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Investigation:

TG-07 (Keller / Oliveira)

LBA Dataset ID:

TG07_SOIL_NUTRIENTS

Originator(s):

MCGRODDY, M.E.

Point(s) of Contact:

ORNL DAAC User Services Office Oak Ridge National Laboratory Oak Ridge, Tennessee 37 (ornldaac@ornl.gov)

Dataset Abstract:

The data come from a fertilization experiment conducted in the Tapajos National Forest, Para between April 1999 and April 2000. Control and fertilized plots were established in both sandy loam and clay soils (n=3 for each). Soil cores were collected every 4 months from August 1999 through April 2000. Soil total C, N and P concentrations as well as sequential Hedley P fractions were measured on both ingrowth and bulk soil cores from each collection. In addition fine root biomass and P pools as well as forest floor mass and P pools were measured at each collection and those data are presented here.

Beginning Date:

1999-04-20

Ending Date:

2000-04-20

Metadata Last Updated on:

2012-05-24

Data Status:

Archived

Access Constraints:

PUBLIC

Data Center URL:

http://daac.ornl.gov/

Distribution Contact(s):

ORNL DAAC User Services Office Oak Ridge National Laboratory Oak Ridge, Tennessee 37 (ornldaac@ornl.gov)

Access Instructions:

PUBLIC

Data Access:

IMPORTANT: The LBA-ECO Project website is no longer being supported. Links to external websites may be inactive. Final data products from the LBA project can be found at the ORNL DAAC. Please follow the fair use guidelines found in the dataset documentation when using or citing LBA data.
Datafile(s):

LBA-ECO TG-07 Forest Soil P, C, and N Pools, km 83 Site, Tapajos National Forest:  http://daac.ornl.gov/cgi-bin/dsviewer.pl?ds_id=1085

Documentation/Other Supporting Documents:

LBA-ECO TG-07 Forest Soil P, C, and N Pools, km 83 Site, Tapajos National Forest:  http://daac.ornl.gov/LBA/guides/TG07_Soil_Nutrients.html

Citation Information - Other Details:

McGroddy, M.E. 2012. LBA-ECO TG-07 Forest Soil P, C, and N Pools, km 83 Site, Tapajos National Forest. Data set. Available on-line [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. http://dx.doi.org/10.3334/ORNLDAAC/1085

Keywords - Theme:

Parameter Topic Term Source Sensor
BIOGEOCHEMICAL CYCLES BIOSPHERE ECOLOGICAL DYNAMICS FIELD INVESTIGATION ANALYSIS
BIOMASS BIOSPHERE ECOLOGICAL DYNAMICS FIELD INVESTIGATION WEIGHING BALANCE
CARBON BIOSPHERE ECOLOGICAL DYNAMICS FIELD INVESTIGATION CARBON ANALYZER
NITROGEN BIOSPHERE ECOLOGICAL DYNAMICS FIELD INVESTIGATION KJELDAHL DIGESTION
PHOSPHORUS BIOSPHERE ECOLOGICAL DYNAMICS FIELD INVESTIGATION COLORIMETER
SOIL BULK DENSITY BIOSPHERE ECOLOGICAL DYNAMICS FIELD INVESTIGATION WEIGHING BALANCE

Uncontrolled Theme Keyword(s):  FERTILIZATION, FINE ROOT BIOMASS, FINE ROOTS, MICROBIAL BIOMASS, MICROBIAL BIOMASS NUTRIENTS, ROOT BIOMASS, SOIL CARBON, SOIL NITROGEN, SOIL PHOSPHORUS

Keywords - Place (with associated coordinates):

Region
(click to view profile)
Site
(click to view profile)
North South East West
Pará Western (Santarém) km 83 Logged Forest Tower Site -3.01700 -3.01700 -54.97070 -54.97070

Related Publication(s):

McGroddy, M.E., W.L. Silver, R.C. de Oliveira, W.Z. de Mello, and M. Keller. 2008. Retention of phosphorus in highly weathered soils under a lowland Amazonian forest ecosystem. Journal of Geophysical Research-Biogeosciences 113(G4).

