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.     

Assessment of Nutritional Status of Guava Seedlings using Preliminary DRIS Norms and Sufficiency Ranges

The objective of this work was to propose preliminary Diagnosis and Recommendation Integrated System (DRIS) norms and derive critical levels and nutrient sufficiency ranges in the leaves of guava plants in commercial nursery conditions. Sixty-eight leaf samples were evaluated from fertilization trials with seedlings. In the low-yield subpopulation (84% of the population), the limiting nutrients by deficiency in descending order were nitrogen (N)> copper (Cu)>phosphorus (P) = potassium (K)> manganese (Mn)> iron (Fe) = zinc (Zn)> sulfur (S)> boron (B) = magnesium (Mg)> calcium (Ca), and the limiting ones by excess in descending order were B > Ca > Fe > Mn > S > Mg > Cu > P > Zn > N = K. The ranges of the appropriate DRIS indices were 24 to 28, 2.4 to 3.1, 21 to 29, 6 to 8, 1.9 to 2.9 and 1.9 to 2.3 (g kg^?1) for the macronutrients N, P, K, Ca, Mg and S, respectively, and 35 to 48, 4 to 15, 68 to 93, 31 to 60 and 180 to 245 (mg kg^?1) for the micronutrients B, Cu, Fe, Mn and Zn, respectively. The dry matter production of guava seedlings was associated with the nutritional status.     

Nutrient accumulation and nutritional efficiencies of cashew genotypes

Efficient cashew plants in relation to nutrition may represent gains in growth and production, especially in low fertility soils. This study aimed to determine the accumulation, the uptake, transport, and utilization efficiencies in different cashew genotypes. Twelve genotypes were evaluated, 10 of the dwarf type, a common type, and a hybrid. The seedlings were grown in plastic pots filled out with organic substrate. Sixty days after sowing, the plants were collected for the determination of dry matter and macro and micronutrients concentrations. Nutrient accumulation in cashew follows the descending order: N?>?K > P?>?Mg?>?Ca?>?S > Fe?>?Mn?>?Cu?>?B > Zn. Overall, for all nutrients, plants from BRS 274 had the high accumulation and utilization efficiency; the CCP 06 and CCP 76 in uptake; and the CCP 76 and BRS 189 in transport.     

Characteristics of fertilizer uptake and biodistribution in strawberry plants in two Japanese cultivars in hydroponic culture

ABSTRACT

The fertilizer absorption characteristics of strawberries are not clear, although appropriate fertilization is definitely necessary to ensure produce quality and quantity. This study aimed to determine the amounts of macro- and micronutrients absorbed during cultivation of strawberries and their biodistribution and utilization in the plant body. We cultivated Japanese strawberries ‘Benihoppe’ and ‘Kirapika’ in small hydroponic equipment containing a nutrient solution and determined the amounts of N, P, K, Ca, Mg, Fe, Mn, B, Zn, Cu, and Mo absorbed during and at the end of cultivation. The results revealed the adsorption levels of these elements during the cultivation period. The nutrient concentrations varied greatly among plant organs. In particular, P and B accumulated at high levels in the leaves and stem, K, Ca, Mg, Mn, Zn, and Cu accumulated in the crown, and N, Fe, and Mo accumulated in the roots. In addition, the uptake levels of N, P, K, Mg, Mn, Zn, and Cu differed between Benihoppe and Kirapika. Our results provide useful information for determining fertilizer application rates in strawberry cultivation.     

Characterization of deficiency symptoms and mineral nutrient content in Acmella oleracea cultivated under macronutrient and boron omissions

Acmella oleracea occurs in the Amazon forest and is widely consumed in regional cuisine and folk medicine. Many studies concerning its active principles are available, but few studies have been carried out regarding mineral nutrition. The aim of this study was to characterize deficiencies symptoms and nutritional content in Acmella oleracea. The experimental design applied was a randomized block with four replications. After blooming, following treatments were applied: complete solution, absence of Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulfur, and Boron. After harvesting, growth and nutrient content of inflorescences, new leaves, old leaves, and stems were assessed. The absence of aforementioned nutrients allowed for characterization of visual deficiency symptoms. The first observed symptom was absence of Nitrogen. The accumulation of macronutrients in inflorescences followed the order N?>?K?>?Ca?>?P?>?S?>?Mg, in new leaves, N?>?K?>?Ca?>?S>Mg?>?P, in old leaves, K?>?N?>?Ca?>?Mg?>?S?>?P, and in stems K?>?N?>?Ca?>?Mg?>?P?>?S. The greatest growth restrictions were observed in nitrogen and calcium absence treatments.     

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.     

