current status of bni research at jircas

Current Status of BNI Research at JIRCAS

GV SubbaraoJIRCAS, Japan

A Collaborative effort with CIAT, ICRISAT and CIMMYT

Collaborators

CIATCIMMYTICRISAT

Tottori UniversityScottish Crops Research Institute

Colleagues contributed from JIRCAS1. T. Ando 2. K. Nakahara3. T. Yoshihashi4. T. Watanabe5. T. Ishikawa6. Y. Yamanaka7. H. Y. Wang (PDF)8. S. Gopalakrishnan (PDF)9. Stuart Pearse (PDF)10. A.K.M. Hussain (PDF)11. Yiyong Zhu (PDF)12. Zhu Yiyong (PDF)13. T. Tsehaye (PDF)

Nearly 70% of the N fertilizer applied is lost to the environment

Amounts to a direct annual economic loss of

US$ 90 billion* [*based on - a) world annual N fertilizer production is 150 million Mg; b) 0.45 US$ kg -1 urea]

Nitrogen fertilizer consumed in 1930s - < 1.0 Tg (million metric tons)

Nitrogen fertilizer consumed in 1960s – 10 Tg Nitrogen fertilizer consumption worldwide in 2010 – 150 Tg (million metric tons)

Energy cost of nitrogen fertilizer – 1.8 to 2 L diesel oil per kg N fertilizerTo produce 150 million metric tons of Nitrogen fertilizer requires

1.70 billion barrels of diesel oil (energy equivalent)

Nitrogen fertilizers – Some facts

http://www.google.com/url?sa=i&source=images&cd=&cad=rja&docid=790hCLcDgjz66M&tbnid=Rbf7vhH6NXebhM:&ved=0CAgQjRwwAA&url=http://oecotextiles.wordpress.com/tag/josh-viertel/&ei=5O7DUfrUAYjMkwXBwICQAQ&psig=AFQjCNGgDrwsqPvK1M-Dk3066MMDbqs79w&ust=1371881572063950

Year

1950 1960 1970 1980 1990 2000 2010 2020

Nit

roge

n ef

fici

ency

in c

erea

l pro

duct

ion

(meg

a to

nnes

cer

eal g

rain

/meg

aton

ns f

erti

lize

r ap

plie

d)

20

30

40

50

60

70

80

Trends in N-fertilization efficiency in cereal production (annual global cereal production divided by annual global application of N-fertilizer) (Source: FAO 2012)

Global food production has tripled during this period, but N-fertilizer applications have increased 10-fold (Tilman et al.,

2001)

Why NUE is <30% in most agricultural systems?

Nitrification and denitrification processes associated with uncontrolled rapid nitrification are largely responsible for the

massive N leakage (>70% of the N fertilizers) and for the low-NUE

Nitrogen Cycle in Typical Agricultural Systems

Soil

OM

Organic N

NH4+

Microbial

N NO3-

>95% of the total soil inorganic N pool

Plant N uptake & Assimilation

Mineralization

Nitrification

Inorganic

N

Crop Residues

NFertilizer

Soil incubation period in days

0 10 20 30 40

Nitr

ific

atio

n (%

)

0

20

40

60

80

100

120

Intensively managed Alfisols

WatershedsConservatively managed Alfisols

Alfisol fields at ICRISAT

WS HP

Nitr

ific

atio

n ra

te ( g

NO

3- g-1

soi

l d-1

)

0

1

2

3

4

5

Alfisol fields at ICRISAT

WS HP

Nit

rifi

cati

on r

ate

(g

NO

3- g-1

soi

l d-1

)

0

1

2

3

4

5

Conservatively managedWatershed Alfisols

Intensively managedHigh-precision Alfisols

Agricultural intensification led to acceleration of nitrification in

intensively-managed production systems

How to achieve low-nitrifying agricultural soils?

