Seasonal dynamics of mineral nutrients and carbohydrates by walnut tree leaves

The dry weight accumulation per leaf as well as the concentration per gram of dry weight and the accumulation of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were determined in walnut tree leaves (Juglans regia L.) during a complete life cycle. Additionally, the dynamics of plant nutrient concentration in leaf petiole sap and carbohydrate accumulation in leaves were studied in relation to the main life cycle events of the walnut tree. Total N, P, K, Cu, and Zn concentrations decreased, whereas that of Ca, Mg, and Mn increased during the season. Iron concentration fluctuated around a mean value. Total N, P, K, Mg, and Cu concentrations detected in younger mature leaves were at the sufficient level, whereas Ca, Fe, Mn, and Zn concentrations were at higher levels as compared to those previously reported. All the detected nutrient accumulations increased abruptly during leaf ontogeny and leaf maturation until a maximum level was attained in the younger mature leaves. Similarly, sucrose, glucose, and fructose accumulation were observed at the same period. The rates of total N, P, Cu, and Zn accumulation were lower than the rates of the observed dry matter accumulation and nutrient concentration dilution. Potassium and Mn accumulation rates were almost equal, whereas those for Ca and Mg were higher as compared to the dry matter accumulation rate. The fast embryo growing phase resulted in a considerable decrease in dry weight, total N, P, K, Cu, Zn, and carbohydrate accumulation, and to a lesser degree in Ca, Mg, and Mn accumulation. Nutrient accumulation reduction in leaves by the influence of the growing fruits were estimated to be: total N 52%, K 48%, P 29.5%, Mg 16.3%, Ca 15%, Fe 51.2%, Cu 55.2%, Zn 37.3%, and Mn 5.4% of the maximum nutrient value of the younger mature leaves. Old leaves preserved nutrients before leaf fall as follows: total N 25.4%, P 45%, K 31%, Ca 74.8%, Mg 76.5%, Mn 89.2%, Fe and Zn 50%, and Cu 37%. Nutrient remobilization from the senescing old leaves before leaf fall were: total N 22.6%, P 25.5%, K 21%, Ca 10.2%, Mg 7%, Fe 3.2%, Mn 5.4%, Cu 8%, and Zn 13.3% of the maximum value in the younger mature leaves. In early spring, the absorption rates of N, P, and Ca were low while those of Mg, Fe, Mn, Cu, and Zn were high. During the fast growing pollen phase, the N, P, Fe, Mn, Cu, and Zn concentrations were reduced. Calcium concentration is supposed to be more affected by the rate of transpiration rather than during the growing of embryo. Calcium and Mg concentrations in the sap were negatively correlated. The detected K concentration level in the sap was as high as 33 to 50 times that of soluble N, 12 to 21 times to that of P, 5 times to that of Ca, and 10 to 20 times to that of Mg. The first maximum of starch accumulation in mature leaves was observed during the slow growing embryo phase and a second one after fruit ripening. Old senescing leaves showed an extensive carbohydrate depletion before leaf fall.     

Pecan leaf analysis: I. Varietal,fertilizer, and seasonal effects

Abstract

Differences in elemental content of pecan [Carya illinoensis (Wang.) K. Koch] leaves among cultivars were found for N, P, K, Ca, Mg, Mn and Zn. Of the 7 elements studied, only leaf K indicated a date by cultivar interaction. Differences in leaf K among cultivars became greater as the season progressed. Increasing rate of application of N‐P‐K fertilizer increased leaf N, Ca, Mn, and Al, but had very little or erratic effect on leaf P, K, Fe, B, Cu, Zn, and Sr. There were very few consistent significant fertilizer rate by date interactions for the 13 elements tested. Seasonal trends for element leaf contents from mid‐May through October were generally downward for N, upward for Ca, Mn, Fe, B, Cu, Al, and Ba and changed very little for Mg, Zn, and Sr. Leaf P and K responses to sampling date varied with year. Large year to year variations in leaf trends over dates suggests difficulty in selecting a period for leaf sampling where little change in leaf levels consistently occurs.     

