黑土旱地改稻田土壤水稳性团聚体有机碳和全氮的变化特征

doi:10.3864/j.issn.0578-1752.2020.08.009

摘要/Abstract

摘要：

【目的】分析东北黑土旱地改稻田后土壤团聚体组成及其稳定性、各粒级团聚体有机碳、全氮含量及其 ¹³C、 ¹⁵N自然丰度值的动态变化,探讨旱地改稻田后土壤团聚体有机碳、全氮的赋存能力及稳定性,揭示旱地改稻田后土壤团聚体及其有机碳、全氮的演变规律。【方法】选择东北典型黑土旱地土壤（种植大豆年限大于60年,作为对照）和改种不同年限的稻田土壤（3、5、10、17、20和25年,改稻田前种植作物均为大豆）,利用土壤团聚体湿筛分离技术和稳定同位素分析技术,研究旱地改稻田后土壤团聚体有机碳、全氮的动态变化特征。【结果】在0—60 cm土层,与对照土壤相比,改种水稻各年限土壤中2—0.25 mm团聚体组成有所减少,0.25—0.053 mm和<0.053 mm团聚体组成有所增加,>2 mm团聚体组成的变化无明显规律,但旱地改稻田不同年限均以2—0.053 mm团聚体为主;团聚体平均重量直径（MWD）与>2 mm团聚体组成之间呈显著线性正相关关系（P<0.01）,与0.25—0.053 mm、<0.053 mm团聚体组成之间均呈显著线性负相关关系（P<0.01或P<0.05）;水稳性团聚体组成变化受水稻种植年限和土层深度的显著影响,而MWD的变化则受土层深度的显著影响。与对照土壤相比,在0—40 cm土层,2—0.25 mm、0.25—0.053 mm团聚体有机碳和全氮含量在改种水稻3年时均有所下降,在改种水稻3—25年间均随水稻种植年限延长大体上呈增加趋势。总体上,2—0.25 mm、0.25—0.053 mm团聚体是赋存有机碳和全氮的主要粒级;在0—60 cm土层,>2 mm团聚体有机碳、全氮含量与其团聚体组成之间呈显著正相关关系（P<0.01或P<0.05）,在0—20 cm土层,2—0.25 mm团聚体有机碳、全氮含量与其团聚体组成之间也呈显著正相关关系（P<0.01或P<0.05）;<2 mm团聚体有机碳和全氮含量的变化受水稻种植年限影响显著,而>0.25 mm团聚体有机碳和全氮含量的变化则受土层深度影响显著。与对照土壤相比,各粒级团聚体中δ ¹³C在改种水稻3年时均明显增加,在改种水稻5年时均明显下降,在改种水稻5—25年间变化不明显,各粒级团聚体中δ ¹⁵N在改种水稻25年间均略有下降。总体上,在改稻田3—25年间,团聚体中δ ¹³C、δ ¹⁵N的变化受水稻种植年限和土层深度的显著影响,其数值均随粒级的减少而增加,相同年限各粒级团聚体δ ¹³C随着土层的加深而增大,δ ¹⁵N无明显变化规律。【结论】东北典型黑土旱地改稻田25年间,土壤中非水稳性大团聚体遭受破坏形成了粒径较小的团聚体,2—0.053 mm水稳性团聚体是有机碳、全氮固存的主要载体,较小粒级团聚体赋存的有机碳较为稳定,其稳定性随水稻种植年限延长、土层加深而增强。

关键词: 黑土, 旱地, 稻田, 水稳性团聚体, 有机碳, 全氮, ¹³C和 ¹⁵N 自然丰度

Abstract:

