Plant Mineral Composition Research Articles

Sulfur and nitrogen interaction affects onion yield and post-harvest quality

Ionic interactions affect the mineral composition of plants, which can cause nutritional disorders with reflections on yield, post-harvest quality, and food safety. Thus, this study evaluated the interaction between nitrogen (N) and sulfur (S) and its effects on onion production and post-harvest quality. The study was conducted in a completely randomized design, with a 3 × 5 factorial scheme and four replications. The treatments consisted of a combination of three S rates (0, 20, and 40 mg dm−3) and five N rates (0, 40, 60, 80, and 100 mg dm−3), applied in the form of calcium sulfate (CaSO4·2H2O) and urea, respectively. It was observed that the interaction between N and S negatively affected onion production, reducing the gain of both fresh and dry mass of the bulb. The N/S ratio ranged from 16.5 to 26.2 and was not influenced by the interaction between N and S. Onion pungency was classified as intermediate. The higher pungency value was obtained with the application of 100 mg dm−3 of N, and 40 mg dm−3 of S. The application of N when combined with 20 mg dm−3 of S contributed to increasing titratable acidity and soluble solids content of onion cv. Diamantina.

Zinc and iron biofortification of crops grown in a vertical farm

With the growing global population and climate change, achieving food security is a pressing challenge(1). Vertical farming has the potential to support local food production and security. In the UK population females and younger adults appear to be particularly vulnerable to micronutrient shortfalls from food sources alone. Levels of micronutrient intakes including zinc and iron are below the recommended daily intake(2). As a Total Controlled Environment Agriculture (TCEA) system, vertical farming employs hydroponics using a nutrient solution which offers opportunities to modulate nutrient uptake, and thus influence plant mineral and vitamin composition(3).In this study we aimed to determine the suitability of different crop types for soilless agronomic biofortification with zinc and iron to achieve biofortified crops.In this study, we investigated the effect of the addition of 20ppm (+20 mg L−1) of zinc (ZnSO4) or iron (Fe-EDTA) to the nutrient solution on the growth and nutritional components in pea microgreens, kale microgreens and kale baby leaf plants. The growth conditions were kept identical throughout the treatments with photoperiod 18 h d-1, temperature 20-22°C and relative humidity at 70-80%. Plant growth, mineral composition, glucosinolate content and protein content were evaluated. Results were analysed using ANOVA (p<0.05, Tukey’s test).It was determined that higher amounts of zinc in the nutrient solution resulted in significantly higher levels of zinc in all three crops (p<0.05), with increases of 205% in pea microgreens, 264% in babyleaf kale and 217% in kale microgreens compared to the control plants. Higher amounts of iron in the nutrient solution resulted in significantly higher levels of iron only in pea microgreens, with an increase of 38% (p<0.05). Neither dosing regimen negatively influenced the overall crop performance.These results suggest that the three different crops are suitable for soilless biofortification with zinc and iron, although pea microgreens were the only crop that had a significant increase in iron upon iron-dosing.

Natural genetic variation underlying the negative effect of elevated CO2 on ionome composition in Arabidopsis thaliana.

The elevation of atmospheric CO2 leads to a decline in plant mineral content, which might pose a significant threat to food security in coming decades. Although few genes have been identified for the negative effect of elevated CO2 on plant mineral composition, several studies suggest the existence of genetic factors. Here, we performed a large-scale study to explore genetic diversity of plant ionome responses to elevated CO2, using six hundred Arabidopsis thaliana accessions, representing geographical distributions ranging from worldwide to regional and local environments. We show that growth under elevated CO2 leads to a global decrease of ionome content, whatever the geographic distribution of the population. We observed a high range of genetic diversity, ranging from the most negative effect to resilience or even to a benefit in response to elevated CO2. Using genome-wide association mapping, we identified a large set of genes associated with this response, and we demonstrated that the function of one of these genes is involved in the negative effect of elevated CO2 on plant mineral composition. This resource will contribute to understand the mechanisms underlying the effect of elevated CO2 on plant mineral nutrition, and could help towards the development of crops adapted to a high-CO2 world.

