Agriculture serves as the primary source of livelihood for approximately half of the working population in Tamil Nadu. However, farmers in the state encounter numerous challenges. In an interview with TNIE, V Geethalakshmi, Vice–Chancellor of Tamil Nadu Agricultural University, one of the leading state agricultural universities in the country, said that due to the rise in temperature and changes in water availability, climate change can affect irrigated agricultural production throughout agro-ecological zones. Excerpts:
Water scarcity has become a major challenge in Tamil Nadu and it depends on neighbouring states for irrigation. How will this impact agriculture? What are the ways to conserve water for agricultural use? Has the TNAU submitted any recommendations to the government regarding this matter?
With 17 major rivers, 61 reservoirs and 41,948 tanks, Tamil Nadu has a total surface water potential of 24864 million Cubic meters (MCM). Most of the surface water is tapped for irrigation purposes and about 24 lakh hectares are irrigated by this water. However, over the last five years, the percentage of safe blocks has declined from 35.6 % to 25.2% while the semi-critical blocks increased. Over-exploitation has already occurred in more than 1/3 of the blocks (35.8%) while eight blocks (2%) have turned saline. Now, the state is managing the scarcity by the adoption of micro irrigation systems, automated irrigation units and conservation of rainwater by artificial recharge units. TNAU also recommends an alternate cropping system especially in the Cauvery Delta Zone if the state does not receive adequate water due from the neighbouring states. TNAU has implemented a World Bank-supported Tamil Nadu Irrigated Agriculture Modernization Project (TNIAMP) for the past 15 years which demonstrates modern irrigation technologies around river basin areas. TNAU also provides recommendations on water harvesting, water storage, groundwater recharge and water use efficiency methods to the government.
What kind of climate challenges are farmers in Tamil Nadu likely to encounter in future? Do we have any strategies or solutions to address the issue?
Agricultural production throughout agroecological zones can be affected by the rise in temperature and changes in water availability. The rain pattern also changed with unseasonal rainfall bringing floods during harvest season.
To mitigate the effect of climate change on farming, soil moisture conservation both in situ (BBF, random tie ridging, mulches) and ex-situ (Farm Pond) methods in rainfed crops are recommended. TNAU strongly recommends the adoption of drip irrigation in upland irrigated crops, alternate wetting and drying methods of irrigation in rice, alternate crops and crop diversification wherever required, an integrated farming system for risk mitigation and multi-stress tolerant crop varieties for drought/flood and high-temperature tolerance as climate resilient technologies for managing the climate change effect. The university also provides village-level weather-based agro-met advisories through mobile to the farming community. We are in the process of developing a long-range (three months) forecast at the block level which will be updated monthly, and an Extended Range of Weather Forecast (15 days) at the village level, which will be updated every week for the planning and midterm correction.
How does the Android application ‘AAS’ developed by the TNAU assist farmers in predicting climate change? How many farmers in the state are benefited by this app?
The Agro Climate Research Centre of TNAU has developed software to send weather-based agro advisory to farmers. By considering the past, present and future weather conditions, agro advisories for five growth stages of 108 crops are developed. Using these details, the weather-based agro advisory will be generated individually for the registered farmer’s own crop through the special AAS software and disseminated as SMS in the local language. This software is the first in India to automate the weather-based agro advisory. The farmers can freely register their mobile number in this portal, and choose their crop and sowing time. The forecast is developed at a 3 km resolution and for 35,640 points of Tamil Nadu, which is twice the number of Tamil Nadu revenue villages. The accuracy of the forecast is >75% and predicts extreme events precisely and alerts the farmers three days in advance with necessary advisories. Currently, more than 48,000 farmers have registered on this app, which is Android-based. The new version of the AI-enabled TNAU – AAS app will be released in a month, which will have new crops, improved advisories, and AI tools and will be available both in iOS and Android. We are expecting to reach over eight lakh farmers by next year.
In the state budget, the agriculture minister said that excessive use of fertilizers, herbicides and pesticides has led to a decline in overall soil fertility. What percentage of soil in the state has been affected by this issue and which districts in the state are mostly affected? How is TNAU going to help the state government in addressing this issue?
From a long-term experiment (2000-2015) conducted under AICRP-Weed Management in the Rice-Rice cropping system, it was found that contamination of soil and deterioration of soil fertility by the application of herbicides at the recommended rate is at a negligible level in Tamil Nadu.
However, the imbalanced use of inorganic fertilizer and negligence of organic manure application will result in declining soil fertility. TNAU is supporting the government in this process with Integrated Nutrient Management (INM) training programs, demonstrations on INM technologies, and access to alternative inputs (manures & bio-fertilizers) and technologies (INM, fertigation, SSNM (LCC), deficiency-based micronutrient fertilization & ST based fertilizer recommendation) in transitioning away from chemical-intensive farming practices by the farmers. The state government, with technical expertise from TNAU, can implement regulations on the excess use of chemical inputs in agriculture based on the land holding and cultivable area. Shortly, TNAU is going to implement a new project on reviving soil health through the application of bio-inputs with the support of the government of Tamil Nadu. The new project will develop new bio-inoculant strains and technologies for restoring the soil health in the state.
TNAU introduced a new non-basmati rice variety called CO58 as a potential substitute for PUSA 1121, specifically suitable for preparing biryani and pulao. What implications might this have for the future of India?
At present only geographically indicated states like the Union Territory of J&K and states of Himachal Pradesh, Punjab, Haryana, Delhi, Uttarakhand and western Uttar Pradesh can only grow basmati rice. Southern farmers and traders don’t have any choice of long slender varieties for export. They focus mainly on short and medium slender rice. The release of CO 58 has provided an opportunity for the southern farmers to grow a long slender biryani rice for the export market.
Farmers have reported a decline in vegetable cultivation within the state. What factors have contributed to this decrease in cultivation in Tamil Nadu? What measures should be implemented to address this issue?
The area under vegetable cultivation is slightly reduced from 3.77 lakh Ha during 2021-22 to 3.65 lakh ha during 2022-23. This may be due to erratic changes in climatic conditions, drought, and diseases. Also, high input costs are forcing the farmers to follow inadequate use of inputs thereby reducing the yield. In addition to the scarcity of skilled labour resources due to migrations, monopoly cultivation of specific vegetable crops leads to either market glut/ yield loss due to severe pest and disease occurrence. These all can be reasons for the decline of vegetable cultivation in Tamil Nadu.
To promote vegetable cultivation in the state, TNAU recommends precision farming technologies, farm mechanisation, irrigation automation, fertigation automation, demand-driven farming, post-harvest management, consolidation of farm produce and market through FPOs and drought mitigation technology in vegetable cultivation.
Since 2007, how many entrepreneurs have been created by the TNAU through Agri-Business Development (ABD)? In what ways does ABD benefit graduates?
Since 2007, TNAU has developed 1,417 incubates, 855 entrepreneurs and 111 startups. The ABD encourages graduates, youth, farmers and women to make use of the services provided by the directorate to realise their vision in life. People with an inclination to innovate, start new agribusinesses, and expand existing businesses could approach the directorate of ABD for mentoring, support and business services.
The graduates can make use of the Agri-Business Directorate activities conducted every year including Ideathon challenges for bringing out the entrepreneurial talents of the students of TNAU, Skill development training programmes and Students’ internships and startup programs. DABD organises guest lectures, workshops, certificate courses, exposure visits and business simulation games for students and motivates them to pursue their dream. Experiential learning courses on digital marketing and agricultural export management are offered to undergraduate students.