nutrient management strategies for ca ludhiana july 2011

8/3/2019 Nutrient Management Strategies for CA Ludhiana July 2011

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Nutrient Management Strategies forConservation Agriculture Systems:Nutrient Expert

Conservation Agriculture: Nurturing Sustainable Production Systems in South Asia, Ludhiana, July 5, 2011

Kaushik Majumdar,Director, IPNI-South Asia Program


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Conservation Agriculture and nutrientmanagement

Challenges of nutrient management in CA

Nutrient Expert


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Conservation Agriculture systems of production aredefined by three key principal elements

No mechanical tillage and minimal soil disturbance;

Permanent organic soil cover specially by plant organicmatter and cover crops;

Diversified crop rotations in the case of annual crops orcrop associations in case of perennial crops, includinglegumes

These three elements in various combinations aim at establishing

and sustaining healthy soil systems that can offer the best crop andlivestock productivities and environmental services within theprevailing ecological and socio-economic conditions whileoptimizing the use of agrochemicals with biological interventions


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Framework of Nutrient management practices in CAsystems :

(i) the biological processes of the soil are enhanced and protected sothat all the soil biota and microorganisms are privileged and that soilorganic matter and soil porosity are built up and maintained;

(ii) there is adequate biomass production and biological nitrogenfixation for keeping soil energy and nutrient stocks sufficient tosupport higher levels of biological activity, and for covering the soil;

(iii) there is an adequate access to all nutrients by plant roots in the

soil, from natural and synthetic sources, to meet crop needs;

(iv) the soil acidity is kept within acceptable range for all key soilchemical and biological processes to function effectively.

Kassam and Friedrich, 2009


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Soil Physical properties and CA

Lower bulk density in CA systems as compared toconventionally tilled plots

Wet tillage increases bulk density

Destruction of soil aggregates

Filling of micropores with finer soil particles

Direct physical compaction caused by implements

Lesser soil penetration resistance in CA systems

Support higher soil aggregation

Reduced soil disturbance

Increased soil organic matter


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Other changes associated with CA

Greater crop residues accumulate on soil surface

Minimized wind and water erosion

Reduced nutrient loss through erosion

Reduced evaporation loss

Increased water infiltration

Lower surface temperature

Cooler soil temperature

Slow nutrient release from soil organic matter

Reduced diffusion of nutrients to the plant roots

Slower mineralization


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Effect of conventional tillage and no-till on grain yieldand N uptake by maize (Moschler & Martens, 1975)

The grain yield response curvesare typical of what is obtained inseveral studies

No till yields are higher at highernitrogen levels

More efficient utilization ofnutrients in no till production

Lower grain yields and N uptakewith no-till at lower N rates canresult from greater immobilization of

fertilizer N, losses of N fromdenitrification and leaching, lowermineralization of N or a combinationof these factors.


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Average yield (kg/ha) and yield loss (kg/ha) in PuddledTransplanted Rice (PTR) and Direct Seeded Rice (DSR) inthe hubs of Indo-Gangetic Plain (2010)

NPK Reduced N

Full PK

N Omission Reduced P

Full NK

P Omission Reduced K

Full NP

K Omission Reduced

PK Full N

Zn

OmissionHaryana PTR (n=8)

Yield 4871 4063 3569 4413 4172 4306 4124 4264 4642

Yield

loss

_ 808 1302 458 699 565 747 607 229

Haryana DSR (n=8)

Yield 5132 4132 3528 4438 4260 4646 4354 4344 4911

Yield

loss

_ 1000 1604 694 872 486 778 788 221

Punjab PTR (n=5)

Yield 4396 3576 2647 3622 3478 3751 3700 3691 3873

Yield

loss

_ 820 1749 774 918 645 696 705 523

Punjab DSR (n=4)

Yield 6053 4625 3775 4683 4572 4989 4889 4556 5219

Yield

loss

_ 1428 2278 1370 1481 1063 1164 1497 834

NPK NOmission

Reduced PFull NK

P Omission Reduced KFull NP

K Omission Reduced PKFull N

Addnl. NP

Bihar PTR (n=6)

Yield 3418 1883 3234 3164 3273 3213 3196 3358

Yield

loss

_ 1535 184 254 145 205 222 60

Bihar DSR (n=6)

Yield 3507 1937 3308 3246 3327 3293 3246 3422

Yieldloss _ 1570 199 261 180 214 261 85


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Challenges in nutrientmanagement in CA


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Challenges

High organic matter

Higher microbial population (immobilization of nutrients) Lower mineralization as less surface area is exposed to microbial action (residue

exists as undisturbed mulch)

High microbial population

High population of nitrifiers but higher population of denitrifiers (gaseous N loss) Requirement of denitrification

Easily available organic substrate

Nitrate

Suitable organism

Existence of large aggregates

High moisture content

Better soil aggregation

Deep penetration and leaching of water

Loss of NO3- and K+ with water


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Nitrogen

Immobilization

Residue load

C:N ratio of residue

Mineralization

Soil temperature

Exposure of organic matter for decomposition

Denitrification

Population of denitrifier

Microsites of oxygen deficit

Leaching

Higher moisture content

Larger aggregate sizes


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N immobilization and mineralization followingaddition of residue to soil (Havlin et al., 2005)

Rapid increase in the number ofheterotrophic organisms at initial stage offresh organic matterdecomposition.elevated CO2 evolution.