Switch to low-nitrifying agricultural systems

Ammonium(NH4

+)Nitrite(NO2

-)

Leaching

Nitrate(NO3

-)

N2O, NO, N2

Greenhouse gasesGlobal warming

Nitrification

OMmineralization Denitrification

Ammonia-oxidizing Bacteria Nitrite-oxidizing Bacteria

Biological Nitrification Inhibition (BNI)

Brachiaria spp. root-produced

nitrificationinhibitors

Microbial Immobilization

of NH4+

Low-Nitrifying Natural Ecosystems High-Nitrifying Modern Agricultural Systems

BL

BL

BL

BL

BL

BL

BL

BL

BL

BL

BL

NFe

rtili

zer

BNI Function and its potential impacts to N-cycling

How to detect and quantify nitrification inhibitors ?

pHLUX209763 bp

(Bg/ II/BamHl)

kat

TrrnPhao

luxAB

PstI

(BamHI/Bg/ II) PstIPstI

BamHI

Physical map of pHLUX20(source: Iizumi et al. 1998)

OM

IM

NH2OH + H2O NO2- + 5H+ + 4e-

NH3 + O2

HAO

c554 c554

UQ

UQH2

NAD(P)H + H+ NAD(P)+

FMNH2FMN

H2O

hv RCOOH

RCHO

O2

Luciferase

NAD(P)+

reductaseCytaa3oxidase

NAD(P)H-FMN

AMO

oxidoreductase

Hypothetical model of interaction between the electron transfer pathways and the luciferasereaction in N. europaea (source Iizumi et al. 1998)

BNI activity is expressd in ‘ATU’

Inhibitory effect from 0.28 mM AT is defined as one

ATU

Pasture grasses

0 1 2 3 4 5 6 7

BN

I-ac

tivi

ty r

elea

sed

from

roo

ts

(AT

U g

-1 r

oot d

ry w

t. d-1

)

0

2

4

6

8

10

12

14

16

18

1. B. humidicola2. M. minutiflora3. P. maximum4. L. perenne5. A. gayanus6. B. brizantha

BNI capacity of pastures JIRCAS-CIAT partnership

Plants release two categories of BNIs

Hydrophobic Hydrophilic

BNI Activity

Mostly confined toRhizosphere

May move out of Rhizosphere

Plant -rootproduced

nitrificationinhibitors

BL

BL

BL

BL

BL

BL

BL

BL

BL

BL

BL

BL

BL

BLBL

BL

BL

BL

BL

Plant Species

BH Sorghum Wheat

BN

I ac

tiviit

y (%

of t

otal

BN

I ac

tivity

)

0

20

40

60

80

100

Hydrophobic-BNIHydrophilic-BNI

Relative importance of hydrophobic- and hydrophilic- BNI activity in three plant

species at 8 d old plants

40 d old plants

8 d old plants

BNI activity added to the soil (AT g-1 soil)

0 5 10 15 20 25

NO

3 co

nce

ntr

atio

n in

soi

l (p

pm

)

0

50

100

150

200

250

Threshold

Releases about 200 to 400 ATU hydrophilic BNI d-1

BNIs provide stable inhibitory effect on

soil nitrification

55 d soil incubation

14

A bioassay-guided purification of BNI activity led to isolation of

Brachialactone, identified as the major nitrification inhibitor

released from the roots of B. humidicola.

A tricyclic terpenoid with a unique 5-8-5 ring system and a g-lactone ring

Similar 5-8-5 ring system

Fusicoccins are produced in some fungi

(Geranylgeranyl diphosphate)

Patented by J IRCAS

GGDP is a precursor in the biosynthesis of terpenoids; also this is the precursor for the synthesis of carotenoids, gibberllins and chlorophylls in plants

11

Subbarao G V et al. PNAS 2009;106:17302-17307©2009 by National Academy of Sciences

0.0 2.5 5.0 7.5 10.0 12.5 15.0 min

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

uV

sample: brachialactone standard (mixture of a and b), 75 μgcolumn: TSK gel super ODS (4.6 x 100 mm)mobile phase: water (A) – acetonitrile (B) flow rate: 1.0 ml/mingradient program: 23% - 43%B (10 min), 43% - 48%B (8 min)

Time (min)

Det

ecto

r res

pons

e

Brachialactone b

Purified Brachialactone HPLC chromatogram

GC-MS-SIM based brachialactone quantification

1617. 0 18. 0 19. 0 20. 0 21. 0 22. 0 23. 0 24. 0 25. 0

0. 1

0. 2

0. 3

0. 4

0. 5

0. 6

0. 7

0. 8

0. 9

1. 0

1. 1

1. 2

1. 3

1. 4(x100, 000)

314.00 (1.11)334.00 (100.00)

Progesterone (IS:1 ppm)

Brachialactone (48 ppm)

19.78minIdentification: m/z 334Quantification: m/z 137

18.65minIdentification: m/z 314Quantification: m/z 314

Quantification & identification was achieved.Brachialactone showed 2 peaks,

which might be caused by keto-enol tautomerism.

