Synergistic effects of integrated nutrient management and gypsum on productivity and profitability of Groundnut [Arachis hypogaea (L.)]

Introduction

Groundnut (Arachis hypogaea L.) is a major oilseed crop of the tropics and subtropics, valued for its high oil (48-50%) and protein (25-30%) content, contributing significantly to food, nutritional and economic security. India is one of the leading producers of groundnut, where the crop plays a vital role in rainfed and irrigated farming systems and improves soil fertility through biological nitrogen fixation (FAO, 2021; Reddy et al., 2022) [2,6] . However, groundnut productivity in many regions remains low due to imbalanced nutrient management and deficiencies of secondary nutrients, particularly calcium and sulphur. Gypsum (CaSO₄•2H₂O) is an important source of calcium and sulphur, both of which are crucial for pod development, kernel filling and oil synthesis in groundnut. Adequate calcium availability in the pegging zone is essential for proper pod formation, while sulphur enhances protein synthesis and oil quality (Alloway, 2020; Tiwari et al., 2021) [1,8] . Integrated Nutrient Management (INM), combining inorganic fertilizers with organic manures and biofertilizers, has emerged as a sustainable strategy for improving nutrient use efficiency, soil health and crop productivity. Several studies have reported that INM enhances growth parameters, yield attributes and quality of groundnut by ensuring balanced nutrient supply and improving soil biological activity (Patel et al., 2020; Meena et al., 2022) [5,4] . Moreover, the integrated application of gypsum with INM practices has shown synergistic effects in improving pod yield, shelling percentage and oil content of groundnut (Singh et al., 2023) [7] . Groundnut productivity is often limited by deficiencies of calcium and sulphur, which are essential for pod development, protein synthesis, and oil quality. Integrated Nutrient Management combined with gypsum can improve nutrient availability, soil health, and crop performance. This study is important to evaluate the effect of INM and gypsum on growth, yield, and quality of groundnut, providing practical strategies for sustainable and profitable production.

Materials and Methods

The field experiment entitled "Synergistic Effects of Integrated Nutrient Management and Gypsum on Productivity and profitability of Groundnut [Arachis hypogaea (L.)]" was conducted during the kharif season of 2024 at the Agricultural Research Farm of Suresh Gyan Vihar University, Jaipur (Rajasthan), on loamy sand soil. The study was laid out in a factorial randomized block design comprising combinations of sixteen treatments viz., two factors with where 4 levels of integrated nutrient management N0: Control, N1: 100% RDF, N2: 50% RDF + 5 ton/ha FYM, N3: 75% RDF + 2.5 ton/ha FYM and four levels of gypsum G0: Control, G1: 100 kg/ha, G2: 150 kg/ha and G3: 250 kg/ha. The groundnut variety as test crop "HNG-10" were used. The experimental farm is located in the south-eastern part of Rajasthan at an elevation 548 m above mean sea level, between 26°92′ N latitude and 75°77′ E longitude, and falls under agro-climatic zone III-A (Semi-Arid Eastern Plain) of Rajasthan. The region experiences a typical semi-arid climate, characterized by wide variations in temperature during summer and winter seasons. The average annual rainfall of Jaipur ranges from 400 to 450 mm, of which nearly 80-85% is received through the south-west monsoon, mainly from July to early September. During the cropping period, the maximum temperature varied from 31.41 to 38.71 °C, while the minimum temperature ranged between 20.71 and 27.85 °C. The relative humidity fluctuated up to 91% during the season. Average daily sunshine hours ranged from 0.68 to 5.01 hours, whereas wind velocity varied between 0.88 and 2.82 km/h. The recorded observations were statistically analyzed using standard procedures as described by Fisher (1950) [3] .

