Comparative assessment of integrated crop management and natural farming on growth, yield components, dry matter production and nutrient dynamics of paddy (Oryza sativa L.)

Introduction

Rice (Oryza sativa L.) is the primary staple food crop for more than half of the global population, particularly in Asia, where it provides the bulk of daily caloric intake (Khush, 2005, Anantha et al., 2024) [12,1] . India is one of the world's leading rice producers, with paddy cultivation covering approximately 44 million hectares annually (FAOSTAT, 2022) [5] . In Telangana and other rice-growing states of India, paddy forms the backbone of agricultural economy and food security (TNAU, 2020) [23] . Conventional agriculture, driven by the Green Revolution's paradigm, relies heavily on synthetic chemical inputs including inorganic fertilizers, pesticides, and herbicides. While this approach has delivered impressive yield gains, it has simultaneously contributed to soil health degradation, groundwater contamination, greenhouse gas emissions and declining farm profitability due to escalating input costs (Tilman et al., 2002, Chaitanya et al., 2017) [22, 3] . These concerns have prompted renewed interest in alternative farming systems that prioritize ecological sustainability. Natural Farming (NF), rooted in the philosophy of Masanobu Fukuoka (1978) [6] and popularized in India through the Zero Budget Natural Farming (ZBNF) framework advocated by Subhash Palekar, seeks to eliminate synthetic inputs entirely. NF relies on biologically active preparations such as Jeevamrutha (fermented microbial inoculant), Bijamrutha (seed treatment) and Mulching to promote soil microbial activity, nutrient cycling and plant health (Chaitanya et al., 2026) [4] . Proponents claim that NF can sustain adequate yields while dramatically reducing input costs and improving long-term soil fertility. Integrated Crop Management (ICM), on the other hand, represents a science-based approach that combines optimal use of chemical fertilizers with good agronomic practices to maximize productivity and efficiency. ICM integrates soil health management, balanced fertilization based on recommended doses and judicious pest and disease management (Pretty, 2007) [18] . ICM is presently the dominant recommended package of practices in most rice-growing regions of India. Despite growing policy interest in NF exemplified by Andhra Pradesh's large-scale ZBNF promotion comparative, field-level scientific data on crop performance between NF and ICM remain limited (Khadse et al., 2017) [11] . Most evaluations of NF in peer-reviewed literature either lack rigorous experimental controls or are confined to short durations. Therefore, a rigorous, farmer-field-based comparative assessment is imperative to generate evidencebased insights for policymakers, extension workers and farmers. The present study was designed to compare the growth parameters, yield attributes, dry matter accumulation and nutrient (N, P, K) content and uptake of paddy under ICM and NF during Kharif 2021, using a paired farmer-field approach.

Materials and Methods

Experimental Site and Design

The present study was conducted at the Regional Agriculture Research Station, Jagtial (18 0 45 ' N, 78 0 45 ' E, 71 m above sea level), Telangana state, semi-arid eco-region of India during Kharif 2021 at eight plots. Plots were selected in pairs: one managed under ICM and one under NF with comparable soil type, irrigation source and rice variety. The experimental design was a randomized paired-field layout with eight replications (n = 8 per treatment).

Crop and Field Management

In ICM fields, recommended agronomic practices were followed as per PJTSAU guidelines: transplanting of 25day-old seedlings at 20 cm × 15 cm spacing and application of fertilizers at 120:60:40 kg ha -1 of N:P₂O₅: K₂O in split doses. Pest and disease management was carried out using chemical pesticides when threshold levels were crossed. Natural Farming fields followed the seed treatment with Bijamrutha, soil application of Jeevamrutha at 200 L ha⁻¹ fortnightly and mulching with crop residues. No synthetic fertilizers, pesticides or herbicides were used. Transplanting was done at similar spacing as ICM.

Observations and Measurements

Growth parameters including plant height (cm) and number of tillers per hill were recorded at 30, 60, and 90 DAT. Yield attributes including panicle length (cm), number of grains per panicle, and number of panicles per hill were recorded at maturity. Dry matter production (kg ha⁻¹) was estimated by sampling five hills per field at 30, 60, and 90 DAT, oven-drying at 65 °C to constant weight, and extrapolating to hectare basis. Grain and straw yield (kg ha⁻¹) were recorded at harvest.