‘Keto’ form ‘Enol’ form

GC-MS-SIM based analytical methodology can have major implications to genetic improvement efforts directed at brachialactone-trait into root systems of Brachiaria sp.

Brachialactone is detected in root tissues and quantification using GC-MS-SIM analysis could be a possibility in future

Preliminary results suggest brachialactone concentration in root tissues can be as high as 0.27 0.01% (dry weight basis)

Brachialactone levels in root tissues could be up to 10 times higher than in root exudates (i.e. about 10% of brachialactone in the root tissues may be released per day from exudation)

GC-MS-SIM analysis improves the detection thresholds for brachialatone levels in the samples and may give better quantification in root tissues and root exudates.

Brachialactone release is highly influenced by growing season

Spring season in Japan appears to have a major influence on brachialactone release in B. humidicola

020

0040

0060

0080

0010

000

1200

0

11.0

1.04

(No.

31)

11.0

1.18

(No.

32)

11.0

2.01

(No.

33)

11.0

2.14

(No.

34)

11.0

3.03

(No.

35)

11.0

3.23

(No.

36)

11.0

3.26

(No.

36…

11.0

4.01

(A-1

)11

.04.

05 …

11.0

4.11

(A-3

)11

.04.

14(A

-5)

11.0

4.18

(A-6

)11

.04.

21(A

-7)

11.0

4.25

(A-8

)11

.05.

10(M

ay-1

)11

.05.

17(M

ay-2

)11

.05.

25(M

ay-3

)11

.06.

07(N

o.37

)11

.06.

21(N

o.38

)11

.07.

06(N

o.39

)11

.07.

25(N

o.40

)11

.08.

08(N

o.41

)11

.08.

23(N

o.42

)11

.09.

08(N

o.43

)11

.09.

26(N

o.44

)11

.10.

11(N

o.45

)11

.10.

24(N

o.46

)11

.11.

07（N

o.47

)11

.11.

25（N

o.48

)11

.12.

05（N

o.49

)11

.12.

19（N

o.50

)12

.01.

04（N

o.51

)12

.01.

16（N

o.52

)12

.01.

30（N

o.53

)12

.02.

16（N

o.54

)12

.02.

27(N

o.55

)12

.03.

05(M

arc…

12.0

3.14

(Mar

c…12

.03.

21(M

arc…

12.0

3.26

(Mar

c…12

.04.

02(A

pril-

1)12

.04.

09(A

pril-

2)12

.04.

13(A

pril-

3)12

.04.

18(A

pril-

4)12

.04.

23(A

pril-

5)12

.05.

8(M

ay-1

)12

.05.

18(M

ay-2

)12

.05.

29(M

ay-3

)12

.06.

05（j

une-

1)12

.06.

05（j

une-

2)12

.06.

18（j

une-

3)12

.06.

25（j

une-

4)12

.07.

06（j

uly-

1)12

.07.

24（j

uly-

2)12

.08.

06(a

ug-1

)12

.08.

20(a

ug-2

)12

.09.

03(s

ep-1

)12

.09.

18(s

ep-2

)12

.10.

11(o

ct-1

)12

.10.

16(o

ct-2

)12

.11.

06(n

ov-1

)12

.11.

19(n

ov-2

)12

.12.

03(d

ec-1

)12

.12.

18(d

ec-2

)13

.01.

07(ja

n-1)

13.0

1.22

（jan

-2)

13.0

2.04

（feb

-1)

13.0

2.18

（feb

-2)

13.0

3.05

（mar

-1)

13.0

3.18

（mar

-2)

13.0

3.25

（mar

-3)

13.0

4.01

（apr

-1)

13.0

4.08

（apr

-2)

13.0

4.22

（apr

-3)

13.0

5.08

(may

-1)

13.0

5.20

(may

-2)

13.0

6.03

(jun-

1)13

.06.

17(ju

n-2)

13.0

7.01

(july

-1)

13.0

7.16

(july

-2)

13.0

7.22

(july

-3)

13.0

8.20

(aug

-1)

13.0

9.03

(sep

-1)

13.0

9.17

(sep

-2)

peak

are

am

AU*s

ec.

date

Ann

ual fl

uctu

atio

n ro

ot e

xdat

e stan

dard

BH

high

BN

I BH

2011 20132012

We need to understand whether these seasonal influence on brachialactone release from root due to production in root tissues or only release from roots is influenced?

