Patterns Of Nutrient Accumulation Research Articles

Foliar Fertilizer Application Alters the Effect of Girdling on the Nutrient Contents and Yield of Camellia oleifera

Improving the economic benefits of Camellia oleifera is a major problem for C. oleifera growers, and girdling and foliar fertilizer have significant effects on improving the economic benefits of plants. This study explains the effects of girdling, girdling + foliar fertilizer on nutrient distribution, and the economic benefits of C. oleifera at different times. It also explains the N, P, and K contents of roots, leaves, fruits, and flower buds (sampled in March, May, August, and October 2021) and their economic benefits. The results showed girdling promoted the accumulation of N and K in leaves in March 2021 (before spring shoot emergence) but inhibited the accumulation of P, which led to the accumulation of P in roots and that of N in fruits in August 2021 (fruit expansion period). Foliar fertilizer application after girdling replenished the P content of leaves in March 2021, and P continued to accumulate in large quantities at the subsequent sampling time points. The N and P contents of the root system decreased in March. In October (fruit ripening stage), girdled shrubs showed higher contents of N and K in fruits and flower buds, and consequently lower relative contents of N and K in roots and leaves but higher content of P in leaves. Foliar fertilizer application slowed down the effects of girdling on nutrient accumulation in fruits and flower buds. Spraying foliar fertilizer decreased the N:P ratio in the flower buds and fruits of girdled plants. Thus, foliar fertilizer spray weakened the effects of girdling on the nutrient content and economic benefits of C. oleifera. In conclusion, girdling changed the nutrient accumulation pattern in various organs of C. oleifera at different stages, increased leaf N:K ratio before shoot emergence, reduced root K content at the fruit expansion stage and the N:K ratio of mature fruit, and promoted economic benefits.

Difference in nutrient accumulation patterns between diapause‐destined and non‐diapause‐destined larvae of Hyphantria cunea

AbstractNutrient accumulation is crucial in insect diapause preparation because insufficient nutrient accumulation can shorten the diapause period, interfere with diapause development completion, and decrease the probability of surviving the overwintering period. The amounts of lipids and carbohydrates stored in diapausing pupae of Hyphantria cunea (Drury) (Lepidoptera: Erebidae, Arctiinae) are greater than those in the non‐diapausing pupae. In this study, we tested the hypothesis that diapause‐destined (DD) and non‐diapause‐destined (NDD) larvae of H. cunea have different nutrient accumulation patterns in penultimate and final instars. The body mass, as well as lipid, carbohydrate, and soluble protein contents, and the efficiency of converting digested food and ingested food into body matter were greater in the DD penultimate and final instars than in the NDD penultimate and final instars. Larger amounts of lipids, carbohydrates, and proteins were absorbed by DD penultimate and final instars and the final instar development period in the DD larvae was prolonged relative to NDD larvae. The activities of fatty acid synthase and glycogen synthase of DD penultimate and final instars were significantly higher than those of NDD larvae. These results suggest that the changes in nutrient accumulation patterns between DD and NDD larvae occur in penultimate and final instars, and that the DD larvae increase their nutrient accumulation during diapause preparation by the combined effect of extending their final‐instar development period and improving their digestive efficiency; they increase their lipid and carbohydrate stores by increasing the activities of fatty acid synthase and glycogen synthase in the fat body.

Nutrient Accumulation Pattern in Mixtures of Wheat and Faba Bean Is Strongly Influenced by Cultivar Choice and Co-Existing Weeds.