Natural genetic variation underlying the negative effect of elevated CO2 on ionome composition in Arabidopsis thaliana

The elevation of atmospheric CO2 leads to a decline in plant mineral content, which might pose a significant threat to food security in coming decades. Although few genes have been identified for the negative effect of elevated CO2 on plant mineral composition, several studies suggest the existence of genetic factors. Here, we performed a large-scale study to explore genetic diversity of plant ionome responses to elevated CO2, using six hundred Arabidopsis thaliana accessions, representing geographical distributions ranging from worldwide to regional and local environments. We show that growth under elevated CO2 leads to a global decrease of ionome content, whatever the geographic distribution of the population. We observed a high range of genetic diversity, ranging from the most negative effect to resilience or even to a benefit in response to elevated CO2. Using genome-wide association mapping, we identified a large set of genes associated with this response, and we demonstrated that the function of one of these genes is involved in the negative effect of elevated CO2 on plant mineral composition. This resource will contribute to understand the mechanisms underlying the effect of elevated CO2 on plant mineral nutrition, and could help towards the development of crops adapted to a high-CO2 world.

Peculiarities of biochemical and mineral composition of lettuce <i>Lactuca sativa</i> L. grown from seeds after long-term storage in the International Space Station

Seed storage of agricultural crops in the conditions of International Space Station (ISS) is an effective method of quick plant breeding aimed to enhance the adaptability, and improve the biologically active compound accumulation and crop yield. Biochemical and mineral composition (ICP-MS) of lettuce grown in greenhouse from seeds stored for one year at the ISS was assessed. High varietal differences in lettuce tolerance to the effect of micro-gravity and radiation were evaluated using the values of yield, biometrical parameters, antioxidant status and plant mineral composition. Among the cultivars studied, i.e. Petrovich, Synthesis, Moskovsky parnikovy, Picnic, Cavalier and Bouquet, only the cvs. Retrovich, Synthesis, Moskovsky parnikovy and Picnik retained seed viability. Significant yield increase was recorded for the cv. Moskovsky parnikovy, while the cvs. Petrovich, Synthesis and Picnic demonstrated a tendency to the yield decrease. Improvement of photosynthetic pigment accumulation due to seed space storage was recorded for the cv. Moskovsky parnikovy and, particularly, the latter cultivar differed from the other cvs. due to the significantly higher proline level and lower MDA levels in leaves. Though space stress did not cause any significant decrease in antioxidant accumulation of plants, the latter demonstrated valuable changes in mineral composition. Among the 23 elements tested, V, Se. Fe and Cr showed higher concentrations compared to those in the control plants. Positive correlations between Ca, Sr, Cd, Cp, Mg, Mo and Pb were recorded (r > 0.9; p < 0.001).

Determination of macro and micronutrients in diferentes species of ora-pro-nóbis and comparison with conventional vegetable

The aim of this work was to determine the proximate composition and contents of iron, copper, manganese, phenolic compounds, phytic acid, total titratable acidity and pH of three species of ora-pro-nóbis (OPN): Pereskia aculeata Miller (PA), Pereskia aculeata var. godseffiana (PAG) and Pereskia grandifolia Haworth (PG) from domestic cultivation. Furthermore, compare the results obtained with a conventional vegetable kale (CM) (Brassica oleracea L. acephala) and evaluate the interrelationships through Principal Component Analysis (PCA). The ora-pro-nóbis species were statistically different from the CM in terms of total titratable acidity, pH, phenolic compounds, iron and copper at a significance level of 5%. The CM and PA showed statistical similarities in relation to protein, carbohydrate and manganese content at a significance level of 5%, while for PA and PG samples statistical similarities were observed for moisture and phytic acid at a significance level of 5%. For OPN species, the minerals concentrations varied from 15.26 ± 6.40 to 25.52 ± 4.72 mg Fe 100 g-1, 1.23 ± 0.81 to 5.31 ± 6.57 mg Cu 100 g-1, 12.00 ± 6.31 to 17.72 ± 13.13 mg Mn 100 g-1. ACP demonstrated that the PAG sample made the greatest contribution to the study, having in its composition the highest levels of iron, copper, phytic acid and moisture. Therefore, the species of ora-pro-nóbis evaluated in this work, even in residential cultivation conditions, proved to be potential sources of minerals, mainly iron, especially the species Pereskia aculeata var. godseffiana. In this way, the evaluation of the proximate and mineral composition of unconventional food plants is relevant for understanding the nutritional composition and increasing the consumption of these vegetables, in their use for food enrichment, as well as in helping to reduce the population's food insecurity.

