Rice straw cover decreases soil erosion and sediment-bound C, N, and P losses but increases dissolved organic C export from upland maize fields as evidenced by δ13C

Se-In Park; Hye In Yang; Hyun-Jin Park; Bo-Seong Seo; Young-Jae Jeong; Sang-Sun Lim; Jin-Hyeob Kwak; Han-Yong Kim; Kwang-Sik Yoon; Sang-Mo Lee; Woo-Jung Choi

doi:10.1016/j.scitotenv.2020.142053

Rice straw cover decreases soil erosion and sediment-bound C, N, and P losses but increases dissolved organic C export from upland maize fields as evidenced by δ¹³C

Sci Total Environ. 2021 Jan 20:753:142053. doi: 10.1016/j.scitotenv.2020.142053. Epub 2020 Sep 1.

Authors

Affiliations

¹ Department of Rural & Bio-Systems Engineering, Chonnam National University, Gwangju 61186, Republic of Korea.
² Department of Rural & Bio-Systems Engineering, Chonnam National University, Gwangju 61186, Republic of Korea; Max Planck Institute for Biogeochemistry, Jena 07745, Germany.
³ Bio R&D Center, CJ Cheiljedang, Suwon, Gyeonggi-do 16495, Republic of Korea.
⁴ Department of Rural Construction Engineering, Jeonbuk National University, Jeonju, Jeollabukdo 57896, Republic of Korea.
⁵ Department of Applied Plant Science, Chonnam National University, Gwangju 61186, Republic of Korea.
⁶ National Instrumentation Center for Environmental Management, Seoul National University, Seoul 08826, Republic of Korea.
⁷ Department of Rural & Bio-Systems Engineering, Chonnam National University, Gwangju 61186, Republic of Korea; AgriBio Institute of Climate Change Management, Chonnam National University, Gwangju 61186, Republic of Korea. Electronic address: wjchoi@jnu.ac.kr.

PMID: 32896739
DOI: 10.1016/j.scitotenv.2020.142053

Abstract

Soil surface with crop residue is effective in reducing soil erosion and carbon (C), nitrogen (N), and phosphorus (P) losses from sloping fields. However, there is a high possibility that surface cover increases export of dissolved organic C (DOC) though relevant field studies under natural rainfall are lacking. In this study, the effects of surface cover with rice (Oryza sativa L.) straw on soil and CNP losses in both dissolved and sediment-bound forms from maize (Zea mays L.) fields were investigated under two fertilization levels (standard and double) × two types of runoff experiments (natural rainfall and artificial irrigation). Changes in soil properties including moisture, temperature, nutrients, and C concentration as well as maize yield were also examined. Surface cover decreased soil and total CNP losses by up to 82% across the experimental plots with some exceptions. However, surface cover increased DOC export in both natural (by 68-82% in total across all events) and artificial (by 3-4 fold) runoff, suggesting that crop residue cover may act as a DOC pollution source of water bodies. The contribution of rice straw to DOC, which was calculated using the δ¹³C of DOC from covered plots (-24.1 to -28.0‰) and control plots (-19.6 to -25.1‰), was 52.5-95.8%. The concentrations of K₂SO₄-extractable and microbial biomass C of the soils did not differ between covered and control plots, suggesting that DOC produced from rice straw was not incorporated into the soils, but rather, was washed out with surface runoff in this study. Surface cover increased maize growth and yield, particularly in double fertilization plots, through improved soil moisture, temperature, and nutrient conditions. To take full advantage of surface cover with crop residue, a further study on reducing DOC loss from crop residue needs to be conducted.

Keywords: Crop residue; Soil erosion; Stable carbon isotope; Surface cover; Surface runoff.

MeSH terms

Agriculture
Oryza*
Phosphorus
Soil*
Zea mays

Substances

Soil
Phosphorus