Brachialactone’s mode of inhibitory action on Nitrosomonas

CompoundConcentration in the in vitro assay, mM AMO pathway HAO pathway

Crude-root exudate (methanol extract) 63.4 + 0.8 63.8 + 0.8Brachialactone 5.0 59.7 + 0.9 37.7 + 0.9Nitrapyrin 3.0 82.3 + 1.5 8.1 + 1.2

Inhibition (%)

Outer Membrane

Inner Membrane

Periplasm

Nitrosomonas

Regulating factors for the Release of BNIs from roots

BNI synthesis and release from roots requires presence of NH4

+

N treatment (NO3-N vs NH4-N grown plants)

NO3-grown NH4-grown

BN

I ac

tivity

of

the

root

tiss

ue (

AT

uni

ts g

-1 r

oot d

ry w

t)

0

50

100

150

200

Root tissue from RE-water treatmentRoot tissue from RE-NH4 treatment

Nitrogen treatment (i.e. NH4-N vs. NO3) of the plants

NO3-grown NH4-grownTot

al B

NI

activ

ity r

elea

sed

duri

ng 1

0 d

peri

od (

AT

uni

ts)

0

200

400

600

800

1000

RE-collected using distilled waterRE-collected using 1 NH4Cl (1 mM)

Functional link between NH4+-uptake and BNI

release

A hypothesis

NH4+

Cytoplasm pH >7

NH4+ NH4

+

H+

H+ATP

ADP + Pi

BNIn-

BNIn-

BNI

Glutamine + H+

glutamate

Is there potential for genetic improvement of BNI capacity in

pastures?

Genetic variability is the primary requirement for genetic improvement in trait/s of interest using

traditional breeding

Is there a genetic variability for BNI capacity?

High-BNI and low-BNI genetic stocks in B. humidicola

B. humidicolaAccession

BNI releasedATU g-1 root dry wt. d-

1

CIAT 26159 46.3

CIAT 26427 31.6

CIAT 26430 24.1

CIAT 679 17.5

CIAT 26438 6.5

CIAT 26149 7.1

CIAT 682 7.5

Panicum maximum 0.1

LSD (0.05) 6.0

Based on evaluation of 40 germplasm accessions in B.humidicola

CIAT’s Collaboration

Note11 sexuals from a total of 40 germplasm accessions were evaluated for BNI capacity; Most sexuals evaluated have BNI capacity similar to the CIAT 679.

A bi-parental population using high-BNI (CIAT 16888) and low-BNI (CIAT 26146) has been developed to identify genetic regions associated with BNI-function using a mapping population derived from crosse between apomictic and sexual germplasm accession of BH that differ in BNI-capacity – CIAT-JIRCAS ongoing collaboration

Date of Root exudate collection during Spring 2012

2nd March 3rd March 4th March 1st April

Bra

chia

lact

one

rele

ase

per

plan

t (p

eak

area

)

0

2000

4000

6000

8000

10000

12000

CIAT 679CIAT 26159

CIAT 26159CIAT 679

Genetic differences in Brachialactone release

capacity High-BNI genotype releases several times higher

brachialactone than standard cultivar

25

Parental lines of RIL population

PVK 801 296-B

BN

I ac

tivity

/Sor

gole

one

rele

ase

per

plan

t

0

10

20

30

40

50

BNI activity (ATU)Sorgoleone (g)

Total BNI activity and sorgoleone levels in root-DCM wash after 8 d growth in root boxes with hydroponic system

(based on 6 times evaluation of 20 seed lings each over a 6 month period)

Parental lines of RIL population characterizationJIRCAS-ICRISAT

partnership

HPLC chromatogram of purified sorgoleone

BNI activity detected only in this peak

NO BNI activity detected in any of these peaks

O

O

OH

O

Chemical structure of sorgoleone, Molecular Weight - 358a P-benzoquinone exuded from sorghum roots

BNI activity released from sorghum roots

Hydrophobic BNIs

Hydrophilic BNIs

Isolation of the major BNI constituent of hydrophobic BNI activity

ED80 = 1.0 ppm

A droplet of sorgoleoneexuding from root tip

296B PVK 801

Sorgoleone-phenotyping system is now developedJIRCAS-ICRISAT

partnership

Bi-Parental Sorghum RIL population (PVK 801 x 296B)

0 50 100 150 200

Sor

gole

one

prod

uced

( g

pla

nt-1

)

0

10

20

30

40

50

PVK801

296B

RIL phenotyping for sorgoleone levels in root-DCM washJIRCAS-ICRISAT partnership

Introducing high-BNI capacity into wheat Is it possible or feasible?