Nutrient Analysis

Plant samples (shoots) at 30 DAT, 60 DAT, and at harvest (straw and grain separately) were analyzed for nitrogen (N) by the Kjeldahl method (Bremner and Mulvaney, 1982) [2] , phosphorus (P) by the vanadomolybdophosphoric acid spectrophotometric method and potassium (K) by flame photometry, following standard procedures (Jackson, 1973; Piper, 1966). Nutrient uptake (kg ha⁻¹) was calculated as: Nutrient uptake (kg ha⁻¹) = Nutrient content (%) × Dry Matter or yield (kg ha⁻¹)/100

Statistical Analysis

Data were subjected to Student's paired t-test to evaluate the significance of differences between ICM and NF at each growth stage (p<0.05). Means and standard errors were calculated for each treatment.

Results

Plant Height

Plant height under ICM was consistently and significantly greater than under NF at all three growth stages (Table 1). At 30 DAT, mean plant height in ICM plots was 54.4 cm compared to 46.8 cm in NF plots (p = 0.00001). The difference widened progressively through the crop growth period at 60 DAT, the respective values were 93.9 cm and 77.3 cm and at 90 DAT, 95.2 cm and 79.6 cm. The highly significant p-values (< 0.05 at all stages) confirm that ICM promoted superior vegetative growth due to assured, balanced nutrition from inorganic fertilizers.

Number of Tillers per Hill

Tiller production showed a more complex pattern (Table 2). At 30 DAT, ICM plots produced a mean of 17.2 tillers per hill while NF plots had 13.0 tillers per hill (p = 0.000284).

However, by 60 DAT, ICM plots recorded significantly higher tillering (17.0 tillers/hill) compared to NF (13.7 tillers/hill; p = 0.019706). At 90 DAT, ICM averaged 7.8 effective tillers/hill versus 4.4 in NF (p = 0.006307).

Yield Attributes

Panicle length, grains per panicle and panicles per hill at harvest (90 DAT) all favored ICM over NF (Table 3). Mean panicle length was 22.8 cm under ICM versus 20.8 cm under NF (p = 0.001839). The number of grains per panicle was markedly higher under ICM (98.8) compared to NF (66.9; p = 0.001168). Panicles per hill at 60 DAT were significantly higher under ICM (5.9 vs. 4.4; p = 0.006078), while panicles per hill at 90 DAT showed no statistically significant difference between systems (8.9 in ICM vs. 6.6 in NF; p = 0.17094). The higher number of filled grains per panicle under ICM is directly attributable to better assimilate supply during reproductive growth enabled by balanced inorganic nutrition.

Dry Matter Production

Dry matter production was substantially higher under ICM at all growth stages (Table 4). At 30 DAT, mean dry matter production under ICM (4864 kg ha⁻¹) was more than double that of NF (2379 kg ha⁻¹; p = 0.00031). This differential widened at 60 DAT (5674 kg ha⁻¹ in ICM vs. 3068 kg ha⁻¹ in NF; p = 0.00001) and at 90 DAT (9921 kg ha⁻¹ in ICM vs. 4969 kg ha⁻¹ in NF; p = 0.00001). Dry matter accumulation is a reliable integrative indicator of photosynthetic capacity, source strength, and nutrient availability. The superior dry matter production under ICM reflects the sustained and balanced nutrient supply from inorganic fertilizers ensuring maximum leaf area index and photosynthate partitioning.

Grain and Straw Yield

Both grain and straw yield were significantly higher under ICM than NF (Table 5). Mean grain yield under ICM was 4265 kg ha⁻¹, which was approximately 47.6% higher than NF (2233 kg ha⁻¹; p = 0.00001). Similarly, straw yield under ICM (5656 kg ha⁻¹) was significantly greater than NF (3025 kg ha⁻¹; p = 0.00001). The grain yield gap of approximately 2032 kg ha⁻¹ between ICM and NF is economically substantial. The lower grain yield in NF fields is consistent with the limited availability of easily plant-available nutrients, particularly nitrogen, during the critical stages of panicle initiation, anthesis and grain filling.

Nutrient Content

Nitrogen content of paddy plants was higher under ICM at all crop stages (Table 6). At 30 DAT, N content was 1.10% (ICM) vs. 1.00% (NF). At 60 DAT it was 0.92% (ICM) vs. 0.80% (NF), and in straw at harvest 0.58% (ICM) vs. 0.48% (NF). Grain N content at harvest was 0.88% (ICM) vs. 0.81% (NF). Phosphorus content was also higher under ICM across all stages, while K content showed minor differences, being marginally higher under NF at 30 DAT (1.67% vs. 1.64%) but lower at subsequent stages. These patterns align with the higher crop biomass and larger nutrient sink under ICM.

