生物炭对双季稻生长与土壤理化性质的影响及其后效

Effects of biochar on double-season rice growth and soil physical and chemical properties and its aftereffects

为探究南方双季稻田施用生物炭的后效,对比分析了当年新施用生物炭(施用量分别为0、20和40 t·hm^(-2),以B0、B_(20)、B_(40)表示)和前2年施用生物炭(施用量与B_(20)、B_(40)相同,分别以Y_(2)B_(20)、Y_(2)B_(40)表示)分别对双季稻生长与土壤理化性质的影响,以期为生物炭的合理施用提供理论和科学依据。结果表明,生物炭及其后效均能够显著提高土壤p H、有机碳和速效钾含量,其中新施生物炭效应增幅均高于生物炭后效。与B0相比,新施生物炭能够显著提高早、晚稻产量与地上部生物量,B_(20)和B_(40)早稻产量分别显著提高6.9%、12.6%,晚稻产量分别显著提高9.4%、8.3%;Y_(2)B_(20)、Y_(2)B_(40)早稻产量相较于B0分别显著下降3.4%、4.6%,对晚稻产量无显著影响。新施生物炭处理中,早稻和晚稻茎、叶中氮素与磷素含量均显著降低,而钾素含量随着生物炭施用量的增加呈显著上升趋势。前2年施用生物炭处理对早、晚稻氮素与磷素吸收量均无显著影响,仅Y_(2)B_(40)显著提高了晚稻钾素吸收量。新施生物炭处理氮、磷、钾吸收量随着生物炭施用量增加均呈上升趋势。与B0相比,B_(40)晚稻氮素吸收量显著增加9.9%,B_(20)和B_(40)早稻磷素吸收量分别显著增加9.9%、9.1%,B_(40)晚稻磷素吸收量显著增加9.1%;B_(20)、B_(40)早稻钾素吸收量分别显著提高22.8%、39.9%,晚稻分别显著提高9.9%、19.5%。综上所述,施用秸秆生物炭对双季稻产量、地上部生物量、养分吸收量与土壤理化性质的影响存在后效作用,但是其后效较短,应考虑适当补施生物炭。

In order to explore the aftereffects of applying biochar in the double-season rice fields in southern China,this study compared and analyzed the effects of new biochar application(application rates are 0,20 and 40 t·hm^(-2),expressed as B0,B_(20) and B_(40))and biochar application two years ahead(the application rate is the same as B_(20) and B_(40),respectively expressed as Y_(2) B_(20) and Y_(2) B_(40))on the growth of double-season rice and the physical and chemical properties of the soil,with a view to providing theoretical and scientific basis for the rational application of biochar.The results showed that biochar and its after effect significantly increased pH,the content of soil organic carbon and available potassium,and the effect of newly applied biochar was higher than that of biochar applied 2 years in advance.Compared with B0,the new application of biochar significantly increased the yield of early and late rice and aboveground biomass.The yields of B_(20) and B_(40) early rice were significantly increased by 6.9% and 12.6% respectively,and the yield of late rice was significantly increased by 9.4% and 8.3% respectively;for Y_(2) B_(20) and Y_(2) B_(40),compared with B0,the yield of early rice decreased significantly by 3.4% and 4.6%,respectively,and had no significant effect on the yield of late rice.In the newly applied biochar treatment,the nitrogen and phosphorus contents in the stems and leaves of early rice and late rice were significantly reduced,while the potassium content showed a significant upward trend with the increase of biochar application.The application of biochar treatment two years ahead had no significant effect on the absorption of nitrogen and phosphorus in early rice and late rice. Only Y_(2) B_(40) significantly increased the absorption of potassium in late rice.The absorption of nitrogen,phosphorus and potassium in the newly applied biochar showed an upward trend with the increase of biochar application.Compared with B0,nitrogen absorption of B_(40) late rice increased significantly by 9.9%,phosphorus absorption of B_(20) and B_(40) early rice increased significantly by 9.9% and 9.1%,respectively,and phosphorus absorption of B_(40) late rice increased significantly by 9.1%;the absorption amount of potassium of B_(20) and B_(40) early rice increased significantly by 22.8% and 39.9%,respectively,and the late rice increased significantly by 9.9% and 19.5%.In summary,there is an aftereffect of the application of straw biochar on the yield,aboveground biomass,nutrient absorption of double-season rice and soil physical and chemical properties,but its aftereffect is shorter,and appropriate supplementation of biochar should be considered.