Simple SummaryGrowing a mixture of two or more crop species, particularly cereals and legumes, can enhance resource use efficiency for growth-limiting resources, such as nutrients. We evaluated the patterns of nutrient accumulation efficiency in different cultivars of faba bean and wheat grown in mixtures with and without the presence of weeds in a growth container experiment. The cultivar used in the mixture determined the amount of nitrogen accumulated by the legumes, but cereals generally accumulated more nitrogen in the mixtures than when grown as sole crops. Competition from weeds resulted in lower nitrogen accumulation in the crop plants, and plant neighbor identity affected the accumulation of other nutrients relative to the accumulation of nitrogen and phosphorus in the plants. Cultivar choice is therefore important for resource limitation and thereby the growth performance of plants grown in mixtures.Cereal–legume mixtures are often associated with higher yields than the components grown as sole crops, but the underlying mechanisms are unclear. The study aims to evaluate how different cultivars in a two-species wheat–faba bean mixture influence above- and below-ground nitrogen (N) accumulation in the plant biomass, whether crop mixing affected the accumulation of other nutrients relative to the accumulation of N and phosphorus (P), and how the nutrient accumulation pattern in sole crops and mixtures is influenced by weed competition. Using a growth container experiment, we investigate nutrient accumulation patterns on specific wheat and faba bean cultivars grown as sole crops and mixtures, and with and without weed competition. We found that cereals in the mixture accumulated more N than in the sole crops, and the cultivar used influenced biomass accumulation in the legumes. Competition from weeds reduced the amount of plant N pools accumulated in the crop plant biomass. Based on stoichiometric scaling exponents, the plant neighbor affected the accumulation of other nutrients relative to the accumulation of N and P. These results are relevant for species and cultivar selection, all of which are important prerequisites for maximizing mixture performance.

Nutrient uptake and Accumulation Patterns in Banana cv. Rasthali (AAB) with respect to Dry Matter Production at Critical Growth Stages

ABSTRACT A field experiment was conducted to assess the nutrients uptake pattern and partitioning of nutrient in banana cv. Rasthali (AAB) at critical growth stages like 10-leaf stage, 20-leaf stage, shooting stage and harvesting stage. From 10-leaf stage to harvesting, the per cent dry matter (DM) accumulation decreased from 43 to 22 in underground segment and increased from 57 to 78 in above ground segment. The sample was partitioned into root, corm, pseudostem, leaf lamina, petiole, peduncle, bunch and male bud, processed and analyzed for macro and micronutrients at different growth stages. The nutrient accumulation pattern with respect to dry matter production was worked out. To produce 38.8 ton banana per hectare, about 396 kg N, 69 kg P, 1044 kg K, 2.2 kg Cu, 5.3 kg Mn, 4.0 kg Zn and 6.5 kg Fe were taken up by banana cv. Rasthali. About 8 to 51% removal occurred through bunch harvest from the total nutrient uptake from the soil and remaining nutrients accumulated in the residual tissues were quantified and given.

Plasticity of nutrient accumulation patterns in diapausing fall webworm pupae.

The accumulation of nutrients during diapause preparation is crucial because any lack of nutrition will reduce the likelihood of insects completing diapause, thereby decreasing their chances of survival and reproduction. The fall webworm, Hyphantria cunea, diapause as overwintering pupae and their diapause incidence and diapause intensity are regulated by the photoperiod. In this study, we test the hypothesis that photoperiod influences energy reserve accumulation during diapause preparation in fall webworm. We found that the body size and mass, lipid and carbohydrate content of pupae with a short photoperiod during the diapause induction phase were significantly greater than those of pupae with a relatively short photoperiod, and the efficiency of converting digested food and ingested food into body matter was greater in the short-photoperiod diapause-destined larvae than the relatively short-photoperiod diapause-destined larvae. We also observed higher lipase and amylase activities in short-photoperiod diapause-destined larvae relative to the counterparts. However, no obvious difference was found in protein and protease in the pupae with a short photoperiod during the diapause induction phase and short-photoperiod diapause-destined larvae compared with the counterparts. Therefore, we conclude that the energy reserve patterns of diapausing fall webworm pupae are plastic and that short-photoperiod diapause-destined larvae increase their energy reserves by improving their feeding efficiency and increase their lipid and carbohydrate stores by increasing the lipase and amylase activities in the midgut.

Determination of Nutrient Accumulation Pattern of New Aromatic Rice (Oryza sativa L.) as Influenced by Different Applied Fertilizers and Plant Spacing

