Nitrate Accumulation In Vegetables Research Articles

Biochar-based molybdenum slow-release fertilizer enhances nitrogen assimilation in Chinese flowering cabbage (Brassica parachinensis).

Low molybdenum (Mo) bioavailability in acidic soil obstructs vegetable nitrogen assimilation and thus increases the health risk of vegetable ingestion due to nitrate accumulation. Constantly providing available Mo in acidic soil is a challenge for decreasing nitrate accumulation in vegetables. In this study, three Mo application methods, including biochar-based Mo slow-release fertilizer (Mo-biochar), seed dressing, and basal application, were investigated to enhance Mo bioavailability in acidic soil and nitrogen assimilation in Chinese flowering cabbage (Brassica parachinensis). The results showed that Mo-biochar constantly and sufficiently supplied Mo nutrients throughout the growing period of Brassica parachinensis, as evidenced by the soil available Mo, plant Mo uptake, and Mo values. The improved Mo supply was attributed to the alleviation of acidic soil (pH from 5.10 to 6.99) and the slow release of Mo adsorbed on biochar. Mo-biochar increased the nitrate reductase (NR) activity by 238.6% and glutamate dehydrogenase activity by 27.5%, indicating an enhancement of the rate-limiting steps of nitrogen assimilation, especially for nitrate reduction and amino acid synthesis. The increase in Mo-containing NR could be directly ascribed to the high level of Mo in Brassica parachinensis. Compared with the control, the nitrate content of Brassica parachinensis decreased by 42.9% due to the nitrate reduction induced by increased NR. Additionally, Mo-biochar was beneficial to vegetable growth and quality. In contrast, the transformation from NO3- to NH4+ was blocked with Mo seed dressing and basal application because of low Mo bioavailability in the soil, resulting in a high nitrate content in Brassica parachinensis. Conclusively, Mo-biochar can slowly release Mo and improve the neutral environment for Mo bioavailability, which is an effective strategy to mitigate the high nitrate accumulation of vegetables planted in acidic soil.

Effect of growth seasons and nitrogen fertilization on the growth, yield and nitrate accumulation of lettuce (Lactuca sativa L.) plants

In modern agriculture, the nitrate accumulation in vegetables has become a serious threat to human health. That caused by an imbalance between nitrate absorption and assimilation in plants. Nitrogen fertilization and light intensity are the main factors affected nitrate accumulation. Therefore, a pot experiment was conducted during two successive summer and winter seasons of 2019/20 at the greenhouse of Fac. Agric., Cairo Univ., Giza, Egypt, on lettuce (Lactuca sativa L. var. longifolia Lam) plants to investigate the effect of growth seasons (summer and winter), different rates (0, 60, 90 and 120 Kg N fed-1) and sources (CO (NH2)2, NH4NO3 and (NH4)2SO4) of nitrogen fertilizers on lettuce growth and nitrate concentrations. The results showed that fresh and dry weight, yield and nutrient contents of lettuce plants increased gradually according to increasing dose of nitrogen, up to 90 Kg N fed-1 and the magnitude of increase, according to different N fertilizers used , was in the following order: CO (NH2)2 > NH4NO3 > (NH4)2SO4. The accumulation of nitrate was higher in winter compared to summer season for both inner and outer leaves.

Nitrate in groundwater and agricultural products: intake and risk assessment in northeastern Iran