Composição mineral de maracujazeiro-azedo cultivado sob irrigação com águas salinas e adubação potássica

ABSTRACT Salt stress is one of the main abiotic factors responsible for limiting agricultural production worldwide, especially in regions with a semi-arid climate, where climatic conditions intensify the effect of salts on plants. The objective of this study was to evaluate the mineral composition of sour passion fruit plants grown under irrigation with saline water and potassium fertilization in a semi-arid region of Brazil. The experiment was carried out under field conditions in São Domingos, PB, Brazil. A randomized block design was adopted, in a 5 × 4 factorial scheme, with five levels of electrical conductivity of irrigation water - ECw (0.3, 1.1, 1.9, 2.7 and 3.5 dS m-1) and four potassium doses - KD (60, 80, 100 and 120% of the K2O recommendation) with 3 replicates. There was an increase in sodium and chloride contents in the stem and leaves of sour passion fruit plants with the increase in ECw levels. Fertilization with 120% of the K2O recommendation associated with irrigation using water with EC of up to 1.1 and 1.6 dS m-1 increased potassium content in the stem and leaves and leaf nitrogen content, respectively, in ‘BRS Sol do Cerrado’ sour passion fruit plants. Fertilization with 60% of the K2O recommendation increased phosphorus content in the leaves of sour passion fruit plants under water salinity of up to 2.2 dS m-1. In the leaves, nutrient contents varied according to the order of concentration N>Cl>P>Na>K, while in the stem the order was N>Cl>P>Na>K, at 160 days after transplanting.

The Effect of One-Year Seed Spaceflight Storage on Yield, Biochemical and Mineral Characteristics of Mature Leafy Vegetables Belonging to Brassicaceae, Apiaceae and Asteraceae Families

Spaceflight is known to produce genetic changes in seeds, usually accelerating aging, though species and varietal differences have been poorly investigated. Comparisons were carried out in terms of yield, biochemical characteristics and mineral composition between mature plants grown from seeds subjected to a one-year spaceflight, belonging to Brassicaceae (Brassica juncea and Eruca sativa), Apiaceae (Anethus graveolens, and Coriandrum sativum), and Asteraceae (Lactuca sativa, six cultivars) families, and non-treated control. Among the studied species, only Brassica juncea and Eruca sativa demonstrated a growth stimulation effect caused by seed spaceflight, while significant growth inhibition was recorded in Apiaceae plants and three cultivars of Lactuca sativa L. No differences in the total antioxidant activity (AOA), polyphenol and ascorbic acid content were detected between ‘space-treated’ and control plants. On the contrary, significant decrease in proline accumulation and increase in malonic dialdehyde and photosynthetic pigments levels were shown by Brassicaceae species. The effect of long-term seed spaceflight on the mineral composition of mature plants was reflected in the inhibition of accumulation of all 24 elements analyzed in Apiaceae plants, except for Se, whose concentration was higher in all ‘space-treated’ plants compared to the control. Spaceflight seed storage increased V levels in lettuce and decreased Na accumulation in all the investigated species. The results reveal species-dependent changes in the accumulation of macro-, micro- and toxic elements in Apiaceae, Brassicacea, and Asteraceae representatives due to spaceflight seed storage. The detected differences in plant elemental composition between ‘space’ treatment and control partly explain the corresponding yield gap and suggest a relationship between mineral status and adaptability. The highest beneficial effect of spaceflight seed storage on yield was recorded in Eruca sativa cultivar, Rusalochka.

Determination of Active Ingredients, Mineral Composition and Antioxidant Properties of Hydroalcoholic Macerates of Vinca minor L. Plant from the Dobrogea Area.

