Seasonal dynamics of mineral nutrients by walnut tree fruits

Walnut (Juglans regia L.) tree fruit showed after the endocarp lignification a fast growing stage during which fresh and dry weights increased abruptly. From the beginning of fruit ripening and during the fast sperm growing stage, fresh weight started to decrease while dry weight continued to increase with a reduced growth rate. Dry weights increased in sperm and decreased in exocarp‐mesocarp tissues during the fast sperm growing stage. The material exit from pericarp tissues was completed in the ripe fruit. By contrast, fresh weight continued to decrease in the tissue. Patterns of nutrient accumulation per fruit increased continuously during the fruit growth period. The observed reductions of nutrient accumulations for total nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in the fruit individuals during the very late fruit stage after fruit ripening, and in conjunction with the pericarp tissues senescence, are supposed to represent mineral nutrient returns from the ripe fruit. Patterns of total N, P, Mg, Fe, and Zn accumulations increased in the exocarp‐mesocarp tissue during the slow sperm growing stage and decreased during the fast sperm growing stage. Potassium accumulation in the tissue increased continuously up to the fruit ripening time. Calcium, Mn, and Cu increased continuously. Patterns of all nutrients in endocarp tissue increased during the slow sperm growing stage and decreased at the fast sperm growing stage. In the sperm tissues, total N, P, Mg, and Ca accumulations increased during the sperm development and slightly decreased in a late stage. The increasing trend of Ca accumulation was temporarily interrupted during the fast sperm growing stage. Iron, Mn, Cu, and Zn accumulations showed no reductions at all. Potassium accumulation was drastically restricted in the tissue with the approach of fruit ripening. Sperm tissues are extraordinary rich in mineral nutrients. Sperm total N, P, Mg, Mn, Zn, Cu, and Fe accumulations represented the 98.1%, 88.2%, 59.2%, 81.5%, 72.3%, 65.6%, and 52.5% of the total nutrients accumulation in the fruit, respectively. Sperm K and Ca accumulations represented only the 13% and 11.6%, respectively. Exocarp‐mesocarp K, Ca, and Mg accumulations represented the 76%, 72% and 37.1% of the total nutrients accumulation in the fruit individual, respectively. Total N and P accumulation in the tissue were detected in very low levels 1.3% and 7%, respectively. Iron, Cu, Zn, and Mn accumulations were detected in the same tissue in ratio values of 27.5%, 22%, 5.4%, and 11%, respectively. Macro‐ and micro‐nutrient accumulations of the endocarp tissues were detected in the lower levels as compared to the other fruit tissues. The estimated values of mineral nutrient returns from the mature fruit individuals were 2.8% for total N, 13% for P, 16.5% for K, 23% for Ca, 12% for Mg, 28.5% for Fe, and 21% for Zn. Manganese and Cu showed no returns at all. The estimated nutrient returns from the sperm tissues were 60% for total N, 67% for P, 22% for K, and 50% for Mg of the total returned nutrient from the fruit individual. The estimated nutrient returns from exocarp‐mesocarp were 100% for Zn, Fe, and Ca, 50% for Mg, 78% for K, 33% for P, and 40% for total N. Calcium, Fe, Mn, Cu, and Zn in the sperm and Mn and Cu accumulations in pericarp tissues showed no returns at all. A restricted nutrient diffusion from exocarp‐mesocarp and sperm tissues to the endocarp tissues is supposed to be possible. These results suggested a pericarp tissue behaviour similar to the old senescing leaves.     

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.     

铁及其它矿质元素在苹果树不同器官中的分布

成龄苹果树果实采收期整株分析结果表明，单株总铁含量4915.78mg，叶、果、根、枝干的铁含量分布为1165.36mg、300.72mg、1500.38mg和1950.43mg，分别占单株总铁量的23.70%、6.12%、30.52%和39.66%。铁浓度以幼嫩根中最高，直径＜0.5cm根中达257.51mg／kg；其次为叶片，达214.09mg/kg；果实中最低，为18.27mg/kg。微量元素在叶中以铁浓度最高，在果实中以硼浓度最高，为29.26mg/kg；大量元素在叶中以氮浓度最高达18300mg/kg，在果实中以钾浓度最高，为6200mg/kg。     

Seasonal dynamics of the mineral nitrogen forms in mountain-meadow alpine soils

The good agreement between the changes in the concentrations of ammonium and nitrate nitrogen, on the one hand, and the mineralization and nitrification activities, on the other hand, was shown in the annual dynamic cycle of the mobile mineral nitrogen concentrations, the net mineralization of its organic compounds, and the net nitrification in mountain-meadow soils of different ecosystems of the Teberda Reserve. The low nitrification activity in the mountain-meadow soils results in the predominance of ammonium nitrogen in its mineral forms during the entire vegetation period. The importance of the fall-winter-spring period, when the mineralization of organic nitrogen compounds proceeds actively and results in the accumulation of ammonium nitrate in the soil up to the beginning of the vegetation period, was emphasized. Due to the long duration of this period, its average contribution to the total annual mineralization is comparable to that of the vegetation period.     

