摘要
【目的】辽春10号和辽春18号小麦是常见的两个小麦品种,但是关于这两个小麦品种在不同施氮量下对维持土壤肥力的差异性方面还未知,因此探讨土壤中活性有机库(微生物量碳氮和土壤可溶性有机碳氮)在各生育期的动态变化,以此来评价土壤活性有机库对不同施氮量的响应以及转化。【方法】以不同品种盆栽小麦为研究对象,在不同施氮量(N0:0 kg·hm^(-2)、N1:45 kg·hm^(-2)、N2:90 kg·hm^(-2)、N3:135 kg·hm^(-2)、N4:180 kg·hm^(-2)、N5:225kg·hm^(-2))的设定下,探究土壤活性有机库在小麦生育期内的动态变化及相互关系。【结果】小麦生育期以及氮水平对土壤微生物量碳氮和可溶性有机碳氮的含量有显著影响(P<0.01);除可溶性有机碳和有机碳外(P>0.05),小麦品种对土壤微生物量碳氮和可溶性有机氮均有显著影响(P<0.01)。施用氮肥能够显著提高土壤微生物量碳氮和可溶性有机碳氮的含量(P<0.05),并且随施氮量的增加,土壤微生物量碳氮和可溶性有机碳氮在N3处理达到最大,然后随施氮量的增加而降低,特别是在N5处理下,土壤可溶性有机碳氮的含量均低于不施氮肥处理(N0);与微生物量氮和可溶性有机碳相比,施用氮肥对土壤微生物量碳和土壤可溶性有机氮含量的增幅更大;土壤微生物量碳/土壤微生物量氮在N5处理下最大(平均值分别为13.28和11.45),而在N3处理下最低(平均值分别为7.94和7.83)。在小麦整个生育期内,土壤微生物量碳氮和可溶性有机碳氮含量均在开花期最大,其次为收获期、拔节期和分蘖期,苗期最小,总的来说,在各个时期土壤可溶性有机碳与微生物量碳以及土壤可溶性有机氮与微生物量氮之间均有着显著的正相关关系(P<0.01);两个不同品种小麦之间,其地上生物量均没有显著差异(P>0.05),但随施氮量的增加,呈先增加后降低的趋势,并且随小麦生育期而增加;而土壤有机碳和土壤全氮也在N3处理达到最大,并且随生育期而增加,在收获期达到最大。【结论】适宜氮量(N3)能够更好地协调土壤中微生物量碳氮和可溶性有机碳氮在小麦生育期内的转化及维持土壤生产力。
【Objective】 Liaochun10 and Liaochun18 are two of the predominant wheat varieties in Northeast China. However, the difference of the two wheat varieties in sustaining soil quality is still not well understood. It is worth to study the responses and transformation of soil microbial biomass C and N（SMBC, SMBN）, soil soluble organic C and N（SSOC, SSON） to different application rates of N. 【Method】 A pot experiment was conducted with different wheat varieties and six treatments were designed, i.e., N0： 0 kg·hm^-2, N1： 45 kg·hm^-2, N2： 90 kg·hm^-2, N3： 135 kg·hm^-2, N4： 180 kg·hm^-2, and N5： 225 kg·hm^-2. The responses of soil microbial biomass C and N, soil soluble organic C and N to different application rates of N fertilizer were studied. 【Result】 Results from repeat measures ANOVA indicated that both sampling period and N rates had significant effects on SMBC, SMBN, SSOC and SSON contents（P〈0.01）. The SMBC, SMBN, SSON were significantly affected by wheat varieties, but not the SSOC and SOC（P〈0.05）. SMBC, SMBN, SSOC and SSON were higher in the N fertilized treatments than N0 treatment（P〈0.05）, and were the highest in the N3 treatment and then decreased with the application rate of N, especially in the N5 treatment, the SSOC and SSON contents were lower than N0. The SMBC and SSON contents were significantly increased in N fertilizer treatments compared to SMBN and SSOC. In addition, while the responses of SMBC, SMBN, SSOC, and SSON to application rate of N were mostly quadratic or cubic equation. SMBC/SMBN was the lowest in the N3 treatment（the mean of two wheat varieties was 7.94 and 7.83, respectively） and the highest in the N5 treatment（the mean of two wheat varieties was 13.28 and 11.45, respectively）. During the wheat growing period, the SMBC, SMBN, SSOC and SSON contents generally were the highest at flowering, followed by harvesting, jointing, tillering and seeding. In general, the impact of treatments（different application rates of N） on SMBC, SMBN, SSOC and SSON was more significant than seasonal fluctuation, and significant positive relationships were found between SSOC and SMBC and between SSON and SMBN（P〈0.01）. There was no significant difference（P〉0.05） in aboveground biomass of wheat between Liaochun 10 and Liaochun 18 throughout most of the wheat growing season, but it was decreased slightly after a increase and tended to the peak in N3 treatment with the application rate of N; SOC and soil TN were the highest in N3 treatment and harvest period. 【Conclusion】 In this experiment, appropriate application rate of N fertilizer（N3, 135 kg·hm^-2） had a high ability to modulate the transformation of SMBC, SMBN, SSOC and SSON throughout the wheat growth period and sustainable soil productivity.
出处
《中国农业科学》
CAS
CSCD
北大核心
2016年第7期1315-1324,共10页
Scientia Agricultura Sinica
基金
国家现代农业产业技术体系水稻产业辽宁创新团队建设(辽农科[2013]271号)