Standardization of Litchi Leaf Nutrient Composition for Tissue Analysis in Sub Tropics of India

ABSTRACT

Variation in leaf nutrient composition with leaf age and position of leaflets was assessed for ‘Calcuttia’ and ‘Dehradun’ litchi cultivars under loam to sandy loam soils of north India. Leaf samples were collected from first to sixth pair of leaflets starting from the apex of terminal shoots to downward positions during December to May at monthly intervals at two locations for three successive years. The leaves were analyzed for N, P, K, Ca, Mg, Fe, Zn, Cu and Mn concentrations. In both litchi cultivars, leaf N, P, Zn and Cu contents remained more in young leaves; whereas, leaf Ca, Mg, Mn and Fe contents were observed higher in older leaves. Leaf K concentration exhibited inconsistent patterns; however, leaf K concentration in pair of leaflets on the shoot declined basipetal, being maximum in upper pair of leaflets and minimum in lower pair of leaflets. Levels of macro and micronutrients exhibited a degree of stability at second and third pair of leaflets when sampled during February–March. Leaf compositions differed significantly during active vegetative growth, flowering, and fruit development. The results revealed that 4–5 months old leaves from autumn flush at second and third pair of leaflets from the apex of terminal litchi shoots at the advent of panicle initiation (February–March) should be collected to assess the nutritional concentrations of litchi orchards under North India conditions.     

Elemental content relationships in greenhouse grown apple seedlings supplemented with copper and peat

Abstract

Apple seedlings from a greenhouse pot experiment, investigating the effects of copper (Cu) and peat amendments on crop performance growing on a Cu‐and potassium (K)‐deficient soil, were characterized for a range of major and trace elements. Concentrations of barium (Ba), calcium (Ca), Cu, iron (Fe), K, magnesium (Mg), manganese (Mn), molybdenum (Mo), sodium (Na), rubidium (Rb), strontium (Sr), and zinc (Zn) in leaf and stem tissues were correlated with treatment and tissue. Addition of Cu, peat and the nature of the tissue had significant impacts on many element concentrations. Generally, increasing Cu resulted in elevated Ba, Fe, Mo, and Sr as well as Cu levels. The presence of peat resulted in reduced levels, generally in both leaf and stem, of Ba, Mg, Mn, Rb, and Zn and increased levels of Fe, K, and Mo. Finally, the vast majority of elemental concentrations were higher in leaf tissue rather than stem, with the exceptions of Na and Zn. Elemental concentration ranges, over all tissues and conditions of added Cu and peat were (mg kg^‐1) Ba 9–49, Ca 6380–16340, Cu 2–11, Fe 10–57, K 4070–16950, Mg 900–4260, Mn 22–197, Mo 0.02–0.19, Na 28–124, Rb 0.7–12, Sr 41–58, Zn 18–48.     

巨桉人工林叶片养分交互效应

在四川巨桉栽培区设立了60个标准地,采用相关分析和矢量诊断法进行分析,以了解巨桉人工林养分的相互作用关系。结果表明,巨桉人工林叶片的养分交互作用较为复杂。N可促进P、K、Ca、Mn等的吸收,但易受到Fe、Zn、高Ca、高Mg的拮抗,而且高N抑制了Mn的吸收;P可促进K、Mg、Mn等的吸收,但易受Zn、Fe、高Mn、高K、高Ca、高Mg的拮抗,而高浓度的P将抑制K、Zn、Fe等的吸收;K对其他养分元素均没有明显的促进作用,但高浓度K限制P的吸收;Ca、Mg之间可相互促进吸收。同时,低浓度的Ca和Mg有利于Fe、Zn的吸收,高浓度的Ca和Mg将对N、P、Fe、Mn、S、B等养分产生拮抗,限制吸收;S可促进Zn的吸收,但易受高Ca、高Mg拮抗;Cu、Zn、Fe、Mn之间主要以拮抗为主。B相互作用较少,对其他养分几乎没有明显的促进作用。     

