Delivery of Hydrologic and Microbial Services by Shrub Rhizospheres to Increase Crop

Productivity and Stability in the Sahel Global Forum for Innovations in Agriculture,

Abu Dhabi, 9-10 March, 2015

Richard P. Dick, Director (dick.78@snr.osu.edu)

Soil Microbial Ecology Laboratory Ohio State University, Columbus Ohio, USA

Senegal    West  Africa  

Senegal ~ 60% of population depends on agricultural economy

Overgrazing Cropping intensification and disturbance

Landscape Exploitation

Increasing rural and urban populations Scavenging for fuel resources

Encroachment of Desert

Challenges of Semi-arid Agroecosystems in the Sahel

Subsistence Faming

Low primary productivity Efficiency of water and nutrients

Sahalian Agroecosystems: Carbon - A Major Agronomic Constraint

Loss of soil organic matter inputs: Decreases nutrient/water efficiency and optimal yields (Badiane et al., 2001; Sanchez et al., 1997) Even with fertilizer applications yields continue to go down over the long-term (Sanchez et al., 1997; Merckx et al., 2001).

1. Unique Research Opportunity •  Shrub-crop rhizosphere interactions/ecology

•  Possible because of minimally mechanized agriculture in the Sahel

•  Food security •  Rural poverty •  Buffering capacity for global climate change •  Desert encroachment

2. Potential Applications for Africa

3. Implications for semi-arid regions worldwide

Dr. Mateugue Diack, Univ of Gaston Berger, Decomposition Dr. Ibrahima Diedhiou, Univ. of Thies, Senegal, Plant ecology Dr. Modou Sene, CNRA/ISRA, Senegal, Hydrology Dr. Richard Dick, Ohio State University, Soil biology Dr. Mamadou Khouma, UNDP (formerly ISRA), GIS and plant nutrition

Dr. Samba Ndiaye, Univ. Thies, (formerly ISRA), Agroforestry Dr. Jay Noller, Oregon State University C and biomass – landscape level Dr. Maria Dragila, Oregon State University, Hydrology Dr. Aminata Badiane, USAID (formerly ISRA), Soil biochemistry Ms. Astou Sene, ISRA, Socio-economics

Phase I – Collaborators USAID ($US 250,000)

US National Science Foundation Project (1.2 $US million)

1999-2008

Dr. Samba N. Samba Agroforestry

Ms. A. Sene Rural Sociology

Dr. Aminata Badiane Soil Biochemistry

Dr. Modou Sene Soil Physics

Dr. Mamadou Sene Agronomy/GIS

Research Coordinator

Dr. Ibrahima Diedhiou Post doc - Plant ecology

Sire Diedhiou, Senegal Soil microbiology

Ekwe Dossa, Togo Soil chemistry Nutrient cycling

Abel Lufafa Uganda

Landscape carbon dynamics

Fred Kizito, Uganda Hydrology/soil physics

PhD Students

Dr. Richard Dick, Ohio State University, Soil Biology Dr. Ibrahima Diedhiou, Univ. of Thies, Senegal, Plant Ecology Dr. Brian Mcspadden Gardener, Ohio State University, Plant Pathology Dr. Hassna Founoune-Mboup, Institut Senegalais de Recherches Agricole, Plant Science Dr. Teamrat Ghezzehei, University of California, Merced, Hydrology, Soil & Env. Physics

Dr. Lydie Lardy, IRD Dakar, Molecular Biology Dr. Yacine Ndour, Institut de Recherche pour le Development, Soil Microbiology Dr. Paul Schreiner, USDA-ARS, Mycorrhizal Fungi Dr. Komi Assigbetse, IRD Dakar, Molecular Biology

Phase II – Collaborators US National Science Foundation Project

(2.6 $US million)

