Effect of phosphorous and zinc on physico-chemical properties of soil of garden pea (Pisum sativum Var. hortense L. CV. Psm-3) under alluvial soil of Prayagraj

Introduction

Garden pea (Pisum sativum L.) is one of the most important cool-season vegetable crops belonging to the family Fabaceae. It is widely cultivated throughout temperate and subtropical regions of the world for its tender green pods and seeds, which are rich in proteins, carbohydrates, vitamins, and minerals. Pea is considered an important dietary component because of its high nutritive value and digestibility. Green peas contain approximately 20-25% protein, appreciable amounts of vitamins A, B, and C, and essential minerals such as phosphorus, calcium, and iron. Role of Phosphorous (P) and zinc (Zn) are essential macro-and micronutrients, respectively, required for optimum growth, nodulation, flowering, and seed development in garden pea. Phosphorus plays a key role in root growth, energy transfer (ATP), nodulation, and efficient biological nitrogen fixation, whereas zinc is involved in enzyme activation, protein synthesis, auxin metabolism, membrane integrity, and pollen formation. Gupta et al. (2017) [3] . Role of Phosphorous (P) and zinc (Zn) are essential macro-and micronutrients, respectively, required for optimum growth, nodulation, flowering, and seed development in garden pea. Phosphorus plays a key role in root growth, energy transfer (ATP), nodulation, and efficient biological nitrogen fixation, whereas zinc is involved in enzyme activation, protein synthesis, auxin metabolism, membrane integrity, and pollen formation. Zinc deficiency adversely affects plant growth by reducing internodal elongation, leaf expansion, and reproductive development. Deficiencies of phosphorus and zinc have been widely reported in the cultivated soils of the North-Eastern Hill region of India, leading to poor crop performance and yield reduction in legumes and vegetable crops. Balanced application of phosphorus and zinc along with major nutrients is therefore essential for improving growth and productivity of garden pea. Several studies have demonstrated that the combined application of phosphorus and zinc significantly enhances growth parameters, yield attributes, and seed quality in legumes, including garden pea Gupta et al. (2017) [3] .

Materials and Methods

The experiment was conducted during Rabi 2025-26 at the Soil Science Research Farm, Department of Soil Science, PRSU, Naini, Prayagraj-211010 (U.P.). The experiment was laid out in Randomized Block Design (RBD) with four levels of Phosphorus and Zinc. The treatments have been replicated three times. The different treatments were employed randomly in each replication. Treatment consists of nine combinations of T 1 Control, T 2 Phosphorous 55 kg ha -1 , T 3 Phosphorous 60 kg ha -1 , T 4 Zinc 10 kg ha -1 , T 5 Zinc 15 kg ha -1 , T 6 Phosphorous 55 kg ha -1 + Zinc 10 kg ha -1 , T 7 Phosphorous 55 kg ha -1 + Zinc 15 kg ha -1 , T 8 Phosphorous 60 kg ha -1 + Zinc 10 kg ha -1 , T 9 Phosphorous 60 kg ha -1 + Zinc 15 kg ha -1 .

RDF for Zinc = 20 kg/ha. Source: Handbook of Agriculture, by ICAR, 2016. The physical properties of the soil samples, namely bulk density (Mg m⁻³), particle density (Mg m⁻³), pore space (%), and waterholding capacity (%), were determined standard analytical procedures described by Muthuvel et al. (1992). The chemical properties of the soil samples were analysed using standard analytical procedures. Soil pH (1:2 soil-water suspension) was determined by the method of Jackson (1973) [6] . Electrical conductivity (dSm -1 ) was estimated using the method described by Wilcox (1950) [12] . Organic carbon (%) was determined by the Walkley and Black's method (1934). Available nitrogen (kg ha⁻¹) was estimated by the method of Subbiah and Asija (1956), while available phosphorus (kg ha⁻¹) was determined using the Olsen et al. (1954) [9] , Available potassium (kg ha⁻¹) was estimated by the method of Toth and Prince (1949), Available Zn were determined by Lindsay and Norvell (1978) procedure using DTPA extractant.