In recent decades, new alternative therapies using drugs containing active ingredients of natural origin have been a hot topic for medical research. Based on the confirmed therapeutic potential of the Vinca minor plant, considered in the specialized literature to be of pharmaceutical interest, the purpose of this study is to determine the chemical and mineral composition of the Vinca minor plant grown in the Dobrogea area, with a view to its use in the formulation of dermal preparations. For this purpose, plant materials were collected from the mentioned area and hydroalcoholic macerates of different concentrations were obtained: 40%, 70% and 96% from leaves (F40, F70, F96) and stems (T40, T70, T96) of Vinca minor plant to determine the optimal extraction solvent. The hydroalcoholic macerates were analyzed via the HPLC method for the identification and quantification of the main bioactive compounds, and two methods were used to evaluate their antioxidant properties: the DPPH radical scavenging test and the photochemiluminescence method. HPLC analysis showed the presence of four indole alkaloids: vincamine, 1,2-dehydroaspidospermidine, vincaminoreine and eburnamonine. Vincamine was the alkaloid found in the highest concentration in Vinca leaves (2.459 ± 0.035 mg/100 g d.w.). The antioxidant activity of Vinca minor hydroalcoholic macerates showed values between 737.626-1123.500 mg GAE/100 g d.w (DPPH test) and 77.439-187.817 mg TE/100 g d.w (photochemiluminescence method). The concentrations of toxic metals Cd, Cu, Ni, Pb in dried leaves and stems of Vinca minor, determined by AAS, were below detection limits.

Mineral composition and production of guava under salt stress and salicylic acid.

The limitation in the quality of water sources for irrigation in the semi-arid region of northeastern Brazil is increasingly present, so it is necessary to use water with high concentrations of salts for agricultural production, which makes the use of elicitors essential to mitigate the harmful effects of salinity on plants. Given the above, the objective of this study was to evaluate the effects of foliar application of salicylic acid on the mineral composition and production of guava plants under salt stress conditions in the post-grafting phase. The experiment was carried out under greenhouse conditions, in a randomized block design, in a 2 × 4 factorial scheme, with two levels of electrical conductivity of irrigation water (0.6 and 3.2 dS m-1) and four concentrations of salicylic acid (0, 1.2, 2.4, and 3.6 mM), with three replicates. During the flowering stage of guava, N, P, and K contents accumulated in the leaves according to the following order of concentration: N > K > P. Foliar application of 1.2 mM of salicylic acid increases the leaf contents of N, P, and K in guava plants grown under irrigation with water of 0.6 dS m-1. Water salinity of 3.2 dS m-1 reduces the growth and production components of guava plants.

Use of halophyte plants on saline soils and evaluation of salt removal efficiency

The main purpose of the study was to evaluate of effectiveness of the halophyte plants on saline soils and use as a salt-tolerant plants. The experimental studies carried out on the halophyte plants (Tetragonia tetragonioides and Portulaca oleracea) and the salt-sensitive crop (Lactuca sativa, L) in the greenhouse. Two experimental studies were conducted on the effects of salt on germination, total yield and mineral composition of the halophyte plants and salt-sensitive crop. Three salinity treatments (saline water solution with NaCl: T1 - 5 dS m−1; T2 - 9.8 dS m−1; and T3 - 20 dS m−1) and a control treatment (T0 - 0.6 dS m−1) were used for the experimental study. The both halophyte plants showed the potential salt (ions) removing species with high yields when grown on saline soils. The results showed that the above halophytes varieties contributed to improved quality and yield of the salt-sensitive crop. Thus, this method has proven to be one of the important solutions in preventing and managing salinity and ensuring the sustainability of agricultural systems. Analysis of the obtained results showed that halophyte plants could be used to improve the management and stability of saline soils and grow them as food crops.

FARM DAIRY EFFLUENT APPLICATION ON AN ARGIUDOLL CULTIVATED WITH ALFALFA (Medicago sativa L.): BIOMASS PRODUCTION AND PERSISTENCE