Data Characteristics (Entity and Attribute Overview):

Data Characteristics:

Data is presented in one comma-delimited ASCII file titled TG07_km83_Tapajos_P_fertilization.csv



Team ID: TG-07

Data contact: Megan McGroddy

Related LBA Data Set Inventory ID: TG07_Soil_Nutrients



column Heading Unit/format Description

Number

1,collection,,month from the initial collection and start of fertilization treatment : 0 (pre-fertilization) ,4,8,12,,,,,,,,,,,,,,,,,,,,,,,

2,collection_date,,collection date is represented as yyyymmdd ,,,,,,,,,,,,,,,,,,,,,,,

3,core_type,,cores were either incubation cores (soil collected in April 1999 and packed into plastic mesh cores which were placed back in the sample location) or direct cores ( soil cores collected on the collection date with no prior manipulation other than fertilzation treatment where appropriate) ,,,,,,,,,,,,,,,,,,,,,,,

4,soil ,,soil class determined by texture: clay or sandy loam (sand),,,,,,,,,,,,,,,,,,,,,,,

5,treatment,,1 means fertilized with 137 kg P per hectare per year, 0 means no fertilizer added: the initial collection was done prior to fertilzer addition so treatment is used to indicate cores in the plots that later received fertilizer,,,,,,,,,,,,,,,,,,,,,,,

6,bulk_density ,Mg per ha,bulk density to a 10 cm depth data reported is a mean of 3 samples ,,,,,,,,,,,,,,,,,,,,,,,

7,resin,kg per ha,water extractable P: collected on anion exchange resin: Hedley P fraction: data reported is a mean of 3 samples for direct cores and a mean of 6 samples for incubation cores,,,,,,,,,,,,,,,,,,,,,,,

8,NaHCO3,kg per ha,0.5M NaHCO3 extractable P; Hedley P fraction: data reported is a mean of 3 samples for direct cores and a mean of 6 samples for incubation cores,,,,,,,,,,,,,,,,,,,,,,,

9,NaOH,kg per ha,0.5M NaOH extractable P; Hedley P fraction: data reported is a mean of 3 samples for direct cores and a mean of 6 samples for incubation cores,,,,,,,,,,,,,,,,,,,,,,,

10,1M_HCl,kg per ha,1M HCl extractable P; Hedley P fraction: data reported is a mean of 3 samples for direct cores and a mean of 6 samples for incubation cores,,,,,,,,,,,,,,,,,,,,,,,

11,conc_HCl,kg per ha,concentrated HCl extractable P; Hedley P fraction: data reported is a mean of 3 samples for direct cores and a mean of 6 samples for incubation cores,,,,,,,,,,,,,,,,,,,,,,,

12,H2SO4,kg per ha,residual P; extracted with a H2SO4 digest; Hedley P fraction: data reported is a mean of 3 samples for direct cores and a mean of 6 samples for incubation cores,,,,,,,,,,,,,,,,,,,,,,,

13,digest_P,mg per kg soil,total soil P measured by modified Kjeldhal digest: data reported is a mean of 3 samples for direct cores and a mean of 6 samples for incubation cores,,,,,,,,,,,,,,,,,,,,,,,

14,soil_N,percent,total soil N measured by dry combustion: data reported is a mean of 3 samples for direct cores and a mean of 6 samples for incubation cores,,,,,,,,,,,,,,,,,,,,,,,

15,soil_C ,percent,total soil C measured by dry combustion: data reported is a mean of 3 samples for direct cores and a mean of 6 samples for incubation cores,,,,,,,,,,,,,,,,,,,,,,,

16,dead_rt_mass,kg per ha,dead root biomass to 10 cm depth roots; 65 degree dry wt: data reported is a mean of 3 samples for both direct cores and incubation cores,,,,,,,,,,,,,,,,,,,,,,,

17,total_rt_mass,kg per ha,total root biomass to 10 cm depth roots; 65 degree dry wt: data reported is a mean of 3 samples for both direct cores and incubation cores,,,,,,,,,,,,,,,,,,,,,,,

18,dead_rt_P,kg per ha,P pool in dead root tissue; from a Kjeldhal digest; analyzed on an ICP: data reported is a mean of 3 samples for both direct cores and incubation cores,,,,,,,,,,,,,,,,,,,,,,,

