ORIGINAL PAPER第一次月考
Biological nitrogen fixation by common beans (Phaolus vulgaris L.)increas with bio-char additions Marco A.Rondon&Johannes Lehmann&
Juan Ramírez&Maria Hurtadoasmble
Received:14December2005/Revid:28September2006/Accepted:29September2006/Published online:24November2006 #Springer-Verlag2006
Abstract This study examines the potential,magnitude, and caus of enhanced biological N2fixation(BNF)by common beans(Phaolus vulgaris L.)through bio-char additions(charcoal,biomass-derived black carbon).Bio-char was added at0,30,60,and90g kg−1soil,and BNF was determined using the isotope dilution method after adding15N-enriched ammonium sulfate to a Typic Haplus-tox cropped to a potentially nodulating bean variety(CIAT BAT477)in comparison to its non-nodulating isoline(BAT 477NN),both inoculated with effective Rhizobium strains. The proportion of fixed N incread from50%without bio-char additions to72%with90g kg−1bio-char added.While total N derived from the atmosphere(NdfA)significantly incread by49and78%with30and60g kg−1bio-char added to soil,respectively,NdfA decread to30
%above the control with90g kg−1due to low total biomass production and N uptake.The primary reason for the higher BNF with bio-char additions was the greater B and Mo availability,whereas greater K,Ca,and P availability,as well as higher pH and lower N availability and Al saturation,may have contributed to a lesr extent. Enhanced mycorrhizal infections of roots were not found to contribute to better nutrient uptake and BNF.Bean yield incread by46%and biomass production by39%over the control at90and60g kg−1bio-char,respectively.However, biomass production and total N uptake decread when bio-char applications were incread to90g kg−1.Soil N uptake by N-fixing beans decread by14,17,and50% when30,60,and90g kg−1bio-char were added to soil, whereas the C/N ratios incread from16to23.7,28,and 35,respectively.Results demonstrate the potential of bio-char applications to improve N input into agroecosystems while pointing out the needs for long-term field studies to better understand the effects of bio-char on BNF. Keywords Biological N fixation.Boron.Charcoal. Molybdenum.Mycorrhiza.15N
Introduction
Growing evidence indicates that many soils around the world have a prence of charcoal particles[biomass-derived black carbon(C),further called bio-char]in different states of interactions with mineral particles in the soil matrix(Goldberg1985;Schmidt and Noack2000).In natural environme
nts,bio-char is added to soils as the residual products of incomplete combustion of biomass from forest or savanna fires(Wardle et al.1998;Bird et al. 1999).There are,however,veral sites where bio-char has been added unintentionally or deliberately as a soil amendment,typically as remnants of charcoal production sites(Chidumayo1994;Mikan and Abrams1995;Young et al.1996;Oguntunde et al.2004),in home gardens and more systematically in so-called Amazonian Dark Earths; the are ancient,very fertile anthrosols generated by the intervention of indigenous communities throughout the Amazon(Lehmann et al.2003c).Under conditions of very low-fertility soils such as in savannas from South America
Biol Fertil Soils(2007)43:699–708
DOI10.1007/s00374-006-0152-z
M.A.Rondon
:J.Ramírez:M.Hurtado
Centro Internacional de Agricultura Tropical(CIAT),
A.A6713,Cali,Colombia
J.Lehmann关爱残疾人作文
Department of Crop and Soil Sciences,Cornell University, Ithaca,NY14853,USA
M.A.Rondon(*)
International Development Rearch Centre,
250Albert Street,P.O.Box8500,Ottawa,ON,Canada K1G3H9 e-mail:mrondon@idrc.ca
and the Amazon Rainforest,additions of modest dos of bio-char to soil were able to increa plant yield and improve veral soil quality indicators(Iswaran et al.1980; Lehmann et al.2003a).
However,foliar N concentrations of crops decread in veral studies when bio-char was added to soil(Lehmann et al.2003a;Rondon et al.,unpublished data),and N availability was found to be lower on the black C-rich Amazonian Dark Earths than adjacent soils(Lehmann et al. 2003b).This N limitation in black C-rich soils was not found for legumes,and nodulation(Sylvester-Bradley et al. 1980),as well as occurrence of nodulating plants(Gehring 2003),were significantly greater in forests on Amazonian Dark Earths than on adjacent soils.Legumes also per-formed better on N-limited soils than grass after bio-char applications(Rondon et al.,unpublished data).The results suggested th
at biological N fixation(BNF)is enhanced by bio-char amendments.Some evidence is provided by results from Nishio and Okano(1991)who found that BNF determined by N difference was15% higher when bio-char was added to soil at the early stages of alfalfa development and227%higher when nodule development was greatest.Several studies indicate that bio-char is an excellent support material for Rhizobium inoculants(Pandher et al.1993;Lal and Mishra1998). However,detailed studies about the relationship between bio-char additions and BNF have not been published.
