Effects of phosphorus-modified biochar as a soil amendment on the growth and quality of Pseudostellaria heterophylla

Abstract

Phosphorus (P) deficiency in agricultural soil is a worldwide concern. P modification of biochar, a common soil conditioner produced by pyrolysis of wastes and residues, can increase P availability and improve soil quality. This study aims to investigate the effects of P-modified biochar as a soil amendment on the growth and quality of a medicinal plant (Pseudostellaria heterophylla). P. heterophylla were grown for 4 months in lateritic soil amended with P-modified and unmodified biochar (peanut shell) at dosages of 0, 3% and 5% (by mass). Compared with unmodified biochar, P-modified biochar reduced available heavy metal Cd in soil by up to 73.0% and osmotic suction in the root zone by up to 49.3%. P-modified biochar application at 3% and 5% promoted the tuber yield of P. heterophylla significantly by 68.6% and 136.0% respectively. This was different from that in unmodified biochar treatment, where tuber yield was stimulated at 3% dosage but inhibited at 5% dosage. The concentrations of active ingredients (i.e., polysaccharides, saponins) in tuber were increased by 2.9–78.8% under P-modified biochar amendment compared with control, indicating the better tuber quality. This study recommended the application of 5% P-modified biochar for promoting the yield and quality of P. heterophylla.

Evaluation of Biochar and Inorganic Fertilizer on Soil Available Phosphorus and Bacterial Community Dynamics in Acidic Paddy Soils for Different Incubation Temperatures

“…Given the alterations in P availability and diversity of the microbial community, the soil pH fluctuations remain a point to emphasize. Previous studies have reported the soil pH increments as a result of biochar and inorganic P amendments [17]. However, in this study, the increments in soil pH with biochar and inorganic P amendments were, perhaps, due to the alkaline nature of the biochar or the occurrence of carboxylic functional groups, as well as its oxidation properties [18].…”

“…Using a spectrophotometer with a 420 nm wavelength, the P concentration was determined. The modified Tabatabai and Bremner (1969) [16] method was used to evaluate the soil phosphatase enzyme activity [17]. Next, 0.1 g of fresh soil was weighed into a 50 mL conical flask, which was then filled with a solution of toluene, modified universal buffer (pH 6.5), and p-nitrophenyl phosphate (PNP).…”

Potential use of Ulva intestinalis-derived biochar adsorbing phosphate ions in the cultivation of winter wheat Tristicum aestivum

“…A better effect of using enriched biochar with phosphorus on plant growth occurred for the longer duration of pot tests, e.g. : 21 days (Nardis et al 2021 ), 65 days (Gunes et al 2014 ), 120 days (Ng et al 2022 ), which suggests conducting longer pot tests in the future using biochar as a soil additive. There were statistically significant differences for measuring the weight of fresh plants, the length of the plants, chlorophyll, and the leaf surface area for different groups, when comparing in a column (marked in Table 8 ).…”

Phosphoric acid surface modified Moringa oleifera leaves biochar for the sequestration of methyl orange from aqueous solution: Characterizations, isotherm, and kinetics analysis

“…The surface structure of raw biochar was different from activated biochars containing higher irregularities with fewer pores due to the low carbonization temperature (350°C) (Fu et al, 2009). However, biochars became highly porous after carbonizing and activating with H 3 PO 4 (Ng et al, 2022), with significantly increased surface area. The SEM images of activated biochars revealed the presence of tunnel‐shaped cracks and cylindrical pores, which acted as diffusion paths for MO molecules (Jjagwe et al, 2021), resulting in the higher sorption of MO compared to raw biochar.…”