Nutrient status of wheat crop in Ludhiana

Abstract

Samples of wheat plants from 5 selected villages of Ludhiana (Punjab, India) were analysed for P, K, Ca, Mg, Zn, Cu, Fe and Mn. The dominant nutritional deficiencies are found to be those of zinc and copper. The extent of hidden hunger is in the order of Zn > Mg > Cu > K. The low concentrations of Zn and Cu are ascribed to the inherent poor fertility status associated with the lighter texture and low organic matter content. The data suggest that the low concentrations of Mg may be due to high availability of K in some soils. A sharp decline in the higher concentrations of P, K, Mg and Zn with the advancement in the growth stage suggests the importance of stage of growth at the sampling time in evaluating the leaf analysis data.     

Seasonal changes in leaf element content of cranberry,vaccinium macrocarpon ait

Abstract

Seasonal changes in leaf element composition were measured at 2‐week intervals in A Oregon cranberry bogs from June 1 to September 15 for a 3‐year period. Nitrogen, P, K, and Zn leaf concentrations decreased during the season while concentrations of Ca, Mg, B, Mn, and Fe increased. Periods of 30‐day minimal internal flux varied from July 15 to September 15, depending on the element. It was concluded that 2 samples, 1 from June 15 to July 15 for Mg, Mn, and Fe and 1 from August 15 to Sep‐ tember 1 for N, P, K, Ca, Cu, B, and Zn, would have to be taken to adequately diagnose the nutrient status of all of the essential elements for cranberry.     

Distribution of nutrient elements along the maize leaf: Alteration by iron deficiency

Distribution often elements along the maize leaf and the effect of iron (Fe) deficiency on these distributions were studied using plants grown in nutrient solution. In both the control and Fe‐deficient leaves, the concentrations of Fe, calcium (Ca), magnesium (Mg), manganese (Mn), zinc (Zn), and boron (B) increased and only that of potassium (K) decreased from leaf base to the leaf tip. Nitrogen (N) and copper (Cu) were the only two elements which showed no gradient of concentration along the entire leaf. Iron deficiency decreased the concentration of Fe by the same extent along the entire leaf length. However, it differentially accentuated the uneven distribution of some elements along the leaf length. For example, Fe deficiency increased the concentrations of Cu and N somewhat uniformly along the whole length the leaf; those of P and K were increased only along the lower two‐thirds of the leaves; and those of Ca, Mg, B, Zn, and Mn mostly along the upper one‐half to one‐third of the leaf length. Potassium was the only element whose concentration was lower at leaf tip than at the leaf base under both Fe‐sufficient and Fe‐deficient conditions. My results indicate that the basal half of maize leaf may be a more suitable part for diagnostic purposes since the concentration of most elements is less subject to alteration in this region, especially if a latent or obvious Fe deficiency is present. In view of these observations, the use of the entire maize leaf for diagnostic purposes may have to be reevaluated.     

