Subsoiling and crop rotation improve root growth of Bt-cotton in Vertisols

Soil compaction is a major physical constraint in cotton production. At present, no information is available on the effects of compaction on the root growth and root anatomy of cotton (Gossypium hirsutum L.). Therefore, we studied the effects of subsoiling (shallow (SSS) and deep (DSS)) and crop rotation (pigeon pea (Cajanus cajan) – cotton (PCR) and radish (Raphanus sativus) – cotton (RCR)) on the root growth of cotton in deep Vertisols during 2017–19. Subsoiling significantly increased the shoot and root length. The root-to-shoot ratio was maximum in DSS (33%), followed by PCR (29%) at the vegetative stage. Scanning electron micro­scopy analysis of the roots indicated a large number of pores and less contraction of xylem and phloem in the subsoiled and rotation treatments than in the control. Furthermore, the SEM-EDAX spectra indicated a greater abundance of major, secondary and micronutrients in subsoiling and crop rotations compared to the control treatment