Effects of Biochar on Biointensive Horticultural Crops and Its Economic Viability in the Mediterranean Climate

Abstract

The effects of biochar on different horticultural crops (lettuce, tomato, sweet pepper, and radish) were evaluated in the Mediterranean climate. Biochar was produced by pyrolysis of Pinus pinaster wood chips at 550 °C and used at 1 (B1) and 2 (B2) kg/m2 application rates on six 3.5 m2 plots in each treatment, with two control plots (B0). No fertilizer was used. Treatment B1 led to a significant increase (p < 0.01) of 35.4%, 98.1%, 28.4%, and 35.2% in the mean fresh weight of radishes, lettuce, tomatoes, and sweet peppers, respectively. Treatment B2 resulted in an improvement of 70.7% in radishes, 126.1% in lettuce, 38.4% in tomatoes, and 95.0% in sweet peppers (p < 0.01). Significant differences between treatments B1 and B2 were observed in the radish, tomato, and sweet pepper crops but not in lettuce. The profitability of biochar application to these crops was studied by considering a biochar price of 800 EUR/t and applying a CO2 fixation subsidy, assuming the updated February 2022 price (90 EUR/t). In lettuce, tomato, and sweet pepper crops, the investment payback period was approximately one year. Application of biochar generated economic benefit either from the first harvest or in the second year. In radish, this period was longer than two years; however, an increase in the annual frequency of cultivation should be studied to optimize the benefit. The dose that provided the greatest benefit was B1 (for all crops, except for sweet pepper). Biochar considerably improved fruit and vegetable yield under the Mediterranean climate; however, further studies are needed to assess the effects of biochar on soil properties and yield to estimate long-term environmental and economic benefits.

Trade‐off between soil carbon sequestration and net ecosystem economic benefits for paddy fields under long‐term application of biochar

“…Zhang et al (2013) showed that the application of biochar in paddy soil could bring economic benefits of 1.5 × 10 3 $ ha −1 without considering the cost of biochar. In general, because the advantages of carbon sequestration may cover some of the cost of biochar (González-Pernas et al, 2022), we propose that government subsidy programs and market mechanisms be implemented to incentivize farmers to use biochar (Xia et al, 2023).…”

Biochar Production from Wastewater Sludge for Application in Sustainable Lettuce Plant Cultivation and Climate Change Mitigation

“…Biochar contributes to building a refractory SOC pool and positively impacts SOC dynamics. Depending on management practices, agriculture can act as a net source/sink for GHGs [9]. Agricultural management practices that can foster soil C sequestration help mitigate climate change.…”

“…For the computation of income from crop improvement, the average price received by farmers for lettuce is considered to be 269.9 EUR/t (equivalent to 0.2699 EUR/kg) [9]. Considering 80,000 plants (www.starkeayres.co.za, accessed on 3 January 2023) per hectare and assuming that the improvement in yield is equivalent to the increase in mean fresh weight of lettuce plant, different benefits for each application rate were determined (see Supplementary Table S1).…”

Medium-Term Effects and Economic Analysis of Biochar Application in Three Mediterranean Crops

“…However, in recent years, environmental awareness in highly developed countries has increased, leading to an increase in the consumption of responsibly cultivated food from sustainably cultivated and organic crops [2][3][4]. Hence, an increasing number of studies are focusing on improving production in an environmentally friendly manner [4], particularly those examining the use of biochar for improving soil quality and crop yield [5][6][7][8][9][10].…”

“…The effects of biochar application observed by other researchers indicate that biochar improves soils by increasing the pH, water and nutrient retention, and cation exchange capacity (CEC) and by enhancing the soil structure and biota [35][36][37], thereby improving plant growth [5][6][7][8]. The effect of biochar application in agricultural environments has been widely studied, reporting particularly good results for horticultural crops [10,[38][39][40][41]. Some authors have reported an improvement in corn yields from amending the soil with biochar [42][43][44].…”