Field and laboratory experiments were conducted at the Bangabandhu Sheikh MujiburRahman Agricultural University, Gazipur, during boro season of 2015-2016 to determine the response of rice crop (BU Dhan 2) to different plant densities under different fertilizer levels. The variety was grown with three fertilizer levels viz. recommended (57-10-8-7-0.9 kg NPKSZn ha-1), 50% higher (114-20- 16-14-1.8 kg NPKSZn ha-1) and 50% lower (28.5-5-4-3.5-0.45 kg NPKSZn ha-1) than recommended level and three plant spacing (20 cm x 25 cm, 20 cm x 20 cm and 20 cm x 15 cm) representing wider, standard and closer plant densities. Nutrient uptake of the variety was higher at higher level of fertilizer and closer plant spacing. The highest grain yield 5.18 t ha-1 of the variety was associated with the highest nutrient uptake under higher dose of fertilizer at closer plant spacing. This treatment combination also showed the highest nitrogen (86.53 kg ha-1), phosphorus (9.85 kg ha-1), potassium (103.9 kg ha-1), sulphur (12.27 kg ha-1) and zinc uptake (265.76 g ha-1) of the variety, although nutrient use efficiency was higher at lower fertilizer level under wider plant density.
 The Agriculturists 2020; 18(1) 31-41

Resource use indicators and carbon stocks in different genotypes and species of gladiolus for precision farming

The present study was carried out to quantify variations in growth, resource use indicators and carbon stocks in different genotypes and different species of Gladiolus for precision production practices. Growth, biomass and nutrient accumulation pattern, and physiological parameters showed significant variations among genotypes of Gladiolus hybrida and species of gladiolus. Leaf area was significantly higher in Arka Kum kum (1557.9 cm2 plant−1). Biomass accumulation was 54% of the total in above ground parts like leaf and spikes, and 46% in below ground corms. Among genotypes of G. hybrida, Arka Amar registered higher total biomass (8159 kg ha−1). Multiple regression indicated significant negative effect of leaf and spike weight on corm biomass (Y corm biomass=˗0.03013–1.0725leaf biomass˗0.4975spike biomass, R 2=0.98) was noticed. Nitrogen removal varied significantly among genotypes of G. hybrida (185–297 kg ha−1). There were marginal differences in P uptake (7.6–11.7 kg ha−1) both among genotypes and species. The potassium requirement was 200 kg K2O ha−1. Higher partial factor productivity and internal utilization efficiency and lower partial nutrient imbalance for P imply that P fertilizer application was more than nutrient demand. Gladiolus system is efficient in carbon sequestration and total carbon stocks in G. hybrida genotypes (19.81–21.63 t ha−1), Gladiolus callianthes (20.76 t ha−1) and Gladiolus psittacinus (22.65 t ha−1). The study indicated differences in nutrient acquisition capacity in genotypes and the need for precision nutrient application to reduce production cost. It is clear that adequate nutrient stocks in the non-harvestable parts are required for below ground corm biomass production.

Temporal and spatial variation of soil microorganisms and nutrient under white clover cover

Cover crops have been implemented for decades as sustainable agricultural soil management practice. However, knowledge about the temporal and spatial variation in soil nutrients and the succession of microorganisms during soil restoration under cover crops maintained for a different number of years are still poorly understood. Here, using the 16S and ITS rRNA gene sequencing techniques, we investigated the evolution of microbial community structure, and the pattern of nutrient accumulation was analyzed in a chronosequence of white clover used as a cover crop for 4, 8, and 13 years in a semiarid orchard on the Loess Plateau, China. Clean tillage was used as the control. We found that 4 years of cover crop had little effect on the soil nutrients, while 8- and 13-year-old cover crops contributed greatly to the soil nutrients. The use of cover crops for 13 years effectively increased the bacterial alpha diversity and the relative abundances of Actinobacteria, Firmicutes and Ascomycota in the 0−20 cm soil layer. These results indicated that long-term organic input stimulated transformation of the dominant population of microorganisms into a population conducive to the decomposition of plant residues. Furthermore, bacteria were more sensitive to the implementation of cover practices than fungi. Notably, on the genus level, the evolution of the bacterial community structure was more stable, while the evolution of the fungal community structure was more disordered with an increase in the years of cover crop. The nitrogen components were the best environmental predictors of the state of the microbial community. Overall, this study adds to our understanding of the patterns of nutrient accumulation and microbial succession under different years of cover crops and has implications for the formulation of a sustainable development strategy in semiarid agriculture systems.