The intensification of dairy production systems has resulted in a higher generation of waste. The aim of this study was to evaluate the impact of different doses of farm dairy effluent (FDE) applied to the soil on aerial biomass production, persistence and chemical composition of alfalfa pastures, in Santa Fe province, Argentina. The study was conducted in four randomized complete blocks with four treatments (FDE doses): 0 m3 ha-1 (T0: without FDE), 82 m3 ha-1 (T1: low rate), 151 m3 ha-1 (T2: medium rate) and 282 m3 ha-1 (T3: high rate). The soil application of FDE increased the total aerial biomass produced (ABP) but reduced the persistence of plants. Total nitrogen (Nt) of alfalfa was significantly higher, but phosphorus (P) concentrations did not vary after the application of FDE to the soil . Ca and Mg concentrations in plants were lower in T3 compared to T0, which can be explained by the imbalance produced in the soil after FDE was applied, presenting high levels of Na, K and NH4-N but low levels of Ca and Mg. Soil application of FDE on alfalfa pastures must be carefully planned in terms of composition and amount to be applied in order to increase biomass production, prevent the decrease in persistence, and control changes in the mineral composition of plants.

Nutritional diversity of underutilized plant species collected from Aegean Region of Turkey

The objective of the present work was to evaluate variability for dry matter, protein and mineral N (nitrogen), P (phosphorus), K (potassium), Ca (calcium), Mg (magnesium) composition of nutritionally important and widely consumed wild edible plants in Aegean region of Turkey, and to assess their mineral diversity using multivariate analysis. The plant material comprises 17 edible plants collected from native found, the data were subject to analysis of variance, and a Pearson correlation test used to determine the correlations between dry matter, protein content and N, P, K, Ca, Mg composition. Principal component analysis was performed on the result of examine compositions and the factor loadings, eigenvalues and percentage of cumulative variance were calculated, the patterns of relationships among nutritive element were shown three-dimension scatter plot. Multivariate analysis revealed considerable variation for the most of concentration and explained 81.49% of total variation accounted for three PC axes. The data reveal that selected wild plant provide significant nutrition and exhibited great variability among the species. Although soil mineral concentration, availability, fertilization and environment may have influenced on nutrient accumulation in plant tissue, genetic variability is considerable influenced on mineral composition of plant.

The content of macro- and microelements in plants of the genus Artemisia under conditions of introduction in the M. M. Gryshko National Botanical Garden of the NAS of Ukraine

Purpose. To determine mineral composition of plants of species of the genus Artemisia (A. dracunculus L., A. abrotanum L. and A. argyi H.Lév. & Vaniot) to determine the possibility of their safe use in the food and pharmaceutical industries of Ukraine. Methods. X‑ray fluorescence method for determining the elemental composition of plant raw materials. Results. The content of mineral elements in plants of the genus Artemisia was determined depending on their ability to absorb elements from the soil and accumulate in the roots and organs of the aerial part was determined. The quantitative content of 21 macro- and microelements was established, and some peculiarities of their migration and distribution in the soil – roots – plant system were revealed. In particular, the aerial part of the studied plants contains K, Fe, Cu, Zn and Mn, which are the most important elements in the life of the plant organism. The content of mesoelements Ca and S is quite high. The amount of toxic elements Pb, Sr and Zr in plants is insignificant. Elements K and S accumulate in the aerial part. The content of elements in the aerial part of plants by decreasing their concentration can be represented in the form of the following series: for Artemisia dracunculus – S> K> Ca> Cl> Fe> Sr> Zn> Mn> Cu> Zr> Rb> Br> Cr; for A. abrotanum – K> Ca> S> Cl> Fe> Zn> Sr> Mn> Cu> Br> Cr> Co> Zr> Rb> Ni; for A. argyi – K> Ca> S> Fe> Cl> Sr> Zn> Mn> Co> Zr> Cu> Rb> Br> Se. The content of toxic elements in the studied plants was lower than the maximum allowable concentrations for plant raw materials and food. Conclusions. For the first time under conditions of introduction in the M. M. Gryshko National Botanical Garden of the NAS of Ukraine in the plants Artemisia dracunculus, A. abrotanum and A. argyi the content of macro- and microelements, which are directly related to the metabolism of biologically active compounds, was determined. The peculiarities of their distribution by plant organs during the transition from soil to aboveground mass have been clarified. The obtained results can be used to evaluate and compare the quality of plant raw materials of the genus Artemisia, to determine the pharmacological properties of these plants associated with some elements of the mineral composition, and their use in the medical and food industries. The obtained data have both scientific and practical significance in the selection of economically valuable plant species for the enrichment of the cultivated flora of Ukraine.