开发矿棉为人工培养土的综合报告

本文综合大量研究资料论述了VAM对植物吸收P、N、S、B、K、Ca、Mg、Na、Zn、Cu、Mn、Fe、Al、Si等矿质元素的影响,并对VAM在减轻或避免重金属毒害等方面的作用进行探讨。     

Decomposition of aboveground and root litter for three desert herbs: mass loss and dynamics of mineral nutrients

Biology and Fertility of Soils - Litter decomposition is an important process in terrestrial C and N cycling, but it is still unclear which factors are controlling litter decomposition and nutrient...     

植物矿质养分吸收的长距离反馈调节研究进展

植物的养分吸收能力受到局部信号和冠-根长距离反馈信号的共同调节。近年局部调节系统的研究进展较快,长距离反馈调节的研究则相对薄弱。本文从养分吸收反馈调节现象的普遍性、 反馈信号的作用模式（促进/抑制）、 反馈信号的鉴定、 反馈信号的作用靶标等方面对该领域研究现状进行了综述,并提出了有待进一步深入研究的问题。     

离子交换树脂膜吸附土壤养分的动力学研究

采用从英国进口的离子交换树脂膜和室内埋置法研究了取自河北玉田县的 4个土壤吸附土壤磷、钾、钙、镁和锰的动力学。结果表明 ,在 0 .5～ 2 4h的吸附时间内 ,随着提取时间的延长 ,树脂膜吸附的土壤磷、钙量和锰量显著增加 ,而吸附的钾量减少。     

植物矿质营养的生态意义 II．植物对矿质养分的吸收、利用和分配

阐述了植物对矿质养分的吸收；植物相对生长率与奢侈吸收；养分的分配与利用效率；养分的储藏与损失方面的研究进展。     

Toxicity of cadmium and its competition with mineral nutrients for uptake by plants: A review

Cadmium(Cd)is a toxic heavy metal occurring in the environment naturally and is also generated through various anthropogenic sources and acts as a pollutant.Human health is affected by Cd pollution in farmland soils because food is the main source of Cd intake in the non-smoking population.For crops,Cd toxicity may result from a disturbance in uptake and translocation of mineral nutrients and disturbance in plant metabolism,inhibiting plant growth and development.However,plants have Cd tolerance mechanisms,including restricted Cd uptake,decreased Cd root-to-shoot translocation,enhanced antioxidant enzyme activities,and increased production of phytochelatins.Furthermore,optimal supply of mineral nutrients is one of the strategies to alleviate the damaging effects of Cd on plants and to avoid its entry into the food chain.The emerging molecular knowledge contributes to understanding Cd uptake,translocation,and remobilization in plants.In this review,Cd toxicity and tolerance mechanisms,agricultural practices to minimize Cd accumulation,Cd competition with essential elements(calcium,copper,iron,zinc,and manganese),and genes associated with Cd uptake are discussed in detail,especially regarding how these mineral nutrients and genes play a role in decreasing Cd uptake and accumulation in crop plants.     

Effect of oxygen deficiency on uptake of water and mineral nutrients by tomato plants in soilless culture

The consequences of oxygen deficiency on the root system of tomato plants in soilless culture at the beginning of the flowering stage were assessed over a 72‐hour period. The study of water uptake and oxygen depletion in the medium was conducted using a process of continuous computerized data processing. Fluctuations in composition of the nutrient solution were monitored every two hours through an analysis of samples. Oxygen deficiency of the nutrient solution had immediate effects on the water and nutrient uptake of the whole plant. The root asphyxia of a tomato plant caused a 20 to 30% decrease of water uptake after 48 hours. After 10 hours it also leads to the end of the uptake process of the nutrients except nitrates. Potassium (K) was the nutrient most sensitive to oxygen deprivation since an efflux into the culture medium was observed after only 4 hours of deprivation. Nitrate uptake was the least affected by oxygen deficiency. The persistent appearance of nitrite in the culture medium 12 hours after the beginning of the asphyxia process could be caused by the reduction of nitrates by the root system of the tomato plant. The plant would use the oxygen from the reduction reaction to ensure the water and nitrate uptake processes which are the two most important limiting factors of plant nutrition. Thus it seems that under root asphyxia conditions the plant would adapt to the new condition by relying on a metabolism of the “nitrate respiration”; type.     

