Constraints of Lateritic Soils in Crop Production

Gaurav JhaL-2014-A-132-M

Soils 511

Lateritic Soils

• In Subtropical and Tropical regions between 25 degrees North and South latitudes.

• Deposits are thick upto 20m.

• Highly ferruginous• Vesicular• Unstratified deposits• Highly weathered• Qualify for Ultisols and Alfisols

with Kandic properties

• Crops for higher topography:1. Cocoa2. Cashew3. Tea4. Coffee5. Rubber• Crops for lower topography:1. Rice2. Banana3. Coconut4. Arecanut

Formation and distribution of lateritic soils

Kerala, Tamil nadu, Orissa, Andhra Pradesh, West Bengal, Karnataka

Profile of Lateritic Soils

Santiniketan, Birbhum (W.B.)

Constraints of lateritic soils

Physical constraints Chemical constraints

Soil erosion and hardening of

laterites

Low water holding capacity

Reduced soil volume due to

concretions and occurrence of

plinthite and petroplinthite

Drought stress

Low CEC

Low organic matter

High acidity

Fe and Al toxicity

High Phosphorus fixation

Poor nutrient status

Physical Constraints

I. Soil erosion and hardening of laterites

Views of Gullies at the

west of Bhatina village,

Rampurhat

Laterites are very much erosion prone soil in India because--- I. It has high erodible kaolinitic clay (B horizon)II. Surface crusting of iron oxidesIII. Light texturedIV. Low moisture retention capacity and V. Less vegetative growth

IRS 1D LISS III FCC image (2001) of the Rampurhat block of Birbhum district in West Bengal(greenishblue patches are gully prone lateritic land).

Ghosh et al (2011)

II. Low water holding capacitySoil Depth(in cm) Available water(%) Infiltration Rate

Lateritic 0-15 3.5 10.8

15-30 4.6

30-60 6.3

Black 0-15 15.3 0.60

15-30 10.2

30-60 13.4

Ushakumari (1986)

Drying out and hardening of upper horizons Forms impenetrable crust This reduces the ability of soils to absorb water Irreversible hardening

III. Reduced soil volume due to concretions and occurrence of plinthite and petroplinthite

Plinthite is a redoximorphic feature in highly weathered soil Product of pedogenesis, it commonly occurs as dark

red redox concretions Changes irreversibly to an ironstone hardpan or to irregular soil

aggregates on exposure to repeated wetting and drying Structure change from angular blocky to massive structure

Chemical Constraints

I. Low Cation Exchange Capacity

Due to lack of organic matter

Hydrous nature of clay

Percent base saturation ranges from 80 to 95 %

which reflects the dominance of basic cations in the

exchange complex

Exchangeable Aluminium is the predominant cation.

Low activity clay, therefore CEC is contributed by

pH-dependent charges

II. High Soil Acidity

Measure of soil acidity in lateritic soils-

1. Exchangeable Hydrogen ion

2. Exchangeable Aluminium ion

3. Effective Cation Exchange Capacity

High acidity attributed to acidic parent material

Three strategies to attenuate soil acidity-

1. Liming to reduce Al-saturation below toxic levels

2. Liming to promote Ca and Mg in soil

3. Use of plant species tolerant to Al, Fe, Mn toxicities Sehgal et al (2000)

Kisiniyio et al (2014)

Effect of lime on exchangeable Al3+ during the cropping period on a western Kenya acid soil

III. High Phosphorus Fixation

High P-fixation is attributable to

1. Hydrous oxides of iron and aluminium

2. Dominance of 1:1 type of clay

3. Increased soil weathering and decreased soluble silica

4. Acidic soils have higher P-fixing capacity

5. Fe and Al phosphates are formed and adsorption reaction occurs

IV. Poor nutrient status

Fe and Al ions occupy negatively charged sites useful to store

nutrients

Extremely weathered laterites are devoid of primary minerals,

bases and silica

1.) Pronounced leaching

2.) Relative accumulation of sesquioxides

Deficiency of P, K, Ca, Mg, Zn, B

Toxicity of Al and Mn

Low soil fertility status

Potentials of lateritic soils

Western Ghats-Mango cultivation

Case Studies on lateritic soils

Bio-reclamation –Converting degraded lateritic soils into productive land in Niger by ICRISAT

Trees intercropped with vegetables under BDL system by ICRISAT, Nigeria

Degraded lateritic soil of Nigeria

Strategy-Bio-reclamation of Degraded Lands (BDL) system which enhanced the conversion of degraded crusted soils into productive lands in Niger by ICRISAT

How it was achieved- By combining indigenous water harvesting technologies (micro-catchments, planting pits and trenches), application of animal and plant residues and plantation of high-value fruit trees and annual indigenous vegetables that are resilient to drought environments

Tree species- Ziziphus mauritiana (Pommedu Sahel), sweet tamarind (Tamarindus indica), the domesticated

Sclerocaria birrea (marula) and the domesticated Acacia senegal

Leafy vegetables-(Cassia tora, Gynandropsis gynandra, Corchorus stridens, Cerathotheca

sesamoides, Leptadenia hastate, Hibiscus sabdariffa and wild Amaranthus).

CASE

STU

DY-1

Advantage of vermicomposted FA over FYM in augmenting growth and yield of the crop.

Vermicomposted FA + NPK100 (A), FYM + NPK100 (B) and yield of potato from these

treatments (C).Location-Birbhum, West Bengal

Chattopadhyay et al (2012)

CASE

STU

DY-2

Conclusions Laterites are formed as a result of continuous wetting and drying for

years and includes alfisols, oxisols and ultisols which are highly

weathered soils.

Lateritic soils are highly weathered soils devoid of major nutrients like P,

Ca, Mg, K, Zn, B etc. Howevever toxicity of Fe and Al may be observed

as they are acidic soils.

Liming in tropical areas are not as effective as in temperate regions due

to low activity clays.

Formation of plinthite layer hinders the root penetration for germinating

crops. However, rice can be grown as it needs hard pan formation during

its growth period.

Vermicomposting and use of fly ash are promising practices to increase

the nutrient use and its efficiency.