Effect of nitrogen and sulphur fertilizers and seed inoculation with rhizobium phaseoli on the nitrogen‐sulphur relationships of bean (phaseolus vulgaris L.)

A greenhouse experiment with beans (Phaseolus vulgaris L.) was performed in order to investigate the effect of nitrogen and sulphur application and seed inoculation on the yield, leaf area, distribution of different nitrogen and sulphur fractions and N/S ratio in shoot, fruit and root.

Inoculation of plants together with nitrogen or sulphur application produces an increase in the concentration of total nitrogen and a decrease in the accumulation of nitrate‐nitrogen and sulphate‐sulphur in shoot, fruit and root. Leaf area increased more with nitrogen than with sulphur application while the highest amounts of fruit dry matter were obtained with sulphur application.

N: S ratios obtained were different according to the part of the plant tested. Sulphur fertilization decreased the N: S ratios in shoot, fruit and root. The data obtained indicate that and adequate N: S ratio can insure maximum production of yield.     

Use of labeled sulphur‐35 for tracing sulphur transfers in developing pods of field‐grown oilseed rape

Abstract

This study was conducted to better understand the dynamics of sulphur (S) transfer between pod walls and seeds of field‐grown oilseed rape by using sulphur (³⁵S) as an investigative tool. Labeling experiments with ³⁵S were carried out to determine the effects of nitrogen (N) and sulphur fertilization on these transfer mechanisms. Sixty‐four plants from field trials fertilized with 200 kg N ha^‐1 in the forms of ammonium nitrate (AN) or urea (U), with or without 75 kg S ha^‐1 in the forms of ammonium thiosulphate and MgSO₄ were sampled. At 30, 43, 56, and 77 days after flowering (DAF), terminal racemes were cut and labeled with ³⁵S‐SO₄ ^2‐. After labeling, pods and seeds were separated into 3 groups according to their position on stem, and measurements of ³⁵S levels were performed accordingly. This short‐term labeling experiment showed that the pod walls retained from 39 to 61% of labeled ³⁵S, according to the different treatments, whereas seeds accumulated from only 1 to 16% of applied ³⁵S. On average, when S was added, a sharp decrease of ³⁵S in seeds from 2.6 to 1.7%, 9.0 to 5.4%, and 14.8 to 7.7% was observed at 30, 43, and 56 DAF, while progressively the percentage values in pod walls increased from 49.6 to 50.5%, 43.1 to 52.2%, and 41.7 to 63.5%, respectively. The increase of ³⁵S in pod walls was found to be tied to the glucosinolate concentration of seeds. By artificially increasing the ratio values of external N‐NO₃ ^‐ to S‐SO₄ ^2‐, these results demonstrated that the transfer of ³⁵S to seeds was more affected by the higher level of N‐NO₃ ^‐ in plant tissues than S‐SO₄ ^2‐ levels. The N/S ratio value above which the transfer of S was disrupted was around 6.     

An estimation of atmospheric deposition input of sulphur and nitrogen oxides to the Kejimkujik watershed : 1979–1987

Daily measurements of the concentrations of major ions in ambient air and in precipitation at Kejimkujik National Park, Nova Scotia, Canada over the period May 1979 to December 1987 are used to estimate the wet, dry and total deposition to the watershed. Variations on three time-scales are apparent. The strongest variation, of up to two orders of magnitude occurs on a day to day basis resulting in a coefficient of variation in the range of 110 to 140%. Deposition is highly episodic with the highest 20% of the daily events accounting for 55 to 60% of the long-term deposition. The most systematic variation is the annual cycle observed for many of the species. The air concentration of SO₂ has the most pronounced cycle with a winter maximum and a summer minimum. The SO _inf4 ^sup= air concentrations show a smaller amplitude and are out-of-phase with SO₂, showing a summer maximum. Air concentrations of HNO₃ and particulate N0 _inf3 ^sup- also have an out-of-phase annual cycle, with a summer maximum and summer minimum respectively. Wet deposition of SO _inf4 ^sup= shows a broad maximum through the summer months, but for NO _inf3 ^sup- no systematic cycle is evident. On an ion equivalent basis, NO _inf3 ^sup- contributes as much as SO _inf4 ^sup= to the acidity of winter precipitation, but only one-third as much in the summer months. Although 8.7 yr is too short a time-scale to establish long term variations with any certainty, there does appear to be an overall downward trend in S concentrations and deposition, but not for N. This is not inconsistent with the trends in the emissions of SO₂ and NO_X in the regions upwind of Nova Scotia. The fraction of the S input to the watershed as dry deposition is estimated to average 22% of the total.     

