Farmer’s response under conventional system and alternate wetting and drying method of paddy cultivation in Karnataka: From flooded fields to sustainable yields

Introduction

Rice (Oryza sativa L.) is a central staple and livelihood crop across India and its production systems exert a major influence on regional water demand, input use and greenhouse-gas emissions (FAO, 2023). Irrigated rice in India occupied roughly 47.8 million hectares and produced about 137.8 million tonnes in the 2023-24 crop year (USDA FAS, 2024). Conventional system of paddy fields, maintaining a standing water layer for most of the crop season, remains the dominant practice in many rice landscapes because it suppresses weeds, moderates the crop microclimate and is well-understood by farmers (Bouman et al., 2007) [4] . However, continuous flooding is highly water-intensive, can accelerate groundwater depletion in water-stressed regions and sustains anaerobic soil conditions that favor methane production and alter nutrient dynamics (Chapagain and Hoekstra, 2011) [11] . These environmental and resource pressures have increased interest in water-saving rice management options that are practical and acceptable to farmers (Carrijo et al., 2017) [5] . Alternate Wetting and Drying (AWD) is an intermittent irrigation strategy designed to reduce seasonal water use while maintaining or improving yield and reducing methane emissions (Bouman et al., 2007) [4] . Fields are typically allowed to drain until the water level drops to about 10 cm below the soil surface, monitored using simple perforated 'pani-pipes', before being reflooded. AWD introduces aerobic phases that improve root aeration and change redoxsensitive nutrient transformations (Belder et al., 2004) [3] . When implemented correctly, AWD can reduce irrigation volume and the number of irrigation events without significant yield penalties (Carrijo et al., 2017) [5] . Adoption of AWD in farmer fields depends as much on socioeconomic and institutional factors as on its agronomic benefits (Lampayan et al., 2015) [13] . Farmers' decisions are shaped by perceived yield risk, familiarity with traditional practices, availability and cost of irrigation (fuel or electricity), labour constraints, and varietal preferences. Limited awareness, uncertainty about implementation and local water-distribution rules can hinder uptake even where AWD offers clear water or cost savings (Lampayan et al., 2015) [13] . Conversely, evident cost savings and strong institutional support can increase farmer confidence and drive the long-term adoption of AWD practices.

Materials and Methods

A study was carried out in major paddy-growing areas of Harihar taluk in Davanagere district, Karnataka. A total of 150 farmers were selected, comprising 75 farmers each practicing conventional system and AWD method of paddy cultivation. The study aimed to document and compare farmer's responses on management practices under the two irrigation systems. Data where collected by personal interviews of paddy growers. Their responses were considered for the purpose of the study. The collected data were tabulated, analyzed and presented in tables for clear interpretation. Descriptive statistics, including mean, range and standard deviation, were calculated as per Sundararaj et al. (1972) [23] . A structured interview schedule was designed with questions on: 1. Variety adoption (number and percentage of farmers) 2. Seed rate (kg ha⁻¹) 3. Total nutrient input (N, P₂O₅, K₂O, S) 4. Number of irrigation days 5. Pesticide and fungicide applications (solid kg ha⁻¹ / liquid ml ha⁻¹) 6. Grain yield (q ha⁻¹)

Results and Discussion

Adoption of varieties

In conventional paddy cultivation, RNR-15048 was the dominant variety, accounting for 90 per cent of the area, followed by Annapoorna (5%), MS-2 (4%) and Nandyal Sona (1%) (Table 1). Under the AWD method, RNR-15048 remained prevalent, though reduced to 66%, while Nandyal Sona (17%), Sampath Gold (9%), Annapoorna (7%) and MS-2 (1%) showed increased adoption (Table 1). Farmers predominantly adopted improved medium-duration varieties, favouring RNR-15048 for its short cycle (120-125 days), blast resistance and high yields (Shankar et al., 2022) [21] . AWD adoption shifted toward waterefficient options like Nandyal Sona and Sampath Gold, mirroring trends in resource-conserving systems (Weerakoon et al., 2011) [26] , underscoring variety selection's role in enhancing resilience and efficiency.

