Carbon isotope discrimination and the factors affecting it in a summer maize field under different tillage systems

PeerJ

article

Jichao Cui¹  Huifang Han¹ 

[1] State Key Laboratory of Crop Biology, Key Laboratory of Crop Water Physiology and Drought Tolerance Germplasm Improvement of Ministry of Agriculture, Shandong Agricultural University

关键词: Tillage methods;    Soil water content;    Leaf area index;    Canopy temperature;    Canopy humidity;   

DOI  :  10.7717/peerj.12891

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Based on two years of field experiments, under different soil tillage methods and straw management practices, which included conventional tillage (CT), subsoiling (SS), rotary tillage (RT), and no-tillage (NT), combined with either straw return (S) or straw removal (0), we characterized the dynamic changes in Δ13C among three height layers [upper (U, 240 cm above the ground), middle (M, 120 cm above the ground), and lower (L, 30 cm above the ground)] of the summer maize canopy. The Δ13C, the factors affecting it, and the relationships between Δ13C and soil water content (SWC), the leaf area index (LAI), canopy microclimate, and the CO2 concentration were elucidated. The results indicated that the Δ13C of summer maize at the pre-filling stage was greater than that at the post-filling stage. Δ13C also varied at different heights, with the order of the Δ13 M. Among the different tillage methods, the Δ13C values were ordered SSS CTS RTS NTS. SSS and NTS significantly increased the LAI; air temperature and relative humidity tended to gradually decrease with the increase in height of summer maize. Correlation analyses of the various influencing factors and Δ13C showed that SWC, LAI, air temperature, and CO2 concentration were all positively correlated with Δ13C, in which LAI and air temperature were significantly or extremely significantly positively correlated with Δ13C. In addition, we show that Δ13C can be used as a prediction index for summer maize yield, providing a theoretical basis for future yield research that may save precious time in summer maize breeding efforts.

【 授权许可】

CC BY