Biochar application with reduced chemical fertilizers improves soil pore structure and rice productivity

Ning An; Lei Zhang; Yaxian Liu; Si Shen; Na Li; Zhengchao Wu; Jinfeng Yang; Wei Han; Xiaori Han

doi:10.1016/j.chemosphere.2022.134304

Biochar application with reduced chemical fertilizers improves soil pore structure and rice productivity

Chemosphere. 2022 Jul:298:134304. doi: 10.1016/j.chemosphere.2022.134304. Epub 2022 Mar 14.

Authors

Ning An¹, Lei Zhang², Yaxian Liu², Si Shen², Na Li¹, Zhengchao Wu³, Jinfeng Yang¹, Wei Han⁴, Xiaori Han⁵

Affiliations

¹ College of Land and Environment, Shenyang Agriculture University, Shenyang, Liaoning, China; National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, Shenyang, Liaoning, China.
² College of Land and Environment, Shenyang Agriculture University, Shenyang, Liaoning, China.
³ Analytical Instrumentation Center, Shenyang Agriculture University, Shenyang, Liaoning, China.
⁴ College of Land and Environment, Shenyang Agriculture University, Shenyang, Liaoning, China; National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, Shenyang, Liaoning, China. Electronic address: hanweiguy@163.com.
⁵ College of Land and Environment, Shenyang Agriculture University, Shenyang, Liaoning, China; National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, Shenyang, Liaoning, China. Electronic address: hanxiaori@163.com.

PMID: 35301997
DOI: 10.1016/j.chemosphere.2022.134304

Abstract

Biochar is an efficient amendment to improve soil quality and crop productivity, but the potential of biochar as a substitute for chemical fertilizers is still unknown. Here we conducted a 6-year field experiment to investigate how partial substitution of biochar to NPK fertilizers affect soil quality and rice yield in the northeast of China. The experiment included three treatments: Control (B0: NPK fertilizers only: 240 kg N ha^-1, 52 kg P ha^-1, and 100 kg K ha^-1); Low-input biochar (B1.5: 95% N, 89% P, 75% K + 1.5 t biochar ha^-1 year^-1); and High-input biochar (B3.0: 90% N, 78% P, 50% K + 3.0 t biochar ha^-1 year^-1). The amounts of NPK application in the biochar treatments were determined according to an equivalent method. We evaluated the soil pore structure characteristics via a CT technology, and investigated soil nutrients, plant biomass, root growth, and grain yields. The results showed that, after the 6-year application, the soil pore structure and rice productivity of B1.5 were significantly improved in compared to those of B0 and B3.0. B1.5 had similar soil available NPK contents, but 6.6% higher rice yield as compared to B0, because of increased root length density (33.2%) and aboveground biomass (10.2%). B1.5 also increased soil macroporosity (>100 μm) (141.4%), fraction dimension (8.4%), and pore connectivity (16.6%) in compared with those of B0. However, B3.0 showed the lowest rice yield due to lower soil available N content (19.2%), macroporosity (28.5%), fraction dimension (5.5%), and pore connectivity (85.3%) than B0. This study demonstrated that a moderate NPK fertilizer replacement by biochar could be an effective practice that improves soil quality, increases rice growth and yield, and reduces the input of chemical fertilizers for rice production.

Keywords: Biochar; Rice production; Soil nutrients; Soil porosity.

MeSH terms

Agriculture / methods
Charcoal
Fertilizers* / analysis
Oryza*
Soil / chemistry

Substances

Fertilizers
Soil
biochar
Charcoal