Seasonal dynamics of macronutrients in aboveground biomass of two herb-layer species in a beech forest

The content of six macronutrients (N, P, K, S, Ca, Mg) in the aboveground biomass of two forest plants representing different life forms (Carex pilosa, a hemicryptophyte, and Dentaria bulbifera, a geophyte) was analysed in relation to selected phenological phases. The ability of the plants to accumulate nutrients from the soil into the biomass was studied using transfer coefficients (TCs). Additionally, we examined the temporal changes in nutrient ratios for both species. The study was performed in a beech ecosystem in central Slovakia (Kremnicke vrchy Mountains). The content of available nutrients in the soil (Eutric Cambisol) decreased as follows: N > Ca > S > Mg > K > P. A higher ability to accumulate all elements into the biomass was found for Dentaria bulbifera in comparison to Carex pilosa. We found different patterns of nutrient accumulation between Dentaria bulbifera (N > K > S > Ca > Mg > P) and Carex pilosa (K > N > Ca > S > Mg > P). Temporal changes in the content of nutrients were more noticeable in Dentaria bulbifera, especially for N, S and P – the content of these nutrients diminished. On the other hand, the content of K and Ca in Carex pilosa rose over time. For both species, the highest TC was detected in the case of P and K. Clear temporal variability was also revealed ​​in some nutrient ratios, e.g., [N:K] and [Ca:P]. We confirmed that the nutrient content, nutrient ratio and transfer of macronutrients from the soil to plant biomass vary throughout the growing season in relation to the phenological phases of the plants. Similarly, the dynamics of both nutrient content and the accumulation of macronutrients in the biomass are related to the life form of the plant.

An extracted tetraploid wheat harbouring the BBAA component of common wheat shows anomalous shikimate and sucrose metabolism

BackgroundThe BBAA subgenomes of hexaploid common wheat are structurally intact, which makes it possible to extract the BBAA subgenomes to constitute a novel plant type, namely, extracted tetraploid wheat (ETW). ETW displays multiple abnormal phenotypes such as massively reduced biomass and abnormal spike development, compared to extant tetraploid wheat with a BBAA genome. The genetic, biochemical and physiological basis underlying the phenotypic abnormality of ETW remains unknown.ResultsTo explore the biochemical basis of these phenotypic abnormalities, we analysed the metabolomic and proteomic profiles and quantified 46 physiological traits of ETW in comparison with its common wheat donor (genome BBAADD), and a durum tetraploid wheat cultivar (genome BBAA). Among these three types of wheat, ETW showed a saliently different pattern of nutrient accumulation and seed quality, markedly lower concentrations of many metabolites involved in carbohydrate metabolism, and higher concentrations of many metabolites related to amino acids. Among the metabolites, changes in shikimate and sucrose were the most conspicuous. Higher levels of shikimate and lower levels of sucrose influence many metabolic processes including carbohydrate and amino acid metabolism, which may contribute to the phenotypic abnormalities. Gene expression assay showed downregulation of a shikimate degradation enzyme (5-enolpyruvylshikimate-3-phosphate synthase) coding gene and upregulation of several genes coding for the sucrose hydrolysis enzyme, which could explain the higher levels of shikimate and lower levels of sucrose, respectively.ConclusionsOur results suggest that significant and irreversible biochemical changes have occurred in the BBAA subgenomes of common wheat during the course of its co-evolution with the DD subgenome at the hexaploid level.

Assessing nutrient uptake pattern with respect to dry matter accumulation in Ney Poovan (AB) banana at critical growth stages

A field experiment was conducted to assess the nutrient uptake pattern and partitioning of nutrients in Ney Poovan banana (AB) at critical growth stages like 10-leaf stage, 20-leaf stage, shooting stage and harvesting stage. From 10-leaf stage to harvesting, the per cent dry matter (DM) accumulation decreased from 42 to 16 in underground segment and increased from 58 to 84 in above ground segment. The sample was partitioned into root, corm, pseudostem, leaf lamina, petiole, peduncle, bunch and male bud, processed and analysed for macro and micronutrients at different critical growth stages. The nutrient accumulation pattern, with respect to dry matter production was worked out. To produce 37.5 t banana ha−1, about 444 kg N, 69 kg P, 933 kg K, 2.4 kg Cu, 7.3 kg Mn, 3.4 kg Fe and 5.9 kg Zn were taken up by Ney Poovan banana. About 10 to 52% removal occurred through bunch harvest from the total nutrient uptake from the soil and remaining nutrients accumulated in the residual tissues were available for in situ recycling. The data provided opportunity for proper fertiliser scheduling to achieve optimum yield with higher nutrient use efficiency and nutrient budgeting in banana ecosystem was also done.

