- dependent nitrate eZux instead of feedback inhibition, mental conditions on nitrate accumulation in plants resulting in similar kinetics for the net nitrate influx. In are discussed in the light of these results. both models, the internal nitrate concentration itself is directly involved in the regulation mechanism as the

Nitrate accumulation in plants: a role for water

Plant nitrate and water contents (g−1 dry weight) were monitored (1) in tomato plants in a growth room, during the day/night cycle with varied light intensities; (2) in two lettuce cultivars during the day/night cycle in a growth room and during growth in a glasshouse. Large, concurrent, and linearly correlated changes in nitrate and water contents were observed in both species and time-scales. Although these changes were dependent on light intensity and other environmental conditions, the slope of their relationship was not affected. Furthermore, when a limiting nitrate nutrition regime was applied to tomato, a significant and concurrent reduction of both plant nitrate and water contents was observed. Thus, when compared on the same water content basis, their nitrate content was only slightly reduced. These nitrate and water content changes were also observed in plant parts, and confirmed, through data extracted from the literature, in a large number of species (annuals and perennials) and other environments (open-field, soil culture). They are interpreted as an effect of homoeostasis for endogenous nitrate concentration (mol m−3), and it is suggested that nitrate content changes (mol g−1 dry wt.) result from the varying size of a water reservoir (m3 g−1 dry wt.) whose nitrate concentration is regulated. From this viewpoint, the concept of critical nitrate concentration is discussed, and it is proposed to introduce explicitly water content in plant nitrogen models.

Nitrate accumulation in plants: a role for water

Plant nitrate and water contents (g -1 dry weight) were monitored (1) in tomato plants in a growth room, during the day/night cycle with varied light intensities; (2) in two lettuce cultivars during the day/night cycle in a growth room and during growth in a glasshouse. Large, concurrent, and linearly correlated changes in nitrate and water contents were observed in both species and time-scales. Although these changes were dependent on light intensity and other environmental conditions, the slope of their relationship was not affected. Furthermore, when a limiting nitrate nutrition regime was applied to tomato, a significant and concurrent reduction of both plant nitrate and water contents was observed. Thus, when compared on the same water content basis, their nitrate content was only slightly reduced. These nitrate and water content changes were also observed in plant parts, and confirmed, through data extracted from the literature, in a large number of species (annuals and perennials) and other environments (open-field, soil culture). They are interpreted as an effect of homoeostasis for endogenous nitrate concentration (mol m -3 ), and it is suggested that nitrate content changes (mol g -1 dry wt.) result from the varying size of a water reservoir (m 3 g -1 dry wt.) whose nitrate concentration is regulated. From this viewpoint, the concept of critical nitrate concentration is discussed, and it is proposed to introduce explicitly water content in plant nitrogen models.

Urea transformation and the adaptability of three leafy vegetables to urea as a source of nitrogen in hydroponic culture

Abstract Substitution of urea for commonly used nitrate fertilizers in hydroponic culture of vegetables would not only avoid excessive accumulation of nitrate in plants but would also reduce the cost of production. This substitution, however, might have adverse effects, such as a dramatic decrease in solution pH, reduced nutrient uptake and possibly urea toxicity per se. Differences in adaptability to urea were found among three species of leafy vegetables, Ipomoea aquatica Fossk., Lactuca sativa L. and Brassica chinensis L. I. aquatica showed the best adaptability, growing normally with urea as the sole nitrogen source in spite of the dramatic pH decrease in the nutrient solution. It was further found that I. aquatica had significantly lower urease activity in the roots than the other two species when urea was supplied to the solution. Tolerance of low pH and avoidance of urea toxicity may be possible mechanisms of I. aquatica's adaptability to urea application in hydroponic culture.