19,total_rt_P,kg per ha,P pool in total root tissue; from a Kjeldhal digest; analyzed on an ICP1/30/2012 data reported is a mean of 3 samples for both direct cores and incubation cores,,,,,,,,,,,,,,,,,,,,,,,

20,dead_rt_N,kg per ha,dead root tissue N pool measured by dry combustion: data reported is a mean of 3 samples for both direct cores and incubation cores,,,,,,,,,,,,,,,,,,,,,,,

21,total_rt_N,kg per ha,total root tissue N pool measured by dry combustion: data reported is a mean of 3 samples for both direct cores and incubation cores,,,,,,,,,,,,,,,,,,,,,,,

22,dead_rt_C,kg per ha,dead root tissue C pool measured by dry combustion: data reported is a mean of 3 samples for both direct cores and incubation cores,,,,,,,,,,,,,,,,,,,,,,,

23,total_rt_C,kg per ha,total root tissue C pool measured by dry combustion: data reported is a mean of 3 samples for both direct cores and incubation cores,,,,,,,,,,,,,,,,,,,,,,,

24,forest_floor_mass,Mg per ha ,forest floor mass 65 degree dry wt: data reported is a mean of 5 samples per plot,,,,,,,,,,,,,,,,,,,,,,,

25,forest_floor_P,kg per ha,forest floor P pool measured by modified Kjeldhal digest; analyzed on an ICP: data reported is a mean of 5 samples per plot,,,,,,,,,,,,,,,,,,,,,,,

26,microbial_P,kg per ha,microbial biomass P determined by chloroform fumigation direct extraction method and measured colormetrically no correction for efficiency used : data reported is a mean of 3 samples for direct cores and a mean of 6 samples for incubation cores,,,,,,,,,,,,,,,,,,,,,,,

27,leachate_P,kg per ha,inorganic P in soil solution leached from the bottom of the root ingrowth cores captured by anion exchange resins and measured colormetrically: data reported is a mean of 6 per plot,





missing data values are represented by -9999





Sample data records:

collection,collection_date,core_type,soil ,treatment,bulk_density,resin,NaHCO3,NaOH,1M_HCl,conc_HCl,H2SO4,digest_P,soil_N,soil_C ,dead_rt_mass,total_rt_mass,dead_rt_P,total_rt_P,dead_rt_N,total_rt_N,dead_rt_C,total_rt_C,forest_floor_mass,forest_floor_P,microbial_P,leachate_P

0,19990429,direct,clay,0,1150,0,28,61,3,51,29,58,0.17,1.89,-9999,-9999,-9999,-9999,-9999,-9999,-9999,-9999,4.08,1.51,-9999,-9999

0,19990429,direct,clay,0,1007,1,30,48,2,41,13,36,0.24,2.66,-9999,-9999,-9999,-9999,-9999,-9999,-9999,-9999,5.53,3,-9999,-9999

0,19990429,direct,clay,0,1072,1,21,38,1,44,16,21,0.21,2.46,-9999,-9999,-9999,-9999,-9999,-9999,-9999,-9999,3.52,2.59,-9999,-9999

0,19990429,direct,clay,1,1135,1,21,39,2,47,12,69,0.19,2.09,-9999,-9999,-9999,-9999,-9999,-9999,-9999,-9999,3.78,2.34,-9999,-9999

0,19990429,direct,clay,1,1041,1,19,45,1,42,22,29,0.21,2.5,-9999,-9999,-9999,-9999,-9999,-9999,-9999,-9999,4.29,2.83,-9999,-9999

0,19990429,direct,clay,1,973,1,32,45,2,39,17,21,0.23,2.61,-9999,-9999,-9999,-9999,-9999,-9999,-9999,-9999,4.91,3.13,-9999,-9999

0,19990429,direct,sand,0,1494,1,41,32,2,15,16,53,0.07,0.91,-9999,-9999,-9999,-9999,-9999,-9999,-9999,-9999,3.98,1.57,-9999,-9999

0,19990429,direct,sand,0,1477,1,39,33,1,32,17,38,0.08,0.98,-9999,-9999,-9999,-9999,-9999,-9999,-9999,-9999,5.77,2.87,-9999,-9999