【Objective】 The objectives of this study were to analyze the composition and stability of soil aggregate, the changes of organic carbon (OC), total nitrogen (TN) content, natural abundance of ¹³C and ¹⁵N in different-sized aggregates, to explore the sequestration and stability of soil aggregate organic C, TN, and to reveal the evolution of soil aggregate organic C, TN changes after the conversion from upland to paddy field in black soil region of Northeast China.【Method】 Soil samples were collected from upland (soybean planted for over 60 years) in typical black soil and paddy soil with different years (3, 5, 10, 17, 20 and 25 years, soybean was planted in all the fields before conversion to paddy field). The dynamic characteristics of OC and TN in soil aggregates were studied by using wet-sieving method and stable isotope analysis technology.【Result】In the 0-60 cm soil layers, compared with the control treatment, the composition of 2-0.25 mm aggregates in the soil of different years after rice planting was decreased, which of 0.25-0.053 mm and <0.053 mm aggregates was increased. There was no obvious change in the composition of >2 mm aggregates, but the different years of dry land change to paddy fields were dominated by 2-0.053 mm aggregates; the mean weight diameter (MWD) of aggregates was significantly positive correlated with the proportion of >2 mm aggregates (P<0.01), and significantly negative correlated with the proportion of 0.25-0.053 mm and <0.053 mm aggregates (P<0.01 or P<0.05). The change of aggregate composition was significantly affected by different rice planting years and soil depth, whereas the MWD was significantly affected by soil depth. Compared with the control soil, in the 0-40 cm soil layer, the OC and TN contents in the size of 2-0.25 mm and 0.25-0.053 mm aggregates were declined in the 3 years, however there showed increased trend with the extension of rice cultivation in 3-25 years. Generally, OC and TN were mainly accumulated in the 2-0.25 mm and 0.25-0.053 mm aggregates. There existed significant positive correlation between OC and TN contents and aggregate composition in > 2 mm aggregates (P<0.01 or P<0.05) in the 0-60 cm soil layers, as well as 2-0.25 mm aggregates in the 0-20cm soil layer (P<0.01 or P<0.05). The OC and TN contents variation in <2 mm aggregates were significantly affected by rice cultivation time, while soil depth significantly affected >0.25 mm aggregates OC and TN contents. Compared with the control soil, the δ ¹³C in each size of aggregates significantly increased in 3 rice planting years and decreased in 5 rice planting years, respectively, while there was no significant change in the 5-25 rice planting years, and the δ ¹⁵N in all size of aggregates decreased slightly during the 25 years of rice replanting. In general, the δ ¹³C and δ ¹⁵N of soil in aggregates were significantly affected by rice cultivation time and soil depth, which increased with the decreasing of aggregate size. The δ ¹³C increased with soil depth in the same year, while δ ¹⁵N had no significant change.【Conclusion】After the conversion from dry land to paddy field for 25 years, non-water-stable macro-aggregates in the soil were damaged and formed into small sized aggregates. The 2-0.053 mm water-stable aggregates were the main carrier of OC and TN sequestration, while OC in small size aggregates more stable, and its stability was increased by the rice cultivation time and soil depth increased.

Key words: black soil, upland, paddy field, water-stable aggregate, organic carbon, total nitrogen, ¹³C and ¹⁵N natural abundance

马原,迟美静,张玉玲,范庆峰,虞娜,邹洪涛. 黑土旱地改稻田土壤水稳性团聚体有机碳和全氮的变化特征[J]. 中国农业科学, 2020, 53(8): 1594-1605.

MA Yuan,CHI MeiJing,ZHANG YuLing,FAN QingFeng,YU Na,ZOU HongTao. Change Characteristics of Organic Carbon and Total Nitrogen in Water-Stable Aggregate After Conversion from Upland to Paddy Field in Black Soil[J]. Scientia Agricultura Sinica, 2020, 53(8): 1594-1605.

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https://www.chinaagrisci.com/CN/Y2020/V53/I8/1594

图/表 7

表1

图1

图2

表2

表3

旱地改稻田后不同年限土壤团聚体有机碳和全氮含量"

