Solis of Goa
“Earth needs to be nurtured with mother’s care because Earth gives everything for sustaining life”
- The main types of soils found in the State of Goa are Coastal Alluvial soil, mixed red and black soil, laterite soil and red sandy soil, which are sub-divided into 32 soil series.
- Type of Solis of Goa predominantly includes Laterites (73.4%), Alluvial & Marshy (11.7%), Coastal sandy soils (10.11%), Saline soils (4.79%) with soil pH ranging 4.5 -6.5.
- The Solis of Goa in general fairly good in organic matter and respond well to the application of N and P fertilizers.
Soil Types of North Goa
Solis of Goa of the district can be classified into 3 types namely
- Laterite soil
- Saline soil and
- Alluvial soil
- Lateritic soil
- It is the major soil type in the district.
- It is highly porous & permeable, slightly acidic with low pH values, low in organic matter, Calcium and Phosphorus.
- Saline soil
- It in the district occurs in the flood plains of Zuari and Mandovi rivers in Tiswadi, Bardez and Ponda taluks.
- It also occurs in Pernem taluk.
- The soil is deep, poorly drained and less permeable. It is saline, high in pH and contains humus and organic matter.
- Alluvial soil
- It occurs as very thin strip along the coastline towards western part of the district.
- It is reddish brown to yellowish, coarse grained and confined to narrow valleys of rivers.
- It is well drained, acidic with low pH and organic content.
Soil Type of South Goa
Solis of Goa of the district can be classified into 4 types namely
- Laterite soil
- Saline soil
- Marshy soil
- Alluvial soil
Lateritic soil
- It is the major soil type in the district.
- It is highly porous & permeable, slightly acidic with low pH values, low in organic matter, Calcium and Phosphorus.
Saline soil
- It in the district occurs in the flood plains of Zuari, Sal, Saleri, Talpona and Galjibagh rivers in Salcete, Marmugao, Quepem and Canacona taluks.
- It also occurs to a very limited extent in Sanguem taluk.
- The soil is deep, poorly drained and less permeable.
- It is saline, high in pH and contains humus and organic matter.
Marshy soil
- It occurs to a large extent in Salcete taluk and towards the western part of Canacona taluk.
- It also occurs in Marmugao taluk.
- This type of soil occurs in low-lying water logged and tidal affected areas.
Alluvial soil
- It occurs as very thin strip along the coastline towards western part of Salcete taluk and also a limited exposure occurs in Canacona taluk.
- It is reddish brown to yellowish, coarse grained and confined to narrow valleys of rivers.
- It is well drained, acidic with low pH and organic content.
Other Aspects related to Solis of Goa
Related to Salinity Aspects
- Salinity is the common soil problem in coastal rice production environments which encompasses 30 % of the net cultivated area of rice grown in Goa State. These lands are locally known as Khazan lands and are characterized by low elevation and high water table.
- The soils are deep, heavy textured, silty clay to silty clay loam having heavier sub horizon.
- The soil pH is slightly acidic to neutral (6.0-7.0), with electrical conductivity 4 to 15 dS m-1 and organic carbon content 6.3-7.7 g kg-1.
- Further, the soil salinity normally exceeds the critical level (> 4 dS m-1) starting from January to June, and then declines through December with the highest magnitude during March – May.
Laterite Solis of Goa(73.4% Area of Goa)
- The word laterite has been derived from the Latin word ‘Later’ which means brick.
- These soils when wet are as soft as butter but become hard and cloddy on drying.
- Therefore, these are widely cut as bricks for use in house construction.
- Formation:
- The lateritic soils are particularly found on high flat erosion surfaces in areas of high(>200cm) and seasonal rainfall.
- The alternating wet and dry seasons lead to the leaching away of the siliceous matter of the rocks leaving behind the compounds of iron and aluminium.
- These are zonal soils.
- Areas: These soils have mainly developed in the higher areas of the Peninsular plateau like in Goa occur around 73%.
- Soil Colour: Reddish brown in colour due to the presence of iron oxide.
Other characteristic features:
- With rain, lime and silica are leached away, and soils rich in iron oxide and aluminium compound are left behind (thus the reddish brown colour).
- Also, humus content of the soil is removed fast by bacteria that thrives well in high temperature.
- These soils represent the end product of decomposition and are generally low in fertility.
- The pebbly crust is the important feature of laterites which is formed due to alteration of wet and dry periods.
- These soils are acidic in character due to leaching.
- Application of manures and fertilisers is required for making these soils fertile for cultivation.
- These soils are poor in organic matter, nitrogen, phosphate and calcium, while iron oxide and potash are in excess.
Suitable crops: Cashewnut.
Alluvial Solis of Goa (Around 11.7% area of Goa)
- Formation: They are mainly derived from the debris brought down from the Himalayas or the silt left out by the retreating sea. Thus they are azonal soils.
- Areas: Around 11.7% area of Goa
- Soil texture: The alluvial soils vary in nature from sandy loam to clay.
- Soil Colour: The colour of the alluvial soils varies from the light grey to ash grey depending on the depth of the deposition, the texture of the materials, and the time taken for attaining maturity.
- Other Characteristic Features:
- These soils lack in nitrogen, phosphorus and humus. However, they are generally rich in potash and lime.
- The soil profile has no stratification.
- Alluvial soils are intensively cultivated.
- In certain areas, these soils are covered with unproductive wind-borne soil called Loess.
- Limitations:
- Allow water to sink into lower strata, and Lack nitrogen (But these soils are capable of fixing nitrogen very rapidly through leguminous crops (peas, beans, cloves etc.)
- Suitable Crops: Wheat, rice, maize, sugarcane, pulses, oilseeds, fruits and vegetables, leguminous crops but rice grown mainly in Goa.