Straw application improved soil biological properties and the growth of rice plant under low water irrigation

Sepideh Bagheri Novair; Hossein Mirseyed Hosseini; Hassan Etesami; Nader Pirmoradian; Behnam Asgari Lajayer; G W Price

doi:10.1016/j.envres.2024.119138

Straw application improved soil biological properties and the growth of rice plant under low water irrigation

Environ Res. 2024 May 14:255:119138. doi: 10.1016/j.envres.2024.119138. Online ahead of print.

Authors

Sepideh Bagheri Novair¹, Hossein Mirseyed Hosseini², Hassan Etesami³, Nader Pirmoradian⁴, Behnam Asgari Lajayer⁵, G W Price⁶

Affiliations

¹ Soil Science Department, University of Tehran, Tehran, Iran. Electronic address: bagherisepideh10@gmail.com.
² Soil Science Department, University of Tehran, Tehran, Iran. Electronic address: mirseyed@ut.ac.ir.
³ Soil Science Department, University of Tehran, Tehran, Iran.
⁴ Department of Water Engineering, Faculty of Agricultural Sciences, University of Guilan, Rasht, 41996-13776, Iran.
⁵ Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada. Electronic address: basgari@dal.ca.
⁶ Faculty of Agriculture, Dalhousie University, Truro, NS, B2N 5E3, Canada.

PMID: 38750999
DOI: 10.1016/j.envres.2024.119138

Abstract

The application of organic amendments is one way to manage low water irrigation in paddy soils. In this 60-day greenhouse pot experiment involving paddy soil undergoing drying-rewetting cycles, we examined the effects of two organic amendments: azo-compost with a low carbon to phosphorus ratio (C:P) of 40 and rice straw with a high C:P ratio of 202. Both were applied at rates of 1.5% of soil weight (w/w). The investigation focused on changes in certain soil biochemical characteristics related to C and P in the rice rhizosphere, as well as rice plant characteristics. The irrigation regimes applied in this study included constant soil moisture in a waterlogged state (130% water holding capacity (WHC)), mild drying-rewetting (from 130 to 100% WHC), and severe drying-rewetting (from 130 to 70% WHC). The results indicated that the application of amendments was effective in severe drying-rewetting irrigation regimes on soil characteristics. Drying-rewetting decreased soil respiration rate (by 60%), microbial biomass carbon (by 70%), C:P ratio (by 12%), soil organic P (by 16%), shoot P concentration (by 7%), and rice shoot biomass (by 30%). However, organic amendments increased soil respiration rate (by 8 times), soil microbial biomass C (51%), total C (TC) (53%), dissolved organic carbon (3 times), soil available P (AP) (100%), soil organic P (63%), microbial biomass P (4.5 times), and shoot P concentration (21%). The highest significant correlation was observed between dissolved organic carbon and total C (r= 0.89**). Organic amendments also increased P uptake by the rice plant in the order: azo-compost > rice straw > control treatments, respectively, and eliminated the undesirable effect of mild drying-rewetting irrigation regime on rice plant biomass. Overall, using suitable organic amendments proves promising for enhancing soil properties and rice growth under drying-rewetting conditions, highlighting the interdependence of P and C biochemical changes in the rhizosphere during the rice vegetative stage.

Keywords: Azo-compost; Microbial biomass carbon; P; Rhizosphere soil; Rhizosphere soil carbon; Rice straw.