Root morphology and the effect of rootstocks on leaf nutrient acquisition of Kinnow mandarin (Citrus nobilis Loureiro × Citrus reticulata Blanco)

ABSTRACTThe study aimed to understand the root morphological character of 1 year old seedling rootstock of citrus genotypes viz., rough lemon, Karna Khatta, Carrizo citrange, Rangpur lime, Troyer citrange, Jatti Khatti and sour orange as well as to investigate the effect of these rootstocks on the leaf mineral composition of Kinnow. Root morphological traits showed significant genotypic variation. Rough lemon seedlings had a higher root length, projected area, surface area, volume and the number of forks. Sour orange was moderate rootstock of the 7 genotypes for most of the root morphological characters, while citrange rootstocks expressed poor root morphology. The rootstocks also imparted significant influence on the leaf mineral composition. Leaf K, Ca and Mg content was recorded maximum in plants grown on rough lemon seedling, while N, P, Fe, Zn, Mn and Cu concentration was higher on sour orange rootstock. Kinnow trees on Rangpur lime rootstock accumulated more Na in their leaf tissue, where as Troyer citrange restricted the accumulation of Na. Considering the root morphological characters and nutrient accumulation pattern, rough lemon and sour orange for areas free from tristeza virus could be suggested as alternative rootstocks for the studied Kinnow mandarin under similar ecological conditions.

Phosphorus Deficiency Alters Nutrient Accumulation Patterns and Grain Nutritional Quality in Rice

The accumulation of biomass and mineral nutrients during the post-anthesis period was investigated in field-grown rice plants cultivated in phosphorus (P)-sufficient vs. P-deficient soil. Phosphorus deficiency reduced biomass accumulation by around 30%, and reduced the accumulation of all nutrients in aboveground plant biomass except sulfur (S) and copper (Cu). Ultimately, grain zinc (Zn), Cu, and calcium (Ca) concentrations were significantly higher in P-deficient plants, while grain magnesium (Mg) concentrations were significantly lower. While P deficiency caused a 40% reduction in the concentration of the anti-nutrient phytate in the grain, this was offset by a 40% reduction in grain starch lysophospholipids, which have positive benefits for human health and grain quality.

Potentilla fruticosa has a greater capacity to translocate phosphorus from the lower to upper soils than herbaceous grasses in an alpine meadow

Potentilla fruticosa is widely distributed in the Northern hemisphere; however, its effect on soil properties in the ecosystems is unknown. We examined the effects of P. fruticosa (a key shrub in the system) on soil organic carbon (SOC) and nutrient accumulation patterns in an alpine meadow on the Qinghai–Tibetan Plateau. In a flat area (about 1200×400m), we extensively sampled aboveground and belowground biomasses, litter accumulation and soils in P. fruticosa and herbaceous plant patches. We also intensively sampled soils down to 1m depth along a 24-m transect that crossed through alternating P. fruticosa and herbaceous plant patches. The aboveground biomass, litter accumulation and root biomass down to 0.5m depth were all significantly greater under P. fruticosa than herbaceous plants. SOC, total nitrogen (N) and phosphorus (P) across 0–0.1, 0.1–0.2 and 0.2–0.3m soil layers were 12%, 17% and 9% greater, respectively, under the P. fruticosa than herbaceous plants. Soil N and P availability in the upper layers was also greater under P. fruticosa than under the herbaceous plants. The intensive sampling revealed that the increases in SOC and total N below P. fruticosa, relative to the herbaceous plant patches, occurred down to 0.8m depth. However, the higher total P concentrations in the upper soils under P. fruticosa occurred at the expense of lower levels of P in the deeper soil layers. Along the 24-m transect, SOC, total N and inorganic N storage in the 1m soil depth increased when P. fruticosa was present; however, total and available P storage fluctuated in the opposite pattern, decreasing when P. fruticosa was present. This indicated that during the succession of the community, greater SOC and N accumulation versus a depletion in P in the top 1-m soil layer occurred under P. fruticosa, compared to under the herbaceous plants. We concluded that there was heterogeneity in the soil nutrient resources that was associated with P. fruticosa patches in the alpine meadows. P. fruticosa had a greater capacity to translocate P from the lower to the upper soils than the herbaceous plants.

