Effects and Economic Sustainability of Biochar Application on Corn Production in a Mediterranean Climate

Abstract

The effects of two types of biochar on corn production in the Mediterranean climate during the growing season were analyzed. The two types of biochar were obtained from pyrolysis of Pinus pinaster. B1 was fully pyrolyzed with 55.90% organic carbon, and B2 was medium pyrolyzed with 23.50% organic carbon. B1 and B2 were supplemented in the soil of 20 plots (1 m2) at a dose of 4 kg/m2. C1 and C2 (10 plots each) served as control plots. The plots were automatically irrigated and fertilizer was not applied. The B1-supplemented plots exhibited a significant 84.58% increase in dry corn production per square meter and a 93.16% increase in corn wet weight (p << 0.001). Corn production was no different between B2-supplemented, C1, and C2 plots (p > 0.01). The weight of cobs from B1-supplemented plots was 62.3%, which was significantly higher than that of cobs from C1 and C2 plots (p < 0.01). The grain weight increased significantly by 23% in B1-supplemented plots (p < 0.01) and there were no differences between B2-supplemented, C1, and C2 plots. At the end of the treatment, the soil of the B1-supplemented plots exhibited increased levels of sulfate, nitrate, magnesium, conductivity, and saturation percentage. Based on these results, the economic sustainability of this application in agriculture was studied at a standard price of €190 per ton of biochar. Amortization of this investment can be achieved in 5.52 years according to this cost. Considering the fertilizer cost savings of 50% and the water cost savings of 25%, the amortization can be achieved in 4.15 years. If the price of biochar could be reduced through the CO2 emission market at €30 per ton of non-emitted CO2, the amortization can be achieved in 2.80 years. Biochar markedly improves corn production in the Mediterranean climate. However, the amortization time must be further reduced, and enhanced production must be guaranteed over the years with long term field trials so that the product is marketable or other high value-added crops must be identified.

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

“…Different models were developed considering numerous factors that affect the costs and savings of amending with biochar. Aguirre et al followed a simplified model for calculating the benefit of improving corn production and for estimating the time required to cover the cost of biochar, considering the price of CO 2 fixation, to which they assigned a value of 30 EUR/t [33]. The price of CO 2 is constantly increasing after COP26, surpassing 90 EUR/t in February 2022 [47].…”

“…In recent years, many studies have assessed biochar effects on soil fertility and on the yield and quality of different horticultural crops, especially under water stress conditions. These studies have shown the efficacy of biochar in pumpkin [29], onion [30], pea [31], lettuce [32], corn [33], cucumber [34], sweet pepper [35], watermelon [36], and tomato [37] crops, among others. Conversely, other studies have not reported significant improvements in yield when supplying biochar [38], usually on soils fertile enough to meet all plant requirements, even under water stress conditions.…”

“…The main objective of this study was to assess biochar effects on different horticultural crops in the Mediterranean region, which has specific climatic conditions given severe water shortage during the warmer months. The biochar used in this study was produced by pyrolysis of Pinus pinaster wood chips, as described by Aguirre et al [33].…”

Impact of Eisenia fetida earthworms and biochar on potentially toxic element mobility and health of a contaminated soil

“…However, a limiting factor to its widespread adoption is the high cost of production due to the use of pyrolytic furnaces, whose functioning depend on external energy supply, though pyrolysis units can be used to produce biochar and at the same time to create energy (Peters et al 2015;Kung and Mu 2019). Moreover, considering also the costs related to transport and distribution into the soil, Aguirre et al (2021) estimated that biochar application costs approximately 190 euros per ton.…”

Biochar-based fertiliser improved the yield, quality and fertiliser utilisation of open field tomato in karst mountainous area

“…It is worth noting that the prerequisite for the largescale application of biochar was the economic feasibility of biochar application (Aguirre et al 2021), however, most of the current research still focuses on the environmental effects of biochar rather than the economic benefits (Owsianiak et al 2021). The main reason was the excessively high input costs of biochar and relatively slow benefits due to a large amount of biochar applied and the high price.…”