It is unclear why BNF increas with bio-char additions. Several possible reasons exist:(1)the N availability in soil is lower due to the high C/N ratio of the bio-char and the resulting N immobilization as indicated from Amazonian Dark Earths(Glar et al.2002;Lehmann et al.2003b);(2) the availability of nutrients other than ,P,K,Ca,Mg, or micronutrients)and the pH are higher(Tryon1948;Mikan and Abrams1995;Lehmann et al.2003a;Oguntunde et al. 2004);and(3)the bio-char enhances mycorrhizal infection, as it is able to rve as a habitat for extraradical hyphae that sporulate in its micropores due to lower competition from saprophytes(Saito and Marumoto2002).Root infection by arbuscular mycorrhizae significantly incread by adding bio-char to alfalfa in a volcanic ash soil(Nishio and Okano 1991).Similarly,mycorrhizal infection incread when bio-char was added to soil that was inoculated with spores of Glomus etunicatum(Matsubara et al.1995).No studies exist that relate BNF to the effects of bio-char on soil chemical or biological properties.
Therefore,this study investigates the influence of various levels of bio-char additions on BNF of common beans(Phaolus vulgaris L.)on an acid Oxisol and relates BNF to soil nutrient availability and mycorrhizal infection. It is hypothesized that bio-char improves BNF by common beans due to decread N availability,incread pH as well as nutrient availability,and greater mycorrhizal infection.Materials and methods
Soils and experimental details
The experiment was conducted at CIAT’s(Centro Inter-nacional de Agricultura Tropical)greenhous in Cali, Colombia.Average daily temperature is25°C,and relative humidity is maintained at around60–70%.Soil sampled from the top0.2m of a clay–loam oxisol(Typic Haplustox) from the Matazul rearch site(4°19′N,72°39′W)at the Colombian Eastern Planes(Llanos)was ud.Roots and visible plant residues were removed,and then the soil was air-dried.Before filling the pots,the soil received a basal do of fertilizer in the equivalent of300kg ha−1of lime, 20kg P ha−1,and20kg N ha−1.Given the very low inherent fertility of the soil,this minimum level of fertilization is required to enable proper plant growth of non-adapted plant species such as common beans(Rao et al.1998).Four replicated pots per treatment were filled with2kg of air-dried soil,and bio-char was added to pots in four rates:0,30,60,and90g bio-char per kilogram of soil.The pots were arranged in a
completely randomized design.
Bio-char production
Bio-char was produced at the bio-char rearch laboratory at the National University in Bogota,Colombia from logs of Eucalyptus deglupta Blume using a large,temperature-controlled kiln.Temperature was maintained at350°C and the oxygen level regulated at15%.Charring time was1h, and a charring batch consisted of20kg of air-dried logs cut into approximately0.2-m long pieces.At the time of application,a subsample of bio-char was manually ground to<2-mm mesh.A size distribution analysis,as well as some physicochemical analys,was performed on a subsample(Table1).The ground bio-char was added and very well mixed with the soil just immediately before filling the pots.Water was then applied to the pots to reach a60%field capacity,and the pots were allowed to stabilize during4weeks before planting,replenishing evaporated water twice a week.
Plant management
Two accessions of common beans(P.vulgaris L.)were ud:a variety(Line CIAT BAT477)known for its high nitrogen fixation ability(Kipe-Nolt and Giller1993)and a non-nodulating isoline(BAT477NN).Usin
g a non-nodulating isoline of the same species is the ideal non-fixing plant control plant required for applying the isotope dilution technique and allows for a very preci quantifica-tion of nitrogen fixation(Danso et al.1993;Giller2001).
Four eds of beans previously inoculated with a peat-bad inoculum of effective Rhizobium(strain CIAT899)were planted and allowed to grow for5days after germination. Then,the two smaller plants in each pot were removed,and the two most vigorous plants were ud for the experiment. Plants were allowed to grow for75days until complete pod filling of the more precocious plants.Moisture was maintained in the pots at50–60%of field capacity by periodical(2-to3-day intervals)weighing of the pots and replenishment of evaporated water.
Isotopic labeling
Five days after germination,when the weak plants were removed,labeled ammonium sulfate(10at.%15N)was added to the soil in water solution(0.026g ammonium sulfate dissolved in100ml of water per pot)at an equivalent do of5kg N ha−1.This small do of N added to the pots was not expected to affect the N fixation process,which could be reduced when high dos of N are applied(Giller2001).The solution was homogeneously distributed over the soil surface.
