Drought resilience and soil degradation in drought-hit Districts of Karnataka: The relevance of regenerative farming

Introduction

Agriculture in India is significantly impacted by two major hydro-meteorological events: drought and flood. Given its heavy reliance on the monsoon for water, Indian agriculture remains vulnerable to these challenges. Nearly one-sixth of the country's geographical area, accounting for 12% of the population, is prone to drought. Additionally, over 68-70% of India's cultivated land is susceptible to drought.

Drought around India Study Area-The Drought Crisis in Karnataka

Drought has become a frequent and distressing phenomenon in Karnataka, affecting nearly 80% of the districts annually. Districts such as Bagalkote, Ballari, Bidar, Chitradurga, Kalaburagi, Koppala, Gadaga, Raichur, and Vijayapura are among the worst hit. Prolonged water scarcity periods severely impact crop yields and push farmers into liability. The lack of consistent rainfall, worsened by climate change, has led to severe water shortages, leaving irrigation systems and rain-fed agriculture vulnerable.

Soil Degradation: A Growing Concern

Soil degradation is the deterioration in soil quality caused by natural processes or human activities. Soil degradation is a significant consequence of the environmental challenges faced by Karnataka. Repeated drought cycles and inadequate agricultural practices have caused a decline in soil organic matter, nutrient loss, and decreased soil fertility. In many districts of Karnataka, people are already struggling with water scarcity, and degraded soils become even less capable of retaining moisture, creating a downward spiral where the land becomes increasingly unproductive. Soil degradation has different effects on nature as well as human well-being. Soil erosion, another significant form of degradation, is a persistent issue.

The intense and erratic rainfall that sometimes accompanies drought can easily wash away topsoil, takes away the essential nutrients required for healthy crop growth. This further lessens the land's capacity to support agriculture and worsens food insecurity in the region. There are different kinds of soil erosions such as Physical, Chemical, and Biological. Physical soil degradation encompasses erosion by wind and water and the deterioration of soil structure. Chemical soil degradation arises from human activities and includes issues such as over-fertilization, salinization, the accumulation of microplastics, and contamination by organic chemicals. The primary Biological soil degradation includes the loss of soil organic matter and a decline in biodiversity.

Source: ICAR NBSS & LUP, Nagpur

Methods to control and mitigate soil degradation

There are a few ways by which we can prevent soil degradation such as by cover cropping, crop rotation, contour planting, adding organic matter, controlling runoff, afforestation, etc. Regenerative farming is also an effective way of preventing soil degradation.

Regenerative Farming: A Sustainable Solution

Regenerative agriculture is a general approach aiming to support the health of soil, water, and biodiversity, intending to benefit farmer communities. Here are key practices associated with regenerative agricultural farming:  Soil Health: Maintaining and building healthy, nutrient-rich soil. This can be achieved by increasing organic matter, promoting microbial activity, and improving soil structure.  Minimal Tillage: Tillage refers to the method used in preparing soil for planting by mechanically disturbing or agitating it. Reduced tillage minimizes soil disturbance, helping to maintain organic matter and soil structure.  Cover Cropping: Planting cover crops helps prevent soil erosion and enhances soil structure. These crops protect the soil from being washed or blown away, while also improving its physical properties by increasing organic matter and promoting better root growth, leading to healthier, more resilient soil. Biodiversity: Promoting a diversity of plant and animal species within the farming system enhances resilience, benefits pollinators, and creates a balanced ecosystem.  Livestock grazing: Holistic grazing ensures livestock contribute positively to improve soil quality through natural herd movements, which helps plants grow and regenerate soil.  Carbon Sequestration: This approach increases soil carbon storage, aiding in the mitigation of climate change.  Agroforestry: This is the practice of incorporating trees into agricultural landscapes, offering substantial benefits in drought-prone regions by providing shade, reducing wind erosion, and enhancing water retention.

The impact of regenerative farming in Karnataka

In response to these challenges, many farmers in Karnataka have adopted to regenerative agriculture practices as a means to address soil degradation and improve the flexibility of their lands to drought and climate variability. Farmers who have adopted regenerative agricultural practices in Karnataka's drought-hit districts are beginning to see the profits. Improved soil health has led to better water retention, which is critical in areas where water is limited. Healthier soils also mean more resilient crops that can withstand periods of heat and drought. Moreover, regenerative practices support carbon sequestration, which can help counteract climate change, a significant factor contributing to the increasing frequency and intensity of droughts in the region.

Regenerative farming offers a pathway to sustainable agriculture in Karnataka, one that not only addresses the immediate challenges of drought and soil degradation but also builds longterm resilience. By embracing these practices, farmers in the state's most vulnerable districts can secure their livelihoods, protect their lands, and contribute to a more sustainable future for agriculture in Karnataka.

Methodology

In Karnataka, several districts are particularly vulnerable to the interconnected challenges of drought, soil degradation, and climate variability, making regenerative agriculture practices vital. Drought, soil degradation, temperature, and rainfall are interrelated parameters that significantly impact agriculture, particularly in regions like Karnataka.

Factors that affect soil degradation

Soil degradation is caused by many factors such as natural, human-induced, Biological, etc. Natural factors include climatic conditions (temperature and rainfall), topography, soil type, and natural disasters like floods, landslides, droughts, etc. Humaninduced factors include Agricultural practices, deforestation, overgrazing, urbanization, pollution, mining activities, irrigation practices, etc. Biological factor includes loss of Biodiversity. We can consider these factors as the main parameters for studying soil degradation.