Nutrient Uptake

The total nutrient uptake (N, P, and K) by the paddy crop was markedly higher under ICM at all crop stages and in grain (Table 7). At 30 DAT, N uptake was 50.91 kg ha⁻¹ under ICM versus 23.89 kg ha⁻¹ under NF. By 60 DAT, N uptake increased to 53.73 kg ha⁻¹ (ICM) and 24.82 kg ha⁻¹ (NF). Straw N uptake at harvest was 32.70 vs. 14.44 kg ha⁻¹, and grain N uptake was 37.48 vs. 17.95 kg ha⁻¹ for ICM and NF respectively. The pattern was similar for P and K uptake, with ICM consistently recording approximately double the nutrient uptake compared to NF. This higher nutrient uptake in ICM is a direct consequence of greater dry matter accumulation and higher concentrations in plant tissue, together reflecting superior nutrient use efficiency when adequate nutrients are supplied.

Discussion

The results of this study demonstrate that ICM significantly outperforms NF on paddy growth, yield, and nutrient dynamics over a single Kharif season. The marked advantage of ICM in plant height, dry matter production, and grain yield is consistent with the well-established role of nitrogen as the most yield-limiting nutrient for rice (Peng et al., 1996). Applied N under ICM at 120 kg ha⁻¹ would be expected to drive greater leaf area development, chlorophyll content, and photosynthetic rate, ultimately translating into superior biomass accumulation and grain filling. The approximately 47.7% yield gap (4265 kg ha⁻¹ in ICM vs. 2233 kg ha⁻¹ in NF) is nearer to some comparisons reported in the literature. Khadse et al. (2017) [11] documented that ZBNF yields ranged from 60-90% of conventional yields, particularly in the short term. Our findings are in agreement with studies that show significant yield depression in fully organic or natural farming systems in the absence of external nutrient inputs in the short term (Gomiero et al., 2011; Seufert et al., 2012) [8,21] . The nutrient uptake data reveal that ICM crops took up approximately twice as much N, P, and K at each growth stage compared to NF crops. This large difference confirms that NF crops were operating under significant nutrient deficiency stress. The Jeevamrutha-based biological inputs used in NF can stimulate microbial activity and nutrient mineralization, but the rate of nutrient release from organic substrates is typically slow and often insufficient to meet crop demand at peak growth stages, especially during panicle initiation and grain filling (Ju et al., 2009; Ladha et al., 2005) [10,13] . The higher tiller number under NF at 30 DAT merits discussion. Initial tillering in rice is driven by the availability of carbohydrates and a moderate N supply. Under NF, the application of Jeevamrutha at transplanting may have temporarily enhanced N mineralization, providing adequate early-stage nutrition. However, the sharp decline in NF tiller numbers at 60 and 90 DAT suggests that this early benefit was not sustained, likely due to insufficient nutrient supply during the active tillering and panicle development phases. The findings of this study must be interpreted within the context of a single-season, cross-sectional comparison. It is important to acknowledge that NF systems are typically designed to transition over multiple years, during which soil microbial biomass, organic matter, and biological nutrient cycling capacity are expected to improve progressively (Reganold and Wachter, 2016) [20] . Long-term studies comparing ICM and NF may reveal narrowing of the yield gap as soil health improves under NF. Furthermore, NF's potential advantages in reduced input costs, improved soil biological health, and lower environmental footprint need to be systematically quantified over multiple cropping seasons (Lori et al., 2017; Gattinger et al., 2012) [14,7] .

Conclusions

This study provides robust field-based evidence that Integrated Crop Management significantly outperforms Natural Farming on all measured parameters of paddy productivity during Kharif 2021 in Telangana, India. ICM recorded 47.6% higher grain yield, 46.5% higher straw yield, more than double the dry matter production, and consistently higher NPK content and uptake compared to Natural Farming. The highly significant differences (p<0.05) at all growth stages confirm the superiority of ICM in meeting crop nutrient demands in the short term. While NF shows initial promise in early tillering and may offer long-term ecological benefits, a single-season assessment cannot fully capture the transitional dynamics of NF systems. Long-term, multi-season studies are recommended to assess the sustainability and productivity trajectory of NF relative to ICM, alongside comprehensive economic and environmental analyses.

