The concept of bio-economic mulching in droughty tropical agroecosystems and its trans-season effects on soil hydro-thermal regime and okra performance

Coarse-textured tropical soils soil hydrothermal properties Organic mulching Rainy-to-dry season interphase Soil Water conservation

Authors

  • Benedict Odinaka Okorie Department of Plant Physiology, Biochemistry, and Genetics. Agricultural University – Plovdiv , Bulgaria
  • Justina O. Obi Department of Crop Science, Faculty of Agriculture, University of Nigeria, Nsukka, 410001, Enugu State , Nigeria
  • Geraldine U. Chioke Department of Soil Science, Faculty of Agriculture, University of Nigeria, Nsukka, 410001, Enugu State , Nigeria
  • Sunday E. Obalum
    sunday.obalum@unn.edu.ng
    Department of Soil Science, Faculty of Agriculture, University of Nigeria, Nsukka, 410001, Enugu State Prince Abubakar Audu University, Anyigba, PMB 1008 Anyigba, Kogi State , Nigeria
  • Chinaza J. Onah Department of Soil Science, Faculty of Agriculture, University of Nigeria, Nsukka, 410001, Enugu State , Nigeria
  • Adaobi L. Nnadi Department of Crop Science, Faculty of Agriculture, University of Nigeria, Nsukka, 410001, Enugu State International Institute of Tropical Agriculture, Ibadan, PMB 5320 Ibadan, Oyo State , Nigeria
  • Charles A. Igwe Department of Soil Science, Faculty of Agriculture, University of Nigeria, Nsukka, 410001, Enugu State, Nigeria. , Nigeria
  • Martin E. Obi Department of Soil Science, Faculty of Agriculture, University of Nigeria, Nsukka, 410001, Enugu State , Nigeria
January 13, 2024
August 2, 2024
November 26, 2024

Mulching is an effective soil-water conservation technique in high-evaporative-demand tropical climates. Because of the drawbacks in bulk application of organic mulches, we introduce the concept of bio-economic mulching (BEM), a one-time low-rate application of organic mulch to improve soil productivity while sustaining economic viability. The study evaluated the effects of BEM (dry-grass mulching at 0, 2, 4, and 6 t ha–1) on soil hydrothermal properties of sandy-loam Ultisols using okra growth during 4–9 weeks after sowing in successive rainy-to-dry/partially rainfed season (PRS) and rainy/completely rainfed season (CRS). During the PRS, soil volumetric moisture content (q) increased (10.02%–25.50%), but soil temperature decreased (37.67–26.67°C) as BEM rate increased. A similar q trend (8.71%–18.37%) occurred during the CRS. Soil thermal conductivity (0.78to 4.88 W m–1 K–1), thermal diffusivity (3.95 × 10–7 to 35.97 × 10–7 m2 s–1), and heat flux (15.00 to 85.56 W m–2) generally decreased as q increased with BEM application rate particularly during the PRS; the reverse prevailed for volumetric heat capacity (1.33 × 106 to 2.25 × 106 J m–3 K–1). Okra plant height differed (BEM-6 > BEM-4 > BEM-2/BEM-0) in the PRS, but BEM-6 and BEM-4 gave the tallest and shortest plants, respectively in the CRS. Fruit yield was 1.8- and 9.5-fold higher in BEM-6 than BEM-4 in PRS and CRS, respectively. Mulch treatment-induced temporal variations in soil q influenced okra performance indices of plant height (r2 = 0.85) and total fresh fruit yield (r2 = 0.69). In droughty tropical environments, BEM implementation at 6 t ha−1 could engender soil hydrothermal regime favoring vegetable production beyond the ‘drier’ first season and even more pronouncedly in the second season.

How to Cite

Okorie, B. O., Obi, J. O., Chioke, G. U., Obalum, S. E., Onah, C. J., Nnadi, A. L., Igwe, C. A., & Obi, M. E. (2024). The concept of bio-economic mulching in droughty tropical agroecosystems and its trans-season effects on soil hydro-thermal regime and okra performance. SAINS TANAH - Journal of Soil Science and Agroclimatology, 21(2), 165-178. https://doi.org/10.20961/stjssa.v21i2.83285