The suitability of groundwater and agricultural products for human consumption requires determining levels and assessing the health risks associated with potential pollutants. Here, particularly pollution with nitrate still remains a challenge, especially for those urban areas suffering from insufficient sewage collection systems, resulting in contaminating soil, endangering food safety, and deteriorating drinking water quality. In the present study, nitrate concentrations in the commonly consumed fruit and vegetable species were determined, and the results, together with the groundwater nitrate levels, were used to assess the associated health risks for Mashhad city residents. For this assessment, 261 water samples and 16 produce types were used to compute the daily intake of nitrate. Nitrate in groundwater was analyzed using a spectrophotometer, and produce species were examined using High-Performance Liquid Chromatography. Ward’s hierarchical cluster analysis was applied for categorizing produce samples with regard to their nitrate content. Additionally, to account for the sanitation hazards associated with groundwater quality for drinking purposes, total coliform and turbidity were also assessed using the membrane filter (MF) technique and a nephelometer, respectively. Nitrate concentrations exceeded the prescribed permissible limits in 42% of the groundwater wells. The outcomes also exhibit significantly higher nitrate accumulation levels in root-tuber vegetables and leafy vegetables compared to fruit vegetables and fruits. Using cluster analysis, the accumulation of nitrate in vegetables and fruits was categorized into four clusters, specifying that radish contributes to 65.8% of the total content of nitrate in all samples. The Estimated Daily Intake (EDI) of nitrate and Health Risk Index (HRI) associated with consumption of groundwater exceeded the prescribed limit for the children’s target group in Mashhad’s south and central parts. Likewise, EDI and HRI values for produce consumption, in most samples, were found to be in the tolerable range, except for radish, lettuce, and cabbage, potentially posing risks for both children and adult consumers. The total coliforms in groundwater were found to violate the prescribed limit at 78.93% of the sampling locations and were generally much higher over the city’s central and southern areas. A relatively strong correlation (R2 = 0.6307) between total coliform and nitrate concentrations suggests the release of anthropogenic pollution (i.e., sewage and manure) in the central and southern Mashhad.

Effect of the Intensity and Spectral Quality of LED Light on Yield and Nitrate Accumulation in Vegetables

At present, trends exist in the production of food for the benefit of human health. The negative effect of an excessive intake of nitrates accumulated in vegetables is well known, causing worldwide concern. Light plays an important role in the accumulation of this ion. The objective of this work was to evaluate the effect of light-emitting diode (LED) spectra used in artificial lighting for horticulture on the accumulation of nitrates in leafy and root vegetables compared with the effects with white LED lights. Two independent experiments were carried out in the culture chamber. In Expt. 1, six species of nitrate accumulators were used: arugula, spinach, lettuce, endive, radish, and beetroot. In Expt. 2, four lettuce cultivars were used. In both experiments, the treatments were two spectra—T1 = AP67 Valoya® and the control (T0) = white Roblan®—at two illumination intensities [high (H) and low (L)] with a 16/8-hour (day/night) photoperiod. The fresh biomass and the concentration of nitrates were measured at 35 days of treatment posttransplantation. An important and significant increase of 50% of the mean fresh weight was obtained in all the species when the light intensity increased. Except for spinach in the low-intensity treatment, all nitrate content values were less than the maximum limits of European regulation. The nitrate content generally decreased with increasing intensity, and this benefit was greater in the T1 treatment. T0 showed a reduction in the nitrate content compared with T1 in only one case, which was the H in beetroot. A large and significant reduction was observed in the nitrate content in T1. For L in Expt. 1, the nitrate decrease was 18%, whereas for H, it was 35%. In Expt. 2, the decrease in the nitrate content was 10% for L and 21% for H. A greater benefit was derived when using the photosynthetic spectrum in the growing chambers under low light intensity.

Selected yield and qualitative parameters of broccoli in dependence on nitrogen,sulfur, and zinc fertilization

The effect of nitrogen (N), sulfur (S), and zinc (Zn) fertilization on the yield quantity and selected qualitative parameters of broccoli was studied in an experiment carried out in Nitra (Slovak Republic) during 2011 and 2012. In this experiment, the following fertilization treatments were tested: control; N200S80 (fertilized to the supply level: 200 kg N ha-1 and 80 kg S ha-1); N200S100 (supply level: 200 kg N ha-1 and 100 kg S ha-1), and N200S100 Zn (supply level: 200 kg N ha-1 and 100 kg S ha-1 + foliar zinc application). Compared to the control treatment, higher broccoli yield was shown at all fertilized treatments. The most significant increase in yield quantity was found at N200S100Zn, i.e. About 59% higher than the control. Application of N200S100Zn was the most suitable fertilization from the standpoint of broccoli quality. The foliar Zn spraying led to a statistically highly significant increase of sulforaphane in broccoli (about 41.1%) compared to the control. The applied N and S fertilization tended to decrease the vitamin C content in broccoli (about 9.2%) against the control. On the other hand, Zn application resulted in a return of the vitamin C content, nearly to its level in control. The results confirmed the well-known fact that nitrogen fertilization leads to nitrate accumulation in vegetables. However, the results of this research indicate that nitrogen fertilization combined with zinc application should be expressed mainly by lower nitrate accumulation in the edible parts of broccoli. The experimental data are interesting, and in terms of growing vegetables for consumption with enhanced quality, promising. This is notable because the formation of many serious diseases is increasing.