Potassium sources impact on cassava plant productivity, quality and mineral composition

In the mineral nutrition of plants, potassium is considered “the element of quality” of harvested products, and its lack or excess can cause decreased or loss of product quality. In this sense, the aim of the present study was to evaluate the productivity, root quality and mineral nutrient levels of the Pretinha cassava cultivar according to potassium sources and doses. Two sources (potassium chloride and potassium sulfate) and five K2O doses (0, 30, 60, 90 and 120 kg of K2O ha−1) were tested, in a randomized block design, with five repetitions. After 11 months of sowing, five plants were manually harvested from the useful area of each plot and the number, diameter, firmness, root moisture and productivity were determined, in addition to the nutritional contents in different plant organs (leaf, stem and root and bark). Fertilization with potassium sulfate promotes higher root productivity, higher P and S levels in leaves and increased N and K levels in root barks. Potassium fertilization promotes a greater number of roots per plant, larger root diameter and greater external firmness, increased K content in plant organs and decreased Ca content in cassava leaves. The use of potassium chloride also increases Cl levels in cassava leaves.

Combined effect of nano-CuO and nano-ZnO in plant-related system: From bioavailability in soil to transcriptional regulation of metal homeostasis in barley

The co-existence of engineered nanoparticles (ENPs) in the environment is an emerging issue remaining poorly investigated. The present study aimed at analyzing the fate of binary mixtures of CuO and ZnO ENPs in a soil-plant system. The ENPs were singly or jointly dosed into soil at 300 mg kg−1 and aged for 7 and 30 days. To evaluate nano-specific effects, individual and combined treatments of metal salts were also applied. Interactions between ENPs and soil-grown barley Hordeum vulgare were determined in terms of biomass, plant mineral composition as well as expression of genes regulating metal homeostasis (ZIP1,3,6,8,10,14, RAN1, PAA1,2, MTP1, COPT5) and detoxification (MT1–3). The bioavailability of Zn and Cu in bulk soil and in the rooting zone was determined using the 0.01 mol L−1 CaCl2 extraction. After combined treatment of ENPs, the extractable concentrations of Cu and Zn were lower than upon individual exposure in bulk soil. The opposite tendency was noted for metal salts. Genes related to metal uptake (ZIP) and cellular compartment (PAA2, RAN1) were mostly up-regulated by single rather than combined application of ENPs. The single and joint exposure to metals salts induced the down-regulation of these genes.

Use of machine learning to establish limits in the classification of hyperaccumulator plants growing on serpentine, gypsum and dolomite soils

The so-called hyperaccumulator plants are capable of storing hundred or thousand times bigger quantities of heavy metals than normal plants, which makes hyperaccumulators very useful in fields such as phytoremediation and phytomining. Among these plants there are many serpentinophytes, i.e., plants that grow exclusively on ultramafic rocks which produce soils with a great proportion of heavy metals. Even though there are multiple classifications, the lack of consensus regarding which parameters to use to determine whether a plant is a hyperaccumulator, as well as the arbitrariness of stablished thresholds, bring about the need to propose more objective criteria. To this end, plant mineral composition data from different vegetal species were analysed using machine learning techniques. Three complementary case studies were established. Firstly, plants were classified in three types of soils: dolomite, gypsum and serpentine. Secondly, data about normal and hyperaccumulator plant Ni composition were analysed with machine learning to find differentiated subgroups. Lastly, association studies were carried out using data about mineral composition and soil type. Results in the classification task reach a success rate over 75%. Clustering of plants by Ni concentration in parts per million (ppm) resulted in four groups with cut-off points in 2.25, 100 (accumulators) and 3000 ppm (hyperaccumulators). Associations with a confidence level above 90% were found between high Ni levels and serpentine soils, as well as between high Ni and Zn levels and the same type of soil. Overall, this work demonstrates the potential of machine learning to analyse data about plant mineral composition. Finally, after consulting the red list of the IUCN and those of countries with high richness in hyperaccumulator species, it is evident that a greater effort should be made to establish the conservation status of this type of flora.

