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In the vast farmlands of Karnataka, a silent crisis is brewing that threatens the future of agriculture and the environment. Recent data from the state's Agriculture Department revealed that more than half of Karnataka's agricultural land suffers from low levels of soil organic carbon (SOC) — a critical indicator of soil health and fertility.
This decline not only endangers crop productivity but also poses a broader environmental threat.
The impact of this crisis is already manifesting in north and central Karnataka following marginally lowering yields and the quality of the yield in various crops such as oil seeds, cotton, groundnut, jowar, maize and millets.
SOC is more than just a soil component — it is the backbone of soil quality. It plays a vital role in water retention, nutrient availability, pH buffering and preventing soil erosion.
Optimal SOC levels are essential for maintaining healthy and productive soils, which are foundational for sustainable agriculture.
Yet, according to the analysis conducted between 2017 and 2024, more than half of Karnataka’s farmland falls below the necessary SOC threshold of 0.5 per cent which signals towards widespread soil degradation.
Experts attribute the alarming drop in SOC levels to several interconnected factors and the foremost among these is the rampant use of chemical fertilisers.
Karnataka ranks amongst the top five states in fertiliser consumption, with usage per hectare surpassing the national average.
In the 2020-21 and 2021-22 fiscal years alone, fertiliser use skyrocketed to over 45 lakh metric tonnes and projections for 2024 suggest even higher demands.
Along with heavy fertiliser use, a decline in the application of organic manure has exacerbated soil degradation.
The rising costs and logistical challenges associated with using cattle manure, which costs approximately Rs 14,000 per acre compared to Rs 3,000 for chemical fertilisers, have pushed farmers to rely heavily on the synthetic alternatives.
This shift is further evidenced by a reduction in Karnataka’s livestock population, which fell from 1.48 crore in 2007 to 1.14 crore in 2019.
The impact of declining SOC is not uniform across Karnataka.
Districts like Kolar, known for its extensive vegetable cultivation, show alarming figures, with over 94 per of its farmland recording low organic carbon levels.
Conversely, districts such as Dakshina Kannada, Uttara Kannada and Udupi, which boast more tree cover and traditional farming practices, exhibit healthier soil conditions with satisfactory SOC levels.
This belt is formed along the coast due to the deposition of alluvium and sediments carried by the rivers and sea waves and the soil here consists of sand and clay which is very rich in organic nutrients.
In these districts, the figures from the state agriculture department indicated that the cropping pattern, practices and yield have remained constant, which is indicated in the output of paddy.
It is another matter that a few thousand acres are being diverted for plantation crops, but the cultivators ensure not to use chemical fertilisers but practice mulching and other bio-friendly methods.
Low SOC levels are directly linked to reduced soil fertility, leading to lower crop yields over time. The districts that have black alluvial soil are the worst affected, namely in the northern parts of the state, which are locally called ‘Eremannu’.
These are derived from the weathering of basalt rocks. Some parts of Belagavi, Vijayapura, Kalburgi, Bidar Yadagir and Bagalkote districts have shallow black soils that are suitable for cotton, groundnuts, oil seeds and even certain types of paddy. Karnataka has 9.2 per cent of its agricultural lands covered by black soil.
Experts in the agriculture department state that poor soil health contributes to increased vulnerability to erosion and water runoff, compounding the impact of climate change on local agriculture.
Also, monocropping and deforestation which are common practices in the state, further strip the soil of its natural nutrients, creating a vicious cycle of environmental degradation.
To combat this growing crisis, agricultural scientists emphasise the importance of adopting sustainable farming practices. Experts in soil science and agricultural chemistry, advocate for the integration of organic and inorganic fertilisers to strike a balance between productivity and soil health. The use of green manure, vermicompost and practices such as mulching post-harvest crop residue on the field can play a significant role in rejuvenating the soil.
“In many districts in the region, we take up mulching after every harvest, but that is not yielding us the expected results. In many taluks like Chennaryapatna (Hassan district) and Tipturu (Tumakuru district), we mulch coconut, areca leaves and forest wastes onto the fields,” Hanumanthappa, an activist from the Central Karnataka Ryatha Sangha — a farmers’ organisation, told DTE.
“There is a need for over 15,000 metric tonnes of mulching agents every season, but we get only a quarter that volume from our sources, it is not economical to transport the mulching material over 100 kilometres,” he added.
Meanwhile, there are farmers in Shivamogga, Ballari, Chitradurga and Davanagere who have installed their own shredding machines for converting the biomaterial into mulching agents.
“And also, there are farmers who have their on-site coco-peat plants, but since the coco peat commands a good market from the traders for urban gardens, particularly the terrace gardens, so the farmers are trading it at a higher price, which makes profitable for them,” Ramesh Gowda, an office bearer of the central Karnataka Raitha Sangha, told DTE.
The Karnataka Agriculture Department has reacted to the urgency of the situation and is taking measures to promote sustainable soil management practices.
In the wake of the findings on depleting SOC, the department has launched one of the biggest-ever plans to collect and analyse soil conditions in over 500,000 soil samples on over 30,000 hectares in different parts of the state.
It is learnt that this sample size has been determined based on the variety of soils in the state.
At the same time, efforts are underway to increase the distribution of green manure seeds and enhance soil testing capabilities. Both of these projects will begin and end in the year 2024.
In addition, the introduction of a dedicated mobile phone app will offer farmers real-time access to soil test results and recommendations, making it easier for them to adopt appropriate soil conservation measures and increase the SOC levels by taking up mulching in an extensive way.
Thus, the soil crisis in Karnataka serves as a stark reminder of the delicate balance required to sustain both agricultural productivity and environmental health.