2011-2016

Phase II – Collaborators

Richard Dick Soil microbiology

Ibrahima Diedhiou Plant ecology

Brian Mcspadden Gardener Microbial diversity

Teamrat Ghezzehei Soil Physics hydrology

Paul Schreiner Mycorrhizal fungi

Yacine Ndour Soil microbiology

Komi Assigbetse Molecular microbiology

Lydie Lardy Nitrogen cycling

Hassna Founoune-Mboup Mycorrhizal fungi

Students

Nathaniel Bogie, PhD Rhizpsphere hydrology

Matthew Bright, PhD Mycorrhizal fungi

Chelsea DeLay, MS Diazotrophs and nitrogen cycling

Spencer Debenport, PhD Beneficial microorganisms

Esther Lattin, MS Enzymes and

microbial communities

Roger Bayala, Post doc Fieid research coordinator

hydrology

3 m 3 m

Dominant Native Shrubs in Farmers’ Fields

1m

"   Northern region, typically sandy "   Mean annual rainfall 300 mm "   Mean annual temperature 30 oC

"   Southern region, higher clay content "   Mean annual rainfall 750 mm "   Mean annual temperature 32oC

Guiera senegalensis Piliostigma reticulatum

G. Senegalensis 3 Mg dry stem+leaves ha-1

P. reticulatum 3 Mg dry stem+leaves ha-1

Shrub Biomass Study Factorial Treatments: Biomass Rate - 1.5 or 3 Mg ha-1

Fertilizer - 0, 0.5, 1.0 or 1.5 X Recommended Rate

Effect of Shrub Residue (absence of shrub plant) and rate of fertilizer in on Crop Yields in Senegal.

‡Values within columns followed by the same superscript letter are not significantly different at P <0.05

Residue Treatment Rate ha-1 2004 Peanut

2005 Millet

2006 Peanut 2007 Millet

--------------------------------------------kg ha-1---------------------------------------

Control No residue 816a 537a 712b 1197c

G. senegalensis Biomass

1.5 Mg 766a 664a 912b 1296c

G. senegalensis Biomass

3.0 Mg 857a 755a 1116a 1609a

P. Reticulatum Biomass

1.5 Mg 615a 583a 908b 1385b

P. Reticulatum Biomass

3.0 Mg 691a 588a 1116a 1479b

NS NS P<0.05 P<0.05

Ekwe Dossa N and P Cycling PhD Candidate

Shrub X Fertilizer Rate (Bambey ~500 mm)

Factorial: 1) + and - Shrub

2) 0, 0.5, or 1.0 Rec. Fret. Rate

Plus Shrub Litter Incorporation

Guiera senegalensis

Minus Shrub

†Rate Shrub No shrub Shrub Increase

Shrub No shrub Shrub Increase

------------ kg ha--1------------- % ---------- kg ha-1 ----------- % 2004 season (Arachis hypogaea) 2005 season (Pennissetum glaucum) 0 190a† 78b 143 218a 11a 1818

0.5 135a 103a 32 359a 148b 142 1.0 153a 116a 36 422a 278b 52 1.5 203a 91b 123 605a 503a 20

Mean 170a 97b 400a 260b 2006 season (Arachis hypogaea) 2007 season (Pennissetum glaucum)

0 384a 273b 41

197a 6b 3183 0.5 542a 449b 21 403a 85b 374

1.0 556a 579a -4 378a 200b 89 1.5 708a 532b 33

622a 174b 257

Mean 547a 458b

400a 116b

Effect of shrub (G. senegalensis) and rate of fertilizer on Crop Yields in the Peanut Basin, Senegal.

‡Values within columns followed by the same superscript letter are not significantly different at P <0.05

†Fertilizer rate is 0, 0.5, 1.0 or 1.5 the recommended NPK rates appropriate for each crop.

(Dossa et al. Agronomy J. 2012)

G. Senegalensis and P. reticulatum are found in farmers’ fields between < 200 to ~ 1200 mm from Senegal to Niger and Chad

Senegal – P. reticulatum

Burkina Faso P. reticulatum Niger

G. senegalensis

Mali G. Senegalensis P. reticulatum

Dramatic Yield Response to Shrub Intercrops:

Why?