JIRCAS-CIMMYT partnership

Plant species

0 1 2 3 4

BN

I ac

tivi

ty r

elea

sed

from

roo

ts

(AT

U g

-1 r

oot d

ry w

t. d-1

)

0

5

10

15

20

25

30

35

NH4-N grown

NO3-N grown

Nobeoka Chinese Spring

L. racemosus

Releases about 150 to 200 AT units of BNI da-1 under optimum conditions

Wild-wheat has high-BNI capacityJIRCAS-CIMMYT

partnership

Leymus racemosus2N=4X =28;

genome Ns NsXmXm

Triticum aestivum L. cv. Chinese Spring

2N=6X =42; genome AABBDD

F1 hybrid Triticum aestivum L. cv. Chinese Spring

2N=6X =42; genome AABBDD

BC1F1 hybrid

BC7F1 hybrid

Production of wheat-Leymus racemosus-addition lines

Two Lr#n L. racemosus chromosomes in wheat detected by florescence in situ hybridization with probe of L. racemosus genomic DNA (green color)

3.9LSD (0.05)

4.97Lr-1-2DtA7Lr-1-2

6.47Lr-1-1DtA7Lr-1-1

6.65Lr-1DA5Lr-1

3.22Lr-1DA2Lr-1

3.7Lr-HDALr-H

4.1Lr-FDALr-F

5.5Lr-kDALr-k

6.4Lr-1DALr-1

13.0Lr-IDALr-I

13.5Lr-jDALr-j

24.6Lr-nDALr-n

BNI released (ATU g-1 root dry wt d-1)

L. racemosuschromosome introduced

Genetic Stock

3.9LSD (0.05)

4.97Lr-1-2DtA7Lr-1-2

6.47Lr-1-1DtA7Lr-1-1

6.65Lr-1DA5Lr-1

3.22Lr-1DA2Lr-1

3.7Lr-HDALr-H

4.1Lr-FDALr-F

5.5Lr-kDALr-k

6.4Lr-1DALr-1

13.0Lr-IDALr-I

13.5Lr-jDALr-j

24.6Lr-nDALr-n

BNI released (ATU g-1 root dry wt d-1)

L. racemosuschromosome introduced

Genetic Stock

BNI released from Chromosome-addition lines derived fromL. racemosus and cultivated wheat (Chinese Spring)

Can the high-BNI capacity of wild-wheat be Transferred/Expressed in cultivated

wheat?Would this be the first step to develop low-nitrifying and low-

N2O emitting wheat production systems?

BA


Lr#nS.3BL

Lr#nS.7BL

Leymus chromosome ‘N’

Transferred to

wheat 7B

ChromosomeBy

Kishii Masahiro

Transferred to wheat 3B

ChromosomeByKishii Masahiro

The short-arm of the Leymus ‘N’ chromosome is translocated to either 7B or 3B wheat chromosome (short-arm) for BNI evaluations

Short arm

long arm

centromere

Courtesy - Kishi

Courtesy - Kishi


Lr#n addition

Lr#nS.3BL

Wheat-Leymus genetic stocks

CS N - add N - sub-3A N - Tr-3B N - Tr-7B

BN

I ac

tivity

rel

ease

d fr

om r

oots

(AT

U g

-1 r

oot d

ry w

t. d-1

)

0

100

200

300

400

500

RE-NH4+

BNI activity release from roots in the presence of

NH4+ in the collection solutions

Courtesy - Kishi

Courtesy - Kishi

BNI activity release is two-fold higher in Lr#N addition and Lr#N translocation line (on 3B wheat chromosome)

compared to Chinese Spring

The above results strongly confirm that BNI-capacity in Leymus is controlled by Lr#N and expressed in wheat background; further the BNI-trait is controlled by short-arm of Lr#n chromosome and its expression depends on the translocation position on wheat


Can the BNI function be effective to control nitrification and nitrous

oxide emissions under field conditions?