基于光谱特征分析的苹果树叶片营养素预测模型构建

该文旨在利用光谱分析技术建立高精度苹果叶片营养素预测模型,为苹果树的精细管理提供技术支持。在苹果树年度生长周期的坐果期、生理落果期和果实成熟期等重要物候期,采集了180个果树叶片样本并测量了果树叶片在可见光和近红外波段的反射光谱,同时在实验室采用化学方法获取了果树叶片的氮素以及叶绿素含量。对于聚类后样本,分别分析了果树叶片反射光谱以及经小波滤波后的反射光谱与叶绿素以及氮素之间的相关关系,而后利用偏最小二乘和支持向量机（SVM,support vector machine）方法分别建立了果树叶片叶绿素和氮素含量的回归模型。研究发现,随着生长阶段的推进,在可见光处的反射率逐渐升高,在近红外处的反射率逐渐降低,且基于小波滤波反射光谱的营养素SVM回归模型精度最高：建立的叶绿素回归模型,其测定系数R2达到0.9920,均方根误差 RMSE为0.0039,验证精度R2达到0.9036,RMSE为0.1979;建立的氮素回归模型,其测定R2和验证R2也达到0.74以上,模型的回归RMSE为0.0554,验证RMSE为0.1215。结果表明,采用支持向量机回归模型可以精确估计果树叶片叶绿素含量,对氮素含量的估计精度也达到了实用化水平。     

不同早实核桃品种叶片矿质元素含量变化及其与产量的关系

试验于2010~2011年连续2年以济源市4个早实核桃品种香玲、鲁光、中林1号、薄丰为试材进行了对比试验,研究了不同采样时期叶片中N、 P、 K、 Ca、 Mg、 Fe、 Cu、 Mn、 Zn 9种矿质营养元素的含量变化及其与产量的关系。结果表明,早实核桃叶片中9种元素的含量在年周期内呈规律性变化,含量高低依次为 Ca＞N＞Mg＞P＞K,Fe＞Mn＞Zn＞Cu。不同品种各元素的含量变幅最大为127.69~169.53 mg/kg（Mn）,最小为2.1~92.26 g/kg（K）。不同早实核桃品种叶片内矿质元素含量的年变化趋势表现为N、 P、 K总体上呈下降趋势,最高含量为展叶期（4月20日）分别为36.79、 5.54、 2.93 g/kg,最低在落叶前期（9月28日）,分别为17.45、 2.66、 1.86 g/kg;Ca、 Mg、 Fe、 Mn 4元素含量的变化总体上表现为前期低后期高;Cu、Zn含量的变化有差异但差异不明显。总的来看, 5~7月份,即新梢速长期（5月20日）至硬核期（7月20日）是核桃树养分稳定的时期, 叶片中N、 P、 K含量之间呈极显著的正相关, N、 P与Ca、 Mg、 Mn、 Cu间呈极显著的负相关,可以认为N、 P、 K之间存在增效作用,Ca、 Mg、 Mn、 Cu 对N、 P 和 K 均存在一定的拮抗作用。元素含量与产量的相关分析表明,N、 P、 K在新梢速长期均与产量达（极）显著正相关,相关系数分别为0.819、 0.843和0.895。因此, 利用叶片进行营养诊断最佳,采样时间以新梢速长期（5月20日前后）为宜。     

Starch deposition in storage organs and the importance of nutrients and external factors

