acid soils

Soils of Meghalaya

• The soils of the hills are derived from gneissic complex parent materials; they are dark brown to dark reddish-brown in colour, varying in depth from 50-200 cm.
• The texture of soils varies from loamy to fine loamy.
• The soils of the alluvial plains adjacent to the northwest and southern plateau are very deep, dark brown to reddish-brown in colour and sandy-loam to silty-clay in texture.
• Soils of Meghalaya are rich in organic carbon, which is a measure of nitrogen supplying potential of the soil, deficient in available phosphorous and medium to low in available potassium.
• The reaction of the soils varies from acidic (pH 5.0 to 6.0) to strongly acidic (pH 4.5 to 5.0).
• Most of the Soils of Meghalaya occurring on higher altitudes under high rainfall belt are strongly acidic due to intense leaching.
• Base saturation of these soils is less than 35 %.
• These Soils of Meghalaya are not suitable for intensive crop production.
• There is not much difference in fertility classes of the Soils of Meghalaya .
• Four Soils of Meghalaya fertility classes, namely, High Low Medium (HLM), High Medium Medium (HMM), Medium Medium Low (MML), Medium Low Medium (MLM) have been established from the soil test data so far compiled in the Soil Testing Laboratory of the State.
• Regarding micronutrient status, it has been observed that almost all the acid soils of the North-Eastern region of the country are deficient in available Boron (B) and Molybdenum (Mo).
• Acid soils of Meghalaya are rated low in available B and Mo.
• Total Zinc, Copper and Manganese contents of these soils vary from 10.00 to 17.25, 17.00 to 71.00 and 110 to 770 ppm (parts per million), respectively and DIPA (Diethylene Triamine Penta Acetic Acid) extractable zinc, copper and manganese contents of these soils ranges from 0.72 to 3.20,n 0.6 to 2.8 and 3.0 to 162.0 ppm respectively.
• A study conducted by the Indian council of Agricultural Research (ICAR) Complex, Shillong revealed that about 40% of the soils of the state contain micronutrients below the critical level.

Major Soils of Meghalaya

• The climate, rock structure, slope and relief within the State differs from place to place and thereby brings heterogeneity in the composition and character of soil in the region.
• Broadly, the soils of Meghalaya are of three types,

1. Red loain or Hills soils,
2. The Lateritic soils,
3. New and old alluviums.

Red loain or Hill Soils

• The red loamy soils are found all along the foot hills and sub-mountain fringes of the region.
• But, these soils are predominant in central upland of Khasi-Jaintia Hills, where the soil is mostly sandy because of the sandstone outcrops, whereas in parts of Ri-Jaintia area the soil tends to be silty.
• They are also rich in organic matter which again tends to be more in higher altitudes because of low temperature.
• The soils on the central, upland region have high moisture content.
• Though the humus content is high, it is devoid of base minerais like calcium, potassium, sodium, etc., except being rich in iron oxides.

Lateritic Soils

• Towards the western part of the central uplands, hill soils are gradually replaced by lateritic soils.
• These hill soils being acidic in nature, have their significance in being suitable for the cultivation of fruits and potatoes and in areas of hill slopes and terraces for the cultivation of rice.
• The southern War Country is practically devoid of any soil cover because of excessive rain.
• The sandstones being disintegrated constantly by rain make the soil, if there is any, extremely sandy.
• Towards the lower part, where the slope becomes t gentler, soil tends to be slightly silty to clay.
• Further down, near the border of Bangladesh, lateritic soils occur in small 60 fringes.
• These soils are highly leached, poor in plant nutrition and acidic in reaction, and thus they do not hold a favourable base for agricultural purposes.
• Along the northern face of the central upland (Bhot Country) lateritic soil is found.
• These soils varying from sandy to silty loam (especially on flat ri’ler valleys) are very much acidic in character and are highly leached.
• Because of extensive Jhum cultivation practised here, the area does not contain any thick and tall forest.
• In the western section of the Garo Hills regions for major part of surface area, the soil cover is lateritic, varying in nature from loam to silty loam (on the river banks and floodplains).
• Further west, nearer to the boarder, lateritic soil occurs on the high ground, but the plains have silty loam to older alluvium.
• Along the border areas, the soil is predominantly alluvial being both older and younger.
• The lateritic soils become workable only after rains and by heavy application of organic matter which may increase the fertility of the soil.

Alluvial Soils

• The alluvial soils, on the other hand, have a wider use by human being, since this type of soil is suitable for cultivation of rice, fruits and vegetables.
• 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.
• The alluvial soils vary in nature from sandy loam to clay.
• 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.

Soil Conservation Policy of Soils of Meghalaya

• Meghalaya soil conservation policy is based on the National Land Use Policy in which land has been described as a mix of soil, water, flora and fauna.
• As per the policy, the main aim of soil conservation in Meghalaya is to develop and maintain the productivity of the land for agricultural purpose as well as for the management of forest.
• The other aims behind soil conservation at Meghalaya is to :
• Prevent droughts and floods by sustaining a balanced relationship between land and water cycle.
• Checking destruction of watersheds from sedimentation, deforestation, land degradation, hydrologic deterioration and soil erosion.
• Secure the employment in rural areas by creating employment opportunities.
• Developing and maintaining spoiled land areas, wastelands and fallows so as to meet the growing demands of land for various sectors.
• Hence to raise awareness for soil conservation around Meghalaya, the state government has set up a Soil and Water Conservation Department that looks after soil conservation in Meghalaya. The department have initiated the following programs in this regard :

1. Jhum Control Programs: It looks after soil deterioration due to jhum or bun cultivation. The program lays stress on arranging a permanent settlement of jhummia family.
2. Watershed Management Programs: The program aims at using the land and vegetation resources for the optimum production at some selective micro watersheds.
3. Soil Conservation Programs: The program aims at removing the risks of soil erosion, land degradation, etc. The farmers have to take up the faulty farming practices.

• For soil conservation of Meghalaya, measures such as erosion control, afforestation, terracing and reclamation, water conservation and distribution, water harvesting and conservation of farm ponds are taken up.
• Meghalaya soil conservation would thereby increase the productivity of the land thereby generating more revenue for the state economy.