Topsoil and subsoil C and N turnover are affected by superficial lime and gypsum application in the short-term

Author(s)

Barcelos, Jessica P. Q. ^{[1, 2]} ; Mariano, Eduardo ^{[1, 2]} ; Jones, Davey L. ^[1] ; Rosolem, Ciro A. ^[2]

Affiliation

^[1] Bangor Univ, Sch Nat Sci, Bangor LL57 2UW, Gwynedd - Wales

^[2] Sao Paulo State Univ, Dept Crop Sci, Sch Agr, Av Univ 3780, BR-18610034 Botucatu, SP - Brazil

• Document type: Journal article
• Source: SOIL BIOLOGY & BIOCHEMISTRY; v. 163, DEC 2021.
• Web of Science Citations: 0

Abstract

Alleviation of subsoil acidity with lime or gypsum increases carbon (C) accumulation in deep layers by stimulating root growth and C and nitrogen (N) inputs at depth. However, the effects of these amendments combined with N fertilization on soil CO2 emissions remain controversial. We evaluated the effects of superficial lime and gypsum application and N-fertilizer on C and N dynamics and microbial C use efficiency (Mic(CUE)) in samples taken from the topsoil (0-10 cm) and subsoil (40-60 cm) of a no-till field experiment carried out in Brazil. We performed a short-term laboratory incubation with C-14-glucose and C-14-arginine to assess C and N mineralization dynamics. Liming increased topsoil pH but had no effect on subsoil acidity. A higher content of organic C, total N, and microbial biomass C and N were found in the topsoil. The addition of soil corrective (lime and gypsum) and N fertilizer had no effect on Mic(CUE) of added C-14-glucose. However, the Mic(CUE) of C-14-arginine was affected by the soil layer, and was higher in the subsoil. After the addition of arginine, net NH4+-N production was highest in the topsoil control, while net NO3--N content was highest with lime + gypsum plus residual N in the same layer. We conclude that while lime and gypsum ameliorate soil acidity, they have minimal effect on C cycling through the microbial biomass, particularly in the subsoil. (AU)

• FAPESP's process: 17/02517-1 - Nitrogen dynamics in a production system using Brachiaria as a cover plant
• Grantee: Eduardo Mariano
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/50305-8 - A virtual joint centre to deliver enhanced nitrogen use efficiency via an integrated soil-plant systems approach for the UK & Brazil
• Grantee: Ciro Antonio Rosolem
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/00398-5 - Nitrogen in soil, plant and atmosphere after limestone and gypsum application on no-tillage system
• Grantee: Jéssica Pigatto Barcelos Putti
• Support Opportunities: Scholarships in Brazil - Doctorate