Metal, nutrient and biomass accumulation during the growing cycle of Miscanthus established on metal‐contaminated soils

AbstractThe energy crop Miscanthus presents high potentials for phytomanagement. Its shoot yield and nutrient accumulation has been extensively characterized in uncontaminated agricultural soils, while very little is known for metal‐contaminated conditions. This study aimed at assessing potential differences in dry matter and metal and nutrient accumulation of the standing aerial biomass in Miscanthus (M. × giganteus) growing in situ on agricultural plots presenting different soil Cd, Pb, and Zn concentrations. Plant samplings were conducted monthly along the growing period from May to December. Cadmium, Pb, Zn, and the concentrations of the nutrients N, P, K, Ca, Mg, and Na were determined in leaves and stems separately. During the growing phase, the maximum dry matter was reached in early in autumn. Whatever the organ, Cd and Zn concentrations were higher on contaminated than on uncontaminated plots. During summer and autumn, Zn and Pb concentrations were higher in leaves than in stems whereas Cd concentrations did not significantly differ between the organs. Concentrations of N, P, K, and Mg decreased across the study period whereas those of Ca and Na increased. Overall, metal and nutrient concentrations depended on plant organ and its development stage. The dry matter and nutrient accumulation patterns were not different between contaminated and uncontaminated plots. The significance of these findings is discussed in light of best phytomanagement practices and potential uses of Miscanthus biomass.

Nutrient Uptake, Partitioning, and Remobilization in Modern Soybean Varieties

The absence of recent data regarding the nutritional needs of modern soybean [Glycine max (L.) Merr.] production systems necessitates a greater comprehensive understanding of nutrient uptake, partitioning, and remobilization. The objective of this study was to evaluate macro‐ and micronutrient accumulation and partitioning in current soybean cultivars. Across 3 site‐years, plants were sampled at seven growth stages and divided into four plant tissue fractions for quantification of nutrient uptake. Accumulation (per ha) of 275 kg N, 21 kg P (48 kg P2O5), 172 kg K (207 kg K2O), 113 kg Ca, 50 kg Mg, 19 kg S, 335 g Zn, 371 g Mn, 325 g B, 849 g Fe, and 63 g Cu were required to produce approximately 3500 and 9500 kg ha−1 of grain and total biomass, respectively. Supplemental fertility modestly increased biomass and yield (2%), but did not alter nutrient partitioning or harvest index. Nutrients with high harvest index (i.e., percentage of total nutrient accumulation partitioned to grain) values included P (81%), N (73%), Cu (62%), and S (61%), which may serve as a limitation to high yield. Seasonal patterns of nutrient accumulation suggested that K and Fe were acquired primarily during late vegetative growth while the uptake of N, P, Ca, Mg, S, Zn, Mn, B, and Cu were more equally distributed between vegetative and seed‐filling growth phases. These results document the rate and duration of macro‐ and micronutrient accumulation in soybean, and highlight the importance of adequate nutrient availability during key crop growth periods.

Effects of Soil Applications of Micro-Nutrients and Chelating Agent Citric Acid on Mineral Nutrients in Soybean Seeds