JIRCAS-CIAT partnership

Roots of B. humidicola release a powerful nitrification inhibitor

Brachialactone

Ammonium(NH4

+)Nitrite(NO2

-)

Nitrate(NO3

-)Ammonia-oxidizing Bacteria Nitrite-oxidizing BacteriaBL

BL

BL BL

Microbial-N

Imm

obili

zatio

n

Min

eral

izat

ion

By blocking the Nitrosomonas function, B. humidicola facilitates NH4

+ to move into mocrobial pool and to remain in the soil system and act as a slow-releasing nitrogen source for Brachiaria growth

Estimations for the BNIs release from B. humidicola

• Active root biomass in a long-term BH pasture being 1.5 Mg ha-1

• (Root mass up to 9.0 Mg ha-1 has been reported in BH pastures)• BNI release rates can be 17 to 50 ATU g-1 root dry wt. d-1

• Estimated BNI activity release d-1 could be 2.6 x 106 to 7.5 x 106 ATU

(CIAT 679) (CIAT 26159)

•1 ATU being equal to 0.6 mg of nitrapyrin

• This amounts to an inhibitory potential equivalent to the application of 6.2 to 18 kg of nitrapyrin application ha-1 yr-1

38

Soil ammonium oxidation rates (mg of NO2− N per kg of soil per day) in field plots planted with tropical pasture grasses (differing in BNI capacity) and soybean (lacking BNI capacity in roots) [over 3 years from establishment of pastures

(September 2004 to November 2007); for soybean, two planting seasons every year and after six seasons of cultivation]

Brachiaria pastures suppressed soil ammonium oxidation



CIAT-Palmira field study 2004-2007

0

0.5

1

1.5

2

2.5

3

3.5

4

Control - Bare soil BH- 16888

ppm

of

nitr

ate

prod

uced

day

-1

CIAT-Palmira field study 2013

39

Cumulative N2O emissions (mg of N2O N per m2 per year) from field plots of tropical pasture grasses (monitored monthly over a 3-year period, from September 2004 to November 2007)


Brachiaria pastures suppressed N2O emissions from the fieldCan BNI function in plants be exploited to develop low-N2O emitting systems then?


BNI capacity of the species (ATU g-1 root dry wt. d-1)

0 10 20 30 40 50 60

Cum

ulat

ive

N2O

em

issi

on

(mg

N2O

-N m

2 y-1

)

0

100

200

300

400

500

Con

Soy

PMBHM

BH-679

BH-16888

High BNI capacity leads to low-N2O emitting systems?

A 3-year field study with soybean and pasture grasses with varying BNI capacities

Can we develop low-nitrifying and low-N2O emitting pasture-production systems through genetic exploitation of BNI trait?

The new MAFF-BNI project (starts from 2014) will test this hypothesis further using genetic stocks of B. humidicola with diverse BNI capacity in root systems


Photo: J. W. MilesExploitation of BNI function in BH for the sustainable agro-pastoral systems?

Characterization of residual effect of BNI from B. humidicola pasture on maize productivity and

Nitrogen use efficiency

OngoingJIRCAS-CIAT partnership

How long the BNI-suppressive effect on nitrification persists?Ongoing


Land Management

0 1 2

Nit

rifi

cati

on r

ate

(mg

NO

2-N

kg-

1 so

il d

-1)

0.00

0.02

0.04

0.06

0.08

0.10

0.12

Native savannaBH

Cultivated fields Maize

BH-BNI effect

Time in years

0 1 2 3 4 5 6A

mm

oniu

m o

xida

tion

rat

e in

soi

l

(mg

NO

2 kg-1

soi

l d-1

)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7Cultivated soils

control

BH-residualscenario-4




Characterization of residual BNI impact on NUE in maize systems An agro-pastoral systems perspective


Maize crop established in a high-BNI field by clearing B. humidicola

Field site – Taluma, Iianos, Colombia

JIRCAS – CIAT collaborative study – CIAT field site at Llanos


120 kg N/ha 240 kg N/ha

B. humidicola field The BH-BNI benefits on Maize growth

Beneficial effects of BNI on subsequent maize crop

Land Management

0 1 2

Nit

rifi

cati

on r

ate

(mg

NO

2-N

kg-

1 so

il d

-1)

0.00

0.02

0.04

0.06

0.08

0.10

0.12

Native savannaBH


BNI-Field


120 kg N ha-1

Beneficial effects of BNI on subsequent maize cropA healthy maize crop in BNI-field with 120 kg N

application

Land Management

0 1 2

Nit

rifi

cati

on r

ate

(mg

NO

2-N

kg-

1 so

il d

-1)