High C:N.insufficient N in thesubstratemicrobes will draw on the

mineral nitrogen leading to immobilization

C:N ratio will start decreasing as thedecay proceeds.C released as CO2while N immobilized from soilsolution.mineralization of N

A combination of high C:N ratio and lowsoil N is expected to reduce N availabilityto plants at initial stages of crop growth

Crops planted immediately after cerealresidue retention will require sufficient

external N application


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Residue decomposing and N, P and K releaseat three wheat growth stages

Yadvinder Singh et al., 2010


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Phosphorus and Potassium

Soil P and K tend to be immobile in the soil Nutrient stratification is an important concern in the

management of P and K in zero-till systems.

Without tillage and soil mixing, P and K may accumulate

at the soils surface (0-5 cm) at the depth of application When soil conditions are dry, nutrients near the surface

may be positionally unavailable for plant uptake


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Effect of zero and conventional tillage on distributionof P and K in a silty clay soil in Manitoba (adapted fromGrant and Bailey 1994)

0 5 10 15 20 25 30 35 40 45

300

400

500

600

700

800

9001000

1100

1200

1300

Depth, cm.

Potassium,m

g/kg

Silty Clay Soil

Conventional Till

Zero Till

0 5 10 15 20 25 30 35 40 45

0

10

20

30

40

50

60

70

Conventional Till

Zero Till

Depth, cm.

Phosphorus

,mg/kg

Silty Clay Soil

0 5 10 15 20 25 30 35 40 45

300

400

500

600

700

800

9001000

1100

1200

1300

300

400

500

600

700

800

9001000

1100

1200

1300

Depth, cm.

Potassium,m

g/kg

Silty Clay Soil

Conventional Till

Zero Till

0 5 10 15 20 25 30 35 40 45

0

10

20

30

40

50

60

70

Conventional Till

Zero Till

Depth, cm.

Phosphorus

,mg/kg

Silty Clay Soil

Soil samples were taken at the end of a 4-year study where P was banded (58 kgP2O5/ha) and K was broadcast (120 kg K2O/ha)


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Nutrient Management in ConservationAgriculture

Soil physical, chemical and biological environment ofconservation systems are different from conventional system

High residueextra N demand by microorganisms for decomposition

of residues and have the potential of higher immobilization and slowermineralization of N

P supply may not be adequate at initial stages and may depend onexternal supply

Greater supply of K from residues are expected but losses throughleaching must be accounted for while estimating requirement

Wetter and cooler soils will influence rate and mechanism of nutrientrelease/loss

Additional stored water increases yield potential and will require greatersupply of nutrients

Data from long term stabilized systems are lacking


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Indigenous Nutrient Supply in ZT & CT

State Haryana Punjab

Scenarios ZT CT ZT CT

Treatments Wheat Yield (kg/ha)

Full NPK yield 5078 4800 4741 4865

Yield loss due to N 3155 2994 1355 1457

Yield loss due to P 1002 711 518 714

Yield loss due to K 817 675 270 852

Nutrient rates(kg/ha)

N P2O5 K2O

180 90 100

ZT Zero tillage with residue retentionCT Conventional tillage with complete residue removal


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Fertilizer Placement

Fertilizer placement decision is critical to optimizefertilizer use efficiency by the crop in no-till conditions

Broadcasting N onto the residue covered surface is notthe most efficient method of application

potential for immobilization by surface residues volatilization losses of N

In-soil band placement of N is usually the most effectivemeans of minimizing immobilization of N in no-till crops

The application of P and K in bands either with, or closeto the seed minimizes tie-up by the soil and increasesearly season uptake by the crop


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Applying the crops entire fertilizer requirements

at seeding can be challenging

Placement of high amounts of nutrients directly with the seed oftencauses reduced germination and delayed emergence resulting inpoor stands and yield loss.

