生物炭基肥对水稻根系有机酸积累和氮代谢的影响

Effect of Biochar-based Fertilizer on Organic Acid Accumulation and Nitrogen Metabolism in Rice Roots

以常规粳稻“盐丰47”为试材,采用盆栽的方式,设常规化肥(T1)、生物炭基肥(T2)和不施氮肥(CK)3个处理,研究不同肥料处理对水稻根系有机酸积累和氮代谢相关生理指标的影响,为辽河平原稻区优化水肥调控措施和减少养分流失提供科学指导。结果表明:与常规化肥相比,生物炭基肥对营养生长期植株根系有机酸含量具有显著影响,其中,苹果酸含量增加了4.98倍,而草酸和酒石酸含量分别降低了50.94%和47.23%;从氮代谢角度来看,生物炭基肥较常规化肥相比根系谷氨酰胺合成酶活性增加了1.38%,亚硝酸还原酶活性降低了1.16%,差异均达显著水平;进一步分析得出,草酸、酒石酸含量与亚硝酸还原酶活性呈显著正相关,而总有机酸、苹果酸和水杨酸含量与各种氮代谢酶活性无显著的相关性。综上,生物炭基肥可促进水稻生育前期根系分泌大量的苹果酸,并可通过增强铵态氮的初级同化和再同化改善植株根系的氮代谢能力。

The conventional japonica rice"Yanfeng 47"as test material was used in this research,three experimental groups(conventional fertilizer,biochar-based fertilizer,and no nitrogen application)were established to study the effects of different fertilizer treatments on nitrogen metabolism-related physiological indicators and organic acid accumulation of rice root through pot experiment.The purpose of our study was to provide a scientific guidance for optimizing water and fertilizer regulation,and reducing nutrient loss in Liaohe Plain Rice Area.The results showed that there was a significant effect on the organic acid content of plant roots during the vegetative growth period when comparing the biochar-based fertilizer against the conventional chemical fertilizer.Among them,the content of malic acid increased by 4.98 times,while the content of oxalic acid and tartaric acid decreased by 50.94%and 47.23%,respectively.As for nitrogen metablolism,Compared with conventional chemical fertilizers,biochar-based fertilizers increased the glutamine synthase activity by 1.38%,while the nitrite reductase activity decreased by 1.16%in plant roots,and the differences reached significant levels.Further analysis shows that the contents of oxalic acid and tartaric acid were significantly positively correlated with the activity of nitrite reductase,while the contents of total organic acid,malic acid and salicylic acid had no significant correlation with the activities of various nitrogen metabolizing enzymes.Clearly,biochar-based fertilizer can promote the root secretion of a large amount of malic acid in the early stage of rice growth,and can improve the nitrogen metabolism of plant roots by enhancing the primary assimilation and re-assimilation of ammonium nitrogen.