Straw and phosphorus applications promote maize (Zea mays L.) growth in saline soil through changing soil carbon and phosphorus fractions

Zhenxin Guo; Wenhua Ye; Hui Wang; Wei He; Yanling Tian; Guoqing Hu; Yanhong Lou; Hong Pan; Quangang Yang; Yuping Zhuge

doi:10.3389/fpls.2024.1336300

Straw and phosphorus applications promote maize (Zea mays L.) growth in saline soil through changing soil carbon and phosphorus fractions

Front Plant Sci. 2024 Jan 19:15:1336300. doi: 10.3389/fpls.2024.1336300. eCollection 2024.

Authors

Zhenxin Guo^#¹, Wenhua Ye^#¹, Hui Wang¹, Wei He^{1

2}, Yanling Tian¹, Guoqing Hu¹, Yanhong Lou¹, Hong Pan¹, Quangang Yang¹, Yuping Zhuge¹

Affiliations

¹ National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Taian, China.
² Observation and Research Station of Land Use Security in the Yellow River Delta, Ministry of Natural Resources (NMR), Shandong Provincial Territorial Spatial Ecological Restoration Center, Jinan, China.

^# Contributed equally.

Abstract

Introduction: Straw return has been widely recognized as an important carbon (C) enhancement measure in agroecosystems, but the C-phosphorus (P) interactions and their effects on plants in saline soils are still unclear.

Methods: In this study, we investigated the effects of straw return and three P application levels, no P fertilizer (Non-P), a conventional application rate of P fertilizer (CP), and a high application rate of P fertilizer (HP), on maize growth and soil C and P fractions through a pot experiment.

Results and discussion: The results revealed that the dry matter weight of maize plant was no difference between the two straw return levels and was 15.36% higher under HP treatments than under Non-P treatments. Plant nutrient accumulations were enhanced by straw addition and increased with increasing P application rate. Straw application reduced the activities of peroxidase (POD), superoxide dismutase (SOD), catalase, and the content of malondialdehyde (MDA) in maize plants by 31.69%, 38.99%, 45.96% and 27.04%, respectively. P application decreased SOD, POD activities and MDA content in the absence of straw. The contents of easily oxidized organic carbon (EOC), particulate organic carbon (POC) and the ratio of POC/SOC in straw-added soils were 10.23%, 17.00% and 7.27% higher, respectively, than those in straw-absent soils. Compared with Non-P treatments, HP treatments led to an increase of 12.05%, 23.04% in EOC, POC contents respectively, while a decrease of 18.12% in the contribution of MAOC to the SOC pool. Straw return improved the P status of the saline soil by increasing soil available P (14.80%), organic P (35.91%) and Ca₂-P contents (4.68%). The structural equation model showed that straw and P applications could promote maize growth (indicated by dry matter weight, P accumulation, antioxidant enzyme activity and MDA content) through improving soil C and P availabilities.

Conclusion: This study provides evidence that straw return together with adequate P supply in saline soil can promote crop nutrient accumulation, attenuate the oxidation damage on crop growth, and be beneficial for SOC turnover and soil P activation.

Keywords: P addition; antioxidant enzyme; particulate organic carbon; saline soil; soil P availability; straw return.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. National Key R&D Program of China (2021YFD190090207, 2021YFD190090101), Natural Science Foundation of Shandong Province (ZR2021MD020), and Major Science and Technology Innovation Projects in Shandong Province (2021CXGC010804).