Row spacing, seed bed utilization (SBU), soil texture, soil moisture,soil variability, fertilizer placement, seed furrow opener, fertilizersource, and crop influence how much fertilizer can be safely appliedwith the seed

The amount of fertilizer that can safely be applied in the seed row decreases asrow spacing increases. With wider rows, at a given rate per hectare the fertilizeris more concentrated and is in greater contact with the seed

Heavier textured soils tolerate more seed row N because the increased cationexchange and water holding capacity reduce ammonia toxicity

Ammonium nitrate is less damaging to the seed than urea. It has a higher saltindex than urea, but does not add to ammonia toxicity

Higher rates of N may be tolerated if CEC is high and seedbed moisture issufficient


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Nutrient Expert


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Objectives of CSISA required a focused, time-boundapproach for tool development

Capability to take forwardimproved nutrient managementrecommendation across largeareas

Rice-Rice and Rice-Wheat

accounts for about 16 millionhectares in India only

Opportunities to work with morepartners and extending soundnutrient management information

through multiple channels

Output: Partnerships and dissemination tools in place for reaching numerous farmers

Indicator of success: Local extension persons contacting farmers with correct message


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Drivers of Nutrient Expert Developmentin India

Requirement of dissemination tool for large scaleadoption of SSNM in areas practicing generalizedfertilizer recommendation, including CSISA operationalarea

Requirement of a nutrient management DSS that canhandle differing tillage and residue managementscenarios

Scope for developing NE in Rice, Maize and Wheat in asystem perspective

Support from partner Institutes and scientists for NE


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How did we proceed to develop NutrientExpert for Wheat and Maize

Rigorous in-house discussion on the framework of NE

Field visits across growing areas to understand the productionsystem and growing conditions

Intensive discussion with NARES, University, CG Institutescientists to modify/improve the developed framework

Use of local experimental data and one-on-one contact withnational scientists to optimize input parameters

Validation trials with wide range of partners and in-season fieldvisits to understand performance of the tool against existing

practices


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Overview A new, computer-based decision support tool

developed to assist local experts to quickly formulate

fertilizer guidelines for wheat and tropical hybrid

maize

Follows the principles of site-specific nutrient

management (SSNM) (Witt et al. 2009)

Allows scientists and extension experts to jointlydevelop novel nutrient management strategies for

evaluation

Nutrient Expert for Wheat and Hybrid Maize

C. Witt, J.M. Pasuquin, M.F. Pampolino, R.J. Buresh, and A. Dobermann. 2009. A manual for the development and participatory

evaluation of site-specific nutrient management for maize in tropical, favorable environments. International Plant Nutrition

Institute, Penang, Malaysia. http://seap.ipni.net


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Nutrient Expert for wheat and Hybrid Maize helps to: Evaluate farmers current nutrient management practices

Develop an optimal planting density (Maize) for a location

Set a meaningful yield goal based on attainable yield

Estimate fertilizer NPK rates required for the selected yield

goal

Translate fertilizer rates into available fertilizer sources

Develop an application strategy for fertilizers (right rate, right

source, right location, right time)

Compare costs and benefits between the farmers current

practice and the recommended practice

What can the software do?

Nutrient Expert for Wheat


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Nutrient Expert for WheatVersion 1.0 Settings About Help Exit

Nutrient Expert for wheat helps you to: evaluate current nutrient management practices determine a meaningful yield goal based on attainable yield estimate fertilizer NPK rates required for the selected yield goal translate fertilizer NPK rates into fertilizer sources develop an application strategy for fertilizers (right rate, right source, right location, right time), and compare the expected or actual benefit of current and improved practices.

CurrentFFP & Yield

SSNMRates

Sources &Splitting

ProfitAnalysis

To start, click a button

First time user? Working in a new location? Make sure to have the Settings right!

Developed in 2010 for validation in 2010-11 wheat season


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Nutrient Expert for wheat validation


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Wheat NE Validation Results

State Tillage Cropping System NutrientExpert

StateRecommendation

Farmers

Practice

Bihar(n = 11)

Conventional Rice-Wheat 3898 3267 3632

UttarPradesh(n = 16)

Conventional Pearl millet-Wheat 5640 5224 5848#

Haryana

(n = 15)


Haryana(n = 15)

Zero till Rice-Wheat 5072 4722 4439

Punjab(n = 6)


Punjab

(n = 8)

Zero till Rice-Wheat 5050 4404 4198

Punjab(n = 4)

Zero till Cotton-Wheat 5700 5050 4583

Punjab(n = 4)

Conventional Cotton-Wheat 5117 4867 4208

# Ample NPK application treatment, part of omission plot studies


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Nutrient Expert for Hybrid Maize-South Asia

Ready for validation trials in coming rainy season


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Farmers yield will be used : as basis for suggesting a yield goal for estimating benefits in Profit Analysis

Farmers fertilizer practice will be used: for estimating costs in Profit Analysis

Farmers Fertilizer Practice


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Suggested fertilizer splitting(rates and timing)

Fertilizer rates are adjusted to field size


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nutrient management strategies for ca ludhiana july 2011

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