0,19990429,direct,sand,0,1260,1,31,14,3,13,10,50,0.07,0.93,-9999,-9999,-9999,-9999,-9999,-9999,-9999,-9999,6.79,2.81,-9999,-9999

0,19990429,direct,sand,1,1209,1,33,18,2,16,8,41,0.08,1.17,-9999,-9999,-9999,-9999,-9999,-9999,-9999,-9999,5.93,3.07,-9999,-9999

Data Application and Derivation:

In addition to its role limiting primary productivity, recent work has suggested that soil P is linked to soil C sequestration capacity in highly weathered soils [Giardina et al., 2004; Li et al., 2006] although the relationship is not currently well understood. Our ability to predict the C fluxes in tropical forest ecosystems under changing climate conditions depends on our understanding of the interaction among soil P pools as well as the regulation of these pools and their relative size by soil environment.

Quality Assessment (Data Quality Attribute Accuracy Report):

Quality Assessment:

Quality Assessment Activities



Forest Floor and Roots:

For C and N analyzes acetanilide (10.36 % N and 71.09 % C) was used as a reference standard. Samples were analyzed in duplicate and rejection criterion was set at > 10% variance between duplicates.



Total P was determined after a H2O2 predigest and modified Kjeldhal digest of ground plant tissue (J.Tilley pers. comm.). NIST Apple leaves were used as a reference standard with a 98 % (+ 2) recovery.



Soil P Pools:

Total P calculated as the sum of the measured sequential fractionation pools in the Hedley Fractionation was compared to total P measured by Kjeldhal digest method with NIST San Joaqin standard soils as a QA and total P measured by HF digest at the Dept. de Geoquimica at the Universidade Federal Fluminense. Due to the cost and risk associated with the HF analysis only 12 samples were included.



Confidence Level or Accuracy Judgment:

The total soil P values by summation corresponded to the measurements by the HF method (estimated method precision of + 25%) but regression analysis suggested that summing of fractions slightly overestimated total P at higher concentrations and underestimated P at lower concentrations.





Measurement Error for Parameters:

Precision limits: Balances for mass measurements + 0.01g, CN analysis + 0.01 % for both C and N, ICP for P in digest solution detection limit 2 ug per liter which translates into a limit of approximately 120 ug per kg soil for fractions analyzed on the ICP. For the colorimeter, the detection limit was higher, approximately 0.1 mg per liter which translates into a limit of approximately

5 mg per kg soil.

Process Description:

Data Acquisition Materials and Methods:

Study Site

The study was conducted in the Tapajos National Forest, 83 km south of Santarem, Para, Brazil (2 degrees 64 minutes S and 54 degrees 59 minutes W). For additional site description see Silver et al. (2000), Keller et al. (2001) and McGroddy et al. (2004).

The planalto area south of Santarem is dominated by well-drained dystrophic yellow-brown lateritic Ultisols (Latossolo Amarelo textura muito argilosa in the Brazilian classification system), derived from the sandy-clayey lithography of the Alter do Chao formation (Cretaceous-Tertiary, Irions 1984). In addition to the dominant Ultisols, deep well drained sand/ sandy-loam soils (Oxisols, Neossolos Quartzarenicos in the Brazilian soil classification system), developed from sandy sediments deposited during the Quaternary, occur in the same region (Rodrigues et al. 1991). Plots for clay soils were located 250 south of the southern boundary of the area marked for selective harvesting while the plots on sandy soils were located 350 m east of the eastern boundary of the same area.

Three study blocks (12 x 100 m) were established on level terrain in each soil type within the Tapajos National Forest. Blocks were divided into five 12 x 20 m plots with fertilization addition and sampling restricted to the interior 4 x 20 m zone of the first, third and fifth plots, leaving the rest of the area as buffer. Plots were located and incubation cores installed in March 1999. Soil collections began in April 1999 and continued every 4 months afterwards through April 2000. Fertilizer was applied to one randomly selected treatment plot in each study block at three points over the course of the study period (May, August and December of 1999). Measurements of soil nutrient concentrations done on 0.5g soil samples are presented on an areal (1 hectare to 10 cm depth) basis calculated by multiplying concentrations by soil bulk density values measured at each plot and collection point using a standard volume soil corer.