Seed rate

The recommended seed rate for paddy is 25 kg acre⁻¹ (62.5 kg ha⁻¹). In conventional system, 84 per cent adhered to the recommended seed rate, while 16 per cent used higher rates (Table 2). Under AWD method, adherence was higher at 89 per cent, with 11 per cent exceeding the recommendation and none below it (Table 2). This elevated compliance, particularly in AWD, underscores effective extension services and awareness of optimal practices. Nonetheless, overuse in both systems (16% conventional, 11% AWD) signals lingering gaps from traditional habits or risk aversion (Pal et al., 2018) [16] . Targeted education on seed rate benefits for AWD-compatible varieties could enhance sustainability and full adoption.

Total nutrient application through inorganic fertilizers and organic manures

Major fertilizers included blends (16:20:0:13, 20:20:0:13, 20:20:0), DAP, urea, SSP, MOP and ZnSO₄, with FYM and sheep penning as primary organics. The nutrient application pattern exhibited notable variation between the conventional and AWD systems (Table 3). In the conventional system, the mean nitrogen application was 162.12 ± 26.15 kg ha⁻¹, ranging from 115 to 197.68 kg ha⁻¹, while phosphorus application averaged 157.27 ± 32.53 kg ha⁻¹ (range: 98.84-197.68). The corresponding mean potassium and sulphur applications were 37.00 ± 24.49 kg ha⁻¹ (0-75) and 42.76 ± 12.78 kg ha⁻¹ (0-55), respectively. Under AWD method, comparatively lower mean nutrient applications were observed, with nitrogen at 141.94 ± 26.73 kg ha⁻¹ (98.84-185.33), phosphorus at 126.70 ± 16.37 kg ha⁻¹ (100-185.33), potassium at 50.00 ± 4.49 kg ha⁻¹ (45-55) and sulphur at 33.47 ± 12.10 kg ha⁻¹ (0-40). Both systems exceeded recommendations (100:50:50 N:P₂O₅:K₂O ha⁻¹) by overapplying N and P for yield security (Mboyerwa et al., 2022) [14] . This overapplication of P persisted in AWD, driven by precautionary mindsets against deficiencies (Alam et al., 2023) [32] . Meanwhile, K and S often fell short due to inconsistent management practices (Dobermann et al., 1998) [7] . Sulphur deficiencies were exacerbated by gaps in extension support (Sachdev and Sachdev, 2002) [18] . Blends dominated, reflecting farmer's preferences for convenient formulations (Lakitan et al., 2018) [11] . Larger farms applied higher N rates, contributing to variability under flooding (Takeshima et al., 2015) [24] . This divergence was common among rice farmers applying NPK (Joshi, 1992) [9] . Organic use remained sporadic, limited by slow agronomic benefits (Khaliq et al., 2006) [10] . Rising labor costs reinforced reliance on synthetics for immediate yields (Rahaman et al., 2020) [18] , favoring quick gains over long-term soil health. 4). This 35 per cent reduction highlights AWD's water-saving potential without yield loss, aligning with reports of up to 30 per cent fewer irrigations while sustaining or boosting outputs (Omwenga et al., 2014) [15] . Optimized dry periods in AWD minimize percolation and enhance productivity (Sujono et al., 2011), promoting cost-effective, sustainable water management over traditional flooding. [12] . AWD altered pest dynamics, curbing populations and slashing liquid pesticide needs by up to 30 per cent through water-mediated control (Carrijo et al., 2017) [5] , advancing sustainable integrated pest management. [20] . AWD's drying intervals disrupted spore germination, narrowing disease complexes and slashing applications for precision control (Bouman et al., 2007) [

, fostering sustainable management.

