Matching of Soil Phosphorus Distribution and Root Distribution in Cotton Field Based on Diffusive Gradients in Thin-Films (DGT)

ABSTRACT

This study aimed to optimize the period of drip phosphorus (P) fertilization to increase P migration distance in soil and content in cotton, so as to achieve the coordinated above and belowground growth of cotton plants. A field experiment was conducted to study soil P in response to P application by drip irrigation during different periods of cotton cultivation using diffusive gradients in thin films (DGT) in situ. The root length density, biomass, P content and lint yield of cotton were investigated. Compared with broadcast P fertilization before plowing, drip P fertilization after sowing significantly increased DGT-P and root length density in the top 0–15 cm soil layer, and significantly increased the biomass P content and lint yield of cotton, but reduced the root/shoot ratio. In addition, drip P fertilization at bud stage could also increase the DGT-P and root length density in the top 0–10 cm soil layer compared with the broadcast P fertilization treatment. Our results indicate that drip P fertilization after sowing is an effective method to expand the vertical migration of P in soil, increase the length, density, and P content of shoot, and improve the growth of cotton.

KEYWORDS:

• cotton
• DGT
• drip irrigation
• phosphorus
• root

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Key Research and Development Program of China (Grant No. 2017YFD0201900), and the National Natural Science Foundation of China (Grant No. 41161039).