Root, microbial and soil P dynamics

Incubation cores were 10 cm high and 6 cm in diameter and were constructed from plastic canvas (Darice 7 count plastic canvas, 2 x 2 mm mesh). A total of 360 root incubation cores were constructed. We selected 216 cores for inorganic P leachate estimates; the bottom of these cores were fitted with 6 cm dia. silk resin bags containing 3 g of Cl charged Biorad AG 85 anion exchange resin beads.

For each core a soil sample was taken using a 6 cm diameter soil corer to a depth of 10 cm. Visible roots and large pieces of organic material were removed by hand and the homogenized soil from each sample was packed into a plastic canvas core thus maintaining representative bulk densities. At each of 15 randomly selected locations within the plot a set of three cores was installed: to allow for fine root biomass measurements as well soil and microbial biomass P measurements. All incubation cores (total of 180 sets or 540 cores) were installed in April 1999.

Cores were collected 4, 8, and 12 months after installation (in August and November 1999 and April 2000). At each time point, we collected 5 sets of cores, we also collected 6 direct soil cores and 5 forest floor samples from each treatment plot for further estimates of soil, root and litter layer P dynamics. Three of the bulk cores were analyzed for fine root biomass and nutrient content and the other three for bulk density and soil and microbial P pools.



Analytical methods

Soil pH in 2 M KCl was determined on a 1:1 slurry of fresh soils from the initial soil collections done in April 1999. These analyzes were done in at the EMBRAPA analytical labs in Belem, PA, Brazil. All further analyzes were done at the University of California, Berkeley. Soil texture was determined for one composite sample from each plot using the Bouyoucos hydrometer method (Gee and Bauder 1976). Total soil C and N were measured on air-dried, ground soils using a dry combustion- reduction method on a CE Instruments NC2500 soil analyzer (CE Instruments Lakewood NJ).



Soil P fractions

Soil P fractions were determined using the modified Hedley fractionation method (Tiessen and Moir 1993, Frizano et al. 2002) on air-dried soil samples. Phosphorus concentrations of the extractant solutions were determined on a Lachat QuickChem 8000 Automated Ion Analyzer (Lachat Instruments Division of Zellweger Analytics, Inc. Milwaukee WI) and for the solutions with strong color on a Thermo Jarrell Ash axial IRIS ICP-AES (Thermo Elemental, Franklin MA). Strong coloration of the inorganic extracts made colorimetric analyzes imprecise so only total pools are reported.

Anion exchange resins

Anion exchange resin bags were stored frozen until they could be analyzed in 2001. Soil and organic matter were washed from the bags with distilled, deionized water, and each bag was extracted with 50 ml of a 0.5 M HCl solution. Bags with holes due to either root or soil fauna activity were re-weighed to get an accurate assessment of mass. Approximately 15 percent of the bags from the final collection point were colonized by root biomass. Plant or fungal uptake of P in the root colonized bags may have caused an underestimation of P captured by the resin and these bags were excluded from the analyzes. Orthophosphate in the extraction solution was determined using a molybdate blue analysis on a Lachat QuickChem 8000 Automated Ion Analyzer.



Chloroform fumigation direct extraction P

An index of microbial biomass P pools was determined using the chloroform fumigation direct extraction (CFDE) technique with acidified NH4F as the extraction solution on fresh soils. Phosphorus concentrations in the extraction solutions were determined on Thermo Jarrell Ash axial IRIS ICP-AES. CDFE-P was calculated as the difference between the P extracted from the fumigated sample and that from the non-fumigated sample. A correction factor for sorption of P released by fumigation was calculated by measuring recovery of a P spike (average recovery of 45% for a spike of 25 ug P g-1 soil in the form of KH2PO4), added to composite soil samples for each texture. All data are reported on a 105 degree C dry weight basis.



