This study aimed to investigate the influence of chemical and structural characteristics of biochar on the development of rice plants grown in fragile sandy soil. An experiment was carried out in pots with the application of four doses (0 ton ha⁻¹; 10 ton ha⁻¹; 20 ton ha⁻¹; 30 ton ha⁻¹) of eucalyptus biochar from four artisanal sources (B1, B2, B3, and B4). Fresh root mass increased by 0.56% with the application of biochar B4 and decreased with the application of biochars B1, B2, and B3 (23.3%; 18.3%; 19.9%). The fresh mass of sheath and leaves decreased by an average of 23.6% and 27%, respectively, with the application of all biochars. Root dry mass increased by 7.8% with the application of biochar B4 and decreased with the application of B1, B2, and B3. The sheath dry mass and leaf dry mass decreased by an average of 20.2% and 25.1%, respectively, with the application of all biochars. The nutrient content, specifically P, K, and N, increased with the application of B1, B2, and B3. The application of biochar B4 (30 ton ha⁻¹) lessened the damage to the photosynthetic apparatus and promoted physiological recovery. The beneficial effect of biochar B4 occurred at a dose of 30 ton ha⁻¹ in the reaction centers, increasing photochemical efficiency in photosystem II. Root development was stimulated by the application of biochar B4, increasing root area by 55% (10 ton ha⁻¹) and 56% (20 ton ha⁻¹ and 30 ton ha⁻¹). The total length increased by 48% with the application of biochar B4 and by 27% with biochar B2 (30 ton ha⁻¹). The length of thick roots and the total root volume were less affected by the treatments, with increases of approximately 11% and 7%, respectively. Although most treatments did not result in higher biomass production compared to the control, there was a notable increase in nutrient content in the aboveground portion, particularly with the application of biochar B2. Furthermore, improvements in photosynthetic parameters and root morphology were observed, particularly when biochar B4 was applied. Overall, the findings of this study indicate that biochars B2 and B4, at rates of 20 and 30 ton ha⁻¹, respectively, hold promise for enhancing cultivation in vulnerable Planosols in the Rio de Janeiro region of Brazil. However, to fully understand the effects on soil properties in different crops and the economic implications of implementing biochar in agriculture, further long-term and large-scale research is necessary.

Graphical Abstract

中文翻译：

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手工生物炭应用于里约热内卢（巴西）脆弱沙质平面土壤水稻种植的效果

本研究旨在探讨生物炭的化学和结构特征对脆弱沙质土壤中水稻植株发育的影响。在盆中进行了一项实验，使用^{来自四个手工}来源（B1、B2、B1 、B2 ^、 B3 和 B4)。施用生物炭B4使鲜根质量增加0.56%，施用生物炭B1、B2和B3使鲜根质量下降（23.3%；18.3%；19.9%）。施用所有生物炭后，鞘和叶的鲜质量分别平均下降了 23.6% 和 27%。施用生物炭B4使根干质量增加了7.8%，而施用B1、B2和B3则减少了根干质量。施用所有生物炭后，鞘干质量和叶干质量分别平均下降20.2%和25.1%。养分含量，特别是磷、钾和氮，随着 B1、B2 和 B3 的施用而增加。^{生物炭B4（30吨ha -1} ）的施用减轻了对光合器官的损伤，促进了生理恢复。生物炭B4的有益作用在反应中心的剂量为30吨ha ^{-1时发生，提高了光系统II中的光化学效率。}施用生物炭B4刺激了根部发育，使根部面积增加了55%（10吨ha ^-1）和56%（20吨ha ^-1和30吨ha ^-1）。使用生物炭B4时总长度增加了48%，使用生物炭B2时总长度增加了27%（30吨ha ^-1）。粗根长度和总根体积受处理影响较小，分别增加约 11% 和 7%。尽管与对照相比，大多数处理并未导致更高的生物量产量，但地上部分的养分含量显着增加，特别是在施用生物炭 B2 的情况下。此外，还观察到光合参数和根系形态的改善，特别是在施用生物炭 B4 时。总体而言，本研究的结果表明，生物炭 B2 和 B4 的用量分别为 20 吨 ha -1 和 30 吨 ha ^-1，有望增强巴西里约热内卢地区脆弱的 Planosols 的种植。然而，为了充分了解对不同作物土壤性质的影响以及在农业中使用生物炭的经济影响，需要进一步的长期和大规模研究。

图形概要