Effect of Crop Geometry and Phosphorus Levels on Growth, Yield and Economics of Kabuli Chickpea (Cicer arietinum L.)

Introduction

Chickpea (Cicer arietinum L.), commonly known as gram or Bengal gram, is the most important protein-rich Rabi pulse crop of India. It is grown in two main types, the smallseeded desi (red) type and the bold-seeded Kabuli (white) type, the latter commanding a premium price in domestic and export markets. Chickpea grains are a rich and affordable source of protein, carbohydrates, fats, minerals and vitamins, and serve as an important vegetarian substitute for animal protein. Globally, India is the largest producer of chickpea, contributing more than two-thirds of the world area and production, with Madhya Pradesh, Rajasthan, Maharashtra, Karnataka and Uttar Pradesh being the leading producing states. Being a legume, chickpea meets a large part of its nitrogen requirement through symbiotic fixation and is therefore a heavy feeder of phosphorus rather than nitrogen. Phosphorus is a key nutrient governing root proliferation, nodulation, energy transfer through ATP synthesis, cell division and the translocation of photosynthates. Adequate phosphorus nutrition enhances nodule development, plant height, branching, pod formation, grain yield and harvest index, while its deficiency is a major constraint limiting the productivity of grain legumes. In most Indian soils the available phosphorus status ranges from low to medium, so a positive and profitable crop response to phosphorus application is widely reported. Crop geometry, through its influence on plant population and the spatial arrangement of plants, regulates the availability of light, moisture, nutrients and space. Plants grown under optimum or wider spacing generally exhibit superior individual growth on account of reduced inter-plant competition, whereas closer spacing favours higher plant density per unit area. The interaction between crop geometry and phosphorus is therefore important, since efficient plant arrangement can improve nutrient-use efficiency and maximise productivity. Determining the most suitable combination of spacing and phosphorus level is essential for achieving higher yields and economic returns in Kabuli chickpea. Keeping these facts in view, the present investigation was undertaken with the objectives of studying the effect of crop geometry on the growth and yield of Kabuli chickpea, evaluating the effect of phosphorus levels on its growth and yield, and working out the economics of the different treatment combinations.

Materials and Methods

Experimental site and soil

The field experiment was conducted during the Rabi season of 2025-26 at the Crop Research Farm, Department of Agronomy, Prof. Rajendra Singh (Rajju Bhaiya) University, Naini, Prayagraj, Uttar Pradesh (25.36° N latitude, 81.86° E longitude, 98 m above mean sea level). The region has a sub-tropical, semi-arid climate with extremes of temperature in both summer and winter. The soil of the experimental field, forming a part of the central Gangetic alluvium, was sandy loam in texture, neutral in reaction (pH 7.0) with an electrical conductivity of 0.56 dS m⁻¹, low in organic carbon (0.62%), medium in available nitrogen (255 kg ha⁻¹) and available phosphorus (18.2 kg ha⁻¹), and medium in available potassium (240.7 kg ha⁻¹).

Experimental design and treatments

The experiment was laid out in a Factorial Randomized Block Design (FRBD) with nine treatment combinations replicated three times, giving a total of 27 plots of 3 m × 3 m (9 m²) each. The treatments comprised two factors: three crop geometries (30×15, 40×15 and 50×15 cm) and three phosphorus levels (40, 50 and 60 kg ha⁻¹). A uniform recommended basal dose of 20-40-20 kg NPK ha⁻¹ was applied through urea, single super phosphate and muriate of potash, the phosphorus being adjusted according to the treatments. The nine treatment combinations are presented in Table 1.

Crop management

The field was ploughed, harrowed and levelled to a fine tilth and laid out as per the design. Kabuli chickpea variety PKV-2 was sown by line sowing at a depth of about 3 cm using a seed rate of 80 kg ha⁻¹, maintaining the row-to-row and plant-to-plant spacing as per the treatments. Gap filling and thinning were carried out to maintain the desired plant population, and two manual weedings were done at about 25 and 45 days after sowing (DAS). Nipping was performed at 30 and 45 DAS, and irrigation was applied as required. The crop was harvested at maturity, sun-dried, threshed, winnowed and the produce recorded plot-wise.

Observations recorded

Growth parameters, namely plant height (cm), number of branches per plant and plant dry weight (g), were recorded at 30, 60 and 90 DAS from five randomly tagged plants per plot. Yield attributes, viz. number of pods per plant, number of seeds per pod and seed index (1000-seed weight, g), were recorded at harvest. Seed yield, straw yield and biological yield were recorded on a net-plot basis and expressed in t ha⁻¹, and the harvest index (%) was computed as the ratio of economic yield to biological yield.

Economics and statistical analysis

The cost of cultivation, gross return, net return and benefitcost (B:C) ratio of each treatment were worked out on the basis of prevailing market prices of inputs and produce. The data were subjected to analysis of variance for a factorial randomized block design as described by Gomez and Gomez (1984). The significance of treatment effects was tested using the F-test, and critical differences (CD) were computed at the 5% level of significance to compare treatment means.

