Abstract:

To investigate the influence of biochar on the consumption of soil microbial carbon sources and spring wheat yield， a randomized block design experiment was devised. 3 nitrogen levels including 0（N0）， 300（N1）， 255 kg hm^-2（N2）and 4 biochar levels including 0（B0）， 10×10³（B1）， 20×10³（B2），30×10³ kg hm^-2（ B3）were tested， resulting in 12 treatments. The carbon source metabolism features of soil microbes and wheat yield were investigated. The results showed that，compared to control （N0B0）， the average well color development （AWCD） and Mcintosh index （U） of each treatment showed an upward trend， with the highest soil microbial AWCD and U values found in the conventional nitrogen fertilizer combined with a medium amount of biochar （N1B2） treatment. They were 0.93 and 5.83， which was 52.5% and 36.3% higher than control， respectively. The Shannon index of soil microorganisms showed an upward trend as the biochar dose increased at the nitrogen fertilizer reduction level. The majority of soil microbes utilized ester carbon sources， but alcohol carbon sources were rarely utilized. Under different conditions， the ability of microbes to utilize different carbon sources varied. Principal component analysis revealed that amino acids， sugars， acids， and alcohols accounted for the majority of changes in soil microbial community consumption of six accessible carbon sources between different treatments. The functional diversity index of the soil microbial population associated positively with spring wheat yield. Spring wheat yields could reach 8 301.35 kg·hm^-2 when treated with N2B2， a 22.1% increase over traditional nitrogen fertilizer （B0N1）. In conclusion， nitrogen fertilizer and biochar could enhance the activity of soil microorganisms， alter the microbial ecology of the soil， support the growth of spring wheat， and increase wheat yield，which could provide a foundation for the application and promotion of biochar in the northern Xinjiang irrigation region.

Key words: nitrogen fertilizer, biochar, microbial functional diversity, yield

摘要：

为探究氮肥减量条件下添加生物质炭对农田土壤微生物碳源利用及春小麦产量的影响，采用随机区组试验设计，设置0（N0）、300（N1）、255 kg·hm^-2（N2）3个氮肥水平和0（B0）、10×10³（B1）、20×10³（B2）、30×10³ kg·hm^-2（B3）4个生物质炭水平，共计12个处理，研究氮肥减量配施生物质炭对麦田土壤微生物群落碳源代谢特征和小麦产量的影响。结果表明，与对照（N0B0）相比，各处理平均颜色变化率（average well color development，AWCD）和Mcintosh指数（U）均呈上升趋势，其中氮肥常规用量配施中量生物质炭（N1B2）处理土壤微生物AWCD、U值最高，分别为0.93、5.83，分别比N0B0处理提高52.5%、36.3%；氮肥减量水平下，随生物质炭用量增加土壤微生物Shannon指数呈增加趋势；土壤微生物主要利用酯类碳源，对醇类碳源利用整体偏低，不同处理下微生物对不同碳源的利用能力有所不同。主成分分析显示，不同处理间土壤微生物群落对6类可利用碳源利用差异主要在于氨基酸类、糖类、酸类和醇类；土壤微生物群落功能多样性指标与春小麦产量呈正相关，当减量氮肥配施中量生物质炭（N2B2处理）时，春小麦产量可达8 301.35 kg·hm^-2，与常规施用氮肥（B0N1处理）相比增产22.1%，综上所述，氮肥配施生物质炭能够提高土壤微生物活性，改善土壤微生物环境，促进春小麦生长，提高产量。研究结果可为生物质炭在北疆灌区的应用和推广提供依据。

关键词: 氮肥, 生物质炭, 微生物功能多样性, 产量