Yield levels

Grain yields across varieties under conventional and AWD systems are shown in Table 7. Under conventional cultivation system, grain yield of paddy varieties varied considerably, with RNR-15048 recording from 38.92 to74.13 q ha⁻¹, Annapoorna from 49.42 to 57.82 q ha⁻¹, Nandyal Sona 54.03 q ha⁻¹ and MS-2 ranging from 49.42 to 61.28 q ha⁻¹, resulting in an overall mean yield of 52.54 ± 8.07 q ha⁻¹. In contrast, under AWD method, yield performance was markedly higher, with RNR-15048 ranging from 58.51 to 86.73 q ha⁻¹, Annapoorna from 67.61 to 81.54 q ha⁻¹, MS-2 from 61.16 to 93.90 q ha⁻¹ and Sampath Gold from 63.01 to 87.77 q ha⁻¹. The overall mean yield under AWD was 74.10 ± 8.05 q ha⁻¹, representing an approximate 41 per cent increase over the conventional system. AWD consistently boosted yields via enhanced root traits and phenology (Price et al., 2013) [17] . It yielded 5-12 per cent increases and water savings in Asian lowlands (Belder et al., 2004) [3] . Nitrogen synergies further amplified efficiency (Abid et al., 2022) [1] . They also boosted productivity (Mboyerwa et al., 2022) [14] , affirming AWD's role in sustainable intensification.

Conclusion

The study demonstrates that AWD method offers a sustainable, resource-efficient and yield-enhancing alternative to conventional system in paddy cultivation. Farmers adopting AWD practices showed significant improvements in water-use efficiency, input optimization and pest-disease management, without compromising productivity. The reduction in irrigation days by nearly one-third, coupled with a 15-41 per cent increase in grain yield, highlights AWD's potential to improve water-use efficiency while maintaining profitability. AWD displayed better adherence to optimal seed rates, improved choice of waterefficient varieties and reduced dependence on pesticides and fungicides. Overall, AWD-driven method represents a critical step toward sustainable rice intensification balancing ecological stewardship, input efficiency and economic viability.