Determination of total sulphur and extractable sulphate in plant materials by inductively‐coupled plasma atomic emission spectrometry

Abstract

Total sulphur and extractable sulphate were determined in plant materials by inductively‐coupled plasma emission spectrometry. For total sulphur, plant material was digested in concentrated nitric acid only. For the sulphate determination, the plant material was extracted with water, sulphate was precipitated as barium sulphate, washed, and redissolved in (NH₄)₄‐EDTA. In the determination of sulphur no spectral interferences were observed, when using the 182.04 nm emission line. The data for total sulphur compared well with a set of certified reference plant samples. For extractable sulphate no such certified plant material is available, but it was established that the proposed procedure did not lead to losses nor interferences.     

Sulphur fertilizer effect on cotton: I. Nitrogen and sulphur status and petiole nitrate‐nitrogen

Abstract

The effect of S fertilization on S and N status and petiole NO₃ ^?‐N in cotton was observed during the growing seasons of 1980 and 1981. Four sites representing 2 soil subgroups were studied using a randomized complete block design with 4 replications. Leaf and petiole sampling began one week prior to bloom initiation and continued weekly for eight weeks. Leaf samples were analyzed for S and N and the petioles for NO₃ ^?‐N. Levels of leaf‐S varied directly with amounts of applied S. Leaf‐N and petiole NO₃ ^?‐N varied directly with amounts of applied N. Though not always significant, petiole NO₃ ^?‐N and leaf‐N showed negative correlations with leaf‐S. These results suggest that knowledge of the cotton plant S status may be necessary to interpret petiole NO₃ ^?‐N for N fertilization of cotton.     

Chemical fractionation,water solubility and temporal distribution of sheep faecal sulphur fractions in grazed pastures receiving long‐term sulphate fertilization

Abstract

Although over 40% of excretal S is returned to intensively sheep ‐grazed pastures as faecal S, limited information is available on faecal S fractions, their water solubility and temporal distribution. This study reports results obtained from sheep faeces returned to grazed pastures which have received long‐term annual sulphate applications for 15–20 years. Five freshly‐voided sheep faecal samples (<100 g moist faeces per sample) per sampling were randomly collected at approximately one month intervals over a one‐year growing season. Faeces were fractionated into total S, inorganic SO₄ ^2‐, ester SO₄ ^2‐, Hi‐reducible S and C‐bonded S. Results obtained showed that faecal total S, ester SO₄ ^2‐ Hi‐reducible S and C‐bonded S fractions varied significantly throughout the year. Carbon‐bonded S was the dominant (>80%) faecal S fraction, regardless of faecal total S content or the time of year faecal samples were deposited. Faecal ester SO₄ ^2‐ and inorganic _SO₄ ^2‐fractions accounted for 3.3–7.1% and 0.1–14% of faecal total S respectively. Thus approximately 3.4–21.1% of faecal total S was estimated to be potentially leached or readily available to pasture plants. The Hi‐reducible faecal S fraction was significantly‐correlated (r = 0.59***; *** = P ≤ 0.001) with HCl‐extractable faecal inorganic S, which was considered to represent faecal total SO₄ ^2‐ (ester SO₄ ^2‐ and inorganic SO₄ ^2‐ fractions).

The solubility of different faecal S fractions was determined by sequential extraction of ground (< 1 mm) faeces three times (30 minutes per extraction) with water or 0.01 M Ca(H₂PO₄)₂ solution (1: 5 ratio of faecal DM: extractant). Both amounts of water‐extractable and Ca(H₂PO₄)‐extractable faecal S fractions were found to vary significantly throughout the year. Ca(H₂PO₄)₂ tended to extract more inorganic faecal S than water, attributed to the presence of phosphate and the low pH (pH=4) of Ca(H₂PO₄)₂ extractant. A significant proportion (15–25%) of faecal S was extracted by water and most (70%) of this water‐extractable faecal S was in the organic S fraction. Water‐extractable inorganic faecal S probably originated from the faecal total SO₄ ^2‐ fraction as shown by their significant correlation (r = 0.45** ‐0.63***; ** = P≤ 0.01; *** = P≤ 0.001). Some of the faecal S in water extracts may also originate from the faecal C‐bonded S fraction, as a significant correlation was obtained between C‐bonded faecal S and either water‐extractable faecal organic S (r = 0.53–0.57***; *** = P ≤ 0.001) or water‐extractable faecal inorganic S (r = 0.40–0.41*; * = P ≤ 0.05).

