Effect of Biochar and Irrigation on the Interrelationships among Soybean Growth, Root Nodulation, Plant P Uptake, and Soil Nutrients in a Sandy Field

Hua Ma,Qirui Li,Stephan Wirth,Dilfuza Egamberdieva,Sonoko D Bellingrath-Kimura,Richard Ansong Omari,Mudan Hou

doi:10.3390/su11236542

Abstract

To investigate the interrelationships among biochar, soil nutrients, and soybean plant growth in more detail, the root nodulation response of soybean (Glycine max L.) to biochar application was analyzed in a field study. We further examined the biochar effect on soil phosphatase activity to elucidate the relationships among biochar, phosphatase activity, and plant phosphorus uptake. Soybean was planted in a sandy field wherein the biochar and irrigation conditions were considered the two treatment factors. In our result, irrigation increased the pod number and plant height by 20.7% and 11.1%, respectively. Irrigation reduced the shoot and root dry matter content by 67.9% and 75.1%, respectively. The nodule number increased by 37% due to biochar addition under irrigated conditions. The soil carbon concentration was elevated by 13.4% with biochar application under rainfed conditions. Acid phosphomonoesterase (APM) was increased by 21.8% in the biochar-incorporated plots under the irrigated condition. Principal component analysis and redundancy analysis suggested that biochar application enhanced the relationships between the nodule number and soil potassium and magnesium concentrations. The correlation between soil sulfur content and nodule number was eliminated by biochar application. APM activity was associated with higher shoot and root phosphorus content and shoot dry weight after biochar application.

Highlights

Biochar is a carbon (C)-rich material with high chemical stability
Biochar produced at low temperatures was reported to have a substantial proportion of nonaromatic C, which may be more prone to oxidation [3,4], that can be used by microorganisms as a C source [5,6]
While shoot dry matter weight increased significantly due to irrigation from 616–625 g m−2 to 694–697 g m−2, there were no significant differences for the root and seed dry weights

Summary

Introduction

Its condensed aromatic structure is considered the main component that is difficult to degrade This stabilized C compound may increase soil C sequestration and reduce CO2 emissions [1,2]. Biochar produced at low temperatures was reported to have a substantial proportion of nonaromatic C, which may be more prone to oxidation [3,4], that can be used by microorganisms as a C source [5,6]. This will provide organic matter content and reduce chemical fertilizer application for a sustainable agrosystem. Biochar was used as an inoculant carrier to enhance the rhizobium survival rate and the soybean nodulation rate [13,14]

Methods

Results

Conclusion