Effect of Bt cotton based cropping system and nutrient management to rabi crops on yield and economics of Bt cotton

Introduction

Cotton (Gossypium hirsutum L.) is a long duration crop hence double cropping can't be possible, however availability of early Bt cotton in the market, permits for growing of crops in sequence immediate after harvest of early Bt cotton. By cultivating the early Bt cotton hybrid, it becomes possible to harvest cotton early and permits for timely sowing of rabi crops Studies from different areas in India showed that diversified cotton production systems can surpass cotton monocropping systems in profitability (Saravanakumar, 2022) [1] and not only diversify risks but also increase productivity. Out of the of the total geographical area (328.7 m ha), nearly half is arable (159.7 m ha) and only 42.6% (about 140 m ha) is actually cultivated, that has remained static over decades, indicating no scope for horizontal expansion. Hence, in order to fulfil the demand of Indias growing population from limited resources, an increase in crop productivity is imperative (Gulati et al. 2023) [2] . An ideal cotton based cropping system should aim at higher yield and net profits per unit area, bring stability into the production system and ensure optimal utilization of the available resources. Research indicates that under cotton based cropping system there is efficient use of resources, resulting into high productivity. As such, cotton which is an exhaustive crop followed by wheat, chickpea, linseed and onion will be very useful for exploring the productivity and profitability of cotton based crop sequence under nutrient management levels to rabi crops for gaining extra economic returns.

Materials and Methods

A field experiment was carried out at Department of Agronomy, Dr. PDKV, Akola during 2020-21 and 2021-22 to study the various Bt cotton based cropping system with different fertilizers levels to rabi crops during both the years. The soil of the experimental field was medium black cotton belonging to vertisols, clayey in texture and slightly alkaline in reaction. The soil was low in organic carbon, low in available nitrogen and phosphorous and fairly rich in potassium. Total rainfall received during 2020-21 season was 771.6 mm (June to Dec 2020) and during the cropping season of 2021-22 was 1085 mm mainly concentrated in June, July, August and September. The experiment was laid out in split plot design with five main plot treatment comprising of crop sequence viz. sole Bt cotton, midlate duration (C 1 ), Bt-cotton (early duration)-Wheat (C 2 ), Btcotton (early duration)-Chickpea (C 3 ), Bt-cotton (early duration)-Linseed (C 4 ), Bt-cotton (early duration) -Onion (C 5 ), and sub plot treatments of nutrient management practices i.e. 75% RDF(N 1 ) and 100% RDF(N 2 ) to rabi crops replicated thrice. Cotton (Gossypium hirsutum L.) variety used for early duration was ACH-5 BG-II Bt (140-150 days) and medium duration was PDKV-JKAL 116 BG-II Bt (160-170 days). The recommended dose of fertilizers were applied to cotton and as per treatment to rabi crops. All the recommended practices and appropriate plant protection measures were adopted. Observations on seed cotton yield, lint yield, stalk yield, biological yield (kg ha -1 ) and harvest index (%) were recorded, from which gross monetary returns, net monetary returns (Rs. ha -1 ) and B:C ratio was calculated. Further analysis was carried out as per the procedure described by Panse and Sukhtame (1985) [3] .

Results and Discussion

Cotton yield (Table 1 and2

) Cropping system

The treatment C 1 , sole Bt cotton(mid-late) recorded significantly higher seed cotton yield (2058, 2110 and 2084 kg ha -1 ), lint yield (724, 743 and 734 kg ha -1 ), stalk yield (3327, 3481 and 3404 kg ha -1 ) and biological yield (5385, 5591 and 5488 kg ha -1 ) over all other treatments during both the years of experimentation and under pooled results. However, all the cropping system treatments were found significantly at par with each other in respect of seed cotton yield, lint yield, stalk yield and biological yield (kg ha -1 ) during 2020-21 and 2021-22. The increase in seed cotton yield (kg ha -1 ), lint yield, stalk yield and biological yield (kg ha -1 ) of C 1 , sole Bt cotton (mid-late) was due to more duration of variety up to January end, which leads more number of bolls picked plant -1 that helps in increased seed cotton yield plant -1 as well as ha -1 . However, all the cropping systems were at par with each other as the single variety was used for all the systems and were harvested at same time leading to no significant difference in seed cotton yield ha -1 . The results are in close agreement with the findings of Charjan and Gaikwad (2001) [4] , Gudadhe et al. (2015) [5] , Turkhede et al. (2017) [6] , Kumar et al. (2022) [7] and Latkar et al. (2024) [8] . The mean harvest index of cotton for the year 2020-21 and 2021-22 was 38.63 and 38.44 per cent, respectively, while the pooled mean of harvest index was over two years was 38.53 per cent. The treatment C 1 , sole Bt cotton (mid-late) recorded higher harvest index of 38.91, 38.84 and 38.87 during 2020-21, 2021-22 and under pooled results over all other treatments, The increase in harvest index of sole Bt cotton (mid-late) was due to longer duration of crop up to January end which increased the number of picking and seed cotton yield. The harvest index was recorded maximum during second year of study than first year of study. Where as all the cropping system treatments were found to be nearly equal in respect of harvest index during 2020-2021 and 2021-2022.