Seasonal dynamics of mineral nutrients by walnut tree reproductive organs

The dry weight accumulation per male and female flower as well as the concentration per gram of dry weight and the accumulation of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were determined in walnut tree (Juglans regia L.) catkins and female flowers at the stage of flower bud and during the flower development. Catkin emergence was accompanied by a very fast hydration of the tissues. After the catkin matured, the fresh and dry weights were reduced. The female flower development period was accompanied by the dry and fresh weight increase. Total N, P, K, Fe, Mn, Cu and Zn concentrations in catkin buds were detected at lower levels, Mg in equal levels, and Ca at higher levels as compared to the nutrient concentrations in young growing leaves. The estimated values of the ratio NCmfb/NCygl were: total N = 0.54, P = 0.83, K = 0.56, Ca = 1.5, Mg = 1.0, Fe = 0.46, Mn = 0.71, Cu = 0.85, and Zn = 0.60. Nutrient concentration in female flower buds was detected in almost equal levels with the exception of total N and Fe. The estimated values of the ratio: NCffb/NCygl were: total N = 0.57, P = 1.1, K = 1.17, Ca = 1.06, Mg = 0.9, Fe = 0.47, Mn = 1.0, Cu = 0.92, and Zn = 0.85. Total N, P, Mn, Cu, and Zn accumulations in the catkin were increased during the fast growing phase and decreased after catkin maturing. Potassium, Mg, and Fe accumulation continued to increase in the mature catkin. Calcium accumulation decreased at a very late mature catkin phase. Total N, P, and K accumulation rates during the catkin fast growing phase were higher than the dry weight accumulation rate. Calcium, Mg, Fe, Mn, Cu, and Zn accumulation rates at the same period were lower or equal to dry weight accumulation rates. In mature catkins, the total N, P, Mn, Cu, and Zn depletion rates were higher than the dry weight depletion rate. The continual increase of K, Ca, Mg, and Fe accumulation in mature catkin resulted in the increase of nutrients concentration also. Total N and P showed the highest remobilization values from mature catkin of 51.4% and 45%, respectively. Calcium, K, Mg, Cu, Mn, and Zn remobilization values estimated to be 22.1%, 7.5%, 3.2%, 45.3%, 33.4%, and 31.8%, respectively. Iron showed no remobilization at all. Nutrients remobilization from catkins as compared to the leaves had almost similar values for total N, Zn, and Cu, higher for P, Ca, and Mn, and lower for Mg, Fe, and K. Accumulation of all nutrients in female flowers increased after fertilization. The dry weight accumulation rate was higher than the nutrient accumulation rates.     

DRIS and geostatistics indices for nutritional diagnosis and enhanced yield of fertirrigated acai palm

Abstract

Information about Açaí palm (Euterpe oleracea Mart.) nutrition, that gives support for yield increase is sparse. The aim of this study was to assess the nutritional status of fertigated Açaí palm by the Index called Diagnosis and Recommendation Integrated System (DRIS), as well as the spatial variability of this Index and its productivity. We achieved a sampling of 80 geo-referenced points in an Açaí palm commercial crop area. Then we assessed the yield and contents of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn. The DRIS evaluation indicated that the frequency of nutrients in suitable status was N?>?S?>?Zn?>?B>Fe?>?K>Ca?>?Mg?>?P>Mn?>?Cu, in deficiency was Mn?>?Ca >?B>Cu?>?Mg?>?Fe?>?K?>?P?>?S>Zn?>?N, and in excess was P?>?Cu?>?Mg?> K?>?N?=?Zn?>?Fe?>?Ca?>?S?=?B?>?Mn. The nutrients N and S were well balanced, whereas Mn, Ca and B were the nutrients with the highest frequency of deficiency. The sampling points were close enough to detect the spatial variability of DRIS Index. Thus, it was possible to observe the patterns for the nutritional deficiencies, occurring at the final part of the irrigation, as well as the variability of the Açaí palm yield. The spatial variability of the DRIS Index was efficient to indicate the points in which fittings in the fertilization doses are required.     

Monitoring Nutrient Status of Guava Fruit Trees in Punjab,Northwest India through the Diagnostic and Recommendation Integrated System Approach

Abstract

The Diagnostic and Recommendation Integrated System (DRIS) was employed for interpreting nutrient analyses of leaf tissue of guava fruit trees (Psidium guajava L.) cultivated in Punjab, northwest India. Standard reference DRIS norms were established for various nutrient ratios and used to compute DRIS indices, which assessed nutrient balance and order of limitation to yield. The DRIS evaluation and sufficiency range approach were equally effective and in agreement for diagnosing deficiencies of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sulfur (S), manganese (Mn), zinc (Zn), and copper (Cu). The results also show that the position of leaf tissue sampled does not have a major effect on the DRIS diagnosis. Nutrient sufficiency ranges derived from DRIS norms were 1.41–1.65, 0.10–0.17, 0.51–0.97, 1.16–2.12, 0.31–0.51, 0.18–0.28% for N, P, K, Ca, magnesium (Mg), and S and were 105–153, 58–110, 15–29, and 6–16 mg Kg^?1 for iron (Fe), Mn, Zn, and Cu, respectively. According to these sufficiency ranges 35, 62, 51, 75, 70, and 68% of samples were sufficient, and 4, 29, 36, 9, 10, and 22% of samples were low in N, P, K, Ca, Mg, and S, respectively. More than 50 and 2% of the guava trees selected for sampling was found to deficient in N and P, respectively. For micronutrients, 15, 6, and 7% of samples were found to be low in Mn, Zn, and Cu.     