Growth,Nutrient Uptake,and Use Efficiency in Dry Bean in Tropical Upland Soil

Dry bean (Phaseolus vulgaris L., cv. ‘BRS Requinte’) is an important legume crop and nutrient availability is one of the most yields limiting factors for bean production in tropical upland soils. A greenhouse experiment was conducted in Brazilian Oxisol to study growth, nutrient uptake, and use efficiency of macro- and micronutrients during growth cycle of bean plant. Plants were harvested at 15, 30, 45, 60, 73, and 99 days after sowing for determination of growth parameters and uptake of nutrients. Root dry weight, shoot dry weight and leaf trifoliate increased significantly (P< 0.01) in a quadratic fashion with the advancement of plant age. However, root-shoot ratio decreased significantly with increasing plant age. Concentrations of nitrogen (N), calcium (Ca), magnesium (Mg), and zinc (Zn) decreased with the advancement of plant age. However, concentrations of phosphorus (P), potassium (K), copper (Cu), and manganese (Mn) increased significantly with the advancement of plant age. Accumulation of macro- and micronutrients significantly increased with the increasing plant age. Accumulation of N, P, K and Cu was higher in the grain compared with root and shoot, indicating relatively higher importance of these nutrients in improving grain yield of dry bean. Nitrogen, P and Cu use efficiency was higher for shoot weight compared to grain weight. For grain production, nutrient use efficiency was in the order of Mg > Ca > P > K > N for macronutrients and Cu > Zn = Mn for micronutrients.     

Compositional Nutrient Diagnosis of a Sample of Plantain from Sur del Lago de Maracaibo (Venezuela)

The aim of the present study was the estimation of reference concentration values for plantain (Musa AAB subgroup plantain cv. Hartón) using the Compositional Nutrient Diagnosis system. Eighty-eight plants were sampled in 2000–2001 in commercial orchards in Sur del Lago de Maracaibo (Venezuela), their yields recorded, and nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), and sodium (Na) concentrations determined in the foliar material. A yield cutoff of 16.98 kg·bunch^?1, obtained after modeling the cumulative variance ratio function versus yield relationships with sigmoidal (Boltzmann) equations, was selected as the value above which plants were regarded as high yielders. Estimations from the high-yield group (N = 31) resulted in the following reference concentrations for macronutrients (in g·kg^?1): 27.4 (N), 2.0 (P), 41.2 (K), 6.5 (Ca), 2.8 (Mg), 1.9 (S), and 0.5 (Na). For micronutrients the reference concentrations were (in mg·kg^?1): 15.6 (Zn), 8.3 (Cu), 64.0 (Fe), and 76.3 (Mn).     

Nutrient Uptake and Use Efficiency of Dry Bean in Tropical Lowland Soil

Dry bean is an important source of protein for the population of South America, and yield of this legume is very low in this continent. Knowledge of nutrient uptake and use efficiency of a crop is fundamental to improve yield. A greenhouse experiment was conducted to evaluate growth, nutrient uptake, and use efficiency of dry bean (Phaseolus vulgaris L., cv. BRS Valente) during the growth cycle. Plant samples were collected at 15, 30, 45, 60, 73, and 94 days after sowing. Root dry weight, maximum root length, shoot dry weight, and number of trifoliates were significantly increased in a quadratic fashion with the advancement of plant age. Root dry weight and number of trifoliates had significant positive association with shoot dry weight. Uptake of nutrients in the grain was in the order of nitrogen (N) > potassium (K) > calcium (Ca) > magnesium (Mg) > phosphorus (P) > iron (Fe) > manganese (Mn) > zinc (Zn) > copper (Cu). Hence, it can be concluded the N requirements for bean is greatest and Cu is minimal compared to other essential nutrients for grain yield. Uptake efficiency for root, shoot, and grain production was in the order of P > Mg > Ca > K > N > Cu > Zn > Mn > Fe. The greatest P-use efficiency among macro- and micronutrients can be considered a positive aspect of mineral nutrition of bean, because recovery efficiency of P in acidic Inceptsols is less than 20%.     

Root Growth,Nutrient Uptake,and Nutrient-Use Efficiency by Roots of Tropical Legume Cover Crops as Influenced by Phosphorus Fertilization