Soil sampling and analys
At the time of planting,a subsample of soil was taken from each pot using a small core auger(15mm external diameter)and covering the entire soil depth.A similar intermediate soil subsample was taken40days after planting.Samples were ud for chemical analys(KCl-extractable NOÀ3and NHþ4,pH,and redox potential).At harvest time,a final soil sample was collected after thoroughly mixing the soil once the roots were removed. Nitrate and exchangeable NHþ4were extracted with20ml 1N KCl for30min by shaking2g field-moist soil on a reciprocating shaker(Eberbach,USA)at40cycles per minute. Nitrate and NHþ4in the extract were quantified colorimetri-cally using a gmented flow analyzer(Skalar Autoanalyzer, Skalar,The Netherlands).Soil reaction was determined with a glass pH electrode(Orion PH meter9156)and redox potential with a redox electrode(Orion,ORP triode9179) using a dual pH and redox,Termo Orion meter model250 (Thermo Electron,Philadelphia,USA).Cation exchange capacity was determined by extracting5g soil with50ml CH3COONH4(pH7)for30min and titrating with NaOH against a color indicator.In addition to the analys described above,a Morgan extraction(McIntosh1969)was performed on the final soil sample(10-g sample in50ml 0.72M CH3COONa:0.52M CH3COOH at pH4.8;30-min shaking),and Ca,Mg,K,Zn,Fe,Cu,and Mn were determined by inductively coupled plasma atomic emission spectro
scopy(ICP-AES,Ciros(CCD),Spectro,Germany). The P values in the extract were below the detection limit of the ICP and were therefore determined by the molybdene ascorbic acid method(Murphy and Riley1962).A10-g soil subsample was ud to obtain the number of mycorrhiza spores according to the procedures described by Sieverding (1983).
yahoojapanPlant sampling and analys
Just before harvest,leaves were tested for chlorophyll levels using a hand-held automated chlorophyll meter (SPAD-502,Minolta,Japan).At harvest time,plants were cut10mm above the soil surface.Plants were parated into pods,leaves,and stems.Leaf area was measured immediately after harvest with a leaf area meter(LICOR LI-3100,Licor,Lincoln,USA).Senescent leaves which had fallen during the growing period were collected in each pot and added to the leaves collected at harvest time.Roots were carefully removed from the soil,including the fine roots,then washed repeatedly with deionized water until a complete removal of adhered soil was achieved.A small subsample of the roots(1g)was ud to count mycorrhizal infection levels(Sieverding1983).The remaining fraction was ud for measuring biomass and for analysis.Each plant component was put in a paper bag and dried in an electric oven at40°C for2days.Plants were removed from the drying oven,allowed to cool,and individually weighed for dry biomass.Each component was then finely grou
nd, and a composite weighted sample of2g was reconstituted using the appropriate proportions of each component.This reconstituted plant sample was ud for chemical and isotopic analysis.Plant and charcoal samples were digested at200°C for1h using a2:1mixture of concentrated nitric and perchloric acid(0.5-g soil in5-ml solution;Zasoski and Burau1977).The solution was evaporated to dryness,
Table1Chemical and physical characteristics of the added bio-char
Bio-char Total C(g kg−1)823.7 Total N(g kg−1) 5.73
pH(H2O)7.00
V olatile matter(%)33.2 Moisture content(%) 1.91 Ash content(%)0.23 Oxygen content(%)13.7
P-Bray2(mg kg−1)49.5 Total P(mg kg−1)580 Total S(mg kg−1)290 Total Mg(g kg−1) 1.31 Total B(mg kg−1)9.35 Total Mo(mg kg−1) 1.36 CEC(mmol c kg−1)46.9 Fraction of material<50μm(%)54 Iodine Number(g kg−1)265.5
dissolved in 0.1N nitric acid and analyzed by ICP-AES as described above.Nitrogen isotope determinations were done by isotope ratio mass spectrometry (Europa Hydra 20/20,PDZ Europa,Nor
thwich Cheshire,UK).Statistical analys
Main effects were computed by analysis of variance using a completely randomized design (SAS Institute,Cary,NC).In ca of significant effects,individual means were compared by least significant difference test at P <0.05if not indicated otherwi.
Results
Biomass production of the N-fixing beans was significantly higher than that of the non-N-fixing isoline across all levels of bio-char additions (Fig.1).Bio-char additions signifi-cantly incread total biomass production by 39%up to 60g kg −1bio-char,but decread biomass to the level of the control with 90g kg −1.Most of the increa in biomass production by the N-fixing beans was caud by greater leaf biomass (Fig.1).Whereas total biomass did not change relative to the control at the highest bio-char application rate,biomass of pods continued to increa in N-fixing plants (Fig.1).