0.00

0.02

0.04

0.06

0.08

0.10

0.12

Native savannaBH



BNI-Field


120 kg N ha-1

Land Management

0 1 2

Nit

rifi

cati

on r

ate

(mg

NO

2-N

kg-

1 so

il d

-1)

0.00

0.02

0.04

0.06

0.08

0.10

0.12

Native savannaBH



Non-BNI-Field

Beneficial effects of BNI on subsequent maize crop

A nitrogen-deficient maize crop in non-BNI-field with 120 kg N application


BNI-Field Non-BNI-Field

2012 Field study at Iianos, Colombia

Nitrogen fertilizer application (Kg ha-1)

40 60 80 100 120 140 160 180 200 220 240 260

Mai

ze g

rain

yie

ld (

t ha

-1)

0

1000

2000

3000

4000

5000

High nitrifying - cultivated fieldsLow nitrifying - BH-BNI

Beneficial effects of BNI on subsequent maize grain yields

BNI is more effective on maize yields at low to moderate N applications but not high-N environments

BNI function is effective in improving NUE only under low- to moderate-N environments and not at high-N environments

BNI-field

Non-BNI-field


Maize plant tissues from various land-use systems

Ear Shoot Root

15N

/14N

rat

io in

pla

nt ti

ssue

s

4.5

5.0

5.5

6.0

6.5

BH-BNIcont.MaizeNative savannah

Beneficial effects of BNI on N recovery by Maize

BNI is effective in improving N recovery by maize in the field (from 15N studies)

BNI-Field

Non-BNI-Field


Land use treatments on Maize

BH-BNI cont.Maize Native savannah

15N

/14N

rat

io in

soi

ls (

0-60

cm

s de

pth)

0.35

0.40

0.45

0.50

0.55

Beneficial effects of BNI on soil-N retention BNI is effective in improving soil-N retention after maize harvest (from 15N

studies)

BNI-Field

Non-BNI-Field


CONCLUDING REMARKS

175 Tg NN-Fertilizer inputs

into Agriculture

53.5 Tg NPlant protein from

Agriculture

3.5 Tg NAnimal protein from Livestock

0.27Tg NHuman system

N-retention

123.5 Tg N LOST (70%)

From Agriculture

48.0 Tg N LOST(90%)

From Livestock

5.0 Tg N LOST(95%)

From Municipal Sewage systems

N-Fertilizer inputs into Agriculture

Plant protein-N

Animal protein-N

Human-N

Nitrogen flow in Human-centric Ecosystems

Annual

Nitrogen pollution epidemic in China

Nitrification facilitates movement of N from agricultural soils to water-bodies (ground water, freshwater lakes, rivers and to oceans) and cause algal

blooms Second Green Revolution?

NH4+

NO3-

Plant uptake

Soil-microbial

uptake

Nitrification

SOMMineralization

N-Fertilizers

Microbial-NImmobilization

Plant litter and

Root exudates

Nitrification opens several pathways in N-cycle for fertilizer-N to escape into the larger

Environment

A fundamental shift towards NH4

+-dominated crop nutrition is

possible?Retention of soil-N in

agricultural soils is critical for the sustainability of

production systems and to prevent N from entering into

water-bodies

Nature 2013, 501:291

BNI function in plants should be exploited to facilitate retention of soil-N within agricultural systems

We must develop new technologies to keep N to remain and recycle within the agricultural systems and not allow into water systems – Nitrification control is keyBNI function can be one such mechanism that can be exploited from a breeding perspective and from a system’s perspective

Take Home Message

Strategic Research Partner – CIAT(Drs. IM Rao; Manabu Ishitani; John Miles; Joe Tohme; Jacobo Arango, Marco Rondon; Maria Pilar Hurtado; Danillo Moreta; Gonzalo Borrero)

Other participating research institutesICRISAT (India)

CIMMYT (Mexico)Tottori University (Japan)

Yokohama City University (Japan)Scottish Crops Research Institute (UK)

Biogeochimieet ecologie des milieuxcontinentaux(France)

CIATTropical pastures-BNI

MAFFGTZ

Forage-CRP(?)

J IRCASBNI Research

CIMMYTWheat-BNI

MAFFWheat-CRP

ICRISATSorghum-BNI

MAFF (?)Dryland cereals-CRP(?)

Thank you for the attention

current status of bni research at jircas

Education