年限 Year (a)	土层深度 Soil depth (cm)	>2 mm		2-0.25 mm		0.25-0.053 mm		<0.053 mm
年限 Year (a)	土层深度 Soil depth (cm)	OC (g·kg^-1)	TN (g·kg^-1)	OC (g·kg^-1)	TN (g·kg^-1)	OC (g·kg^-1)	TN (g·kg^-1)	OC (g·kg^-1)	TN (g·kg^-1)
0	0-20	4.2±0.1	0.3±0.0	14.0±1.5	1.1±0.1	7.7±1.0	0.6±0.1	4.0±0.5	0.3±0.1
	20-40	3.2±0.3	0.2±0.0	10.2±0.7	0.8±0.1	7.1±0.5	0.5±0.1	3.1±0.2	0.2±0.0
	40-60	1.1±0.5	0.1±0.0	7.8±2.1	0.6±0.2	4.6±0.2	0.4±0.0	2.8±0.9	0.2±0.1
3	0-20	2.3±0.4	0.2±0.0	5.7±0.1	0.4±0.0	6.1±0.6	0.5±0.1	3.4±0.4	0.3±0.0
	20-40	0.5±0.1	0.0±0.0	4.7±0.4	0.4±0.0	6.0±1.0	0.5±0.1	4.4±0.9	0.4±0.1
	40-60	0.7±0.2	0.1±0.0	4.9±0.3	0.4±0.0	4.9±1.5	0.4±0.1	3.7±1.1	0.3±0.1
5	0-20	4.4±0.7	0.4±0.8	10.1±0.5	0.8±0.1	7.3±1.2	0.6±0.1	3.9±0.4	0.3±0.0
	20-40	1.6±0.5	0.1±0.0	8.2±0.5	0.6±0.0	9.8±0.6	0.8±0.1	5.2±0.6	0.4±0.1
	40-60	0.6±0.3	0.1±0.0	6.6±1.1	0.5±0.0	8.7±1.0	0.7±0.1	5.7±0.8	0.5±0.1
10	0-20	2.6±0.5	0.2±0.0	8.2±1.6	0.6±0.1	9.1±1.0	0.7±0.1	5.1±0.7	0.4±0.1
	20-40	2.4±1.3	0.2±0.1	7.1±1.0	0.6±0.1	8.8±0.8	0.7±0.0	5.7±0.8	0.5±0.1
	40-60	0.6±0.2	0.0±0.0	6.4±0.5	0.5±0.1	9.2±1.2	0.7±0.1	6.4±0.7	0.5±0.1
17	0-20	8.3±1.0	0.7±0.2	11.2±0.1	0.9±0.2	6.3±0.9	0.5±0.2	3.5±0.3	0.3±0.1
	20-40	6.9±0.9	0.5±0.1	9.0±1.9	0.6±0.1	8.7±2.4	0.6±0.2	4.6±0.9	0.3±0.0
	40-60	0.7±0.1	0.1±0.0	8.8±0.8	0.7±0.1	9.3±0.1	0.8±0.1	6.8±0.9	0.4±0.0
20	0-20	3.1±0.3	0.2±0.0	11.3±1.1	0.8±0.1	11.4±1.6	0.8±0.1	6.0±0.6	0.4±0.0
	20-40	1.9±0.9	0.1±0.0	9.9±1.5	0.7±0.1	8.4±0.5	0.7±0.1	6.2±0.7	0.5±0.1
	40-60	2.2±0.7	0.2±0.1	11.4±0.6	0.7±0.1	7.6±0.4	0.8±0.1	4.4±0.5	0.3±0.0
25	0-20	5.9±0.8	0.4±0.1	15.2±1.8	1.1±0.2	10.9±1.9	0.8±0.2	4.4±1.3	0.3±0.1
	20-40	4.1±1.9	0.3±0.2	10.7±1.1	0.8±0.1	9.6±0.6	0.7±0.1	4.3±1.3	0.3±0.1
	40-60	1.6±0.4	0.2±0.1	5.8±0.9	0.8±0.2	5.9±0.7	0.7±0.1	4.9±0.9	0.5±0.1
双因素方差分析的P值P values of two-ways ANOVA
年限Year		0.030^*	0.070^ns	0.000^***	0.000^***	0.000^***	0.001^***	0.004^**	0.009^**
土层Soil depth		0.000^***	0.000^***	0.000^***	0.000^***	0.004^**	0.884^ns	0.328^ns	0.143^ns
年限×土层 Years×Soil depth		0.680^ns	0.550^ns	0.790^ns	0.220^ns	0.960^ns	0.436^ns	0.228^ns	0.281^ns

表3

表4

表5

旱地改稻田后不同年限土壤团聚体中的δ13C和δ15N"

