From CK Nayak
NEW DELHI: Meghalaya is among the northeastern states which have witnessed serious land degradation due to acidification over the years affecting agriculture, stated a report by the Indian Space Research Organisation (ISRO) and the National Remote Sensing Centre (NRSC).
According to a new draft report on land degradation prepared by ISRO and NRSC, large areas of land in the northeastern states have already degraded due to the adverse effects of climate change.
Among the top seven states with the highest increase in land degradation in the last 10 years are Nagaland, Manipur, Mizoram and Meghalaya followed by Assam and Arunachal Pradesh.
“The report also states that the most common cause of land degradation is acidification. In the top eight states in the country where acidification is most rampant, seven are in the North East,” it added.
After Uttar Pradesh and Rajasthan, Nagaland stands third with 47 per cent of its land area under degradation, followed by Manipur at 38 per cent, Mizoram at 35 per cent and Meghalaya at 28 per cent.
Acidification decreases the quality of soil and reduces productivity significantly. In a region which is predominantly dependant on agriculture, such loss of arable land could spell doom for people’s livelihood.
One of the major causes of this degradation could be increased frequency of high rainfall in the region, the study pointed out.
The degradation could in fact be one of the contributing factors for surface floods, flash floods and landslides which have been reported throughout the region this year.
Five states — Assam, Manipur, Tripura, Mizoram and Nagaland — witnessed minor to major floods in 2018.
The highest among these is Nagaland where almost 7.5 lakh hectares of land is acidic and constitutes around 45 per cent of the total area of the state. Manipur comes second with 6.3 lakh hectare of acidified land, which is more than 28 per cent of its total geographical area.
In states like Arunachal Pradesh and Assam, degradation has been caused by water erosion rather than by acidification. The report does not give affected land area figures for the remaining states, which include Meghalaya.
Acidity is measured in terms of concentration of hydrogen ions (pH) in the soil as they are essential for the formation of all acids. Acidification of soil or land takes place when the pH balance of the soil shifts towards acidic nature due to an excessive presence of hydrogen ions.
Soil acidity increases when metallic minerals like calcium, magnesium, potassium and sodium are lost from the soil and only hydrogen ions remain. These minerals get removed from soil due to heavy rainfall and flooding. They are also removed along with the residue of crops or hay during crop harvesting.
The land in the North East is naturally acidic due to heavy rainfall but climate change has induced high frequency of heavy rainfall which has accelerated acidification.
Preventive measures against soil acidification include using lime and organic manures to rejuvenate the quality of soil.
Acidification can also be remedied by adopting nutrient management practices and smart crop selection both of which would prove to be difficult to implement in landlocked regions.