Critical nutrient concentrations and antagonistic and synergistic relationships among the nutrients of NFT‐grown young tomato plants

Critical concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), and manganese (Mn) with respect to dry matter yield end antagonistic and synergistic relationships among these nutrients were studied in which tomato (Lycopersicon esculentum L.) was grown in recirculating nutrient solution (NFT). Increments of nutrient elements in the nutrient solution increased the proportional rate of the corresponding nutrient elements. Increasing levels of N negatively correlated with plant P and positively correlated with Ca, Fe, and Zn. Iron and Mn contents of the plants were increased and N, K, Ca, and Mg were decreased as a function of P applied. Increases in K in the nutrient solution caused increases in the concentrations of K, N, P, and Zn, and decreases in the concentration of Ca and Fe. Applied Ca increased the concentrations of Ca and N, and decreased the concentrations of P, Mg, Fe, Zn, and Mn. Potassium, Ca, and Fe contents of the plants were decreased and Zn increased, while N, P, and Mn were not affected by the increasing levels of external Mg. Iron suppressed the plant Mg, Zn, and Mn contents. Synergism between Zn and Fe was seen, while P, K, Ca, Mg, and Mn contents were not affected by Zn levels. Potassium, Ca, Mg, and Fe were not responsive to applied Mn, however, N and P contents of the plants were decreased at the highest levels of Mn.     

Foliar nutrient status of field grown tissue cultured and budded Apple trees

Nutrient concentrations in leaves of self‐rooted apple trees propagated by tissue culture (TC) were compared to the same cultivars budded on seedling, MM 106, and M.26 rootstock planted at two sites, Beltsville, MD and Kearneysville, WV. Leaf samples were monitored annually for 3 years after planting for N, P, K, Ca, Mg, Mn, Fe, Cu, B, Zn and Al from ‘Ozark Gold’ and ‘Stayman’ apples at both sites and ‘Northern Spy’ at Beltsville only. Leaf K and Mn concentrations tended to be higher in trees on M.26 and MM 106, while Ca was higher in TC or seedling trees. Foliar Mg was lower in trees budded on MM 106. Variation in P concentrations was greatest over years, while leaf N and Fe displayed only slight variation among rootstocks. Leaf B and Zn did not exhibit any consistent trends and Cu and Al were not affected by year, rootstock, cultivar or site.     

李营养累积、分布及叶片养分动态研究

基于保障生态和果品安全以及合理实施果园养分管理的前提,对大石早生李树体各部位营养元素积累、分布以及各营养元素的周年变化规律进行了分析.结果表明:①营养元素在各个器官的相对含量,除K、Zn在果实中含量最高外,N、P、Ca、Mg均以叶片中含量为最高,以叶片做营养诊断是适宜的.②大石早生李树体营养元素N、P、K、Ca、Mg、Fe、Zn的元素比值为10.00:1.26:6.42:12.57:2.46:1.87:0.14.⑧100 kg鲜果的养分吸收量分别为:N 772.47g,P74.25 g,K 730.33g,Ca874.16 g,Mg 169.82 g,Fe 66.05 g,Zn 7.53 g,N:P:K的比例为1.00:0.10:0.95.④N、P、K、Ca、Mg、Fe、Zn、Mn、Cu的含量随物侯期呈规律性变化.生长季初期,N、P、K、Zn、Cu的含量迅速下降,Fe、Mn、Ca、Mg呈逐渐上升的趋势;中期这9种元素总体变化幅度较小;后期Fe,Cu.N、P、K的含量呈下降趋势,Mn、Zn、Ca,Mg依然上升.本结果既丰富了国内李营养理论,同时又为制定合理的施肥措施及建立绿色优质果品科技示范基地提供了理论依据.     