Significant amounts of faecal inorganic SO₄ ^2‐ and ester SO₄ ^2‐ fractions were removed by Ca(H₂PO₄)₂ extractant. The Ca(H₂PO₄)₂‐extractable faecal inorganic S was significantly correlated (r = 0.73***^; *** = P ≤ 0.001) with water‐extractable faecal inorganic S.     

Winter wheat fertilizing using nitrogen–sulphur fertilizer

Precise field experiments were established on two sites with winter wheat under different soil-climatic conditions in the Czech Republic. Four treatments were fertilized with same dose of nitrogen (200 kg N ha^?1) and increasing dose of sulphur (0, 10, 20 and 40 kg S ha^?1) using nitrogen–sulphur (N–S) fertilizer with calcium sulphate form. Soil and plant aboveground biomass samples were taken in the stages of development BBCH 26–28; 30–32; 37–39; 49–51. The winter wheat grain yield ranged between 7.20 and 10.86 t ha^?1 and had an increasing trend with increasing sulphur dose. Although the differences were usually not statistically significant, there were found increasing tendencies of bioavailable sulphur content in soil with increasing S split doses. Soil S content decreased with time probably due to plant uptake. Sulphur dose did not influence the S content in plant aboveground biomass. The total S contents in grain after harvest ranged between 0.09% and 0.14% and were not significantly influenced with the fertilizing treatment. The same statement is valid for the S content in straw, which ranged between 0.03% and 0.11%. Both, S content in winter wheat seeds and straw were strongly influenced by the site conditions.     

Effects of iron nutritional status and time of day on concentrations of phytosiderophores and nico‐tianamine in different root and shoot zones of barley

The diurnal pattern in concentrations of phytosiderophores (PS) and its precursor nicotianamine (NA) was studied in different root and shoot zones of iron (Fe)‐sufficient and Fe‐deficient barley (Hordeum vulgare L. cv. Europa) grown in nutrient solution. Roots were separated into apical (0–3 cm) and basal zones (>3 cm) and shoots into young (3 cm basal zones of youngest two leaves) and old (remaining zones of youngest two leaves and oldest leaf) parts. The main PS in barley was identified as epi‐hydroxymugineic acid (epi‐HMA). Regardless of the sampling zone and time of day, epi‐HMA concentrations were several times higher in Fe‐deficient than in Fe‐sufficient plants and several times higher in the roots than in the shoots. In roots and shoots, epi‐HMA concentrations were always higher in the younger compared with the older zones. In both root zones of Fe‐deficient plants, an inverse diurnal rhythm occurred in epi‐HMA concentrations and in its release by the roots. In contrast, such a rhythm was absent in roots of Fe‐sufficient plants and in the shoots regardless of the Fe nutritional status. Nicotianamine concentrations in roots were not affected by the Fe nutritional status in apical zones but slightly enhanced under Fe deficiency in basal zones. In contrast to roots, NA concentrations in both shoot parts were lower in Fe‐deficient than in Fe‐sufficient plants. Regardless of the Fe nutritional status in roots and shoots, NA concentrations were higher in young than in old parts and no consistent diurnal variations were observed. The results suggest that PS are also synthesized in the shoot, although at much lower rates than in roots. As with roots, PS synthesis in the shoot is enhanced under Fe deficiency and is mainly localized in young growing tissue. The distinct diurnal rhythm in PS release in roots is apparently not regulated by variation in the rate of PS synthesis during the day.     