Starch is an important agricultural product deposited in vegetative and reproductive storage organs (sinks) of various crop species. Starch yield may in some cases be limited by photosynthesis, i.e. source-limited. This is particularly true for starch synthesized in potato tubers. Here, the physiological sink is characterized by a symplastic phloem unloading path. In reproductive storage tissues (seeds), however, photosynthates must pass the apoplast on their path from phloem unloading to the storage cell. In cereal grains, phloem unloading of sucrose and poslunloading processes rather than photosynthesis may thus control starch synthesis (sink-limited). Various limiting steps along the path of photosynthate movement from the phloem to the storage cells are considered. The primary organic carbon for starch synthesis is sucrose. Sucrose delivered to the storage cell is metabolized to UDPglucose and fructose by means of sucrose synthase activity. Concerning sucrose breakdown the role of cell-wall bound invertase is not well defined. Competition for UDPglucose consumed for growth or storage may be a crucial process in photosynthate partitioning. High starch yields of crops require an undisturbed growth of the sink organ and an optimal filling of sink amyloplasts with starch. The most important form of organic carbon imported into amyloplasts of storage organs (cereal grain and potato tuber) and used for starch synthesis is glucose 1-phosphate. It is still to be clarified whether the rate of glucose 1-phosphate absorption has a direct impact on starch yield. In cereals, the total amount of starch accumulated depends significantly on the duration of grain filling. Ample nutrient and water supply at the post-anthesis stage prolongs the period of grain filling and hence favours starch production. High temperature reduces the activity of soluble starch synthase with negative consequences for starch accumulation. The biochemical and physiological implications of these stress factors are discussed. Recently, successful transgenic manipulations of starch synthesis in crop plants have increased starch yield.     

Cadmium effects on influx and transport of mineral nutrients in plant species

Solution culture experiments were conducted under controlled environmental conditions to determine the effects of cadmium(II) [Cd(II)] activity (0, 8, 14, 28, 42, and 54 μM) on influx (IN) into roots and transport (TR) from roots to shoots of zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), calcium (Ca), magnesium (Mg), phosphorus (P), and sulfur (S) in ryegrass (Lolium perenne L.), maize (Zea mays L.), white clover (Trifolium repens L.), and cabbage (Brassica oleracea var. capitata L.). Shoot and root dry matter (DM) decreased with increased external Cd, and plant species differed extensively. Ryegrass and cabbage were relatively tolerant to Cd toxicity compared to white clover and maize. Influx and TR of Cu, Zn, Fe, Mn, Ca, and Mg were lower with increasing external Cd compared to controls, and species also differed. Influx and TR of P were enhanced in each species with up to 14 μM Cd, decreased in white clover and cabbage at higher Cd levels, while in maize and ryegrass continued to increase as Cd increased. Influx and TR of S were high in white clover at 8 μM Cd and decreased as Cd increased. Influx of S was high in ryegrass, but TR of S remained relatively constant as Cd increased. Influx and TR of S did not significantly change in maize, but decreased in cabbage as Cd increased. With Cd up to 14 μM, decreases in both IN and TR of Zn, Fe, Mn, Ca, and Mg were greater in white clover than in cabbage. Sensitivity of the dicotyledonous plant species to Cd toxicity might have been associated with Cd effects on IN and TR of Fe, Mn, Ca, and Mg. However, differences in plant sensitivities to Cd toxicity between ryegrass and maize were not reflected in Cd effects on IN and TR of mineral nutrients.     

Distribution and redistribution of mineral nutrients and dry matter in grain sorghum as affected by soil salinity

A study was made of the effects of soil salinity on dry matter production, grain yield, and the uptake, distribution and redistribution of mineral nutrients in irrigated grain sorghum. Soil salinity (EC, 3.6 mS/cm) reduced seedling establishment by 77%, and dry matter and grain yields per plant by 32%; grain yield/ha was reduced by 84%. Salinity reduced grain number per head, but not individual grain size. The accumulation of dry matter and most nutrients was reduced by salinity, but the distribution and redistribution of nutrients within the plant were largely unaffected. Redistributed dry matter provided 52 and 31% of the grain dry matter for control and salt‐affected plants, respectively. Salt‐affected plants had a greater proportion of their sulfur (S), magnesium (Mg), sodium (Na), and chloride (Cl) in stems and leaves than control plants at maturity. Grain had 50–90% of the nitrogen <N), phosphorus (P), S, and Mg, 20–50% of the potassium (K), manganese (Mn), zinc (Zn), and copper (Cu), but < 20% of the calcium (Ca), Na, Cl, and iron (Fe) contents of the whole plant. Over 65% of the N and P, and from 20 to 30% of the K, S, Mg, Cu, and Zn was redistributed from the stem and leaves to grain. There was no redistribution of Ca, Na, Cl, Fe, and Mn. Leaves were more important than the stem as a source of redistributed N, but the leaves and stem were equally important as sources of redistributed P, K, S, Mg, and Cu. Redistribution from the stem and leaves provided 80% of the K and 20–50% of the N, P, S, Mg, Zn, and Cu accumulated by grain. Concentrations of Na, and especially Cl, were high in vegetative organs of salt‐affected plants, but not in grain. It was concluded that although moderate salinity was detrimental to the establishment and yield of grain sorghum, it had little effect on patterns of distribution and extents of redistribution of mineral nutrients.     