The proportion of N derived from biological N fixation (NdfA,Fig.2)significantly incread from 50%without bio-char additions to 72%with 90g kg −1bio-char added to soil.The total N from BNF,however,peaked already at an application of 60g kg −1due to the low biomass production (Fig.1;significant main effect P =0.0059)and foliar N concentrations (Table 2)at 90g kg −1.Similarly,le
af area and shoot/root ratios were greatest at 30and 60g kg −1,respectively,and not at the maximum bio-char application of 90g kg −1(Fig.3).
The N concentrations in plant tissue were significantly lower in the non-N-fixing than in the N-fixing bean variety (Table 2).Additionally,N concentrations of N-fixing beans significantly decread with greater bio-char appli-cations (Table 2).Plant P,K,Ca,Mg,and B concen-trations significantly incread with bio-char applications,whereas tissue S,Zn,Cu,and Mn concentrations did not change,and plant Fe and Al concentrations significantly decread (Table 2).Molybdenum levels were only detectable in the highest bio-char do in the N-fixing plants.Concentrations of Mo in plant tissue of the non-nodulating beans,however,were detectable and signifi-cantly incread with bio-char additions.In general,tissue concentrations of nutrients other than N were greater in non-N-fixing than in N-fixing beans.This led to a similar total nutrient uptake by N-fixing and non-N-fixing beans (Fig.3).Similar to the respon in biomass production and
B i o m a s s p r o d u c t i o n (g p o t -1)
123456
选修课英文7
Bio-char applied (g kg -1)0
30
60
90
B i o m a s s p r o d u c t i o n (% o f t o t a l )
2040
60
80
100
Bio-char applied (g kg -1)
英语翻译在线翻译
30
60
90
Fig.1Biomass production and yield of common beans [P .vul-garis L.;N-fixing (BAT477)and non-N-fixing (BAT477NN)strain]grown on a Typic
Hapludox as a function of added bio-char;bars with the same small letter within one plant part and with the same capital letter between isolines within the same bio-char application rate are not significantly different at P <0.05(n =4)
control,both the number of spores and colonization were significantly greater in N-fixing than in non-N-fixing beans.The species identified were Enthrophospora sp.,Glomus sp.,and Scutellospora sp.
Fig.2Proportion of N derived from biological N fixation (NdfA)or from soil (NdfS)by common beans (P .vulgaris L.)grown on a Typic Hapludox as a function of added bio-char;bars with the same small or capital letter are not significantly different at P <0.05(n =4)
Table 2Tissue nutrient concentrations of N-fixing (BAT477)and non N-fixing (BAT477NN)bean isolines (P .vulgaris L.)grown with different dos of bio-char Bean variety Bio-char (g kg −1)N P
S
K
Ca
Mg
Fe
Al帝国理工学院
Zn Cu Mn
B
Mo (g kg −1
)(mg kg −1)N-fixing
018.7a 1.08d 2.09bc 13.0c 8.6cde 1.26d 1.31a 4.10ab 13443.549.0b 1.35e 0.10b 3017.4ab 1.20d 1.60c 12.9c 7.3e 1.38d 1.23ab 4.19ab 15146.335.6c 1.32e nd 6017.7ab 1.11d 1.60c 14.1bc 8.2de 1.39d 0.79c 2.49d 9426.633.6c 2.16de 0.09b 9016.0b 1.29cd 1.96bc 17.0a 10.2bc 1.45cd 0.91bc 3.28abc 18336.035.0c 4.01bcd 0.43b Non N-fixing
011.6c 1.52bc 2.26b 15.7ab 9.2cd 1.45d 1.34a 4.40a 20138.950.2b 3.34cde 1.63c 3012.3c 1.78b 2.53b 16.8ab 11.1ab 1.83b 1.10abc 3.74abc 14339.254.3b 6.35ab 2.31b 6010.5c 1.53bc 2.34b 16.0ab 11.2ab 1.74bc 1.03abc 3.24abc 26136.554.7b 5.69bc 2.07b 90
12.9c 2.22a 3.52a 17.5a 12.3a 2.23a 1.02abc 2.63cd 13643.168.3a 8.25a 3.23a Variety effect a ******************ns ns ns ns ******nd Bio-char effect a
ns
***
**
**
**
***
ouz*
*
ns
ns
ns
元音字母有哪些
**
雄安县
***
Values within one column followed by the same letter are not significantly different at P<0.05(N=4).a
Main effect of all treatments;*,**,***,and ns significant at P<0.05,0.01,0.001,and not significant,respectively b
Only 1–2replicates were above the detection limit of 0.05mg kg −1.ND not detected,NS not significant