脐橙幼苗新老叶片养分含量对大、中量元素短期缺乏的差异性响应

  【目的】  对比大、中量养分短期缺乏下脐橙新、老叶片中11种必需元素含量及变化,并分析缺素导致的营养元素间的相互影响。  【方法】  以一年生枳砧纽荷尔脐橙幼苗为试材进行了砂培试验。以完全营养液为对照 (CK),设置缺氮 (?N)、缺磷 (?P)、缺钾 (?K)、缺钙 (?Ca)和缺镁 (?Mg)处理,测定不同处理脐橙叶片（老叶和新叶）生长指标及矿质元素含量。  【结果】  所有缺素处理均导致叶片叶绿素含量降低,生物量减少,以缺氮处理最为显著。缺氮降低了叶片N、Ca、Cu、Mo含量;缺磷降低了叶片P、K、Mo含量;缺钾降低了叶片K含量;缺钙降低了叶片N、Cu、Zn、Mo含量但增加了P含量;缺镁降低了叶片Ca、Mg、Zn、Mo含量但增加了K含量。以必需矿质元素为变量分别对各处理老叶和新叶进行主成分分析,老叶中第一主成分 (PC1)明显将缺钾处理与其他处理区分开,与对照相比,缺钾老叶离子组成变化为N (?3%)、P (+1%)、K (?71%)、Ca (+11%)、Mg (+39%)、B (+16%)、Mn (+11%)、Fe (+32%)、Cu (?7%)、Zn (+14%)、Mo (?63%);新叶中PC1明显将缺氮处理与其他处理区分开,缺氮新叶离子组成变化为N (?53%)、P (+8%)、K (+7%)、Ca (?14%)、Mg (+11%)、B (+55%)、Mn (+51%)、Fe (?14%)、Cu (?57%)、Zn (+4%)、Mo (?25%)。老叶和新叶中元素含量呈正相关的元素是N-Cu、N-Ca、Mg-Mn和Cu-Mo,呈负相关的是K-Zn。  【结论】  脐橙幼苗老叶对钾的短期缺乏反应最敏感,缺钾会显著降低老叶中K和Mo含量并增加Mg和Fe含量,而新叶对氮素的短期缺乏最敏感,缺氮显著降低新叶中N、Ca、Cu和Mo含量。短期缺少P、Ca和Mg对脐橙幼苗叶片中的养分含量影响较小。     

Elemental and chemical concentration in peach tree short life and healthy trees

Abstract

Elemental concentrations of N, P, K, Ca, Mg, Fe, Al, Zn, Mn, and Cu in peach tree short life (PTSL) trees were compared to concentrations in apparently healthy trees in the same orchard. Leaf and stem concentration of K were significantly less and concentrations of Fe and Al were significantly greater in PTSL trees than healthy trees. Leaf concentrations of Ca and Mg and stem concentrations of N, P, and Cu were also significantly less in PTSL trees than healthy trees. Increased levels of Fe and Al and a K:Fe ratio of less than 150:1 in the leaves and stems was associated with PTSL.

There were no detected differences in prunasin, amino acid, or sugar content of PTSL and healthy trees in leaf and stem samples, but significant differences in elemental content suggest some type of stress on the root system of PTSL trees.     

Inoculation of ‘Golden Delicious’ Apple Trees on M9 Rootstock with Azotobacter Improves Nutrient Uptake and Growth Indices

ABSTRACT

Roots of young ‘Golden Delicious’ apple on M9 rootstock were inoculated with four strains of Azotobacter chroococcum, which were isolated from various soils. Effects of these strains in combination with different levels of nitrogen (N) fertilizer and compost on plant growth and nutrient uptake were studied over two seasons. Therefore, a factorial arrangement included four strains of A. chroococcum, two levels of N-fertilizer (0 and 35 mg N kg^?1soil of ammonium nitrate) and two levels of compost (0 and 12 g kg^?1 soil of air-dried vermicompost). Among the four strains, AFA₁₄₆ was the most beneficial strain, as it increased leaf area, leaf potassium (K), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and boron (B) uptake and root N, phosphorus (P), potassium (K), Mn, and Zn. The combination of AFA₁₄₆ strain, compost and N fertilizer increased leaf uptake of Ca, Mg, Fe, Mn, Zn, and B, and root uptake of P, K, Ca, Mg, Mn, and copper (Cu), and root dry weight.     

