Effect of Cropping Intensity on Soil Physical Properties: A Study on Bulk Density, Particle Density and Porosity at Kalaroa Upazila in Satkhira District

Abstract

Intensive land use and frequent tillage practices are common in high cropping intensity regions like Bangladesh. Although the role of fertilizers on yield has been widely studied, effect of tillage intensity on physical health of soil remains under explored, particularly in multiple cropping areas. Our investigation is to explore the effect of cropping intensities on key physical properties of soil: bulk density, particle density, and porosity, in Kalaroa Upazila, Satkhira district. Soil samples from four distinct cropping intensities (200%, 250%, 300%, and 350%) were collected during the Rabi season from surface layers (0–15 cm) of “Ishurdi” soil series. Standard laboratory analyses including the core method for bulk density, pycnometer method for particle density and porosity estimation from density values were conducted. Tillage frequency ranged from 9 to 14 operations per year across the plots. Results indicated that increasing intensity generally led to reduced bulk density and porosity, while particle density exhibited minor variations. The lowest bulk density (1.247 g/cm³) and porosity (41.12%) were recorded in the most intensively cultivated plot (350% intensity, 14 tillages/year), suggesting potential degradation of soil structure due to over-cultivation. In contrast, moderate tillage (250% intensity) maintained the highest porosity (51.46%), indicating better soil aeration and structure. This study underscores that excessive intensity can adversely affect soil physical properties, diminish its capacity to support sustaiSnable crop production.

Introduction

The rising global population, changing diets, and increasing demand for biofuels require a significant boost in crop production. While discussions often focus on inputs like water, nutrients, and energy, the physical condition of soil is often overlooked—especially in countries like Bangladesh. Although chemical fertilizers play a major role in crop yield, long-term productivity depends equally on maintaining soil physical health through practices like tillage.

Objective

This study investigates how varying tillage and cropping intensities affect soil physical properties—specifically bulk density, particle density, and porosity—in Kalaroa Upazila, Satkhira District, Bangladesh, where intensive farming is common.

Methodology

• Location & Sampling: Soil samples from 4 plots (C1 to C4) in the Rabi season were collected from the 0–15 cm layer. The plots represented cropping intensities of 200%, 250%, 300%, and 350%.

• Field Characteristics: All sites are part of the Ganges tidal floodplain, with level terrain and clay to clay loam soils.

• Tests Conducted:

  • Particle size analysis using the Bouyoucos hydrometer method.

  • Bulk density using the core method.

  • Particle density using the pycnometer method.

  • Porosity was calculated from bulk and particle density.

  • Statistical analysis was done using MSTAT-C.

Key Findings

1. Particle Density

• Ranged from 2.62 to 2.70 g/cm³.

• Slight variations were found across cropping intensities but not statistically significant.

• C3 (300%) showed the highest particle density.

2. Bulk Density

• Significant variation observed.

• Highest bulk densities (~1.40 g/cm³) occurred in C1 and C3, while the lowest was in C4 (350%).

• Intensive cultivation appeared to reduce bulk density, potentially due to better soil structure from frequent tillage.

3. Porosity

• Significantly affected by cropping intensity.

• C2 (250%) had the highest porosity (51.46%), while C4 (350%) had the lowest (41.12%).

• Intensive cropping negatively affected porosity, reducing total pore space and possibly soil health.

Conclusion

Field experiments were conducted on 4 different plots in Kalaroa Upozilla. The study was carried out to observe the changes in soil physical properties with the change in cropping intensity. The findings of the study are summarized below. Particles density values varied insignificantly in different cropping intensity. Highest intensity showed the lowest bulk density. Porosity became decreased with increasing intensity of cultivation. The determined soil physical parameters, bulk density, particle density and soil porosity, were unfavorably changed with increasing cropping intensity which may cause ultimately deterioration of soil health.

References

[1] Benjamin, J.G.; Nielsen, D.C. and Vigil, M.F. 2003. Quantifying effects of soil condition on plant growth and crop production. Geoderma, 116:137-148. [2] Blake, G.R. and Hartge, K.H. 1986b. Particle density. In: Kiute (ed.) Methods of soil Analysis. American Society of Agronomy, Madison, Wisconsin, USA, pp. 363- 376. [3] Bouyoucos, G. J. 1936. Directions for Making Mechanical Analysis of Soils by the Hydrometer Method. Journal of Soil Science, 42(3). [4] Brady, N.C. 1990. The Nature and Properties of Soils. 10th Edition. Prentice Hall of India, Private Limited, New Delhi. [5] Dexter, A. R. 1999. Soil mechanics relation to tillage implements and root penetration in low land soils. pp. 261-275. In: Soil Physics and Rice. International Rice Research Institute, los Banos. Philippines. [6] FAO, 2010. Food and Agriculture Organization of the United Nations. FAO online document, Retrieved on February 4, 2010. [7] Keyzer, M.A.; Merbis, M.D.; Pavel, I.F.P.W. and van Wesenbeeck, C.F.A. 2005. Diet shifts towards meat and the effects on cereal use: Can we feed the animals in 2030? Ecological Economics, 55: 187-202. [8] Pradhan. S. B. 1992. Status of fertilizers use in developing countries of Asia and the Pacific Region. pp. 47. In: Proceedings of Regional FADINAP Seminar. [9] Rose, E.; Rarthes, B.; Martias, C.; Tiessen, H. and Vledk, P. L. G. 2001. Organic matter management for soil conservation and productivity restoration in Africa. Nutrient Cycling in Agroecosystems, 61(12): 159-170. [10] Rost, S.; Gerten, D.; Hoff, H.; Lucht, W.; Falkenmark, M. and Rocktröm, J. 2009. Global potential to increase crop production through water management in rainfed agriculture. Environmental Research Letters, 4: 1-9. [11] Singh, S.S. 2004. Principles and Practices of Agronomy. 3rd Edition. Kalyani Publishers. New Delhi, pp. 152-159. [12] SRDI, 2006. Upazilla Nirdeshika Guide, Soil Resource and Development Institute, Dhaka. [13] Strickling, E. 1956. Relationship of porosity to water stability. Journal of Soil Science, 80:331-335. [14] Xu, D. and Mermoud, A. 2001. Top soil properties as affected by tillage properties in North China. Soil and Tillage Research, 60: 11-19.

Copyright

Copyright © 2025 Sheikh Yesin Ali, Md. Sanaul Islam, Shaikh Motasim Billah, Md. Mostafijur Rahman, Md. Shaheen Miah, Shah Mohammad Kamrul Hasan, Md. Rayhan Kabir, Mahmudul Hasan Chowdhury. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.