Root biomass and nutrient content

Roots were washed through a series of three Nalgene sieves (sieve opening sizes: 2.0, 0.5 and 0.2 mm respectively) to remove soil particles and extraneous organic material. Fine roots (< 2mm dia.), considered most active in nutrient uptake, were sorted into live and dead categories based on appearance and tensile strength (Vogt and Persson 1991), dried at 65 degrees C and weighed to determine mass. Samples from replicate plots were bulked as necessary to provide enough tissue for nutrient analyzes, and ground in a Wiley mill. Total tissue C and N were measured on a CE Instruments NC2500 soil analyzer (CE Instruments Lakewood NJ). Fine root tissue P concentrations were determined on a Thermo Jarrell Ash axial IRIS ICP-AES after a modified Kjeldhal digest (Parkinson and Allen 1975).



Forest floor phosphorus and soil bulk density, carbon and nitrogen

Forest floor samples were dried at 50 degrees C for 3 days and weighed to determine mass. A set of sub-samples was dried at 65 degrees C and a conversion factor was developed to calculate mass on a 65 degrees C dry weight basis. Samples were ground in a Wiley mill and passed through a 40 mesh. A 0.5 g sub-sample was ashed at 550 degrees C for 4 h in order to determine the inorganic composition of each sample. Total P concentrations were determined as described for the root tissue and reported on a 65 degree C dry weight and ash free basis.

Bulk density was determined by measuring fresh weight of soil from 3 cores (282.6 cm3 volume, 0-10 cm depth) from each plot and a fresh to oven dry (105 degrees C) conversion developed from a subsample from each core. Air-dried soils from each collection were passed through a 2 mm sieve, ground, and analyzed for total C and N using the methods described for root tissue.

References:

Frizano, J., A.H. Johnson, D.R. Vann and F.N. Scatena (2002), Soil phosphorus fractionation during forest development on landslide scars in the Luquillo Mountains, Puerto Rico. Biotropica, 34, 17-26.



Gee, G.W., and J.W. Bauder (1986), Particle-size analysis. In A. Klute (ed) Methods of Soil Analysis. Part I. Physical and Mineralogical Methods. ASA-SSSA, Madison, WI. USA



Giardina, C.P., D. Binkley, M.G. Ryan, J.H. Fownes and R.S. Senock (2004), Belowground carbon cycling in a humid tropical forest decreases with fertilization. Oecol., 139, 545-550.



Irions, G. (1984), Clay minerals of Amazonian soils. In H. Sioli (ed) The Amazon: Limnology and Landscape Ecology of A Mighty Tropical River and Its Basin. Dr. J.W. Junk Publishers, Dordrecht



Keller M., M. Palace and G. Hurtt (2001), Biomass estimation in the Tapajos National Forest, Brazil - Examination of sampling and allometric uncertainties. For. Ecol. Manage., 154, 371-382.



Li, Y., M. Xu, X. Zou. (2006), Effects of nutrient additions on ecosystem carbon cycle in a Puerto Rican tropical wet forest. Glob. Change Biol., 12, 284-293.



McGroddy, M., W.L. Silver and R.C. de Oliveira Jr. (2004), The effect of phosphorus additions on decomposition dynamics in a seasonal lowland Amazonian forest. Ecosystems, 7, 172-179.



Parkinson, J.A. and S.E. Allen (1975), A wet oxidation process suitable for the determination of nitrogen and mineral nutrients in biological materials. Comm. Soil Sci. Plant Anal., 6, 1-11.



Rodrigues, T.E., R.C. Oliveira Jr, M.A. Valente et al. (1991), Caracterizacao fisico-hidrica dos principais solos da Amazonia. I. Estado do Para. Convenio EMBRAPA-FAO. Relatorio mimeografado.



Silver W.L., J. Neff, M. McGroddy et al. (2000), Effects of soil texture on belowground carbon and nutrient storage in a lowland Amazonian forest ecosystem. Ecosystems, 3, 193-209.



Tiessen, H. and J.O. Moir (1993), Characterization of available P by sequential extraction. In: MR Carter (ed) Soil Sampling and Methods of Analysis. Lewis Publishers, Boca Raton.



Vogt, K.A. and H. Persson (1991), Measuring growth and development of roots. In: JP Lassoie and TM Hinkley (eds) Ecophysiology of forest trees: techniques and methodologies. CRC Press, Boca Raton.

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