Influence of foliar application of mineral nutrients at different growth stages of guava

Foliar application of nutrients enhances efficient use along with quick response. The experiment was undertaken to study the effect of foliar application of mineral nutrients viz., boron (B), zinc (Zn), calcium (Ca), and potassium (K) sprayed at different growth stages viz., at fruit set and at two weeks after fruit set of guava (Psidium guajava L.). Increase in plant canopy and minimum seed index was in Zn (0.03%) sprayed at fruit set. Fruit size, sugar: acid, and organoleptic score were better in K (0.5%) sprayed at two weeks after fruit set. Increased yield in Zn (0.01%) and pectin enhancement with B (0.03%) was found at two weeks after fruit set, respectively. Minimum physiological loss in weight of fruits was with Ca (0.5%) sprayed at two weeks after fruit set. In general, for most of the desirable characters 0.5% potassium (K) spray at 2 weeks after fruit set had better results.     

根域容积对藤稔葡萄幼树生长及营养元素吸收的影响

高密度栽培下果树的根系生长会受到抑制,根系的竞争使地上部生长发育改变,促进早果和丰产[1].研究表明,葡萄等多种果树限制根域对促进开花、提早结果和提高果实品质等方面有良好效果[2-3].采用根域限制技术,控制根系使其生长在一定的容积内,提高根系的密度,可以使肥水供给有的放矢,但有关根域限制与根系的营养吸收的关系报道不多.为此,开展根域容积对葡萄的根系矿质元素吸收的影响和根域限制作用机理的研究,为葡萄栽培管理和施肥提供依据.     

X射线荧光光谱法在测定土壤及植物矿质养分方面的应用

X射线荧光(XRF)光谱分析法有快速、无污染、分析成本低且可多元素同时分析和原位检测等优点,已经成为土壤、植物矿质养分测定的重要手段。文章介绍了应用X射线荧光光谱仪测定土壤植物矿质养分的基本原理与工作原理,重点综述了X射线荧光光谱仪在土壤及植物体矿质元素测定方面的研究进展及影响因素,并对X射线荧光分析方法在农业方面的应用前景进行了展望。X射线荧光光谱仪测定的元素范围是元素周期表中从钠到铀。该仪器广泛应用于艺术品鉴定、考古学、食品安全、能源、矿产勘探、电子材料和土壤重金属的研究。使用XRF仪器定量测定土壤、植物矿质元素时,其测定结果受到仪器本身、样品含水量、样品颗粒大小以及土壤有机质含量等因素的影响。有研究证明,通过使用大量的校准样本集对光谱仪进行校准,XRF可用作土壤中元素总浓度的快速测定,还可以实现便携式X射线荧光(p XRF)光谱仪在实验室、田间原位条件下,对植物体矿质元素进行定量分析。     

Revegetation of mineral clay soils: shrub and tree species compared

Several species of shrubs and trees used in the revegetation of clay mineral soils in Northern Appennine region were compared. The trial site, a quarry land, with clay soil with high pH and a little organic matter was arranged in three randomized block designs. The trial tested the following shrub species Rhamnus cathartica, Colutea arborescens, Euonymus europea, Viburnum opulus, Sambucus nigra, Cotinus coggygria, Coronilla emerus, Crataegus monogyna, Ligustrum vulgare, Prunus spinosa, Spartium junceum, Cornus sanguinea, Paliurus spina‐christi and the tree species Fraxinus excelsior, Fraxinus angustifolia, Corylus avellana, Sorbus domestica, Prunus avium, Acer monspessulanum, Ostrya carpinifolia, Pyrus communis var. pyraster, Ulmus minor, Fraxinus ornus and Acer campestre. The present study was designed to test the adaptive response of the species transplanted in clay soil without preparatory tilling or dressing operations. The overall 9 year data indicate differences in the species tested: Spartium junceum, Ligustrum vulgare and Cotinus coggygria were the shrubs adapted to these edaphics conditions and planting practises together with Sorbus domestica, Pyrus pyraster, Fraxinus ornus and Fraxinus angustifolia. Animal damages were also evaluated. Copyright © 2007 John Wiley & Sons, Ltd.