Contrasting patterns of nutrient dynamics during different storm events in a semi-arid catchment of northern China

Nutrient discharge during storm events is a critical pathway for nutrient export in semi-arid catchments. We investigated nutrient dynamics during three summer storms characterized by different rainfall magnitude in 2012 in a semi-arid catchment of northern China. The results showed that, in response to storm events, nutrient dynamics displayed big variation in temporal trends of nutrient concentration and in nutrient concentration-flow discharge relationships. Nutrient concentrations had broader fluctuations during an extreme storm than during lesser storms, whereas the concentration ranges of the a moderate storm were no broader than those of a smaller one. The different concentration fluctuations were caused by storm magnitude and intensity coupled with the antecedent rainfall amount and cumulative nutrients. Correlation coefficients between nutrient concentrations and flow discharge varied from positive to negative for the three different events. There were no consistent hysteresis effects for the three different events, and no hysteresis effects were observed for any of the variables during the moderate storm (E2). Our findings provide useful information for better understanding nutrient loss mechanisms during storm events in semi-arid areas of a monsoon climate region.

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Assessment of errors in nutrient analyses of roots

Soil Research ◽

10.1071/sr9941275 ◽

1994 ◽

Vol 32 (6) ◽

pp. 1275 ◽

Cited By ~ 11

Author(s):

RK Misra

Keyword(s):

Soil Contamination ◽

Nutrient Concentration ◽

Clay Soil ◽

Nutrient Content ◽

Nutrient Loss ◽

Nutrient Concentrations ◽

Root Sample ◽

Nutrient Analyses ◽

And Storage

Errors in nutrient analyses of roots may arise from soil adhering to roots, the method of root separation from soil and storage of root samples. Experiments were conducted on fine roots of Eucalyptus nitens from a clay soil to establish a method for estimating true concentrations of nitrogen (N), phosphorus (P) and potassium (K) in root samples (i.e. unbiased by the soil adhering to roots), and to test the adequacy of measurements of ash residues of root samples for estimating the quantity of soil adhering to roots. Results indicated that nutrient concentrations on the basis of ash-free weight of root samples approached true nutrient concentrations of roots when the quality of soil adhering to roots was small, and the nutrient concentration of soil was much lower than the roots. Estimates of true nutrient concentrations of roots calculated from the information on the weight of soil adhering to roots and the nutrient concentration of the soil were satisfactory in the prediction of nutrient content of roots for a range of soil-contamination. The factor which accounted for contamination, and helped estimation of true concentrations from measured concentrations, depended on the magnitude of soil contamination and the relative concentrations of nutrients in roots and soil. Wet separation (washing) of roots from soil compared with dry separation resulted in 24% loss of K. With various methods of storage of washed root samples, the level of soil contamination was 5-20% of the root sample. Submergence of roots in water for 15 days after washing reduced the concentration of N, P and K in roots to 84, 50 and 54% of those roots which were dried immediately following washing. The rate of nutrient loss from roots was greater for K than for N and P when washed samples were stored submerged. On the basis of this study, it is recommended that roots, after separation from soil, should be dried as soon as possible with a minimum exposure of roots to wet conditions. Estimates of soil adhering to roots, and nutrient concentration of the adhering soil, are required to infer correct concentrations of nutrients in root samples.

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Removing Harvest Residues from Hardwood Stands Affects Tree Growth, Wood Density and Stem Wood Nutrient Concentration in European Beech (Fagus Sylvatica) and Oak (Quercus spp.)

10.21203/rs.3.rs-814871/v1 ◽

2021 ◽

Author(s):

Sanjoy Roy ◽

Jean-Michel Leban ◽

Bernd Zeller ◽

Gregory Van-Der-Heijden ◽

Arnaud Reichard ◽

...

Keyword(s):