References

1. Abid AA, Zhang Q, Adil MF, Batool I, Abbas M, Hassan Z, et al. Nitrogen optimization coupled with alternate wetting and drying practice enhances rhizospheric nitrifier and denitrifier abundance and rice productivity. Front Plant Sci. 2022;13:927229.
2. Alam MS, Khanam M, Rahman MM. Environment-friendly nitrogen management practices in wetland paddy cultivation. Front Sustain Food Syst. 2023;7:1020570.
3. Belder P, Bouman BAM, Cabangon R, Guoan L, Quilang EJP, Yuanhua L, et al. Effect of water-saving irrigation on rice yield and water use in typical lowland conditions in Asia. Agric Water Manage. 2004;65(3):193-210.
4. Bouman BAM, Lampayan RM, Tuong TP. Water Management in Irrigated Rice: Coping with Water Scarcity. Los Baños (Philippines): International Rice Research Institute (IRRI); 2007.
5. Carrijo DR, Lundy ME, Linquist BA. Rice yields and water use under alternate wetting and drying irrigation: a metaanalysis. Field Crops Res. 2017;203:173-181.
6. Chapagain AK, Hoekstra AY. The blue, green and grey water footprint of rice from production and consumption perspectives. Ecol Econ. 2011;70(11):749-758.
7. Dobermann A, Cassman KG, Mamaril CP, Sheehy JE. Management of phosphorus, potassium, and sulfur in intensive, irrigated lowland rice. Field Crops Res. 1998;56(1-2):113-138.
8. Food and Agriculture Organization (FAO). The Future of Food and Agriculture -Drivers and Triggers for Transformation. Rome: Food and Agriculture Organization of the United Nations; 2023.
9. Joshi DV. A Study on Paddy Cultivation Pattern by Tibetan Rehabilitants and Their Socio-Economic Characteristics, Mundgod Taluk, Karnataka. M.Sc. (Agri.) Thesis. Dharwad: University of Agricultural Sciences; 1992.
10. Khaliq A, Abbasi MK, Hussain T. Effects of integrated use of organic and inorganic nutrient sources with effective microorganisms (EM) on seed cotton yield in Pakistan. Bioresour Technol. 2006;97(8):967-972.
11. Lakitan B, Hadi B, Herlinda S, Siaga E, Widuri LI, Kartika K, et al. Recognizing farmers' practices and constraints for intensifying rice production at riparian wetlands in Indonesia. J Life Sci. 2018;85:10-20.
12. Lampayan RM, Palis FG, Flor RJ, Singleton GR. Impact of alternate wetting and drying (AWD) on rice pest and the environment. Phil J Crop Sci. 2016;41(1):65-72.
13. Lampayan RM, Rejesus RM, Singleton GR, Bouman BAM. Adoption and economics of alternate wetting and drying water management for irrigated lowland rice. Field Crops Res. 2015;170:95-108.
14. Mboyerwa PA, Kibret K, Mtakwa P, Aschalew A. Rice yield and nitrogen use efficiency with system of rice intensification and conventional management practices in Mkindo irrigation scheme, Tanzania. Front Sustain Food Syst. 2022;6:802267.
15. Omwenga KG, Mati BM, Home PG. Determination of the effect of the system of rice intensification (SRI) on rice yields and water saving in Mwea irrigation scheme, Kenya. J Water Resour Prot. 2014;6(10):895-901.
16. Pal G, Bhaskar KU, Kumar SJ, Sripathy KV, Agarwal DK. A study on sources and management of paddy seed in Eastern Uttar Pradesh, India. J Econ Manag Trade. 2018;21(7):1-7.
17. Price AH, Norton GJ, Salt DE, Ebenhoeh O, Meharg AA, Meharg C, et al. Alternate wetting and drying irrigation for rice in Bangladesh: Is it sustainable and has plant breeding something to offer? Food Energy Secur. 2013;2(2):120-129.
18. Rahaman A, Hasan MK, Islam MR. Factors affecting adoption of BRRI released Aus rice varieties in Mymensingh District. Int J Agric Econ. 2020;5(5):198-206.
19. Sachdev P, Sachdev MS. Role of sulphur in rice production. J Nucl Agric Biol. 2002;31(1):1-13.
20. Savary S, Willocquet L, Pethybridge SJ, Esker P, McRoberts N, Nelson A. The global burden of pathogens and pests on major food crops. Nat Ecol Evol. 2019;3(3):430-439.
21. Shankar M, Khan MA, Bharath T, Pallavi S, Himabindu T, Naaik RB, et al. Popularization of improved short duration rice variety Telangana Sona (RNR 15048) through frontline demonstrations in Nalgonda District, Telangana. J Crop Weed. 2022;18(3):206-212.
22. Sujono J, Matsuo N, Hiramatsu K, Mochizuki T. Improving the water productivity of paddy rice (Oryza sativa L.) cultivation through water saving irrigation treatments. Agric Sci. 2011;2(4):511-517.
23. Sundararaj N, Nagaraju S, Venkataramu MN, Jaganath MK. Designs and Analysis of Field Experiments. Bangalore (Karnataka): University of Agricultural Sciences; 1972.
24. Takeshima H, Adhikari RP, Poudel MN, Kumar A. Farm household typologies and mechanization patterns in Nepal Terai. IFPRI Discuss Pap. 2015;1-56.
25. USDA FAS. Grain and Feed Update: India. GAIN Report Number IN2024-0055. Washington (DC): USDA Foreign Agricultural Service; 2024.
26. Weerakoon WMW, Mutunayake MMP, Bandara C, Rao AN, Bhandari DC, Ladha JK. Direct-seeded rice culture in Sri Lanka: Lessons from farmers. Field Crops Res. 2011;121(1):53-63.