Improved Water Relations

Improved Nutrient Status Beneficial Microorganisms

Increased Soil Organic Matter and Nutrient Availability

(Dossa et al., 2008; 2009)

•  Root turnover •  Litter inputs from aboveground biomass

Shrub Roots go very deep

•  Roots grow to 10 meters or more •  Perform hydraulic lift – movement of water through

roots from wet subsoil to surface soil at night when PS stops (Kizito et al., 2012)

Shrub impact on water balance

" Hydraulic lift under dry

conditions " Ground water recharge with

excess precipitation " No competition of shrubs with

crops for water

WATER TABLE

ET P

ΔSW

Gin

DP

Crop

Shrub

?

Kizito et al. 2006; 2012

Shrub Rhizosphere Promotes Beneficial Microorganisms Harbor bacteria and fungi for crop roots that:

- increase nutrient availability - provide plant growth promoting hormones - increase N fixation by free living microbes

Promote mycorrhizal fungi-infecting shrubs/crops: - common hyphal connections of shrub to crop roots - improves water relations of crops - promote P and other nutrients for crops

0 1 2 3 40

20

40

60

80

100

Wet season

Distance from Center of Shrub (R=canopy radius)Center R/2 1 R 2 RM

icrob

ial B

iom

ass C

(µg g

-1)

Dry season

Rhizosphere soil

Non-rhizospheresoil

Dry season

Wet season

Soil Microbial Biomass C (incubation-fumigation) (0-20 cm depth) in the Wet and Dry Season of P. reticulatum (n=3).

Microbial Diversity with PLFA Analysis

Variance explained (PCA): 64% Correlation with Axis 1

! Fungi, 18:2ω6c (0.89) ! Actinomycetes, 10Me 18:0 (0.86) ! 15:0 3OH (0.85) ! Rhizosphere effect (p<0.001) ! Seasonal effect (p<0.02)

PLFA

Axis 1

Axi

s 2

Rainy season Dry season Rhizosphere Bulk Non-rhizosphere P. reticulatum : red color G. senegalensis: black color

(18

%)

(46 %)

Non-rhizosphere soil

Bulk soil Rainy season

Bulk soil Dry season

Rhizosphere

Rainy season Dry season Rhizosphere Bulk Non-rhizosphere P. reticulatum : red color G. senegalensis: black color

Common  Mycorrhizal  Hyphal  Network  

Shrub Crop

Mycorrhizable  Roots  (<  2mm)  

Guiera  senegalensis  (dicot)  

Millet  (C4  grass)  

 Hyphae,  Vesicle,  Arbuscule  Spore  

AMF  Structure  ExplanaJon  

Millet  Root   G.  senegalensis  Root  

Mescosm for studying hydraulic redistribution relative to microbial and crop responses in rhizo- vs. mycorrhizo-spheres.

G. senegalensis Millet

Perforated 35 m stainless steel sheet coated with PTFE

tap root chamber

water container 15 m air gap

mycorrhizae fungi

75 cm

Root chamber

Investigation of Mycorrhizal Hyphal Connections from Shrub to Millet

Mescosm Study Field Study

Millet under water stress in mesocosm: Effect of Mycorrhizal hyphae

Intact microcosm Turned microcosm Hyphae connections No hyphal connection

Paradigm shift Biogeochemical processes can proceed in

the dry season of arid regions. Hydraulic lift maintains microbial communities and activities – Therefore, driving processes that can improve crop yields – notably nutrient release for crop uptake

Overall Conclusions Shrubs can act as “mother” plant for crops

Shrub Rhizospheres: ü  Increase microbial diversity/activity ü  Harbor beneficial microorganisms ü  Are performing hydraulic lift ü  Increase nutrient availability and decomposition rates