Wood Density ◽

Tree Growth ◽

Nutrient Concentration ◽

Nutrient Loss ◽

Nutrient Concentrations ◽

Valuable Insight ◽

Harvest Residues ◽

Stem Wood ◽

Tree Nutrition ◽

The Impact

Abstract Background: Increased exportation of harvest residues from forests, to mitigate excessive demand for woody biomass, have reportedly diminished soil mineral resources and may lead to degraded tree nutrition and tree growth. However, as nutrients become less available in the soil, the remobilization of nutrients in biomass tissues (plant internal cycling) helps sustain tree nutrition. Our study aims to quantify the impact of Removing Harvest Residues and Litter (RHRL) during five years on tree growth, wood density and stem wood nutrient concentrations in young beech and oak forest stands.Result: Our study found that, RHRL significantly decreased the tree growth ring width, by 14%, and wood density, by 3%, in beech trees, in the near bark rings. RHRL also significantly reduced the nutrient concentration in the near bark and near pith area of both species. Mg, Na and S were found lower by 44%, 76% and 56%, respectively, in the near bark area of beech trees, and K, Ca, Mg, Na, S and Fe were lower by 20%, 25%, 41%, 48%, 41% and 16%, respectively, in the near bark area of oak trees. K and Mg concentrations decreased more strongly in the near pith area compared to the near bark area suggesting internal translocation of these two elements. Conclusion: In beech trees, wood density proved to be an important factor while quantifying the effect of removing harvest residuals on the tree growth and biomass. Soil nutrient loss intensified the remobilization of nutrients contained in older tree rings (close to the pith) towards newly formed rings (close to bark). In our study, in beech trees, K was found to be the most recycled major nutrient. These results demonstrate the potential of such analysis for providing valuable insight into the effect of RHRL in premature stands on the physiological adaptive strategies of trees and an indication of soil fertility and acidity status.

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Leaf-tissue Nutrient Dynamics in Mature Muscadine Cultivars Carlos and Noble in Georgia and North Carolina

HortTechnology ◽

10.21273/horttech04765-20 ◽

2021 ◽

pp. 1-11

Author(s):

Tekan S. Rana ◽

Erick D. Smith ◽

Cain Hickey ◽

Mark Hoffmann

Keyword(s):

North Carolina ◽

Nutrient Concentration ◽

Nutrient Dynamics ◽

Leaf Tissue ◽

Wine Industry ◽

Nutrient Concentrations ◽

Vitis Rotundifolia ◽

Vine Growth ◽

Mn Concentration ◽

Tissue Nutrient Concentration

More than 3000 acres of commercial muscadine (Vitis rotundifolia) vineyards exist in the southeastern United States. The muscadine wine industry is generating an economic impact of $1 billion in North Carolina alone. Muscadines have been cultivated since the 1800s, but muscadine vineyard fertilizer programs, tissue sampling, and nutrient sufficiency ranges continue to be based on anecdotal knowledge. While seasonal changes in tissue nutrient concentration are well documented in bunch grape (Vitis vinifera), questions remain about the seasonal and cultivar-dependent dynamics of muscadine leaf tissue nutrient concentrations. The aim of this study was to assess temporal and cultivar-related differences in tissue nutrient concentration of mature commercially grown muscadines. Leaf tissue nutrient concentration of the muscadine cultivars Carlos and Noble were assessed in three vineyards (Piedmont North Carolina, north Georgia, and south Georgia) at bloom, véraison, and postharvest in 2018 and 2019. Our results show that nitrogen (N), phosphorus (P), and manganese (Mn) were generally above the recommended sufficiency ranges, with calcium increasing over the season—and N, P, and potassium decreasing over the season. ‘Carlos’ had significantly higher levels of N and P, compared with ‘Noble’, while ‘Noble’ showed higher Mn concentration than ‘Carlos’. With this evaluation, we demonstrate the need for a modification in muscadine tissue nutrient sufficiency ranges that are based on cultivar and vine growth stage.

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Quantifying Drought Resistance of Drylands in Northern China from 1982 to 2015: Regional Disparity in Drought Resistance

Forests ◽

10.3390/f13010100 ◽

2022 ◽

Vol 13 (1) ◽

pp. 100

Author(s):

Maohong Wei ◽

Hailing Li ◽

Muhammad Adnan Akram ◽

Longwei Dong ◽

Ying Sun ◽

...

Keyword(s):

Drought Resistance ◽

Regional Differences ◽

Arid Regions ◽

Vegetation Index ◽

Temporal Trends ◽

Northern China ◽

Ecosystem Productivity ◽

Negative Effect ◽

Dryland Ecosystems ◽

Semi Arid

Drylands are expected to be affected by greater global drought variability in the future; consequently, how dryland ecosystems respond to drought events needs urgent attention. In this study, the Normalized Vegetation Index (NDVI) and Standardized Precipitation and Evaporation Index (SPEI) were employed to quantify the resistance of ecosystem productivity to drought events in drylands of northern China between 1982 and 2015. The relationships and temporal trends of resistance and drought characteristics, which included length, severity, and interval, were examined. The temporal trends of resistance responded greatest to those of drought length, and drought length was the most sensitive and had the strongest negative effect with respect to resistance. Resistance decreased with increasing drought length and did not recover with decreasing drought length in hyper-arid regions after 2004, but did recover in arid and semi-arid regions from 2004 and in dry sub-humid regions from 1997. We reason that the regional differences in resistance may result from the seed bank and compensatory effects of plant species under drought events. In particular, this study implies that the ecosystem productivity of hyper-arid regions is the most vulnerable to drought events, and the drought–resistance and drought–recovery interactions are likely to respond abnormally or even shift under ongoing drought change.