Characterization and antioxidant activity of the complex of tea polyphenols and oat β-glucan

Few data are available about the effects of complexation of polyphenols with polysaccharide on their bioavailability. The complex of tea polyphenols (TP) with oat β-glucan was characterized by ultraviolet-visible spectrometry, Fourier transform infrared spectrometry, differential scanning calorimetry, atomic force microscopy, and solid-state (13)C NMR spectroscopy. The results indicated that the bonds which governed the interaction between TP and oat β-glucan were strong hydrogen bonds. The in vitro antioxidant activity of TP, β-glucan, their complex, and physical mixture was assessed using four systems, namely, DPPH(?), OH(?), and O(2)(?-) scavenging activities and reducing power. The complexation and blending of TP and β-glucan exhibited different impacts on the index of in vitro and in vivo antioxidant capacities. In the concentration range of 0.5-2.5 mg mL(-1), the complex had highest O(2)(?-) scavenging activity, whereas the highest OH(?) scavenging activity was found with the physical mixture. For antioxidant testing in vivo, there was no significant difference between the complex and the physical mixture in terms of glutathione peroxidase activity and levels of malondialdehyde and total antioxidant capacity in serums. However, the complex exhibited much higher activities of superoxide dismutase and glutathione peroxidase in livers than the physical mixture. The present study provided a deeper understanding of the influence of molecular interaction between TP and oat β-glucan on their antioxidant activities.     

Speciation and biochemical transformations of sulfur and copper in rice rhizosphere and bulk soil—XANES evidence of sulfur and copper associations

Purpose  

Contamination of heavy metals in soil and its subsequent accumulation along the food chain is a potential risk to human health. Cu speciation in soil–plant system, particularly on the availability to plant roots, has obtained great attention. X-ray absorption near-edge structure spectroscopy (XANES) provides information about the bonding of Cu soil components at the molecular scale. In paddy soils, changes of redox conditions led to microbially mediated sulfur transformation, thus affecting heavy metal behavior. The objective of this work was to investigate how sulfur transformation in a paddy soil affected Cu biogeochemical processes.     

Effect of Calcium and Boron Sprays on Yield and Quality of “Elsanta” Strawberry

Abstract

The aim of the experiment was to examine the effects of foliar applications of calcium (Ca) and boron (B) on yield and fruit quality of “Elsanta” strawberries grown on a sandy loam soil with low status of available B. The study was conducted in 1999–2000 at a commercial strawberry plantation in Central Poland. Cold‐stored strawberries were planted in 1998 at a spacing of 0.25 × 0.8 m. The following treatments were applied: (i) five sprays of Ca as CaCl₂ at a rate of 1.5 kg Ca ha^?1 spray^?1 with addition of Tween 20 adjuvant at 0.1%; the first spray was performed at the petal fall stage and the next at 5‐day intervals; (ii) three sprays of B as Borvit material at a rate of 160 g B ha^?1 spray^?1 at the beginning of flowering and 5, and 10 days later; (iii) sprays of B and Ca as in the combination of (i) and (ii). Plants sprayed with water served as the control. Results showed that fruit and leaves from Ca‐treated plants had increased Ca concentrations. Sprays with B increased status of this microelement in fruit and leaf tissues. Treatments did not affect total and marketable fruit yield, mean berry weight, the number deformed fruit, soluble solids concentration and titratable acidity of fruit at harvest. Fruit sprayed with Ca or B plus Ca were firmer and more resistant to Botrytis rot at harvest and after 3 days of holding at 18°C compared to those of control plots. Moreover, sprays of Ca or B plus Ca increased soluble solids concentration and titratable acidity of fruit after 3 days of holding at room temperature. These results indicate that sprays of CaCl₂ with addition of Tween 20 should be recommended to improve quality and shelf‐life of strawberry fruit, particularly in proecological production where application of fungicides is restricted.     