Micro-nutrient deficiency in soil results in crop yield loss and poor seed quality. Correcting this deficiency is normally done by foliar or soil application. The objective of this research was to determine the effects of soil applications of five micro-nutrients (Mn, Cu, Zn, Mo, and B) alone and in combination with a chelating agent citric acid (CA) on soybean leaf and seed nutrients. Source of micro-nutrient compounds were MnCl2, CuCl2, ZnCl2, MoO3, and H3BO3. Our hypothesis was that micro-and macro-nutrients may be transported to leaves and then to seeds at different rates. They may interact synergistically or competitively during the uptake process. A greenhouse experiment was conducted at Mississippi Valley State University, Itta Bena, Mississippi, USA. Soybean cultivar, Bolivar (maturity group V), was applied with micro-nutrients-chelating agent citric acid at V3 and R3 (pod initiation) stage. The results showed that applications of Cu, Zn, B and Mo increased three unrolled trifoliate leaves Cu, Zn, B by 26.5%, 13.8%, 113% and Mo increased to 179 mg/kg, respectively in the leaves. Also, the application of “Cu, Zn, B and Mo increased Cu, Zn, B by 55.5%, 8.2%, 28.6% and Mo increased to 202 mg/kg” respectively in soybean seeds. Application of Mn had no direct effect on increasing Mn either in leaves or in seeds, however, Mn and Mn + CA treatment affected other mineral contents. Application of Cu, Zn, Mo, B and CA increased macro-nutrients K, N, P, Mg, and S. Irrespective of the applications, the nutrient increase trend in seed was Na > Fe > Zn > Mn > B > Cu > Mo. However, Mo application resulted in the following seed nutrient accumulation pattern: Na > Mo > Fe > Zn > Mn > B > Cu. This may suggest that Mo had higher mobility to seeds than other micro-nutrients. Combination of soil application of Mo + CA increased Mo in leaves at V3 stage; however, Mo + CA soil application during pod-filling stage had no significant effects on Mo accumulation in seeds. The current research showed that some micro-nutrient application with the chelating agent CA could increase seed nutrients. Since these results are conducted under greenhouse experiments, further research under field conditions is needed before conclusive recommendations are made.

Effects of Five Naturally Occurring Sugars on the Longevity, Oogenesis, and Nutrient Accumulation Pattern in Adult Females of the Synovigenic Parasitoid Neochrysocharis formosa (Hymenoptera: Eulophidae)

Neochrysocharis formosa (Westwood) (Hymenoptera: Eulophidae), one of the dominant natural enemies of agromyzid leafminers, is a synovigenic parasitoid. We compared the longevity, oogenesis, and nutrient levels of female wasps provided with 10% solutions of five naturally occurring sugars. All five sugars significantly increased the longevity of female wasps, which was 6.5-9.3-fold higher than that of parasitoids provided with water only. We found no significant difference in longevity of female wasps fed on glucose versus fructose or trehalose versus melezitose, but longevity of wasps fed on glucose or fructose was significantly longer than those fed on trehalose or melezitose. Also, we examined the oosorption capability of wasps fed on the five sugars. Some mature eggs were present in the ovaries of newly emerged females, but these were fully reabsorbed within 72h when wasps were starved. Once wasps were fed with any of the sugars, the number of mature eggs increased at first and then decreased due to oosorption. The longevity and oogenesis dynamics of female wasps fed on five sugars were related with their function of hydrolysis and digestion. As female wasps have no lipogenesis capability, by acquiring exogenous sugars for oogenesis, they can either maintain or exceed the original level of capital nutrients held on adult emergence because none of the wasps' glycogen need be metabolized to burn as sugar.

The nutrient accumulation pattern and cycling in natural secondary forests in North China. A case study from the Caijiachuan watershed, Shanxi Province