References

1. Anantha KC, Penjarla R, Challa VR, Bairi R, Kurella CS, Gokenapally S, et al. Phosphorus transformation and balancing under a long-term rice-rice cropping system in an inceptisol of India. Journal of Plant Nutrition. 2024;47(18):3035-3050.
2. Bremner JM, Mulvaney CS. Nitrogen-total. In: Page AL, editor. Methods of Soil Analysis. Part 2: Chemical and Microbiological Properties. Madison, WI: American Society of Agronomy; 1982. p. 595-624.
3. Chaitanya AK, Mandal B, Hazra GC, Bandyopadhyay PK, Pramanik M. Effect of long-term use of different source of organics on soil aggregate fractions. International Journal of Pure and Applied Biosciences. 2017;5(4):1368-1375.
4. Chaitanya A, Ravi PK, Reddy CV, Omprakash S, Balram N. Influence of organic, inorganic and integrated nutrient management on productivity, nutrient uptake and soil biological properties of sesame. International Journal of Environment and Climate Change. 2026;16(4):87-95.
5. FAOSTAT. Food and Agriculture Organization Corporate Statistical Database. Rome: Food and Agriculture Organization of the United Nations; 2022. Available from: FAOSTAT.
6. Fukuoka M. The One-Straw Revolution: An Introduction to Natural Farming. Emmaus, PA: Rodale Press; 1978.
7. Gattinger A, Muller A, Haeni M, Skinner C, Fliessbach A, Buchmann N, et al. Enhanced top soil carbon stocks under organic farming. Proceedings of the National Academy of Sciences USA. 2012;109(44):1822618231.
8. Gomiero T, Pimentel D, Paoletti MG. Environmental impact of different agricultural management practices: Conventional vs. organic agriculture. Critical Reviews in Plant Sciences. 2011;30(1-2):95-124.
9. Jackson ML. Soil Chemical Analysis. New Delhi: Prentice Hall of India; 1973.
10. Ju XT, Xing GX, Chen XP, Zhang SL, Zhang LJ, Liu XJ, et al. Reducing environmental risk by improving N management in intensive Chinese agricultural systems. Proceedings of the National Academy of Sciences USA. 2009;106(9):3041-3046.
11. Khadse A, Rosset PM, Morales H, Ferguson BG. Taking agroecology to scale: The Zero Budget Natural Farming peasant movement in Karnataka, India. Journal of Peasant Studies. 2017;45(1):192-219.
12. Khush GS. What it will take to feed 5.0 billion rice consumers in 2030. Plant Molecular Biology. 2005;59(1):1-6.
13. Ladha JK, Pathak H, Krupnik TJ, Six J, van Kessel C. Efficiency of fertilizer nitrogen in cereal production: Retrospects and prospects. Advances in Agronomy. 2005;87:85-156.
14. Lori M, Symnaczik S, Mäder P, De Deyn G, Gattinger A. Organic farming enhances soil microbial abundance and activity-A meta-analysis and meta-regression. PLOS ONE. 2017;12(7):e0180442.
15. Peng S, Cassman KG, Virmani SS, Sheehy J, Khush GS. Yield potential trends of tropical rice since the release of IR8 and the challenge of increasing rice yield potential. Crop Science. 1999;39(6):1552-1559.
16. Peng S, Garcia FV, Laza RC, Sanico AL, Visperas RM, Cassman KG. Increased N-use efficiency using a chlorophyll meter on high-yielding irrigated rice. Field Crops Research. 1996;47(2-3):243-252.
17. Piper CS. Soil and Plant Analysis. Bombay: Hans Publishers; 1966.
18. Pretty J. Agricultural sustainability: Concepts, principles and evidence. Philosophical Transactions of the Royal Society B: Biological Sciences. 2007;363(1491):447-465.
19. Pretty J, Benton TG, Bharucha ZP, Dicks LV, Butler Flora C, Godfray HCJ, et al. Global assessment of agricultural system redesign for sustainable intensification. Nature Sustainability. 2018;1(8):441446.
20. Reganold JP, Wachter JM. Organic agriculture in the twenty-first century. Nature Plants. 2016;2(2):15221.
21. Seufert V, Ramankutty N, Foley JA. Comparing the yields of organic and conventional agriculture. Nature. 2012;485(7397):229-232.
22. Tilman D, Cassman KG, Matson PA, Naylor R, Polasky S. Agricultural sustainability and intensive production practices. Nature. 2002;418(6898):671-677.