Nitrate accumulation in leafy vegetables and its relationship with water

Abstract Present studies show that nitrate accumulation is the major factor influencing the water uptake by vegetables, but there is lack of knowledge on how the relationship between nitrate and water concentrations in different vegetable tissues. We determined nitrate accumulation and water content in vegetables of rape, Chinese cabbage, and spinach under different nitrogen levels (experiment I), 29 spinach cultivars (experiment II), and 27 rape cultivars (experiment III). The results from experiments I–III showed a highly linear relationship between nitrate accumulation and water content, and the levels thereof in different organs of the vegetables revealed that the petiole exhibited the best correlation between them compared with the root and leaf blade. These suggest that (1) vegetables with high water content have high nitrate content, (2) water content in the petiole can be used to screen cultivars with low levels of nitrate accumulation, and (3) increasing soil water content in agronomic practice is essential to decreasing nitrate accumulation in vegetables.

EFFECT OF ORGANIC FERTILIZERS ON NITRATE ACCUMULATION IN VEGETABLES AND MINERAL NITROGEN IN TROPICAL SOILS OF MOROGORO, TANZANIA

SUMMARYNitrogen (N) nutrition is a key factor for vegetable growth and yield. However, different rates of nitrogen fertilization may trigger different responses to vegetables. A survey was conducted to investigate the effect of soil fertility management practices on nitrate concentration in vegetables. The survey results were used to plan experiments on the effect of chicken and cattle manures on nitrate levels in Chinese cabbage (Brassica rapa) and amaranthus (Amaranthus cruentus) grown in Tanzania and the patterns of mineral nitrogen in soils under open field conditions. Chicken or cattle manure at 200, 300 kg N ha−1and 170 250 kg N ha−1for Chinese cabbage and amaranthus respectively, and control were compared in a randomized complete block design. We observed a higher nitrate content in fertilized Chinese cabbage at day 30 than at day 44 after sowing, ranging from 3243 to 4993 mg kg−1fresh matter regardless of the N source and rates. Only application of manures at high levels (250 kg N ha−1) induced significantly (p< 0.05) higher nitrate contents in amaranthus at day 28 after sowing, although there was a clear indication of nitrate accumulation even at 170 kg N ha−1application. Soil NH4+-N + NO3−-N in both Chinese cabbage and amaranthus plots were increased with increasing N application rates and differences between control and amended soils were significant (p< 0.01). There was a positive relationship between NO3−concentration in vegetables and NO3−-N in the rooted top soil layer (0–15 cm). However, higher NH4+concentrations depressed NO3−build up in crops and a significant negative relationship between soil (NH4+-N)/(NO3−-N) ratio and crop NO3−content was found. It is concluded that low manure application rates result in similar yields to high rates but reduces nitrate accumulation in vegetables and excess mineral nitrogen in soils.