In order to examine the nutrient content, and the distribution and accumulation patterns of individual nutrients in the natural secondary forests (NSFs), sample NSF plots were selected in the Caijiachuan watershed on the Loess Plateau. On the basis of a comprehensive field inventory to the NSFs in Caijiachuan watershed, a 40 m × 40 m sample plot was selected as the representative plot. Each tree plant was then measured to select the standard tree in accordance with a diameter-scale. For measurement of the biomass in the above-ground part of the tree, it was divided into parts and measured. The study measured the concentration of the 5 major macronutrients (namely N, P, K, Ca and Mg) and the 8 major micronutrients (namely Cd, Fe, Mn, Cu, Zn, Pb, Ni and B) in plant organs. An appropriate amount of the samples were weighed and exposed to H2SO4-H2O2 using the Kjeldahl heating digestion method. While N content was measured with the semi-micro determination method, P content was measured using vanadium molybdate yellow colorimetric method HNO3-HClO4 ICP heating digestion method was applied to determine the contents of Ca, Mg, K, Na, Fe, Cu, Zn, Mn, B, Cd, Pb, Ni. As for soil samples, corresponding approaches were employed to work out the contents of each of the above-mentioned nutrient elements. Among the tree, shrub and herbaceous layers, the content of macro-nutrients follows the sequence of Ca > N > K > Mg > P, compared with their counterpart of K > N > Ca > P > Mg in the litter layer. For the micronutrient contents, similar sequences (i.e., Fe > Mn > Zn > B > Cu > Pb > Ni > Cd) were observed in the tree, shrub and litter layers; whereas the herbaceous layer demonstrated a different sequence of Fe > Mn > B > Zn > Cu > Pb > Ni > Cd. Within the NSF ecosystem, total accumulation of the 5 major macronutrients (excluding that in the soil) reached 1089.82 kg/ha, of which the tree layer took up the largest share, 40.82%, followed in turn by the shrub layer (31.28%), the herbaceous layer (12.55%) and the litter layer (15.36%). In terms of nutrient-concentration in the plant organs within the tree layer, the overall sequence can be expressed as branches > roots > wood > bark > leaves. The total accumulation of the 5 major macro-nutrient in the soil reached 634.97 t/ha. In terms of the accumulation coefficients in each of the layers, the general pattern can be summed up as: shrub layer > tree layer > herbaceous layer, and N > P > Ca > K > Mg. In terms of the plant organ accumulation coefficients at the tree layer, the sequence was leaves > branches > roots > bark > wood. As for the accumulation coefficients of the micronutrients, the overall sequences for the tree layer, the shrub layer and the herbaceous layer can be listed as Cd > B > Zn > Cu > Mn > Ni > Pb > Fe; Cd > B > Zn > Mn > Cu > Ni >Pb > Fe and Cd > B > Mn > Zn > Cu > Ni > Pb > Fe, respectively. The study also revealed that the macronutrients that are absorbed, assimilated and returned by the NSF stand annually reached 99.054kg/(ha·year), 49.155 kg/(ha·year) and 49.899 kg/(ha·year), respectively, demonstrating a well-balanced state of nutrient cycling. With an average of 0.0013, the absorbance index of the macro-nutrients was ranked in the following sequence, N > P > K > Ca > Mg; whereas their utilization and cycling indexes were respectively sequenced as K > P > N > Mg > Ca and K > P > N > Mg > Ca. For the micronutrients the corresponding annual figures were 117.35 g/(ha·year), 50.96 g/(ha·year) and 66.39 g/(ha·year), respectively. The micronutrients, as a whole, showed a relatively small absorbance index (e.g.,Cd was the largest =0.0036). The average utilization index of all the microelements was 0.12.

Mineralogical impact on long-term patterns of soil nitrogen and phosphorus enzyme activities

During long-term ecosystem development, both soil mineralogical composition and nutrient contents change, thus possibly altering microbial nutrient cycling by constraining substrate accessibility. In addressing the mineral impact on nitrogen (N) and phosphorus (P) cycling, we determined microbial abundances, activities of N-hydrolyzing (aminopeptidases, protease, urease) and P-hydrolyzing (phosphatase) enzymes and the potential substrate availability as well as their physicochemical and mineralogical controls in whole soil profiles along the 120 kyr-old Franz Josef chronosequence (New Zealand). Pedogenic soil iron (Fe) and aluminum (Al) resided initially (<1 kyrs) in metal-humus complexes, changed to poorly crystalline Fe and Al at intermediate-aged sites (1–12 kyrs) and into dominance of clay and crystalline Fe oxides at the oldest site. Despite this, organic C (OC) and organic N (ON) stocks increased only slightly with soil age, whereas organic P (OP) stocks decreased continuously. In organic layers, enzyme activities were mainly regulated by ON and OP concentrations, whereas in mineral soils, mineral–enzyme relations were more complex and included both, direct and indirect effects. Protease, urease, and phosphatase activities were inhibited by mineral interactions, especially with poorly crystalline Fe and Al oxides, whereas aminopeptidases were less affected by mineralogical properties. On a pedon basis, most N-hydrolyzing enzyme activities per ON stocks responded negatively to increasing stocks of poorly crystalline Fe and Al minerals, but were also affected by the C:N ratio of labile organic substrates. Profile-based phosphatase activities per OP stock were highest at the oldest sites having the largest stocks of clay and crystalline Fe oxides. Overall, our study indicates that long-term mineral changes create distinct patterns of nutrient accumulation and N- and P-enzyme activities at both horizon and pedon scale, with a variable extent of the mineralogical effect for the different N-hydrolyzing enzymes.