Assessing the Impact of Natural Farming Practices on Quality Parameters of Cotton (Gossypium hirsutum)

Cotton plays a vital role in agriculture and the textile industry and secures livelihoods of over 250 million people. In India, cotton cultivation occupies  the largest area globally, accounting for 25% of cotton area (Muthukrishnan et al., 2017). During 2022-23, India’s cotton production spanned about 130.49 lakh ha, yielding 337 lakh bales with a productivity of 439 kg ha^-1 (Indiastat, 2023). Though the adoption of synthetic agrochemicals and high-yielding  varieties during the green revolution increased cotton production but resulted in soil degradation, reduced water systems and fertility decline in traditionally cotton-growing regions (Kumar et al., 2022). As people become more aware of the dangers of pesticides and hazardous chemicals, there is a rising demand for organic products. Green manures and organic additions should be used to promote long-term soil health. India takes the lead in organic cotton cultivation, emphasizing diverse and sustainable ecosystems. Key practices include the use of organic manures, Beejamirit, Ghanajeevamirit, Jeevamirit, vermicompost, intercropping with green manures, crop rotation, bio-fertilizers, bio-pesticides and botanicals. Global organic cotton production in 2015-16 reached 1.08 lakh tonnes, with India, China, Kyrgyzstan, Turkey and the United States as the top five producers, yielding 60184, 14187, 7981, 7577 and 4524 tonnes respectively (Mageshwaran et al., 2019).
       
Since 2016, the US, India and Brazil dominated global cotton production and exports, with respective exports of 3.8, 1 and 2.1 Mt in 2020. Conversely, China, Vietnam and Bangladesh were top importers, with imports of around 2.2, 1.4 and 1.2 Mt in the same year. Europe and the US anticipate a post-COVID sustainable clothing surge, while India witnesses growing demand for eco-friendly cotton. The projected worldwide cotton production aims for 13 Mt by 2025. In 2020, 11% of the textile industry incorporated certified organic cotton, with leading firms using 0.84 Mt of cotton lint. About 85% (0.72 Mt) of total cotton consumed was sustainably sourced, influenced by the rising trend of sustainable cotton sourcing (Voora et al., 2020). Scientists globally study cotton to develop high-yield, quality varieties for the textile industry. In this article, organic, natural and integrated agricultural practices are examined in relation to the important fiber quality metrics of length, strength, fineness, uniformity ratio and micronaire value.

The field experiments were conducted at Tamil Nadu Agricultural University, Coimbatore (11°N latitude, 77°E longitude, 426.7 m altitude) in sandy clay loam soil. Initial soil analysis showed low available nitrogen (213 kg ha^-1), medium available phosphorus (16 kg ha^-1) and high available potassium (886 kg ha^-1). Cotton variety CO 17 was chosen and its quality was evaluated for two years (2021-22 and 2022-23). The experiment was set up in a randomized complete block design with 9 treatments and 3 replications. The treatments are as follows.
 
Treatment details
 
T₁:   Control (No input addition except manual weeding).
T₂:   Complete natural farming (NF) practices (Bijamirit + Ghanajeevamirth + Jeevamirth + mulching + Intercropping + Whapasa).
T₃:   Natural farming practices 1 (without Bijamirt + Ghana jeevamirth + Jeevamirth).
T₄:   Natural farming practices 2 (without crop residue mulching).
T₅:   Natural farming 3 (without intercropping). 
T₆:   Natural farming 4 (without whapasa).
T₇:   Organic farming (OF) practices (5 t ha^-1 FYM + 2.5 t ha^-1 Vermicompost).
T₈:   Integrated crop management (ICM) (50 % organic + 50% inorganic with bio-pesticide).
T₉:   Integrated crop management (ICM) (50 % organic + 50% inorganic with chemical pesticide).
       
The treatments T₈ and T₉ were maintained separately, adjacent to the Organic and Natural farming area, with a plot size of 12 m × 8.4 m. Table 1 displays the nutrient content and applied quantity of manures.


 
Crop cultivation practices
 
Natural farming
 
According to Palekar (2006), cow-based organic formulations (Beejamirit, Ghanjeevamrit and Jeevamirit) were used in Natural farming plots. Ghanjeevamrit was incorporated before sowing at a rate of 250 kg ha^-1. Jeevamrit was applied twice a month at a rate of 500 l ha^-1 through irrigation water. Beejamirit was used for seed treatment. Green gram (cv. DGGV 2) intercrop sown between cotton rows. No weeding in natural farming plots. Mulching @ 5 t ha^-1 with millet straw was done immediately after sowing. Alternate row and furrow irrigation (Whapasa) method was adopted. Ecological engineering method used for plant protection, including cowpea as border/trap crop and Organic pesticide (3 G) applied as a foliar spray.
 