Roots are important organs that supply water and nutrients to growing plants. Data related to root growth and nutrient uptake by tropical legume cover crops are limited. The objective of this study was to evaluate root growth of tropical legume cover crops and nutrient uptake and use efficiency under different phosphorus (P) levels. The P levels used were 0 (low), 100 (medium), and 200 (high) mg kg^?1 of soil, and five cover crops were evaluated. Root dry weight, maximum root length, and specific root length were significantly influenced by P and cover crop treatments. Maximum values of these root growth parameters were achieved with the addition of 100 mg P kg^?1 soil. The P?×?cover crops interactions for all the macro- and micronutrients, except manganese (Mn), were significant, indicating variation in uptake pattern of these nutrients by cover crops with the variation in P rates. Overall, uptake pattern of macronutrients was in the order of nitrogen (N) > calcium (Ca) > potassium (K) > magnesium (Mg) > P and micronutrient uptake pattern was in the order of iron (Fe) > Mn > zinc (Zn) > copper (Cu). Cover crops which produced maximum root dry weight also accumulated greater amount of nutrients, including N, compared to cover crops, which produced lower root dry weight. Greater uptake of N compared to other nutrients by cover crops indicated that use of cover crops in the cropping systems could reduce loss of nitrate (NO₃ ^?) from soil–plant systems. Increase in root length and root dry weight with the addition of P can improve nutrient uptake from the soil and lessen loss of macro- and micronutrients from the soil–plant systems.     

Diagnosis and Recommendation Integrated System for Monitoring Nutrient Status of Mango Trees in Submountainous Area of Punjab,India

Abstract

The Diagnosis and Recommendation Integrated System (DRIS) was used to identify nutrient status of mango fruit trees in Punjab, India. Standard norms established from the nutrient survey of mango fruit trees were 1.144, 0.126, 0.327, 2.587, 0.263, 0.141% for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S), and 15, 3.5, 145, 155, and 30 mg kg^?1, respectively, for zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), and boron (B) in dry matter. On the basis of DRIS indices, 16, 15, 12, 17, and 16% of total samples collected during nutrients survey of mango trees were low in N, P, K, Ca, and Mg, respectively. For micronutrients, 19, 18, 12, 20, and 6% samples were inadequate in Zn, Cu, Fe, Mn, and B, respectively. DRIS‐derived sufficiency ranges from nutrient indexing survey were 0.92–1.37, 0.08–0.16, 0.21–0.44, 1.71–3.47, 0.15–0.37, and 0.09–0.19% for N, P, K, Ca, Mg, and S and 11–19, 1–6, 63–227, 87–223, and 16–44 mg kg^?1 for Zn, Cu, Fe, Mn, and B, respectively.     

Effects of excess aluminum on mineral uptake in mycorrhizal sorghum

Soil acidity is often associated with toxic aluminum (Al), and mineral uptake usually decreases in plants grown with excess Al. This study was conducted to evaluate the effects of Al (0, 35, 70, and 105 μM) on Al, phsophorus (P), sulfur (S), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn,) and copper (Cu) uptake in shoots and roots of sorghum [Sorghum bicolor (L.) Moench, cv. SC283] colonized with the vesicular‐arbuscular mycorrhizal (VAM) fungi isolates Glomus intraradices UT143–2 (UT143) and Glomus etunicatum UT316A‐2 (UT316) and grown in sand (pH 4.8). Mycorrhizal (+VAM) plants had higher shoot and root dry matter (DM) than nonmycorrhizal (‐VAM) plants. The VAM treatment had significant effects on shoot concentrations of P, K, Ca, Fe, Mn, and Zn; shoot contents of P, S, K, Ca, Mg, Fe, Mn, Zn, and Cu; root concentrations of P, S, K, Ca, Mn, Zn, and Cu; and root contents of Al, P, S, K, Ca, Mg, Fe, Mn, Zn, and Cu. The VAM effects on nutrient concentrations and contents and DM generally followed the sequence of UT316 > UT143 > ‐VAM. The VAM isolate UT143 particularly enhanced Zn uptake, and both VAM isolates enhanced uptake of P and Cu in shoots and roots, and various other nutrients in shoots or roots.     

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.     

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.     

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。     

中国烤烟中部叶矿质营养元素浓度状况

于20012～004年,从重点植烟县采集了410个烤烟中部叶样品,运用ICP测定方法和概率密度分布函数对其氮、钾、磷、钙、镁、硫、锰、铜、锌、硼、钠、铁、氯13个矿质元素的浓度特征进行了分析。结果表明:1)大量元素的变异系数较小,中量元素其次,微量元素较大;2)除氮、镁、硫、铜、锌、钠、铁外,其他元素的浓度在品种之间的差异显著,但不同指标在品种之间的高低秩序不同,例如,云烟87的磷浓度显著地高于云烟85、K326的磷浓度,而钾浓度按K326、云烟87、云烟85依次降低;3)所有元素在省份之间的差异极显著,但不同元素在地区之间的高低秩序不同,例如,河南烟叶的钾浓度显著地低于其他省份,贵州烟叶的氯离子浓度显著地高于其他地方;4)钾、磷、钙、硫、硼、钠在烟叶中的浓度符合正态分布,氮、镁、氯、锰、铜、锌、铁在烟叶中的浓度符合对数正态分布;5)氮、磷、钾、钙、镁、硫、锰、铜、锌、硼、钠、铁、氯的正常浓度范围分别为1.18～2.34、0.11～0.30、0.87～2.83、0.99～3.64、0.1～0.8、0.25～0.9、25.18～601.65、2.1～37.271、3.11～105.421、2.6～55.62、163.02～503.11、97.6～384.2、0.07～0.53(氮、磷、钾、钙、镁、硫、氯的单位为%,其余为mg/kg);6)氮、钾、氯、钾/氯比四个因素符合国际型优质烟叶质量标准的概率只有0.726、0.379、0.193、0.829,目前我国烤烟营养不够协调的主要方面是养分浓度偏低。     