Effects of Sewage Sludge Stabilization Processes on Soil Fertility, Mineral Composition, and Grain Yield of Maize in Successive Cropping

The final disposal of sewage sludge (SS) in agricultural areas is considered economically and environmentally viable, but few studies on the effects of sludge stabilization processes on SS fertilizing potential are available. The present study evaluated two forms of SS stabilization on the shoot biomass, yield, and concentration of nutrients in the soil and plants in three successive maize croppings. The raw sludge was chemically stabilized (CSS) and composted (TSS) through the addition of calcium oxide and co-composting with plant residues, respectively. Five rates of each type of SS (0, 10, 20, 30, and 40 t ha−1 dry weight) were applied to the soil in a family farm of NE Brazil. A mineral fertilization treatment was used to assess the SS fertilizer potential. Changes in soil chemical characteristics (pH, organic matter, and nutrient available contents), plant mineral composition, and maize biomass and yield were assessed at each crop cultivation. Applying sewage sludge to the soil elevated the soil organic matter and the availability of N, P, Fe, Mn, Zn, and Cu, reflecting in higher accumulation of these nutrients by plants. The CSS was more efficient in increasing soil pH than SS composting. In the first harvest, maize yield in CSS was 34% higher than that obtained with mineral fertilization. The two types of sludges had different effects on soil characteristics, plant mineral composition, and maize yield. The CSS residual effect on soil pH can dismiss soil liming. Composted sludge maintained higher soil organic matter levels in the soil with the successive croppings and promoted higher soil N concentrations in the first two croppings. Both sludges increased and maintained adequate available P concentrations in the soil throughout the successive crops. The results support SS’s efficiency in providing nutrients to plants, improving soil properties, and boosting crop productivity in low-input agriculture systems.

Effect of Tillage Practices and Cultivation Year on Natural Mycorrhization and Mineral Uptake of Durum Wheat during Tillering Stage under Rainfed Conditions

Conservation agriculture has been proposed as an alternative to conventional agriculture to mitigate the climate change impact and ensure food security. This study examined the effect of conventional tillage (CT) and no tillage (NT) on mycorrhization and mineral elements uptake of durum wheat for three cultivation years during the tillering stage. The experiment was conducted in a referential farm (Krib, Siliana, North West Tunisia). The results showed that tillage practices (T) had significant effect on mycorrhization rate (MR) for the first cultivation year and the highest mycorrhization rate was noted for NT with 24%. Moreover, tillage (T) had no significant effect on plant mineral composition in tillering stage for the three cultivation years. The cultivation year (Y) had showed significant effects on P and K amounts for both tillage practices when it had no effect on Ca and Na amounts. The interaction T x Y had no significant effect on mineral elements concentration. Mycorrhization rate (MR) showed significant negative correlation with K. For partial correlation based on Tillage practices, MR showed significant negative correlations with P and K. Considering the partial correlation based on cultivation year, MR had no significant correlations with the studied parameters (P, K, Ca and Na concentrations). This work expands our knowledge on durum wheat natural mycorrhization and mineral elements uptake as influenced by tillage practices helping decision makers in upscaling the adoption of no tillage in Tunisia under rainfed conditions

Disturbance in Mineral Nutrition of Fenugreek Grown in Water Polluted with Nanosized Titanium Dioxide.

Nanoparticle (NPs) toxicity in the plant has drawn considerable attention. Fenugreek plants were cultivated for 16 days in hydroponic experiments and treated with 50 and 100mg L- 1 titanium oxide (TiO2) NPs of two sizes [23 ± 1.6nm (D1) and 83 ± 15nm. (D2)]. The level of Ti in roots was higher than that of leaves and stems of plants treated with 100mg L- 1 of TiO2 NPs (D1, D2). Ti caused a depletion of Ca and Mn compared with root control. The titane (Ti) damage to root cellular membranes could alter the plant's capacity to absorb and transport some nutrients. In our study, increasing the size of TiO2 NPs produced increases in the contents of Mg, Zn and Mn, and a decline in the contents of Fe and Cu in leaves and stems. In roots, Fe and Cu decreased after TiO2 NPs (D2) exposure. Changes in the fenugreek plant mineral composition were assessed, and physiological disturbances could be directly correlated with exposure to NPs.