红壤区施用稻草源生物炭对烟叶钾含量的影响

Application of Rice Straw-derived Biochar Increasing Potassium Content of Tobacco Leaves in Red Soil

在红壤区,土壤钾素缺乏严重限制了烟草的需钾能力和品质提升。本研究以稻草源的生物炭为切入点,分别在水稻土和旱地红壤上设不施钾肥(CK)、化学钾肥(FK)、60%化学钾肥配施40%的稻草钾肥(60%FK+40%SK)、60%化学钾肥配施40%的生物炭钾肥(60%FK+40%BK)等4个处理,分析烤烟产量和烟叶钾素含量以及土壤速效钾含量。结果表明,与CK和FK相比,60%FK+40%SK和60%FK+40%BK处理可以显著提高烟叶产量和烟叶钾含量,且水稻土明显高于旱地红壤。在所有处理中,均呈现出60%FK+40%BK处理的增幅最高。与CK相比,水稻土上60%FK+40%BK、60%FK+40%SK和FK处理的土壤速效钾含量分别增加了48.43%、40.88%和11.95%,旱地红壤上的增幅分别为29.63%、22.96%和20.00%。进一步分析表明,土壤速效钾含量与烟叶钾含量呈显著的正相关关系(p<0.05)。通过拟合方程发现,盆栽试验条件下,水稻土和旱地红壤的速效钾含量增加10mg/kg,烟叶钾含量可以增加0.12%,但还有待进一步验证。因此,在红壤地区,施用稻草源的生物炭可以替代40%的化学钾肥,且可以保证烟叶产量和提高烟叶钾含量。

In the red soil area,soil potassium (K)deficiency severely limites the K uptake and quality of tobacco.In this study,one field experiment of straw-derived biochar application was carried out in red upland and paddy soil,which including non K fertilizer (CK),chemical K fertilizer (FK),60%chemical K with 40%straw K fertilizers (60%FK + 40%SK),and 60%chemical K with 40%biochar K fertilizers (60%FK +40%BK).The yield of tobacco leaves,K content and the content of soil available K (sodium tetraborate method)were analyzed.60%FK +40%SK and 60%FK +40%BK treatments could significantly increase tobacco yield and the K content of tobacco leaves than CK and FK, and the paddy soil was significantly higher than that of upland soil.Among all treatments,60%FK +40%BK treatment was the highest in tobacco yield and K content of tobacco leaves.This was related to the increase of soil available K through biochar and straw.Compared with CK,soil available K content in paddy soil increased by 48.43%,40.88% and 11.95% on 60% FK +40% BK,60% FK +40% SK and FK,respectively,and it was 29.63% 22.96% and 20.00% in upland soil,respectively.Meanwhile,there was a significant positive correlation between soil available K content and K content of tobacco leaves (p<0.05).The fitted equations showed K content in tobacco leaves could increase by 0.12%, while the soil available K contents increase by 10 mg/kg in paddy and upland red soils.However,the fitted equation would be verified through field experiments.Therefore,the application of straw-derived biochar can replace 40% of chemical K fertilizers,and also guarantee tobacco yield and improve the tobacco K content.