Impact of Wood Biochar and Its Interactions with Mycorrhizal Fungi, Phosphorus Fertilization and Irrigation Strategies on Potato Growth

Abstract

Biochar amendment to soil has the potential to improve soil quality and increase crop yield. Arbuscular mycorrhizal fungi (AMF) provide beneficial plant services of stress alleviation with respect to phosphorus (P) deficiency and drought. The aim of this study was to explore interactive effects of biochar with AMF, P fertilization levels and irrigation strategies on growth of potato plants. Potato plants were amended with wood biochar of 0.74 % w/w (B+) or not (BÀ), fertilized with phosphorus of 0.11 mg P g À1 soil (P1) or not (P0), irrigated with full irrigation (FI) or partial root-zone drying irrigation (PRD) and inoculated with AMF of Rhizophagus irregularis (M+) or not (MÀ) in split-root pots in a sandy loam soil. Plants were analysed for growth performance, P and nitrogen (N) uptake and water use efficiency (WUE). Biochar adsorption of mineral P and N in aqueous solution was tested in subexperiment. B+ significantly decreased plant biomass production except under P0 FI MÀ, where B+ increased plant biomass. This growth stimulation was counteracted by treatments of P1, PRD and M+. B+ significantly decreased plant leaf area, P and N uptake and WUE, but had no significant effect on root biomass and soil pH. The positive plant growth response to AMF was substantially reduced by biochar amendment. The wood biochar had no adsorption for mineral N, and it had 0.96 % adsorption for mineral P in aqueous solution. The results suggested that the negative effect of wood biochar application on plant growth may due to the reduced plant uptake of P and N and the possibility of phytotoxic effects of wood biochar on potato growth. It was concluded that the wood biochar used in current study had negative impact on plant growth and P/N uptake and it is not recommendable to apply this wood biochar to mycorrhizal agro-system, to soil fertilized with high rate of P or to soil suffering water deficiency.

Nutrient uptake and growth of potato: Arbuscular mycorrhiza symbiosis interacts with quality and quantity of amended biochars

“…Such decrease was also found by Liu et al. () for low temperature wood biochar, which could be due to different feedstock of biochar. On the other hand, arbuscular mycorrhizal fungus (AMF) inoculation generally increased potatoes' nutrient uptake and growth and alleviated the negative effect of biochar.…”

“…The detected negative effects of wood biochar on potato growth were to some extent, but not fully, compensated by AMF inoculation in the study by Liu et al. ().…”

“…Positive effect of combined application of biochar and AM on P uptake of maize was found ( Warnock et al., ; Mau and Utami , ). However, negative effect of wood biochar was found on the biomass gain of potato plants inoculated with AMF ( Liu et al., ), which may be related to the reduced plant uptake of N and P, or a potential phytotoxic effects of biochar. Biochar type ( Steinbeiss et al., ) and application rate ( Warnock et al., ) both influence microbial activity in the soil.…”

Biochar amendment of fluvio‐glacial temperate sandy subsoil: Effects on maize water uptake, growth and physiology

“…Liu et al. () found similar negative effects of a wood biochar on potato growth, which they also ascribed to possible ethylene effects. Thus, the photosynthesis per plant integrated over leaf area and time may not have been enhanced by biochar.…”

“…Apart from the importance of increasing the available soil water content, increased water‐holding ability at the same soil water potential is expected to both ease the ability of plants to take up water as well as plant nutrients. The former due to better root contact (Herkelrath, Miller, & Gardner, ; Jensen, Svendsen, Andersen, & Lösch, ), the latter due to less tortuosity of the diffusion pathway in soil (Liu et al., ). The significant increase in the water content at FC for B3 was responsible for the significantly higher water content during the drying cycle in year one.…”