Organic farming and integrated crop management
 
 Seeds treated with Trichoderma viride (5 g kg^-1) and Bacillus subtilis (5 g kg^-1). Cotton seeds were dibbled with specific spacing (60 × 15 cm) and seed rate (15 kg ha^-1). Pre-emergence herbicide of pendimethalin @ 1.0 kg ha^-1 was applied in an integrated plot followed by hand weeding @ 40 DAS. Manual weeding was done twice on 20 and 40 DAS was performed as per treatments. Irrigation was given at intervals with a withholding period. Cowpea was used as a trap crop for T₇ and T₈. Pest repellent (3G extract spray) was used for T₈. Yellow sticky traps, Pheromone traps (12 No’s ha^-1) and neem oil (3%) was sprayed to control pests and TNAU Panchagavya (3%) spray was used for growth promotion in organic farming plots. Seed cotton yield was determined by weighing mature kapas collected plot-wise. All these practices were followed for two years.
 
Data collection and fiber quality analysis
 
Kapas sample were collected from each plot, weighing 100 seed cotton. Laboratory gin was used to separate seeds and lint. Seed yield and lint yield were determined. According to Santhanam (1976), Ginning percentage was calculated.
                
The cotton fiber analyzer available at the Department of Cotton, TNAU, Coimbatore was used for cotton quality analysis and a 100 g fiber sample was enough to generate reports on various quality parameters. A single operator can finish testing in a matter of seconds. The data were statistically analyzed using R Software (Gopinath et al., 2021) with the grapesAgri1 package, Version 1.0.0.

The data collected from the two years of research on assessing the impact of natural farming practices on quality parameters of cotton were presented and discussed on aspects like cotton yield and quality parameters.
 
Yield
 
Natural farming practices significantly affected seed cotton yield (Fig 1a and 1b). Integrated Crop management (T₈) practice showed the highest yields of 2178 and 2232 kg ha^-1 in 2021-22 and 2022-23, respectively. These treatments outperformed effects of organic and natural farming inputs like jeevamirit, beejamirit and ghanajeevamirit. Organic farming practices achieved yields of 1695 and 1768 kg ha^-1 in 2021-22 and 2022-23, respectively, next to ICM practices. Complete natural farming (T₂) consistently achieved the highest seed cotton yield in both years. The trend was also observed in seed yield and lint yield, as shown in Table 2. Previous studies (Sahito et al., 2016; Yaqoob et al., 2016) indicated that a strong positive correlation between lint yield and fiber fineness and Velmurugan et al., (2022) found that Panchagavya, Trichoderma viride and water (control) treatments influenced SVPR 2 cotton seed yield and quality and improved lint quality. As regards ICM, it combines inorganic fertilizer and organic manures to enhance yield and  synchronizes crop nutrient demand with soil nutrient release, minimizing losses through leaching, runoff, volatilization and immobilization (Tarfeen et al., 2023) while  lower yields in recommended dose nutrient application with organic manure compared to ICM and OF due to slow nutrient release was reported by  (Mishra and Chaturvedi, 2023). The yield gap between chemical fertilizers, organic manures and natural farming practices decreased from the second year onwards which may be  attributed to gradual nutrient release from organic manures, as seed cotton yield was strongly correlated with lint yield, while lint yield showed a strong positive correlation with lint percentage (Desalegn et al., 2009).
 

 

 
Quality characters
 
Fiber quality is crucial to technology acceptance. Considering all parameters is essential to ensure fiber quality as it affects prices apart from Productivity. However, farming practices showed no significant variations in fibre qualities of cotton (Table 2 and 4).
 
Ginning percentage
 
Natural farming methods did not significantly differ in the ginning percentage, according to the experiments (Table 2). Bharathi et al., (2018) and Muthukrishnan et al., (2017) made comparable observations, finding that the ginning percentage values were marginally higher with fertilizer management approaches than the no manure treatment in both years. According to earlier studies (Monicaa et al., 2020; Tariq et al., 2018), fertilizer amounts did not affect the proportion of cotton that was ginned.
 