年限 Year (a)	土层深度 Soil depth (cm)	>2 mm		0.25 mm		0.25-0.053 mm		<0.053 mm
年限 Year (a)	土层深度 Soil depth (cm)	δ¹³C (‰)	δ¹⁵N (‰)	δ¹³C (‰)	δ¹⁵N (‰)	δ¹³C (‰)	δ¹⁵N (‰)	δ¹³C (‰)	δ¹⁵N (‰)
0	0-20	-24.1±0.2	6.5±0.2	-24.1±0.1	6.7±0.4	-24.1±0.2	6.7±0.3ab	-24.1±0.2	7.0±0.2
	20-40	-24.2±0.1	6.8±0.1	-24.1±0.1	7.3±0.2	-23.9±0.1	7.4±0.2ab	-23.8±0.2	7.4±0.0
	40-60	-24.1±0.1	6.2±0.3	-23.7±0.1	7.0±0.1	-23.8±0.0	6.6±0.3ab	-23.8±0.1	7.0±0.3
3	0-20	-23.7±0.2	5.4±0.5	-23.6±0.1	6.2±0.4	-23.3±0.1	6.3±0.3ab	-23.2±0.1	6.3±0.2
	20-40	-23.7±0.3	6.1±0.4	-23.4±0.3	6.3±0.1	-23.3±0.2	6.6±0.2ab	-23.0±0.3	6.5±0.3
	40-60	-23.7±0.6	4.7±0.6	-23.2±0.4	5.8±0.3	-23.0±0.4	6.1±0.2ab	-23.1±0.3	6.0±0.3
5	0-20	-24.3±0.3	6.9±0.5	-24.3±0.2	6.7±0.4	-24.2±0.2	6.8±0.2ab	-24.0±0.1	6.0±0.3
	20-40	-24.5±0.1	6.2±0.1	-24.3±0.1	6.7±0.1	-24.1±0.1	6.7±0.0ab	-24.0±0.1	6.8±0.1
	40-60	-24.6±0.1	5.9±0.3	-23.9±0.2	6.6±0.2	-23.9±0.2	7.0±0.3ab	-23.6±0.1	6.7±0.2
10	0-20	-24.7±0.1	6.0±0.4	-24.7±0.1	5.7±0.3	-24.3±0.2	6.1±0.3ab	-24.1±0.2	6.1±0.2
	20-40	-24.5±0.1	5.8±0.1	-24.3±0.1	6.2±0.1	-24.0±0.2	6.5±0.3ab	-23.9±0.2	6.4±0.1
	40-60	-24.4±0.4	6.0±0.1	-24.0±0.2	6.7±0.2	--23.9±0.2	6.9±0.2ab	-23.8±0.1	7.0±0.2
17	0-20	-24.6±0.3	6.2±0.1	-24.6±0.2	6.1±0.1	-24.5±0.1	6.1±0.3b	-24.3±0.1	6.3±0.4
	20-40	-24.2±0.1	6.3±0.2	-23.9±0.1	6.6±0.2	-23.9±0.1	6.7±0.1ab	-23.8±0.0	6.5±0.2
	40-60	-24.5±0.3	6.5±0.1	-24.0±0.3	7.0±0.1	-24.1±0.2	7.0±0.1ab	-23.9±0.2	7.3±0.2
20	0-20	-24.7±0.1	6.2±0.1	-24.5±0.1	6.4±0.1	-24.2±0.1	6.7±0.1ab	-24.1±0.1	6.6±0.1
	20-40	-23.8±0.4	6.5±0.3	-24.0±0.2	6.9±0.3	-24.0±0.2	7.1±0.2ab	-23.7±0.1	7.2±0.0
	40-60	-23.9±0.1	7.0±00.3	-23.8±0.2	7.0±0.2	-23.7±0.2	7.1±0.2ab	-23.7±0.2	7.0±0.1
25	0-20	-24.7±0.3	5.7±0.1	-24.6±0.1	6.0±0.2	-24.3±0.2	6.2±0.2ab	-24.2±0.2	6.3±0.2
	20-40	-24.2±0.3	6.6±0.2	-24.0±0.3	6.9±0.1	-23.9±0.4	7.5±0.5a	-23.8±0.3	7.7±0.2
	40-60	-24.5±0.5	6.4±0.5	-24.3±0.7	6.2±0.5	-24.1±0.6	6.2±0.4ab	-23.9±0.6	6.2±0.4
双因素方差分析的P值 P values of two-ways ANOVA
年限Year		0.020^*	0.010^**	0.010^**	0.000^***	0.000^***	0.045^*	0.000^***	0.020^*
土层Soil depth		0.280^ns	0.490^ns	0.000^***	0.003^**	0.010^**	0.020^**	0.020^*	0.000^***
年限×土层 Years×Soil depth		0.690^ns	0.100^ns	0.810^ns	0.132^ns	0.970^ns	0.035^*	0.950^ns	0.130^ns