Results and Discussion

Integrated nutrient management with Treatment N3: 75% RDF + 2.5 ton/ha significantly enhanced growth parameters i.e. plant height (69.70 cm), number of leaf area index (2.92) and dry matter accumulation (27.64 g/plant) at harvest over control but remained statistically at par with N2: 50% RDF + 5 ton/ha FYM presented in table-1 and fig1. The significant improvement in growth parameters under treatment N3 (75% RDF + 2.5 t/ha FYM), as evidenced by higher plant height, leaf area index and dry matter accumulation at harvest over the control, may be attributed to the synergistic effect of inorganic fertilizers and organic manure. Integrated nutrient management ensures a balanced and continuous supply of nutrients, improves soil physical condition, enhances microbial activity and promotes better root growth, which collectively favor photosynthetic efficiency and biomass production. The comparable performance of N3 with N2 (50% RDF + 5 t/ha FYM) indicates that partial substitution of chemical fertilizers with FYM can effectively meet the nutrient requirement of the crop and sustain vegetative growth. Similar improvements in growth attributes of groundnut under integrated nutrient management have also been reported by Patel et al. (2021) [5] , Meena et al. (2022) [4] and Singh et al. (2023) [7] , who attributed enhanced growth to improved nutrient availability and soil health under combined application of organic and inorganic sources. Further results revealed that the application of G3: gypsum @ 250 kg/ha, recorded which was statistically at par with G2: gypsum @ 150 kg/ha, recorded maximum growth parameters viz., plant height (69.67 cm), number of leaf area index (2.88) and dry matter accumulation (27.61 g/plant) at harvest over control presented in table-1 and fig1. Further results revealed that application of gypsum significantly enhanced growth parameters of groundnut over the control. The treatment G3 (gypsum @ 250 kg/ha) recorded maximum plant height, leaf area index and dry matter accumulation at harvest, though it remained statistically at par with G2 (gypsum @ 150 kg/ha). The improvement in growth attributes can be attributed to adequate supply of calcium and sulphur through gypsum, which play a crucial role in cell division, chlorophyll formation, photosynthetic activity and overall biomass production. Calcium availability in the root and pegging zone enhances root growth and nutrient uptake, while sulphur improves protein synthesis and enzymatic activity, leading to better vegetative growth. Similar enhancement in growth parameters of groundnut due to gypsum application has been reported by Tiwari et al. (2021) [8] , Meena et al. (2022) [4] and Singh et al. (2023) [7] . Further, results revealed that application of N3: 75% RDF + 2.5 FYM/ha obtained significantly higher pod yield (3235 kg/ha), haulm yield (3628 kg/ha), protein content in kernel (25.88%) and oil content in kernel (48.05%) being statistically at par with N2: 50% RDF + 5.0 ton FYM/ha presented in table 2 and fig2. Further results revealed that application of N3 (75% RDF + 2.5 t/ha FYM) resulted in significantly higher pod yield, haulm yield, protein content and oil content of groundnut compared to the control, and remained statistically at par with N2 (50% RDF + 5.0 t/ha FYM). The improvement in yield may be attributed to enhanced growth, better nutrient availability and efficient translocation of assimilates towards reproductive parts under integrated nutrient management. Increased protein and oil content in kernels under N3 could be due to improved nitrogen availability from inorganic fertilizers and sustained nutrient release from FYM, which favor protein synthesis and lipid metabolism. The comparable performance of N3 with N2 suggests that balanced integration of organic and inorganic nutrient sources can optimize yield and quality while reducing dependence on chemical fertilizers. Similar improvements in pod yield and quality parameters of groundnut under integrated nutrient management have been reported by Patel et al. (2021) [5] , Meena et al. (2022) [4] and Singh et al. (2023) [7] . Whereas; application of G3: gypsum @ 250 kg/ha, recorded which was statistically at par with G2: gypsum @ 150 kg/ha recorded significantly higher pod yield (3231 kg/ha), haulm yield (3626 kg/ha), protein content in kernel (25.82%) and oil content in kernel (48.03%) presented in table 2 and fig-2. Application of gypsum significantly improved pod yield, haulm yield and quality parameters of groundnut over the control. Treatment G3 (gypsum @ 250 kg/ha) recorded the highest pod yield, haulm yield, protein content and oil content in kernel, though it remained statistically at par with G2 (gypsum @ 150 kg/ha). The beneficial effect of gypsum may be attributed to adequate supply of calcium and sulphur, which play a vital role in pod development, kernel filling, protein synthesis and oil biosynthesis. Calcium availability in the pegging zone ensures proper pod formation, while sulphur enhances enzymatic activity and improves kernel quality. Similar positive responses of groundnut in terms of yield and quality due to gypsum application have been reported by Tiwari et al. (2021) [8] , Meena et al. (2022) [4] and Singh et al. (2023) [7] . Among economics of groundnut crop in terms of net returns (₹105848/ha) and B:C (2.83) were significantly higher under N2: 50% RDF + 5.0 ton FYM/ha. However, gross returns (₹1147018/ha) followed same pattern of yield and growth parameters. Among gypsum level, application of G3: gypsum @ 250 ton/ha recorded significantly higher gross returns (₹146726/ha), net returns (₹114434/ha) and B:C (3.52). The economic analysis indicated that treatment N2 (50% RDF + 5.0 t/ha FYM) produced significantly higher net returns (₹105,848/ha) and benefit-cost ratio (2.83), reflecting the economic advantage of greater substitution of inorganic fertilizers with organic manure. Although gross returns followed the trend of yield and growth parameters, the lower cost of cultivation under N2 resulted in superior profitability. This underscores the importance of integrated nutrient management in minimizing input costs while sustaining crop productivity.

Among gypsum levels, application of G3 (gypsum @ 250 kg/ha) recorded significantly higher gross returns (₹146,726/ha), net returns (₹114,434/ha) and B:C ratio (3.52), which may be attributed to increased pod yield and improved kernel quality due to adequate calcium and sulphur nutrition. Similar economic benefits of integrated nutrient management and gypsum application in groundnut have been reported by Meena et al. (2022) [4] and Singh et al. (2023) [7] .

Conclusion

The study concluded that integrated nutrient management with 50% RDF + 5.0 t ha⁻¹ FYM proved most economical, while 75% RDF + 2.5 t ha⁻¹ FYM ensured higher growth, yield and quality of groundnut. Application of gypsum @ 250 kg ha⁻¹ further enhanced productivity and profitability, highlighting the importance of balanced nutrient and secondary nutrient management for sustainable groundnut production.

References

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2. FAO. FAOSTAT statistical database. Rome: Food and Agriculture Organization of the United Nations; 2021.
3. Fisher RA. Statistical methods for research workers. 11th ed. Edinburgh: Oliver and Boyd; 1950. p. 1-354.
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