Results and Findings Year-wise drought occurrence

From 2013 to 2023, the number of drought occurrences shows an increasing trend. The data highlights fluctuations in drought frequency, with the highest occurrences recorded in 2023 (21). Notable peaks occurred in 2016 and 2018, while 2021 saw the lowest number (4). Overall, the data indicates a general rise in drought events over the decade, suggesting intensifying drought conditions and the need for enhanced management strategies. Table 1 and Figure 4 show Year-wise drought occurrence.

District-wise drought occurrence

The data on drought occurrences across various districts reveals that Yadgir experienced the highest number of droughts, with 16 occurrences. Bidar, Chitradurga, and Vijayapura each reported 15 droughts. Other districts with significant drought occurrences include Koppala (13), Ballari and Raichur (12 each), and Bagalkote and Kalaburagi (11 each). In total, there were 120 reported drought occurrences across these districts. Table 2 and Figure 5 show District-wise drought occurrence.

Season-wise drought occurrence

In Karnataka district, season-wise drought occurrence varies based on climatic patterns. Among the three agricultural seasons Kharif (June to September), Rabi (October to February), and Zaid (March to May), drought conditions were less frequently observed during the Kharif season. In Bagalkote, Ballari, and Yadgir districts there is a severe drought in the Rabi season, followed by the Ballari district. Also, it may be noted that Chitradurga, Koppala, Raichur, Vijayapur, and Yadgir reported consistent drought occurrence in the Rabi and Zaid seasons. In Ballari, drought occurrences were the same in all three seasons. Table 3 and Figure 6 show Season-wise drought occurrence.

4 and Figure 7 show Season-wise drought occurrence. and Yadgir and Kalaburagi (0.26), had 12 to 16 drought occurrences. This indicates that lower soil moisture levels are associated with more frequent drought events. Overall, the data, totalling 120 drought occurrences, highlights the relationship between soil moisture and drought frequency. Table 5 and Figure 8 shows Season-wise drought occurrence Temperature shows a moderate positive correlation with drought, suggesting that higher temperatures may exacerbate drought conditions. NDVI shows weaker relationships with drought, with NDVI displaying a moderate but non-significant negative correlation.

Conclusion

The drought-hit districts of Karnataka face a multifaceted web of challenges, including rising temperatures and erratic rainfall patterns to severe soil degradation. Analyzing the interrelationships among rainfall, temperature, land surface temperature (LST), normalized difference vegetation index (NDVI), soil moisture index (SMI), standardized precipitation index (SPI), and drought occurrences offers valuable insights into agricultural productivity. Variations in temperature and rainfall patterns significantly influence LST, which in turn affects soil moisture levels and vegetation health, as reflected by the SMI and NDVI, respectively. By studying the SMI, NDVI, SPI, and the frequency of droughts across selected districts of Karnataka, one can effectively assess trends in land degradation and their potential impact on agriculture. Accurate monitoring of these parameters is crucial for understanding and addressing land degradation. However, adopting regenerative farming practices can effectively address these challenges. Regenerative farming not only revitalizes the health of the soil but also strengthens the resilience of the agricultural system, providing a sustainable answer to the environmental challenges facing Karnataka's farming community. As more farmers adopt this approach, the future of agriculture in Karnataka's drought-prone regions looks more promising and sustainable.

References

1. Diwan AD, et al. Regenerative agriculture. Indian Farming. 2021;71(12):3-8.
2. Mossad A, Alzaba AA. Drought forecasting using stochastic models in a hyper-arid climate. Atmosphere. 2015;6:410-430.
3. Mishra AK, Singh VP. Drought modeling -A review. J Hydrol. 2011;403:157-175.
4. Dai A. Drought under global warming: a review. Wiley Interdiscip Rev Clim Change. 2011;2:45-65. DOI: 10.1002/wcc.81.
5. Montgomery DR. Soil health and the revolutionary potential of conservation agriculture. In: Woodhead Publishing Series in Food Science, Technology and Nutrition, 2021, p. 21929.
6. Suma AP. Forecasting anthrax in livestock in Karnataka State using remote sensing and climatic variables. Int J Sci Res. 2015;2319-7064.
7. Popescu E, et al. Reducing the effects of drought and degradation of agricultural soils, in the context of climate change, through the application of regenerative ecological technologies, 2022 Apr 29. DOI: 10.5772/intechopen.104446.
8. Miller-Klugesherz JA, Sanderson MR. Good for the soil, but good for the farmer? Addiction and recovery in transitions to regenerative agriculture. J Rural Stud, 2023, 103. https://doi.org/10.1016/j.jrurstud.2023.103123.
9. Adikari KE, et al. Evaluation of artificial intelligence models for flood and drought forecasting in arid and tropical regions. Elsevier, 2021.
10. Schreefel L, et al. Regenerative agriculture-the soil is the base. Global Food Security, 2020 Sep, 26. https://doi.org/10.1016/j.gfs.2020.100404.
11. Mishra A, Desai V, Singh V. Drought forecasting using a hybrid stochastic and neural network model. J Hydrol Eng. 2007;12:626-638. DOI: 10.1061/ASCE1084-0699200712:6626.
12. Patil R. Drought modelling and forecasting using ARIMA and neural networks for Ballari District. J Indian Soc Agric Stat. 2020;74(2):149-157.
13. Khangura R, et al. Regenerative agriculture-A literature review on the practices and mechanisms used to improve soil health. 2023.
14. Khangura R, et al. Regenerative agriculture-A literature review on the practices and mechanisms used to improve soil health. Sustainability. 2023;15:2338. https://doi.org/10.3390/su15032338.
15. Reibsame et al. Drought and natural resource management in the United States: impacts and implications of the 198789 drought. Boulder, CO: Westview Press, 1991, p. 174.
16. Sherwood S, Uphoff N. Soil health: research, practice and policy for a more regenerative agriculture. Appl Soil Ecol. 2000 Aug;15(1):85-97.