Pecan leaf analysis: II. Linear correlation with sampling date over a 5‐year period

Abstract

Linear correlations between pecan leaf element concn for 13 elements and 37 different sampling date pairs were determined to study the closeness of the relationship of leaf element conen across dates and years. Correlations were highly significant for leaf Mg, Zn, Mn, and Ba; only fair for Ca, Fe, B, Al, and Sr; and poor for N, P, K, and Cu. Data indicated that the period of the first week of July through the first week of August was about as good as any other period for sampling for all elements.     

Patterns of mineral nutrient fluctuations in soybean leaves in relation to their position

Dry weight accumulation in blades for the trifoliolate leaf as well as the concentration per gram of dry weight and accumulation of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were determined during the vegetative and reproductive phases at different leaf positions of soybean [Glycine max (L) Merrill, var. Halle] grown in the field without fertilization. The leaf blades at each position were sampled three times at seven day intervals. Mature (middle) leaves showed a higher rate of dry weight accumulation particularly during the vegetative stage in comparison to the older (lower) and younger (upper) leaves. These differences increased with the progress of plant growth. The minimization to zero of the rate of dry weight accumulation in blades after the development of pods is differentiated in leaves of different age. The N, P, and K concentration in leaf blades increase and those of Ca and Mg decrease from older (lower) to mature (middle) and younger (upper) leaves. Rates of N and P accumulation at the vegetative stage are greater than the rate of dry weight accumulation. During the reproductive stage, P mobilization and transport to reproductive sinks was observed. Older and mature leaves sustain significant levels of N and P up to the end of the plant life cycle. In the upper leaves, the decline of N and P concentration during the same period is ascribed to dilution and change of the carbon/nitrogen (C/N) ratio due to the late increase of dry weight. Potassium in blades of mature and upper leaves seems to be mobilized to reproductive sinks. This did not seem likely for the lower leaves. High Ca concentration in the blades was attributed to the high level of available Ca in the soil, combined with the prevalence of dry growth conditions during the summer. The rate of Ca accumulation is smaller than the rate of dry weight accumulation during the vegetative stage and greater during the reproductive one. The Mg fluctuations indicate a small influence of reproductive sinks on Mg concentration in the blades. The older leaves have the greatest Ca and Mg concentrations compared to the mature and upper leaves. In lower leaves, indications of faster Mg redistribution are found. Iron, Cu, and Zn concentrations in the blades are higher before flowering, then afterwards in a contrary manner than that for Mn. A decline of Fe, Cu, Zn, and Mn concentration in blades from the lower to the mature and upper leaves was determined. Iron shows the greatest change with the highest concentration being during the early vegetative stage and a rapid decline shortly afterwards. Older leaves were found to be significant Fe reserves during the vegetative stage, while after pod development, they present an impressive accumulation of Zn and Mn.     

Fertilization via carbonated water and mineral concentrations in a tomato crop

Abstract

In our experiments, application of carbonated water (CW) modified the nutritional status of a field‐grown tomato crop. Fruit concentrations of zinc (Zn), copper (Cu), iron (Fe), and manganese (Mn) were initially increased by CW, after which they were similar to the controls (Zn and Mn) or lower (Cu and Fe). Leaf concentrations of the same group of elements were also increased in the later growth stages. Calcium (Ca) and magnesium (Mg) in the earlier stages showed diminished concentrations in all plant parts in response to CW treatment; later on, a slightly higher Ca content was found in the fruit and lower in the leaves, while the fruit Mg content was decreased. Higher cation contents were found in the plant in response to the higher irrigation frequency and interaction with CW effect was detected in most of the cases. In the first period, leaf and fruit contents of all elements, except for Mg in the fruit were increased by daily irrigation. In the second one, leaf content of all nutrients was also increased; the fruit content of Mg, Ca and Zn was increased, while that of Cu, Fe, and Mn was decreased.