Effect of High‐Molybdenum Compost on Soils and the Growth of Lettuce and Barley

A pot experiment evaluated the growth of lettuce (Lactuca sativa L.) and barley (Hordeum vulgar) and accumulation of molybdenum (Mo) in plants and soils following amendments of Mo compost (1.0 g kg^?1) to a Truro sandy loam. The treatments consisted of 0 (control), 12.5, 25, and 50% Mo compost by volume. The Mo compost did not affect dry‐matter yield (DMY) up to 25% compost, but DMY decreased at the 50% compost treatment. The 50% compost treatments increased the soil pH an average of 0.5 units and increased the nitric acid (HNO₃)–extractable Mo to 150 mg kg^?1 and diethylenetriaminepentaacetic acid (DTPA)–extractable Mo to 100 mg kg^?1 in the growth medium; the same treatment increased tissue Mo concentration to 569 and 478 mg kg^?1 in the lettuce and barley, respectively. Plants grown in the 25% compost produced about 55 mg kg^?1 of total Mo in the growth medium; this resulted in tissue Mo concentration of 348 mg kg^?1 in lettuce and 274 mg kg^?1 in barley without any phytotoxicity. Our results suggested that 55 mg Mo kg^?1 soil would be an appropriate limit for Mo loading of soil developed from compost additions, a value which is presently greater than the Canadian Council for Ministers of the Environment (CCME) Guidelines for the use of type B compost in Canada.     

Effect of cooking on concentrations of β-estradiol and metabolites in model matrices and beef

Because beef food products are generally cooked prior to consumption, the behavior of chemicals in these cooked foods is important in estimating human exposure. The heat stability of the natural estrogen β-estradiol (β-E2) and its metabolites α-estradiol (α-E2), estrone (E1), and several catechol estrogens was examined in heated vegetable oil and aqueous solutions. The chemicals were also incorporated into regular and extra lean ground beef and subjected to cooking. E1 and E2 were stable in aqueous solutions at 100°C, whereas the catechol estrogens exhibited first-order decay curves with half-lives of 2-10 min. Their stability improved to the same level as the other test chemicals when an antioxidant was added to the solution, suggesting that their disappearance was due to oxidation rather than thermal degradation. E1 and E2 were also stable in heated vegetable oil (160-180°C), whereas catechol estrogen decreased 30-50% over the 2 h duration of the experiments. Chemical losses from cooked beef appear to be related to the fat content of the beef, with greater losses occurring in regular ground beef (25-30%), compared to extra lean ground beef (5-20%). This study shows that cooking reduces but does not eliminate the potential for dietary exposure to growth promoters in ground beef.     

Effects of vesicular‐arbuscular mycorrhizas and phosphorus on water status and growth of apple

Apple (Malus hupehensis Rehd) seedlings were grown in sterilized and non‐sterilized soil with or without phosphorus (P) added and inoculated by VA mycorrhizal (VAM) fungi (Glomus versifome Daniels et Tappe and Glomus macrocarpum Tul et Tul). In sterilized soil, the VAM infection increased the transpiration rate (Tr.) of the leaves, reduced the stomatal resistance (Sr.) and the permanent wilting percentage (PWP) and enhanced the rate of recovery of the plant from the water stress and the plant growth (e.g. leaf number, stem diameter and dry weight). It also increased absorption of most minerals, especially Zn and Cu by the roots and weakened the P‐Cu and P‐Zn interactions. Phosphorus fertilization had some positive effects on the water status, P nutrition and growth, but it reduced the Cu concentration. VAM improved the water status and enhanced drought tolerance of the trees by enhancing absorption and translocation of water by the external hyphae. The efficiency of inoculation in nonsterile soil was not obvious.     

Fixation and Recovery of Added Phosphorus and Potassium in Different Soil Types of Pulse‐Growing Regions of India

Abstract

Fixation and recovery of added phosphorus (P) and potassium (K) were studied in different soil types of pulse‐growing regions. Amounts of P and K fixed increased in all the soils irrespective of type and texture. With the increase in levels of added P and K, maximum P fixation was observed at lower levels of added P (50 mg kg^?1). Alfisols showed maximum P‐fixation capacity (92.7%), followed by Vertisols (86.5%) and Inceptisols (76.6%) at 50 mg kg^?1 added P. However, K fixation increased with increasing levels of added K up to 200 mg kg^?1, and thereafter fixation either decreased or was maintained at similar levels. Vertisols showed higher K fixation than Inceptisols and Alfisols. Fertilizer P requirement per unit increase in available P in soil was highest in Bangalore (3.23) and lowest in Delhi (2.38). Fertilizer K requirement per unit increase in available K in soil was highest in Raipur and Gulbarga (1.75) and lowest in Ranchi (1.28).     