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Does Geijera parviflora Lindl. (Rutaceae) facilitate understorey species in semi-arid Australia?

The Rangeland Journal ◽

10.1071/rj07032 ◽

2007 ◽

Vol 29 (2) ◽

pp. 207 ◽

Cited By ~ 9

Author(s):

A. D. Warnock ◽

M. E. Westbrooke ◽

S. K. Florentine ◽

C. P. Hurst

Keyword(s):

Soil Moisture ◽

Species Composition ◽

Seed Bank ◽

Nutrient Concentration ◽

Species Abundance ◽

Soil Nutrient ◽

Nutrient Concentrations ◽

Arid Zones ◽

Understorey Vegetation ◽

Semi Arid

Species composition under tree canopies often differs from that of surrounding micro-environments. In arid and semi-arid zones, trees can be beneficial to understorey vegetation. This study examined zones of vegetation composition and soil physiochemical parameters associated with Geijera parviflora Lindl. The importance of shade, rainfall redistribution, seed bank and soil moisture were examined. Species abundance, soil moisture, seed bank composition, rainfall redistribution and soil nutrient concentration were measured under five randomly selected mature G. parviflora trees in south-western New South Wales, Australia. To complement the findings from this study, artificial shade plots were constructed in a canopy-free area and species abundance measured seven months after shade construction. The study demonstrated that G. parviflora was associated with zonation of understorey vegetation. Two zones of understorey vegetation were found in relation to G. parviflora: (i) under the tree canopy with high species diversity, and (ii) beyond the canopy, this community being dominated by Dissocarpus paradoxus throughout the year with Crassula colorata appearing after rainfall. The zone beyond the canopy also had lower soil nutrient concentrations. Soil moisture, nutrient concentration and the seed bank density were significantly higher under the canopy. However, the canopy reduced precipitation reaching the soil surface. The effects of the canopy on understorey species composition and soil moisture were enhanced after winter rainfall. Artificial shade increased species abundance and richness under a 90%-shading treatment. The results indicated that G. parviflora generated spatial heterogeneity over the broader plant community increasing species richness, abundance and diversity under the canopy. This emphasises the importance of arid zone trees in conserving understorey plant diversity. Shading, soil nutrient concentration and increased seed bank density and soil moisture appeared to be key influences on the plant communities under the canopy.

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Persistence and Replacement of Preplant Fertilizers from Highly Leached Peat-based Root Media

HortScience ◽

10.21273/hortsci.30.4.763e ◽

1995 ◽

Vol 30 (4) ◽

pp. 763E-763

Author(s):

John A. Biernbaum ◽

William R. Argo ◽

Brian Weesies ◽

Allen Weesies ◽

Karen Haack

Keyword(s):

Nutrient Concentration ◽

Water Soluble ◽

Lower Half ◽

Nutrient Loss ◽

Nutrient Concentrations ◽

Root Media ◽

The Media ◽

Saturated Media ◽

Series Of Experiments ◽

Soluble Fertilizer

A series of experiments was conducted to quantify the rate of nutrient loss from a container medium in a 15-cm-wide (1.3-liter) pot with a container capacity (CC) of 0.7 liter/pot under mist propagation and to determine the effectiveness of reapplying fertilizer to medium at 90% of CC with either top watering or subirrigation. Reducing the volume of water applied per day decreased the rate of nutrient leaching. Based on CC leached (CCL), the rate of nutrient loss was similar for all treatments. Differences in the rate of macronutrient removal from the media were measured, but, by 2 CCL, the concentration of all nutrients tested was below acceptable levels for the saturated media extract. With top watering, reapplying water-soluble fertilizer (WSF) at volumes under 0.2 liter/pot did not affect the nutrient concentration in the lower half of the pot at WSF concentrations up to 86 mol N/m3. Applying up to 0.8 liter/pot did increase nutrient concentrations in the lower half of the pot, but the media nutrient concentrations were lower than that of the applied WSF concentration. Applying WSF with subirrigation was limited by the moisture content of the media prior to the irrigation.

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