Results and Discussion

Plant height

Plant height increased progressively with crop age and was significantly influenced by crop geometry and phosphorus levels at 60 and 90 DAS, while differences at 30 DAS were non-significant (Table 2). Among the crop geometries, the widest spacing of 50×15 cm recorded the tallest plants at 60 DAS (59.86 cm), and 40×15 cm gave the maximum height at 90 DAS (78.79 cm), both being significantly superior to the closer spacing of 30×15 cm. The greater height under wider spacing may be attributed to reduced inter-plant competition for light, moisture and nutrients, which favoured better stem elongation and vegetative growth.

Increasing phosphorus levels significantly increased plant height at 60 DAS, with the highest value (60.31 cm) recorded at 60 kg ha⁻¹, whereas the effect at 90 DAS was non-significant. The improvement in height with phosphorus may be ascribed to its role in root proliferation, cell division, energy transfer and improved nodulation, which together enhanced nutrient acquisition and vegetative growth. The interaction effect was significant at 60 and 90 DAS; the maximum height at 90 DAS (81.90 cm) was recorded under 40×15 cm with phosphorus at 40 kg ha⁻¹ (T4). These findings are in agreement with Ali et al. (2018) [1] and Singh et al. (2019) [14] .

Plant dry weight

Plant dry weight was significantly affected by both factors at 60 and 90 DAS (Table 3). The widest spacing of 50×15 cm produced the maximum dry matter at all stages, recording 9.

Number of branches per plant

The number of branches per plant increased with crop age and responded significantly to crop geometry and phosphorus at 60 DAS, the differences at 30 DAS being non-significant (Table 4). Wider spacing of 50×15 cm produced the maximum number of branches (3.52 at 30 DAS and 14.88 at 60 DAS), reflecting the better availability of growing space, light and nutrients to individual plants. Among phosphorus levels, the highest dose of 60 kg ha⁻¹ recorded the greatest branching (14.82 at 60 DAS). The treatment combination 50×15 cm with phosphorus at 60 kg ha⁻¹ (T9) recorded the maximum branches (15.24 at 60 DAS). The favourable effect of phosphorus on branching is consistent with the observations of Kumar et al. (2022) [7] .

Yield attributes and yield

Crop geometry and phosphorus levels exerted a marked influence on the yield attributes and yield of Kabuli chickpea (Table 5). Among the crop geometries, the widest spacing of 50×15 cm recorded the highest number of pods per plant (59.30), seeds per pod (3.56), seed yield (1.96 t ha⁻¹), straw yield (4.58 t ha⁻¹) and biological yield (13.81 t ha⁻¹). The superior performance under wider spacing may be attributed to reduced competition for light, moisture, nutrients and space, which improved photosynthetic activity, flowering and pod development and favoured greater translocation of assimilates to the reproductive structures.

Increasing phosphorus levels up to 60 kg ha⁻¹ significantly improved pods per plant (59.87), seed yield (1.79 t ha⁻¹) and straw yield (4.22 t ha⁻¹), confirming the important role of phosphorus in tissue differentiation, carbohydrate metabolism, sugar translocation and the development of a well-spread root system. The seed index, however, was not significantly affected by either factor. Among the interactions, the treatment 50×15 cm with phosphorus at 60 kg ha⁻¹ (T9) recorded the maximum seed yield (2.14 t ha⁻¹), straw yield (4.68 t ha⁻¹), seeds per pod (3.80) and seed index (42.23 g), whereas 50×15 cm with phosphorus at 50 kg ha⁻¹ (T8) recorded the highest number of pods per plant (60.90), biological yield (14.52 t ha⁻¹) and harvest index (40.45%). These results corroborate the findings of Yadav and Meena (2020) [16] , Rathi et al. (2020) [12] and Balai et al. (2020) [2] .

International Journal of Agriculture and Food Science https://www.agriculturaljournals.com

Economics

The economics of the different treatment combinations are presented in Table 6. The cost of cultivation varied marginally from ₹ 34,145 to ₹ 34,345 ha⁻¹ owing to the differing quantities of phosphatic fertiliser. Gross return, net return and the benefit-cost ratio increased appreciably with wider spacing and higher phosphorus levels, mainly through their positive effect on seed and straw yields. The maximum net return (₹ 86,815 ha⁻¹) and the highest benefit-cost ratio (2.54) were recorded under the treatment 50×15 cm with phosphorus at 50 kg ha⁻¹ (T8), closely followed by 50×15 cm with phosphorus at 60 kg ha⁻¹ (T9) with a net return of ₹ 86,302 ha⁻¹ and a B:C ratio of 2.51. Although T9 produced the highest seed yield, T8 emerged as the most remunerative treatment because of its favourable balance between produce value and cost of cultivation, indicating that the moderate phosphorus level of 50 kg ha⁻¹ combined with wider spacing optimised profitability. The lowest net return and B:C ratio were obtained under the closest spacing with the lowest phosphorus level (T1). These findings are in conformity with the economic responses reported by Kumawat et al. (2020) [9] and Kumar et al. (2023).