Crop Productivity P  Shrub residues do not inhibit yield & can increase yield P  Shrubs do not compete for water with crops P  Shrubs assist crops through drought periods P  Non-thermal systems with shrub present increase crop

yields dramatically with G. senegalensis P  Shrubs decrease time to maturityb

Publications Diack, M., M. Sene, A. N. Badiane, M. Diatta, and R. P. Dick. 2000. Decomposition of a native shrub (Piliostigma

reticulatum) litter in soils of Semiarid Senegal. J. of Arid Soil Research and Rehabilitation 14(3):205-218. Iyamuremye, F., V. Gewin, R.P. Dick, M.Diack, M.Sene, A.N. Badiane, and M. Diatta. 2000. Carbon, nitrogen,

and phosphorus mineralization of agroforestry plant residues in soils of Senegal. J. of Arid Soil Research and Rehabilitation 14:359-371.

Badiane, A.N., A. Faye, C.F. Yamoah, and R.P. Dick. 2002. Compost and mineral fertilizers for millet production by farmers in semi-arid Senegal. Biol. Ag. Hort. 19:219-230.

Lufafa, A., I. Diédhiou, S. Ndiaye, M. Séné, M. Khouma, F. Kizito, R.P. Dick, and J.S. Noller. 2008. Carbon stocks and patterns in native shrub communities of Sénégal’s Peanut Basin. Geoderma 146: 75-82

Kizito, F., M. Dragila, M. Sène, A. Lufafa, I. Diedhiou, E Dossa, R.P Dick, M Khouma, A. Badiane, and S. Ndiaye. 2006. Seasonal soil water variation and root dynamics among two semi-arid shrubs coexisting with Pearl millet in Senegal, West Africa. J. of Arid Environments 67:436.

Lufafa, A., Wright, D., Bolte, J., Diédhiou, I., Khouma, M., Kizito, F., Dick, R.P., Noller, J.S., 2008. Regional carbon stocks and dynamics in native woody shrub communities of Senegal’s Peanut Basin. Agriculture, Ecosystems and Environment 128:1–11.

Kizito, F., M. Senè, M. I. Dragila, A. Lufafa, I. Diedhiou, E. Dossa, R. Cuenca, J. Selker, R. P. Dick. 2007. Soil water balance of annual crop-native shrub systems in Senegal’s Peanut Basin. Ag. Water Management 90:137 – 148.

Dossa, E.L. M. Khouma, I. Diedhiou, M. Sene, F. Kizito, A.N. Badiane, S.A.N. Samba, and R.P. Dick. 2009. Carbon, nitrogen and phosphorus mineralization potential of semiarid Sahelian soils amended with native shrub residues Geoderma 148:251–260

Dossa .E. L., J. Baham, M. Khouma, M. Sene, F. Kizito, R.P. Dick. 2009. Phosphorus Sorption and Desorption in Semiarid Soils of Senegal Amended with Native Shrub Residues Soil Science 173:669-682.

Publications (continued) Lufafa, A.; Diedhiou, I.; Ndiaye, N.A.S.; Sene, M.; Kizito, F.; Dick, R.P.; Noller, J.S.

Allometric relationships and peak-season community biomass stocks of native shrubs in Senegal's Peanut Basin. Journal of Arid Environments73:260-266.

Diedhiou, S., A.N. Badiane, I. Diedhiou, M. Khoum, A.N.S Samba, M. Sène and R.P. Dick. 2009. Succession of Soil Microbial Communities during Decomposition of Native Shrub Litter of Semi-Arid Senegal. Pedobiologia 52:273—286.

Dossa , E.L.,S. Diedhiou & J. E. Compton, K. B. Assigbetse & R. P. Dick. 2010. Spatial patterns of P fractions and chemical properties in soils of two native shrub communities in Senegal. Plant Soil 327:185–198

Kizito, F., M. I. Dragila, M. Senè, R. J. Brooks, F. C. Meinzer, I. Diedhiou, M. Diouf,, A. Lufafa, R.P. Dick, J. Selker, R. H Cuenca. 2012. Hydraulic Redistribution by Two Semi-arid Shrub Species: Implications for Sahelian Agro-ecosystems. J. Aird Environments. 83:69-77.