Annual and Seasonal Variations of Trace Metals in Atmospheric Suspended Particulate Matter in Islamabad, Pakistan

Total Suspended particulate matter (TSP) in urban atmosphere of Islamabad was collected using a high volume sampling technique for a period of one year. The nitric acid–perchloric acid extraction method was used and the metal contents were estimated by atomic absorption spectrophotometer. The highest mean concentration was found for Ca at 4.531 µg/m³, followed by Na (3.905 µg/m³), Fe (2.464 µg/m³), Zn (2.311 µg/m³), K (2.086 µg/m³), Mg (0.962 µg/m³), Cu (0.306 µg/m³), Sb (0.157 µg/m³), Pb (0.144 µg/m³) and Sr (0.101 µg/m³). On an average basis, the decreasing metal concentration trend was: Ca > Na > Fe > Zn > K > Mg > Cu > Sb > Pb > Sr > Mn > Co > Ni > Cr > Li > Cd ≈ Ag. The TSP levels varied from a minimum of 41.8 to a maximum of 977 µg/m³, with a mean value of 164 µg/m³, which was found to be higher than WHO primary and secondary standards. The correlation study revealed very strong correlations (r?>?0.71) between Fe–Mn, Sb–Co, Na–K, Mn–Mg, Pb–Cd and Sb–Sr. Among the meteorological parameters, temperature, wind speed and pan evaporation were found to be positively correlated with TSP, Ca, Fe, K, Mg, Mn and Ag, whereas, they exhibited negative relationships with relative humidity. On the other hand, Pb, Sb, Zn, Co, Cd and Li revealed significant positive correlations with relative humidity and negative with temperature, wind speed and pan evaporation. The major sources of airborne trace metals identified with the help of principle component analysis and cluster analysis were industrial emissions, automobile exhaust, biomass burning, oil combustion, fugitive emissions, resuspended soil dust and earth crust. The TSP and selected metals were also studied for seasonal variations, which showed that Na, K, Zn, Cu, Pb, Sb, Sr, Co and Cd peaked during the winter and remained lowest during the summer, while Ca, Fe, Mg and Mn were recorded highest during the spring.     

番茄对氮磷钾及中微量元素的吸收规律研究

通过田间试验研究了番茄生长过程中对氮、磷、钾及中微量元素的吸收分配规律.通过试验,测定番茄各个时期根系、茎秆、叶片、果实中氮、磷、钾、钙、镁、铁、锰、铜、锌的含量,旨在发现番茄各时期矿质元素的吸收规律.研究表明:随番茄生长发育的进行,氮、磷、钾及中微量元素在根、茎、叶中的分配率均呈降低的趋势,而果实中各元素分配率持续提...     

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.     

Diagnosis and recommendation integrated system approach for major and micronutrient diagnostic norms for apple (Malus Domestica Borkh) under varying ages and management practices of apple orchards

Various approaches for the Diagnosis and Recommendation Integrated System (DRIS) indices were employed like Beaufil's ER, Elwali and Gascho and Jones. As per the Beaufil's approach of DRIS indices, the nutrient requirements in the initial stage of the apple tree were magnesium > nitrogen > sulfur > phosphorus > copper > zinc > iron > manganese > boron > calcium > potassium (Mg > N > S > P > Cu > Zn > Fe > Mn > B > Ca > K) and in the later stage at 40–50 years, the nutrient requirements were S > Cu > Mg > Fe > P > N > Ca > Mn > K > Zn > B, thus demanding a foliar application of magnesium salt and urea which are required in high amounts in the initial stage; however in the later stage, the yield depression was not attributed to the nutrient deficiency but rather trees' genetic make-up which destabilizes the higher yield in the period of 50 years. Nutrient sufficiency ranges for apple derived from DRIS norms were 1.91–2.24, 0.18–0.26, 1.11–1.61, 1.74–1.88, 0.30–0.33 and 0.28–0.30% for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S), respectively.