Nutrient Management

Nutrient management to rabi crops showed non-significant influence on seed cotton yield, lint yield, stalk yield and biological yield (kg ha -1 ) during 2020-21. Where as, during second year of study, residual effect of application of 100% RDF to rabi crops recorded significantly highest seed cotton yield (1928 kg ha -1 ), lint yield (703 kg ha -1 ), stalk yield (3100 kg ha -1 ) and biological yield (5028 kg ha -1 ) over 75% RDF application to rabi crops. Nutrient management to rabi crops had marked and favorable influence on growth and yield parameters. These favorable influence might be attributed to sustain release of nutrients in the soil through mineralization of organic matter that have facilitated better crop growth. That resulted on highest seed cotton yield and significantly highest lint yield and other parameters also. Similar results were reported by Kumbhar et al. (2008) [9] , Das et al. (2004) [10] , Mahavishnan et al. (2005) [11] , Senthivelu et al. (2009) [12] , Ramesh et al. (2017) [13] , Chaudhari et al. (2022) [14] , Sanjivkumar et al. (2022) [15] and Latkar et al. (2024) [8] . Residual effect of application of 100% RDF to rabi crops recorded marginal increase in harvest index over 75% RDF application to rabi crops during both the years of experimentation. Similar results were reported by Mahavishnan et al. (2005) [11] and Sanjivkumar et al. (2022) [15] .

Economics Cropping system (Table 3)

The gross monetary returns and net monetary returns of cotton were significantly influenced by different cropping systems during both the years and pooled analysis. Treatment C 1 -Sole Bt cotton mid-late recorded significantly higher gross monetary returns (113508, 127107 and 120308 Rs ha -1 ) and net monetary returns (67189, 79047 and 73118 Rs ha -1 ) as compared all other cropping systems during both the years of experimentation and pooled data. Where as, all the cropping systems treatments were at par with each other in respect of GMR, NMR during 2020-21 and 2021-22 and pooled analysis. The higher benefit cost ratio was obtained under C 1 -sole mid-late Bt cotton i.e. 2.45, 2.64 and 2.55 during 2020-21, 2021-22 and pooled data, respectively than all the other cropping systems. The increase in the GMR, NMR of (mid-late) cotton (C 1 ) and higher benefit cost ratio was due to higher yield of mid-late cotton than other Bt cotton in cropping systems. All the cropping systems were at par with each other as single variety was used in all the cropping systems. Similar results were reported by Turkhede et al. (2017) [6] , Muhammad et al. (2023) [16] and Latkar et al. (2024) [8] .

Nutrient management

Nutrient management to rabi crops showed non-significant differences on GMR, NMR during 2020-21. During the year 2021-22 residual effect of application of 100% RDF to rabi crops recorded significantly higher GMR (116182 Rs ha -1 ) and NMR (72238 Rs ha -1 ) of cotton over 75% RDF application. This might be due to residual effect of N and P applied to preceding rabi crops as well as nutrients available from crop residue which accounted for significant improvement in growth and yield of cotton crop. The results are in conformity with the findings of Charjan and Gaikwad (2001) [4] and Mahala (2019) [17] . As regards BC ratio of cotton, residual effect of application of 100% RDF (N 2 ) to rabi crops showed higher benefit cost ratio of 2.35, 2.64 and 2.50 during 2020-21, 2021-22 and in pooled data, respectively as compared to application of 75% RDF to rabi crops which recorded lower BC ratio during both the years and pooled data. This might be due to higher net monetary returns received due to maximum yield produced under 100% RDF than lower level of fertilizer. Similar results are reported by Charjan and Gaikwad (2001) [4] and Mahala (2019) [17] . The interaction effect between cropping system and nutrient management to rabi crops were not significant in respect of seed cotton yield, lint yield, stalk yield and biological yield' gross monetary returns, net monetary returns and BC ratio than all other cropping systems during both the years of experimentation and under pooled results over all other treatments.