Upper half mean length
 
The UHML is a crucial quality parameter in cotton fiber that determines the spinning value. Cotton fiber development occurs in four phases: initiation, elongation, secondary deposition and maturation. There was no significant difference in UHML among different farming practices (Fig 2). The UHML values ranged from 25.50 to 28.89 mm for 2021-22 and 23.6 to 26.9 mm for 2022-23 (Table 4). Barotova et al., (2023), UHML had classified 9 types (1a, 1b, 1, 2, 3, 4, 5, 6, 7) as depicted in Table 3. The CO 17 variety falls under types 4 to 7, indicating it is a medium staple length and it was confirmed by Gunasekaran et al., (2020) with recorded values of 26.9 and 27.6 g/tex. Different fertilizer levels had no impact on fiber quality, consistent with findings by Bharathi et al., (2018); Tariq et al., (2018). Sankaranarayanan et al., (2018) observed that varying fertilizer levels and planting systems did not significantly affect fiber length. Since quality parameters are primarily determined by genetics and minimally influenced by management practices, there were no significant differences, as supported by Gacche and Gokhale (2018); Xu et al., (2023).
 

 

 

 
Fiber strength (Str)
 
Fiber strength plays a crucial role in determining the durability and resilience of cotton textiles during processing. It remained unaffected by organic, natural and integrated farming practices in both years (Fig 2). The values ranged from 22.1 to 27.1 g/tex for 2021-22 and 23.0 to 29.5 g/tex for 2022-23, as shown in Table 4. Similar findings were reported by Gunasekaran et al., (2020); Velmurugan et al., (2022). Fiber strength was not influenced by different nutrient doses, as supported by Bharathi et al., (2018); Tariq et al., (2018) ; Gacche and Gokhale (2018); Sankaranarayanan et al., (2018). Strong cotton fibers yield robust yarns and fabrics, enhancing spinning efficiency. Longer and finer fibers generally result in stronger yarns, whereas shorter and coarser fibers are weaker and prone to breakage. Hence, cotton fibers with higher strength are deemed superior in quality and preferred for textile manufacturing (Desalegn et al., 2009).
 
Uniformity index (Unf)
 
Uniformity Index is vital for assessing cotton fiber quality as it indicates the consistency of fiber length within a sample. Length uniformity directly influences spinning efficiency, yarn uniformity and yarn strength, reflecting the level of consistency within a sample (Desalegn et al., 2009). However, in this study, there were no significant differences observed in the Uniformity Index among the treatments for both years (Table 4). A higher uniformity index ensures consistency in yarns and fabrics during textile production. Varying nutrient doses did not impact the quality parameter of uniformity ratio, which is consistent with findings reported by Bharathi et al., (2018); Sankaranarayanan et al., (2018); Tariq et al., (2018).
 
Fiber elongation (Elg)
 
Factors like fiber maturity, fineness and moisture content play a role in cotton fiber elongation, but it was not influenced by different management practices. The values for elongation remained consistent between 5.5% and 6.1% in both years (Table 4). Higher fiber maturity typically leads to lower elongation, while finer fibers exhibit higher elongation. Moisture content also affects elongation, with dry fibers having lower elongation compared to moist fibers. Hulihalli and Patil (2008) found that different fertilizer levels did not significantly affect fiber elongation.
 
Fiber fineness
 
Fiber fineness refers to the diameter of cotton fibers, which is crucial for determining appearance, strength and processing characteristics as endorsed by Desalegn et al., (2009). However, farming practices did not affect fiber diameter. However, the Fineness values ranged from 144 to 188 d/tex in 2021-22 and 108 to 125 d/tex in 2022-23 (Table 4). Finer fibers with smaller diameters are preferred for high-quality apparel and fine fabrics, resulting in softer and more uniform textiles. Coarser fibers with larger diameters are suitable for heavy-duty applications like denim, providing strength. Both planting geometries (Gacche and Gokhale, 2018) and varying nutrient doses (Ahmad and Raza 2014) had no impact on fiber fineness.
 
Micronaire (Mic)
 
Micronaire values can range from 2.5 to 7.5, with lower values indicating finer and more matured fibers, while higher values suggest coarser and less mature fibers. In this study, the Micronaire value  ranged from 4.52 to 5.50 µg/inch in 2021-22 and for 2022-23, it was 4.15 to 5.66 µg/inch (Table 4). While, Gunasekaran et al., (2020) recorded Micronaire values of 4.3 and 4.4 µg/inch for the Cotton variety (CO 17) from different trial locations. This parameter also did not influence by different nutrient doses as supported by the findings of Bharathi et al., (2018); Sankaranarayanan et al., (2018); Tariq et al., (2018).

Two-year field experiments showed that natural farming, organic farming and integrated crop management had no discernible impact on the quality of cotton fiber. Integrated plots yielded more and had the same fiber quality as that of organic and natural farming, indicating that sustainable production of high-quality fiber is possible.

The Department of Agronomy and Nammazhvar Organic Farming Research Centre at TNAU in Coimbatore provided technical assistance, lab facilities for our research, for which the authors are thankful.

There will be no conflicts of interest when this article is published.