EFFECTS OF EXTRANEOUS GLUTAMIC ACID ON NITRATE CONTENTS AND QUALITY OF CHINESE CHIVE

The accumulation of nitrate in vegetables is paid close attention to for one's health in world. This paper highlights researching effects of extraneous glutamic acid (Glu), which is middle product in path of nitrogen metabolism, on nitrate accumulation in Chinese chive (Allium tuberosum Rottler Spreng) by means of spraying leaves with glutamic acid solution. Glutamic acid solution at concentration level of 0.5-10 mmol·L -1 decreased nitrate contents in Chinese chive leaves. Especially, treatment of Glu at 5 mmol·L -1 produced an obvious increase of 15.1%. However, total-N (nitrogen) content increased in Chinese chive leaves as increasing of Glu concentration at range of 0.5-10 mmol·L -1 . Meanwhile, activity of nitrate reductase (NR) and glutamine synthetase (GS) raised by a wide margin, and chlorophyll content increased from 13.7 to 29.5%. In addition, contents of free amino acid, soluble protein, and soluble sugar also increased. The results showed that extraneous glutamic acid did not only improve activity of NR named as N-reducing-driving-pump and activity of GS called first driving pump in path of N assimilation, but also provides enough reducing force e - , ATP and C-framework, e.g., α-ketoglutarate for glutamate synthase (GOGAT) which is called the second driving pump in path of N assimilation. Therefore, spraying glutamic acid on leaves accelerated assimilation of nitrate in Chinese chive leaves. As a result, application of glutamic acid did not only reduce nitrate accumulation, but also improved quality of Chinese chive.

Nitrate and nitrite in Australian leafy vegetables

A market survey of Australian leafy vegetables and a winter and spring experiment with Swiss chard were conducted to examine nitrate and nitrite levels in leaves. The relationship between growth response to nitrogen (N) supply and light level and accumulation of N in leaves was of particular interest. The survey that included 7 types of lettuce and endive (Asteraceae), 6 leafy Asian vegetables (Brassicaceae), and Swiss chard and spinach (Amaranthaceae) showed that fresh leafy vegetables available during a 6-month period on the Australian market can range in nitrate-N from 12 to 1400 mg/kg fresh weight and nitrite-N from 0 to 37.5 mg/kg. Some samples exceeded the limits for nitrate and nitrite based on international food safety standards. The response of Swiss chard to N supply and light was investigated. The accumulation of nitrate in Swiss chard was primarily influenced by increasing N supply and not by light level. Light conditions for all treatments in both the winter and spring experiments exceeded the critical level (~200 μmol/m2.s) required to increase leaf nitrate. Growth and leaf nitrate concentration were higher for spring, associated with average minimum to maximum temperatures of 18–39°C, compared with 14–28°C for winter. Treatment effects on nitrite-N in Swiss chard could not be determined because nitrite was only detected in one-third of plants. The importance of N supply in affecting nitrate accumulation in vegetables is highlighted by the Swiss chard experiments. It confirmed that nitrate accumulation occurs at optimal to supra-optimal nitrate supply, emphasising for growers the undesirable effect of excessive fertiliser use.

Accumulation of Nitrate in Vegetables and Its Possible Implications to Human Health

In recent times, there are two kinds of completely opposite viewpoints about the impacts of nitrate on human health. To further objectively understand the effects of nitrate on human health, both of harmfulness and possible benefits of nitrate to human body, it is discussed in this review from the aspects of nitrate accumulation in vegetables, the source of nitrate ingested into human body, and the transformation of nitrate in human body, as well as the pathogenesis and physiological functions of nitrate metabolism.

시설채소재배지의 토양특성과 흡착제 종류별 염류경감 효과

Salt accumulation in the plastic film house soils under continuous cultivation condition causes problems such as salt damages to plants, nitrate accumulation in vegetables, groundwater contamination, etc. due to excess application of fertilizers. Objective of this research was to find an optimum adsorbent to reduce salt concentration in the soil solution of plastic film house soils, where crop injuries have been observed due to the salt accumulation. The soils were significantly high in available P , exchangeable Ca and Mg , as compared to those of the average upland soils in Korea. Soils were treated with each of adsorbent such as ion-exchange resin, zeolite, rice bran, etc. at 2% level and prepared into saturated-paste samples. After equilibrium, soil solution was vacuum-extracted from the soil and measured for changes of the pH, EC, and concentrations of . Rice bran effectively removed in the soil solution up to 100%. Efficiency was decreased in the orders of rice bran > ion-exchange resin > zeolite. Removal efficiencies of zeolite and ion-exchange resin for were ranged from 1 to 65% and from 7 to 61%, respectively. Ion-exchange resin was also effective for removing . Overall results demonstrated that rice bran and ion-exchange resin could be applicable for salt accumulated soil to remove the respective anion and cation.

