生物炭对潮土磷有效性、小麦产量及吸磷量的影响

Effects of biochar on phosphorus availability and wheat yield in a fluvo-aquic soil

为探究玉米秸秆生物炭对潮土磷素有效性、小麦产量及吸磷量的影响,采用室内盆栽试验,在潮土中添加0、0.2%、1.0%和5.0%(即CK、MB0.2、MB1.0、MB5.0处理)4个水平的生物炭,分析了不同生物炭用量下潮土磷素有效性、小麦产量及磷素吸收的变化特征。结果表明,随着时间的推移,同一处理下土壤有效磷(AP)含量均逐渐减少,但总体变化不大。在3个关键生育期,土壤AP含量均随生物炭用量的增加而增加;与CK处理相比,成熟期MB0.2、MB1.0和MB5.0处理的土壤AP含量分别显著增加了11.3%、30.5%和167.1%。土壤AP含量与土壤pH、电导率(EC)及有机碳(SOC)含量呈极显著正相关,与土壤磷酸酶活性则呈显著负相关。研究还发现,MB1.0和MB5.0处理产量较CK均显著增加,其中MB1.0处理产量增幅最大,达33.7%。小麦收获后,籽粒磷含量、吸磷量随生物炭用量的增加而增加,其中MB5.0处理的籽粒磷含量和吸磷量均显著高于其它处理,增幅范围分别为21.4%~30.8%、23.0%~68.9%;而处理间植株磷含量和吸收量均无显著性差异(P>0.05)。因此,施入中、高量(MB1.0、MB5.0)生物炭有利于提高潮土磷素有效性、小麦产量及籽粒磷素吸收。

The objectives of this study were to explore the effect of maize straw biochar on soil phosphorus(P)availability,wheat yield and P uptake in a fluvo-aquic soil.In this study,a pot experiment was conducted to investigate the variation characteristics of P availability,wheat yield and P uptake under the application of biochar at ratios of 0,0.2%,1.0% and 5.0%(i.e.,CK,MB0.2,MB1.0 and MB5.0).The results showed that the soil available P(AP)content in each treatment decreased gradually over time,but there was no significant difference.In three growth periods,soil AP contents increased with the increase of biochar rates.The soil AP content increased in the MB0.2,MB1.0 and MB5.0 treatments by 11.3%,30.5% and 167.1% compared with CK treatment,respectively.The soil AP content was positively correlated with soil pH,electrical conductivity(EC)and soil organic carbon(SOC)contents,and negatively correlated with soil phosphatase activity.The results also found that grain yield increased significantly in the MB1.0 and MB5.0 treatments compared with CK,and the MB1.0 treatment showed the largest increase in yield by 33.7%.After wheat harvest,P content and uptake by the grain increased with the increase of biochar rates.The P content and uptake by the grain were significantly higher in the MB5.0 treatment than other treatments,ranging from 21.4% to 30.8% and 23.0% to 68.9%,respectively.However,there was no significant difference in P content and uptake by the plant among treatments(P>0.05).Therefore,the application of biochar at medium and high rates(MB1.0 and MB5.0)were beneficial to improve the soil P availability,grain P uptake and yield.