Background: 400 million hectares of Vertisols, which have high amounts of smectite clay with good shrink-swell qualities, are located worldwide primarily in tropical/subtropical climates. Agriculture and infrastructure face difficulties when managing Vertisols due largely to the intensive cultivation of crops (like Gossypium arboreum or Asiatic cotton).
Objectives: The objectives are to (1) describe how different clays affect shrink–swell behavior; (2) review ways that moisture fluctuations impact soil cracking patterns and structure; and (3) evaluate how the root systems of G. arboreum influence soil moisture and chemical balance. Finally, we will describe soil physical properties, agricultural productivity, and infrastructure stability implications.
Methods: An exhaustive synthesis of virtually all peer reviewed literature, along with accompanying nine supporting data tables and five conceptual models, was completed. This synthesis combined data analysis for all three types of soil (physical, chemical and hydraulic) with regards to several important parameters such as bulk density, porosity, hydraulic conductivity, and swell pressure under a variety of managements or land use conditions.
Results: The increase in seasonal swell-shrink amplitude of the soil cultivated with Gossypium arboreum was between 15 and 30% greater than that of the unripe soil due to the extraction of water from the soil during the reproductive growth period (maturity) of the cotton plant. The clay mineralogy of the smectite-rich soil exaggerated the swelled and cracked state of the soil. Maximum swell pressures in irrigated cotton systems reached up to 420 kPa, which poses a significant risk to shallow infrastructure, such as roads, foundations, and irrigation networks. Physical properties of soil were significantly affected, including decreased porosity, as well as changes in the hydraulic conductivity. To reduce structural damage were successful drip irrigation, subsoil chisel tillage, and the use of lime stabilization.
Conclusions: The relationship between Vertisol characteristics and the cultivation of Gossypium arboreum increases the shrink-swell action of Vertisol leading to profound implications concerning the sustainability of agriculture and the resilience of infrastructure. The need for an integrated management strategy that combines soil physical properties, field management of crops and engineering technology is paramount for addressing the dynamic nature of Vertisol. Future research efforts should focus on models that can provide long-term estimates, and the development of microbiome-based, biological agents to stabilize soil, as well as remote sensing types of monitoring for crack dynamics to facilitate climate-smart land use planning.