Dose-specific biochar effects on cotton yield under drought: Genotypic variations in the arid U.S. cotton belt

Authors: ZHANG, JINFA - New Mexico State University; ZHU, YI - New Mexico State University; AHMAD, MONTASIR - New Mexico State University; GHIMIRE, RAJAN - New Mexico State University; IDOWU, OMOLILU - New Mexico State University; PARISH, SHANNON - New Mexico State University; SPARKS, ERIN - University Of Delaware; ADHIKARI, SUSHIL - Auburn University; LAMBA, JASMEET - Auburn University; Tumuluru, Jaya Shankar; Whitelock, Derek

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/28/2026
Publication Date: 1/30/2026
Citation: Zhang, J., Zhu, Y., Ahmad, M., Ghimire, R., Idowu, O.J., Parish, S.N., Sparks, E., Adhikari, S., Lamba, J., Tumuluru, J., Whitelock, D.P. 2026. Dose-specific biochar effects on cotton yield under drought: Genotypic variations in the arid U.S. cotton belt. Agronomy Journal. 16(3). Article 346. https://doi.org/10.3390/agronomy16030346.
DOI: https://doi.org/10.3390/agronomy16030346

Interpretive Summary: There is a lack of studies on biochar's effects in the US Cotton Belt, particularly regarding abiotic stresses in the semi-arid and arid Southwest and West. This study examined the impact of biochar at four application rates (0, 6.25, 12.5, and 25.0 t ha-1) on cotton yield under well-watered (WW) and drought stress (DS) conditions in New Mexico, focusing on six cotton genotypes. Drought significantly reduced boll numbers (BN) by 37.6%, boll weight (BW) by 5.8%, lint percentage (LP) by 4.0%, seedcotton weight (SCW) per plant by 42.5%, and lint weight (LW) per plant by 45.2%. Among the genotypes, Pima cotton DP 359 RF showed the least reduction (23-33%) from drought, while DP 2020 B3XF was the most sensitive (45-48% reduction). Under DS, biochar at 12.5 t ha-1 resulted in the highest SCW and LW and the lowest decreases in BN, BW, and SCW compared to the control, with no interaction between genotype and biochar. However, no significant differences were observed under WW conditions. This study indicates that biochar can positively affect cotton yield under drought stress in semi-arid and arid regions.

Technical Abstract: Different abiotic stresses, including drought, have become prevalent in world cotton (Gossypium spp.) production. Biochar, a form of charcoal produced from biomass by pyrolysis, can be used as a soil amendment to improve soil physical, chemical, and biological characteristics, and cotton growth and productivity. However, there is a lack of studies on the use and effect of biochar in the US Cotton Belt to address abiotic stresses, especially in the semi-arid and arid Southwest and West regions. This study was conducted to examine the effects of biochar at four different application rates (0, 6.25, 12.5, and 25.0 t ha-1) on cotton yield and yield components in six tetraploid cotton genotypes including one Pima (G. barbadense L.) and five Upland cottons (G. hirsutum L.) under well-watered (WW) and drought stress (DS) conditions in the arid New Mexico. The six cotton genotypes consistently showed that DS at the flowering stage significantly decreased boll numbers (BN) by 37.6%, boll weight (BW) by 5.8% and lint percentage (LP) by 4.0%, and thereby seedcotton weight (SCW) per plant by 42.5% and lint weight (LW) per plant by 45.2%. However, the Pima cotton DP 359 RF had the lowest reduction (23-33%) in BN, SCW, and LW by drought, while DP 2020 B3XF was the most sensitive to drought with 45-48% reduction. Under DS conditions, biochar at the rate of 12.5 t ha-1 had the highest SCW and LW, and the lowest reduction in BN, BW, SCW, and LW by drought, significantly different from the control with no biochar; and there was no genotype × biochar interaction for any of the traits. However, the four biochar rates did not significantly differ in BN, BW, SCW, and LW under WW conditions, suggesting no positive effects of biochar on cotton productivity under non-drought conditions. This study has demonstrated that biochar has positive effects on cotton yield and yield components in alleviating drought stress, suggesting its utility in cotton production in semi-arid and arid areas.