Effect of levels of take‐all and phosphorus fertiliser on the dry matter and grain yield of wheat

In a field experiment with wheat (Triticum aestivum L.), the effect of the percentage severity of take‐all on the production of dried tops and grain and the kernel weight (mg/seed) was measured when different amounts of phosphorus (P) fertiliser were applied. The soil was severely P deficient. The amounts of P fertitiser varied from nil P (deficient) to 40 kg P/ha (adequate) applied annually. The levels of Gaeumannomyces graminis tritici (Ggt) were generated by four cropping sequences. The levels of percent severity of Ggt on plant roots ranged from low (<10% of wheat plant roots infected) to high (70% of roots infected by Ggt). Yield of dried tops, grain, and kernal weight, all increased as the level of P applied increased, but the amount of Ggt infection decreased. No grain was produced where no P was applied. The percentage increase in yield due to declines in the severity of take‐all was greater as the level of P applied increased. Increasing levels of P fertiliser help control the severity of Ggt (%) only where the initial level of Ggt with nil P fertiliser are moderate to low. Where the levels of Ggt severity are >65% the effectiveness of P in reducing the levels of Ggt severity rapidly declined. The percentage severity of Ggt affected the efficiency of plants to use P fertilisers. For each cropping sequence, a Mitscherlich function described the grain yield response to P fertiliser. The maximum grain yield (A coefficient) and the curvature coefficient (C) both declined with increases in the level of Ggt severity (%). For example, the C was significantly reduced from 0.134±0.03 for the least Ggt severity (%) to 0.00446±0.001 where Ggt was not controlled. The kernal weight (mg/seed) was increased by P application and decreased by Ggt infection.     

Fruit set and yield of Pepino Dulce response to nitrate‐nitrogen and salinity levels and thinning of side branches and trusses 1

Three pepino dulce (Solanum muricatum Ait.) selections were fertigated with nitrate‐nitrogen at 3, 6, or 12 mmol/L, and 0,3, or 6 dS/m chloride ions. Plants treated with nitrate‐nitrogen at 6 mmol/L bore heavier yields of larger fruit than those at 3 mmol/L. Further increase in nitrate‐nitrogen application to 12 mmol/L did not result in yield increase. Salt decreased yield in all cases. Heavy fruit set was recorded in plants trimmed to two main shoots, and thinning to three sets per truss resulted in even fruit distribution between trusses.     

Effect of Incorporation of Wheat Straw and Urea into Soil on Biomass Nitrogen and Nitrogen-Supplying Characteristics of Paddy Soil

Pot experiments were carried out to study the effect of incorporation of wheat straw and/ or urea into soil on biomass nitrogen and mineral nitrogen and its relation to the growth and yield of rice.The combined appliation of wheat straw and urea increased much more biomass nitrogen in soil than the application of wheat straw or urea alone and consequently increased the immobilization of urea nitrogen added and reduced the loss of urea nitrogen.An adequate nitrogen-supplying process to rice plant could be obtained if C/ N ratio of the material added was about 20.The three yield components of rice were affected significantly by the status of nitrogen supplying.More than 30mg N/ kg soil of mineral nitrogen at effective tillering stage,panicle initiation stage and filling stage should be maintained in order to get high rice yield,though the criteria varied with the different experimental conditions.     

Morphology and water barrier properties of nanobiocomposites of κ/ι-hybrid carrageenan and cellulose nanowhiskers

The current study presents the development and characterization of novel carrageenan nanobiocomposites showing enhanced water barrier due to incorporation of cellulose nanowhiskers (CNW). CNW, prepared by acid hydrolysis of highly purified α cellulose microfibers, were seen to have a length of around 25-50 nm and a cross section of ca. 5 nm when dispersed in the matrix. The nanobiocomposites were prepared by incorporating 1, 3, and 5 wt % of the CNW into a carrageenan matrix using a solution casting method. Morphological data (TEM and optical microscopy) of the nanocomposites containing CNW were compared with the morphology of the corresponding biocomposites containing the original cellulose microfibers and the differences discussed. Thermal stability by TGA, water vapor permeability, and percent water uptake were also determined. The main conclusion arising from the analysis of the results is that the nanobiocomposites containing 3 wt % of CNW exhibited the lowest reduction in water vapor permeability, that is, ca. 71%, and that this reduction was largely attributed to a filler-induced water solubility reduction. This fully biobased nanoreinforced carrageenan can open new opportunities for the application of this biopolymer in food-packaging and -coating applications.