The Joint Application of Phosphorus and Ammonium Enhances Soybean Root Growth and P Uptake

Author(s)

Rosolem, Ciro Antonio ; Batista, Thiago Barbosa ; Dias, Patricia Pereira ; da Motta Neto, Laudelino Vieira ; Calonego, Juliano Carlos

• Document type: Journal article
• Source: AGRICULTURE-BASEL; v. 12, n. 6, p. 9-pg., 2022-06-01.

Abstract

It has been shown that the joint application of phosphorus (P) and ammonium (N-NH4+) increases maize root proliferation and P acquisition by maize in alkaline soils, but this has not been shown in acidic soils for legumes. A greenhouse experiment was conducted to assess the effect of the joint application of P and NH4+ on soybean root growth and P acquisition. Soybean was grown in glass-walled pots without P, with monoammonium phosphate (MAP) and triple super phosphate (TSP) applied on the soil surface or localized. The soil P increased irrespective of the P source and localization. The rhizosphere pH was decreased by MAP, while the soil bulk pH was not affected. The TSP increased the root length by 55% and MAP by 76% over the control, and the number of root tips increased by 21% with TSP, 58% with MAP applied on the soil surface, and 78% with MAP localized. The soybean dry matter, N and P uptake, and P use efficiency were increased by P fertilization, mainly with MAP localized. The joint application of P and ammonium decreases the soybean rhizosphere pH, which results in root proliferation early in the cycle, and eventually in higher P uptake and use efficiency. (AU)

• FAPESP's process: 15/04200-0 - Phosphorus conservation in cropping systems
• Grantee: Ciro Antonio Rosolem
• Support Opportunities: Regular Research Grants