Dossa, E.L. M. Khouma, I. Diedhiou, M. Sene, F. Kizito, A.N. Badiane, S.A.N. Samba, and R.P. Dick. 20012. Crop Productivity and Nutrient Dynamics in a Shrub (Guiera senegalensis) -Based Farming System of the Sahel. Aronomy J. 104:1255–1264.

Diedhiou1, S., E.L. Dossa, A.N. Badiane, K.B. Assigbetsee, I. Diedhiou, N.A.S. Ndiaye5, M. Khouma, M. Sène and R.P. Dick. 2012. Microbiology and Macrofaunal Activity in Soil beneath Shrub Canopies during Residue Decomposition in Agroecosystems of the Sahel. Soil Science Society of America J. Soil Science Soc. Am. J. 77:501-511

Dossa, E.L. I. Diedhiou, M. Khouma,, M. Sene, A.N. Badiane, S.A.Ndiaye, K.B. Assigbetse, S. Sall, A. Lufafa, F. Kizito, S. Diedhiou, and R.P. Dick, and J. Saxena 2012. Crop productivity and Nutrient Dynamics in a Shrub (Piliostigma reticulatum) -Based Farming System of The Sahel. Agron. J. 105:1237-1246.

WEST AFRICAN SHRUB INTER-CROPPING INITIATIVE:

ALearning and Observatory Network Focused on Subsistence Farm Families

Guiding principles

Gender neutral Locally defined criteria of success

Integrate ‘expert’ and ‘non-expert’ knowledge

World Agroforestry Centre, Nairobi, Kenya Ohio State University

Technology Development

Participating Countries: Burkina Faso, Mali, Niger, Senegal

Approach On-farm demonstration and technology development A. Test and demonstrate: Optimized shrub-crop system – high shrub density/no burning

vs. Traditional management – low shrub density/coppicing& residue burning

B. Monitoring: C sequestration, soil quality, crop water stress levels and yield, and socio-economic impacts of shrub-based farming systems C. Farmer-researcher data analysis and interpretation

Expected Results: Technology Adaptation and Transfer

Successful shrub-based farming options in the Sahel documented, and findings made available to stakeholders (FBO, NGO, government agencies, ) for decision making.

Farmer-centered decision-support tools will be developed using focus sessions, workshops, and field surveys.

Expected Products 1.  Roadmap for scaling and fundamentals for full

technology transfer campaigns

2.  Optimized Shrub-Crop Manuals for agricultural professionals and policy makers - local language and French for both literate and illiterate end users

3.  Smart Phone apps and technology transfer platforms – including real time crop management information transfer

Expected Products (continued)

4.  Website Model for farmers and ag professionals with downloadable and printable extension instruments - local language and French

5.  Carbon Credit Calculator - App for smart phones that uses easily measurable above ground measurements to verify C sequestration rates at the farmer level

Richard Dick

School of Environment an Natural Resources

Ohio State University dick.78@snr.osu.edu

Thank You Questions?

Reestablishment Technology

1.  Grow seedling in spring season P. reticulatum by seed; G. senegalensis by layering mother plant

2.  Transplant seedling into farmers fields during wet season

3.  Allow seedlings to grow without further irrigation over dry season.

Stem from mother plant

New seedling growth

Dr. Ibrahima Diedhiou

Cooperating Farmer

Shrub Reproduction

Piliostigma reticulatum Interplanting for Mango Seedling

Establishment Plant mango on established P. reticulatum

Hydraulic lift “irrigation” High mango seedling survival – likely because of

water and improved soil quality

1 Year Mango Seedling

Pruned Piliostigma reticulatum plant

Piliostigma reticulatum

1 Year Mango Seedling