Exploring the effect of different application rates of biochar on the accumulation of nutrients and growth of flue-cured tobacco (Nicotiana tabacum)

Abstract

BackgroundBiochar application has become one of the most potential tools to improve soil fertility and plant growth for sustainable and eco-friendly agriculture. However, both positive and negative effects of biochar application have been recorded on plant growth and soil fertility.MethodsThis study investigated the impact of different application rates (0, 600, 900, 1200, and 1800 kg/ha) of biochar on the soil nutrient contents, accumulation of nutrients and dry matter in different plant parts, and growth of flue-cured tobacco plants under field conditions.ResultsResults demonstrated that soil organic carbon pool and carbon/nitrogen ratio were increased proportionally with the increasing dosage of biochar, 25.54 g/kg and 14.07 g/kg compared with control 17 g/kg and 10.13 g/kg, respectively. The contents of soil total nitrogen were also significantly increased after biochar application in the middle (1.77 g/kg) and late-growth (1.54 g/kg) stages of flue-cured tobacco than in control (1.60 g/kg and 1.41 g/kg, respectively). The contents of soil nitrate nitrogen were also higher under low (600 and 900 kg/ha) application rates of biochar and reduced when higher (1200 and 1800 kg/ha) dosages of biochar were applied. However, it was observed that varying application rates of biochar had no impact on soil ammonium nitrogen content during the growth period of flue-cured tobacco plants. The nutrient accumulation (N, P, K) in different parts of flue-cured tobacco plants was significantly increased under a low application rate of biochar, which enhanced the soil and plant analyzer development values, effective leaves number, growth, dry matter accumulation, and leaf yield of flue-cured tobacco. In contrast, the high biochar application rate (1200 and 1800 kg/ha) negatively impacted nutrient accumulation and growth of flue-cured tobacco.ConclusionConclusively, the optimum application of biochar (600 and 900 kg/ha) is beneficial for plant growth, soil fertility, accumulation of nutrients, and dry matter in different plant parts. However, excessive biochar application (> 900 kg/ha) could inhibit flue-cured tobacco plant growth. This study provides a theoretical foundation for biochar application in tobacco and other crop production to obtain agricultural sustainability and economic stability.

Transcriptome profiling reveals the impact of various levels of biochar application on the growth of flue-cured tobacco plants

“…Tobacco stems left over after harvesting tobacco leaves were used as raw material for the preparation of biochar. For collection of tobacco stem, the tobacco plants were topped completely, and tobacco stem biochar (BC) was prepared by pyrolysis at 450 ℃ for 4 h [ 7 ]. Morphological analysis of BC was performed using scanning electron microscopy (SEM; FlexSEM1000) according to the methodology of Nafees, et al [ 30 ].…”

“…Tobacco plants were treated by first-flower topping, usually retaining about 18 to 22 leaves, depending on the plant’s growth. The plant agronomic traits, such as plant height, leaf number, stem circumference, maximum leaf length, maximum leaf breadth, and other pertinent data, were measured in accordance with the China Tobacco Industry Standard YC/T 142–1988 [ 7 ]. All the data were recorded at 60 d (late peak growth stage) and 100 d (lower leaf maturity stage) from each plot (10 plants/plot).…”

“…All the data were recorded at 60 d (late peak growth stage) and 100 d (lower leaf maturity stage) from each plot (10 plants/plot). The leaf area was calculated using the following formula [ 7 ]: …”

“…Five tobacco plants from each plot per treatment were removed and divided into three parts (roots, stems, and leaves). The plant parts were incubated at 105 ℃ for 30 min and then dried at 80 ℃ for 48 h. The dry weight of each plant part was measured, and biomass accumulation was calculated using the following formula [ 7 ]:…”

“…Biochar (BC) is a naturally derived bio-stimulant that can profoundly enhance plant growth and improve soil fertility and stress resistance [ 7 – 9 ]. BC is derived from organic waste, crop residue, animal or poultry manure, etc., by heating at high temperatures (300–700 °C) in an oxygen-deficient environment in a process known as pyrolysis [ 10 – 12 ].…”