Results and Discussion

Effect of Various Treatment Combination on Soil Physical Properties

Bulk density (Mg m -3 ) Bulk density of soil was increase according to depth which was found to be maximum 1.336 Mg m -3 at 0 -15 cm and 1.356 Mg m - 3 at 15-30 cm in treatment T 1 which was followed by 1.313 Mg m -3 at 0 -15 cm and 1.329 Mg m -3 at 15-30 cm in treatment T 2 . Whereas, Minimum 1.159 Mg m -3 at 0 -15 cm and 1.245 Mg m - 3 at 15-30 cm in T 9 . Bulk density is an important physical property of soil that reflects soil compaction, pore space distribution, and root penetration capacity. However, since the observed differences were non-significant, it can be inferred that phosphorus and zinc fertilization had little direct influence on soil physical structure during a single cropping season.

Particle density (Mg m -3 ) of soil was increase according to depth which was found to be maximum 2.610 Mg m -3 at 0 -15 cm and 2.657 Mg m -3 at 15-30 cm in treatment T 1 which was followed by 2.540 Mg m -3 at 0 -15 cm and 2.620 Mg m -3 at 15-30 cm in treatment T 2 . Whereas, Minimum 2.349 Mg m -3 at 0 -15 cm and 2.368 Mg m -3 at 15-30 cm in T 9 . The results indicate that levels of phosphorus and zinc tended to increase particle density, although the magnitude of change was relatively small. The values obtained in the present investigation fall within the normal range reported for mineral soils. Similar Findings were reported by Kumar et al. (2020) [7] .

Water holding capacity (%) of soil was increases according to depth which was found to be maximum 49.88% at 0 -15 cm and 49.29% at 15-30 cm in treatment T 9 which was followed by 49.20% at 0 -15 cm and 48.49% at 15-30 cm in treatment T 8 . Whereas, Minimum 43.64% at 0 -15 cm and 42.45% at 15-30 cm in treatment T 1 respectively. These results are consistent with those of by Vasava et al. (2020) [10] .

Percentage Pore Space (%) Percent Pore space (%) of soil was increases according to depth which was found to be maximum 54.20% at 0 -15 cm and 52.22% at 15-30 cm in treatment T 9 with application of (Phosphorus 60 kg ha -1 + Zinc 15 kg ha -1 ) which was followed by 52.43 at 0 -15 cm and 51.04% at 15-30 cm in treatment T 8 with application of (Phosphorous 60 kg ha -1 + Zinc 10 kg ha -1 ). Whereas, Minimum 45.15% at 0 -15 cm and 43.40% at 15-30 cm in treatment T 1 respectively. Similar findings were reported by Hussain et al., (2022) [4] .

Effect of Various Treatment Combination on Soil

Chemical Properties pH of soil w/v (1:2.5) pH of soil was increase according to depth which was found to be maximum 7.30% at 0 -15 cm and 7.37% at 15-30 cm in treatment T 1 with application of (Control) which was followed by 7.28% at 0 -15 cm and 7.33% at 15-30 cm in treatment T 2 with application of (Phosphorous 55 kg ha -1 ). Whereas, Minimum 6.68% at 0 -15 cm and 6.83% at 15-30 cm in treatment T 9 with application of (Phosphorus 60 kg ha -1 + Zinc 15 kg ha -1 ) respectively. Zinc application, in combination with phosphorus, may have influenced the exchange reactions in the soil solution, indicating that phosphorus and zinc application had only a limited effect on soil reaction.

EC of soil was increase according to depth which was found to be maximum 0.423 dSm -1 at 0 -15 cm and 0.441 dSm -1 15-30 cm in treatment T 1 which was followed by 0.414 dSm -1 at 0 -15 cm and 0.421 dS m -1 at 15-30 cm in treatment T 2 . Whereas, Minimum 0.330 dSm -1 at 0 -15 cm and 0.343 dSm -1 at 15-30 cm treatment T 9 . Present findings agree with the observation of Hussain et al., (2022) [4] .