Conclusion

On the basis of one season of experimentation, it may be concluded that crop geometry and phosphorus levels significantly influenced the growth, yield attributes, yield and economics of Kabuli chickpea under the agro-climatic conditions of Prayagraj. Wider spacing of 50×15 cm and phosphorus application at 60 kg ha⁻¹ were the most favourable for growth and productivity, the treatment 50×15 cm with 60 kg P₂O₅ ha⁻¹ (T9) recording the maximum seed yield of 2.14 t ha⁻¹. However, from the economic standpoint, sowing at 50×15 cm with phosphorus at 50 kg ha⁻¹ (T8) proved most remunerative, giving the highest net return (₹ 86,815 ha⁻¹) and benefit-cost ratio (2.54). Therefore, for higher productivity coupled with profitability, Kabuli chickpea may be sown at 50×15 cm spacing with 50-60 kg P₂O₅ ha⁻¹. As these conclusions are based on a single season, confirmation over additional seasons and locations is suggested before formulating a firm recommendation.

References

1. Ali Q, Ahsan M, Khan MZ. Effect of phosphorus levels on growth and yield of Cicer arietinum L. Journal of Agricultural Research. 2018;56(2):145-152.
2. Balai CM, Kumawat P, Bairwa RK, Meena LR. Effect of phosphorus and zinc levels on growth, yield and yield attributes of Cicer arietinum L. International Journal of Chemical Studies. 2020;8(4):2845-2849.
3. Das S, Pareek BL, Kumawat A, Dhikwal SR. Effect of phosphorus, Rhizobium and phosphate-solubilizing bacteria on growth, yield and nutrient uptake of Cicer arietinum L. Legume Research. 2013;36(6):511-514.
4. Dora MK, Khare JP. Effect of phosphorus levels and crop geometry on growth and yield of Cicer arietinum L. International Journal of Current Microbiology and Applied Sciences. 2018;7(3):1234-1239.
5. Gomez KA, Gomez AA. Statistical Procedures for Agricultural Research. 2nd ed. New York: John Wiley and Sons; 1984.
6. Kanaujia SP, Singh RK, Singh A. Effect of crop geometry and phosphorus levels on growth and yield of Cicer arietinum L. Legume Research. 2017;40(6):10251030.
7. Kumar A, Umesha C, Raju B. Effect of phosphorus and boron levels on growth and yield of Cicer arietinum L. The Pharma Innovation Journal. 2022;11(9):1840-1844.
8. Kumar S, Meena BL, Yadav SS, Sharma SK. Effect of phosphorus and boron on growth, yield and economics of Cicer arietinum L. International Journal of Environment and Climate Change. 2023;13(10):22212229.
9. Kumawat N, Yadav RK, Singh M, Dudwe TS, Tomar IS. Effect of phosphorus and bioinoculants and their residual effect on succeeding Cicer arietinum L. Indian Journal of Agricultural Sciences. 2020;90(2):320-325.
10. Lalrinzuali K, Singh V, Pradhan S. Influence of phosphorus and biofertilizers on growth and productivity of Cicer arietinum L. International Journal of Plant and Soil Science. 2023;35(24):451-458. International Journal of Agriculture and Food Science https://www.agriculturaljournals.com
11. Patel JK, Patel DD, Patel NM. Effect of phosphorus application on nodulation, yield and residual soil fertility in chickpea-wheat cropping system. Indian Journal of Agronomy. 2021;66(3):275-281.
12. Rathi A, Meena RS, Yadav SS. Effect of crop geometry and phosphorus levels on productivity and phosphorususe efficiency in chickpea. Annals of Agricultural Research. 2020;41(4):365-372.
13. Sharma P, Singh VK, Yadav R. Effect of spacing on growth, yield attributes and seed yield of Cicer arietinum L. Legume Research. 2020;43(5):621-626.
14. Singh R, Singh D, Yadav AK. Effect of plant spacing on growth and yield of chickpea under semi-arid conditions. Journal of Pharmacognosy and Phytochemistry. 2019;8(3):1523-1527.
15. Singh R, Singh V, Tiwari D, Masih A. Effect of biofertilizer, plant geometry and phosphorus levels on growth and yield of Cicer arietinum L. International Journal of Current Microbiology and Applied Sciences. 2020;9(11):2456-2463.
16. Yadav RK, Meena SS. Response of chickpea to phosphorus levels under irrigated conditions. International Journal of Chemical Studies. 2020;8(5):2100-2104