Conclusion

Sole Bt cotton (mid-late) recorded significantly highest seed cotton yield, lint yield, stalk yield, biological yield and harvest index as well as GMR, NMR as compared to all other cropping systems during both the years and under pooled results. However, all the cropping systems were found significantly at par with each other in respect of above parameters. The higher BC ratio was obtained under sole mid-late Bt cotton. Nutrient management to rabi crops showed non-significant influence on above mentioned parameters during 2020-21. Residual effect of application of 100% RDF to rabi crops recorded significantly highest seed cotton, lint, stalk and biological yield GMR, NMR and higher benefit cost ratio of 2.35 and 2.64 of cotton over 75% RDF application to rabi crops.

References

1. Table 3: Gross monetary returns, net monetary returns (Rs ha -1 ) and B:C ratio of cotton as influenced by different treatments during 2020-21 and 2021-22 and pooled analysis of two years Treatments Gross monetary returns (Rs. ha -1 ) Net monetary returns (Rs. ha -1 )
2. Saravanakumar S. Multitier cropping system for enhancing profitability in cotton. Indian Farm. 2022;72:2-3.
3. Gulati A, Paroda R, Puri S, Narain D, Ghanwat A. Food system in India: challenges, performance and promise. Cham: Springer; 2023. doi:10.1007/978-3-031-15703-5_43.
4. Panse VG, Sukhatme PV. Statistical methods for agricultural workers. New Delhi: Indian Council of Agricultural Research; 1985.
5. Charjan YD, Gaikwad CB. Integrated nutrient management in cotton (Gossypium hirsutum)-wheat (Triticum aestivum) sequence on Vertisol. Indian J Agron. 2001;50(3):176-180.
6. Gudadhe N, Dhonde MB, Hirwe NA. Effect of integrated nutrient management on soil properties under cottonchickpea cropping sequence in vertisols of Deccan Plateau of India. Indian J Agric Res. 2015;49(3):207-214.
7. Turkhede AB, Nagdeve MB, Karunakar AP, Gabhane VV, Mohod VD, Mali RS. Diversification in cotton-based cropping system under mechanization in rainfed condition of Vidarbha of Maharashtra, India. Int J Curr Microbiol Appl Sci. 2017;6(9):2189-2206.
8. Kumar S, Turkhede AB, Wankhede R, Meena AK. Growth, yield and quality of cotton in cotton-based intercropping system under organic and rainfed condition. Pharma Innov J. 2022;11(2):154-157.
9. Latkar AS, Yadgirwar PV, Surpam AN, Rathod DL. Study of Bt cotton-based cropping systems in Central Vidarbha Zone of Maharashtra. J Agric Res Technol. 2024;49(1):1417.
10. Kumbhar AM, Buriro UA, Junejo S, Oad FC, Jamro GH, Kumbhar BA, et al. Impact of different nitrogen levels on cotton growth, yield and N-uptake planted in legume rotation. Pak J Bot. 2008;40(2):767-778.
11. Das A, Prasad M, Shivay YS, Subha KM. Productivity and sustainability of cotton (Gossypium hirsutum L.)-wheat (Triticum aestivum L.) cropping system as influenced by prilled urea, farmyard manure and Azotobacter. J Agron Crop Sci. 2004;190:298-304.
12. Mahavishnan K, Prasad M, Bhanu RK. Integrated nutrient management in cotton-sunflower cropping system in the sandy loam soils of north India. J Trop Agric. 2005;43(12):29-32.
13. Senthivelu M, Padian BJ, Surya PA. Dry matter production and nutrient removal in wet-seeded rice-cotton cropping sequence under irrigated nutrient management practices. Oryza. 2009;46(4):279-289.
14. Ramesh S. Effect of organic manures and inorganic fertilizers on productivity and economics of rice-cotton cropping system. J Emerg Technol Innov Res. 2017;4(10):658-664.
15. Chaudhari JH, Sadhu AC, Sonani VV, Chauhan SA. Chickpea performance as influenced by nutrient management and their residual effects on succeeding fodder sorghum. J Agri Search. 2022;9(1):29-36.
16. Sanjivkumar V, Baskar K, Manoharan S, Solaimalai A, Ravindra C, Gopinath KA. Response of rainfed Bt cotton to different crop residues application on yield, soil fertility and nutrient uptake under deep black vertisols. Agric Sci Dig. 2022:1-7. doi:10.18805/ag.D-5501.
17. Marral MWR, Ahmad F, Ul-Allah S, Rehman AU, Farooq S, Hussain M. Influence of transgenic (Bt) cotton on the productivity of various cotton-based cropping systems in Pakistan. Agriculture. 2023;13:276:1-15.
18. Mahala P, Chaudhary MR, Garhwal OP. Effect of integrated nutrient management on growth and yield of rabi onion and its residual effect on succeeding okra crop. Indian J Hortic. 2019;76(2):312-318.