Organic carbon (%) of soil was increases according to depth which was found to be maximum 0.547% at 0 -15 cm and 0.536% at 15-30 cm in treatment T 9 which was followed by 0.529% at 0 -15 cm and 0.513% at 15-30 cm in treatment T 8 . Whereas, Minimum 0.443% at 0 -15 cm and 0.434% at 15-30 cm in treatment T 1 respectively. Similar results were also reported by Yadav et al. (2021) [11] .

Available Nitrogen kg ha -1 of soil was found to be maximum 311.53 kg ha -1 at 0 -15 cm and 308.19 kg ha -1 at 15-30 cm in treatment T 9 which was followed by 309.16 kg ha -1 at 0 -15 cm and 297.49 kg ha -1 at 15-30 cm in treatment T 8 . Whereas, Minimum 263.16 kg ha -1 at 0 -15 cm and 260.49 kg ha -1 at 15-30 cm treatment T 1 . Our results are in line with Hussain et al., (2022) [4] .

Available Phosphorous kg ha -1 of soil was increase according to depth which was found to be maximum 22.81 kg ha -1 at 0 -15 cm and 19.26 kg ha -1 at 15-30 cm in treatment T 9 which was followed by 21.84 kg ha -1 at 0 -15 cm and 18.75 kg ha -1 at 15-30 cm in treatment T 8 . Whereas, Minimum 16.96 kg ha -1 at 0 -15 cm and 15.77 kg ha -1 at 15-30 cm treatment T 1 . A similar trend was also observed by Vasava et al., (2020) [10] .

Potassium (kg ha -1 ) Available potassium of soil was increase according to depth which was found to be maximum 220.42 kg ha -1 at 0 -15 cm and 210.67 kg ha -1 at 15-30 cm in treatment T 9 which was followed by 216.95 kg ha -1 at 0 -15 cm and 207.65 kg ha -1 at 15-30 cm in treatment T 8 . Whereas, Minimum 191.23 kg ha -1 at 0 -15 cm and 186.55 kg ha -1 at 15-30 cm treatment T 1 . These findings are in accordance with the results reported by Hussain et al., (2022) [4] .

Available Zinc (mg kg -1 ) of soil was found to be maximum 0.419 mg kg -1 at 0 -15 cm and 0.411 mg kg -1 at 15-30 cm in treatment T 9 which was followed by 0.412 mg kg -1 at 0 -15 cm and 0.406 mg kg -1 at 15-30 cm in treatment T 8 . Whereas, Minimum 0.336 mg kg -1 at 0 -15 cm and 0.287 mg kg -1 at 15-30 cm in treatment T 1 . These findings are in agreement with the observations reported by Yadav et al. (2021) [11] , Effect of all treatment on Available nitrogen (kg ha -1 ), Available phosphorus (kg ha -1 ), Available potassium (kg ha -1 ), Available Zinc (mg kg - 1 ) in soil.

Conclusion

Treatment -9 with application of (Phosphorus 60 kg/ha + Zinc 15 kg/ha) was seen to be best for all the physio-chemical, growth, yield and economics parameters. T 9 led to a statistically significant increase in yield components, achieving the highest green pod yield (115.77 q ha -1 ), number of pods per plant (11.15), and pod length (8.32cm). Economic analysis in confirms that T 9

was the most profitable treatment, delivering the maximum net profit of ₹1,84,549.07 ha⁻¹ and the highest benefit-cost ratio of for optimal growth, maximum green pod yield, and the highest economic returns in garden pea cultivation, of PRSU's Department of Soil Science in Naini, Prayagraj, for his enthusiastic interest in and support of the study project. I like his insightful criticism and practical recommendations for improving the caliber of my work.

Acknowledgement

AcknowledgementThe authors express their gratitude to the Hon'ble Vice Chancellor

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