Effects of Nitrogen and Phosphorus Fertilization on Plant Growth and Nitrate Accumulation in Vegetables

Experiments were carried out on a vegetable field with Peking cabbage (Brassica pekinensis lour. rupr.), cabbage (Brassica chinensis var. oleifera makino and nemoto), green cabbage (Brassica chinensis L.), spinach (Spinacia oleracea L.), and rape (Brassica campestris L.) to study the effects of nitrogen (N) forms and rates, and phosphorus (P) fertilization on their growth and nitrate accumulation. The results indicated that application of ammonium chloride, ammonium nitrate, sodium nitrate, and urea significantly increased the yields and nitrate concentrations of Peking cabbage and spinach. Although N forms had no significantly different effect on yields, input of nitrate N fertilizer increased nitrate accumulation in vegetables much more than did ammonium N. Vegetable yields were not increased continuously with N rate, and an excess input of N fertilizer more or less reduced plant growth, leading to yield decline for the earlier harvests. This trend was also true for nitrate concentrations in some vegetables and at some sampling times. However, as a whole, nitrate concentrations in vegetables were positively correlated with N rates. As a result, addition of N fertilizer to soil was the major cause for vegetables increasing their nitrate contents. Effects of P fertilization on vegetable growth and nitrate accumulation were species and sampling-time dependant. By addition of P fertilizer, yields of green cabbage and rape were increased, while those of spinach and cabbage had no significant changes. The nitrate concentration was significantly decreased in green cabbage, but significantly increased in cabbage and rape by P fertilization at the second harvest. Different organs had different amount in nitrate accumulation, and it was found that nitrate concentrations were much higher in roots, stems, and petioles than in blades at any N rate.

Nitrate accumulation reduction using chloride in the nutrient solution on lettuce growing by NFT in semiarid climate conditions

Nitrate accumulation in vegetable represents a serious threat to man's health. Different methods have been reported to reduce the nitrate accumulation in lettuce and other leafy vegetables with or without variation in the yield. The aim of this experiment was to show the different behavior of some cultivars of lettuce using the replacement of N‐NO3 for chloride in the nutrient solution during last week before harvest. The trial was carried out with three lettuce cultivars: Domino, Elvira, and Daguan and took place in southern Spain (Almería) under greenhouse by NFT. The results indicated a correct method to decrease nitrate content in leafy vegetables and perhaps sulphate could be an anion to study their effect in this way.

Nitrate accumulation in vegetables and its relationship to quality

SummaryMany plants, especially leafy vegetables, accumulate nitrate under low light conditions as uptake of nitrate exceeds reduction. Nitrate may harm the health of the consumer as it can be converted to nitrite causing methaemoglobinaemia or carcinogenic nitrosamines. To take directional measures during the growth of vegetables which will decrease the nitrate content, physiological knowledge about the nitrogen economy of the plant is needed. In this review the physiological role of nitrate as osmoticum and its relationship with carbon utilisation will be described; some practical implications for growers and the consequence for quality of the product will be discussed.

Soil Fertilization and Nitrate Accumulation in Vegetables1

AbstractFive different rates of nitrogen were applied to plots upon which were grown several different varieties of vegetables. Nitrogen fertilization caused significant increases in nitrate content in red radishes, kale, mustard, and turnip roots and tops. The maximum accumulation of nitrates appeared to vary with species, but differences in harvest dates between species precluded valid statistical tests of the differential accumulations. No significant differences in nitrate accumulation were found between varieties of the same species. Early maturing vegetables tended to accumulate more nitrate than late maturing varieties at a given rate of fertilization. Differences in nitrate content were observed at different sampling dates. The absence of phosphorus, potassium, or lime, or the presence of trace elements in the fertilizer treatment had no significant influence on nitrate accumulation.