表5

参考文献 41

[1]	WANG Y, ZHANG J H, ZHANG Z H . Influences of intensive tillage on water-stable aggregate distribution on a steep hillslope. Soil and Tillage Research, 2015,151:82-92.
[2]	HUANG R, LAN M L, LIU J, GAO M . Soil aggregate and organic carbon distribution at dry land soil and paddy soil: the role of different straws returning. Environmental Science & Pollution Research, 2017,24(36):1-11.
[3]	SIX J, BOSSUYT H, DEGRYZE S, DENEF K . A history of research on the link between (Micro) aggregates, soil biota, and soil organic matter dynamics. Soil and Tillage Research, 2004,79(1):7-31.
[4]	LIU Y, HU C, HU W, WANG L, LI Z G, PAN J F, CHEN F . Stable isotope fractionation provides information on carbon dynamics in soil aggregates subjected to different long-term fertilization practices. Soil and Tillage Research, 2018,177:54-60.
[5]	贾树海, 张佳楠, 张玉玲 . 东北黑土区旱田改稻田后土壤有机碳、全氮的变化特征, 中国农业科学, 2017,50(7):1252-1262.
	JIA S H, ZHANG J N, ZHANG Y L . Changes of the characteristics of soil organic carbon and total nitrogen after conversation from upland to paddy field in black soil region of Northeast China. Scientia Agricultura Sinica, 2017,50(7):1252-1262. (in Chinese)
[6]	ZHAO J S, CHEN S, HU R G, LI Y Y . Aggregate stability and size distribution of red soils under different land uses integrally regulated by soil organic matter, and iron and aluminum oxides. Soil and Tillage Research, 2017,167:73-79.
[7]	徐香茹, 汪景宽 . 土壤团聚体与有机碳稳定机制的研究进展. 土壤通报, 2017,48(6):1523-1529.
	XU X R, WANG J K . A review on different stabilized mechanisms of soil aggregates and organic carbon. Chinese Journal of Soil Science, 2017,48(6):1523-1529. (in Chinese)
[8]	ZHENG H B, LIU W R, ZHENG J Y, LUO Y, LI R P, WANG H, QI H . Effect of long-term tillage on soil aggregates and aggregate-associated carbon in black soil of Northeast China, PLoS One, 2018,13(6):e199523.
[9]	ZOU P, FU J R, CAO Z H, YE J, YU Q G . Aggregate dynamics and associated soil organic matter in topsoils of two 2,000-year paddy soil chronosequences. Journal of Soils & Sediments, 2015,15(3):510-522.
[10]	WANG P, LIU Y L, LI L Q, CHENG K, ZHENG J F, ZHANG X H, ZHENG J W, JOSEPH S, PAN G X . Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence. Scientific Reports, 2015,5:15704.
[11]	李昌新, 黄山, 彭现宪, 黄欠如, 张卫建 . 南方红壤稻田与旱地土壤有机碳及其组分的特征差异. 农业环境科学学报, 2009,28(3):606-611.
	LI C X, HUANG S, PENG X X, HUANG Q R, ZHANG W J . Differences in soil organic carbon fractions between paddy field and upland field in red soil region of South China. Agro-Environment Science, 2009, 28(3):606-611. (in Chinese)
[12]	YAN X, ZHOU H, ZHU Q H, WANG X F, ZHANG Y Z, YU X C, PENG X . Carbon sequestration efficiency in paddy soil and upland soil under long-term fertilization in Southern China. Soil and Tillage Research, 2013,130:42-51.
[13]	SUN Y N, HUANG S, YU X C, ZHANG W J . Differences in fertilization impacts on organic carbon content and stability in a paddy and an upland soil in Subtropical China. Plant and Soil, 2015,397(1):189-200.
[14]	HUANG S, PAN X H, GUO J, QIAN C R, ZHANG W J . Differences in soil organic carbon stocks and fraction distributions between rice paddies and upland cropping systems in China. Journal of Soils and Sediments, 2014,14(1):89-98.
[15]	PAN G X, WU L S, LI L Q, ZHANG X H, GONG W, WOOD Y . Organic carbon stratification and size distribution of three typical paddy soils from Taihu lake region, China. Environmental Sciences, 2008,20(4):456-463.
[16]	毛霞丽, 陆扣萍, 何丽芝, 宋照亮, 徐祖祥, 杨文叶, 徐进, 王海龙 . 长期施肥对浙江稻田土壤团聚体及其有机碳分布的影响. 土壤学报, 2015(4):828-838.
	MAO X L, LU K P, HE L Z, SONG Z L, XU Z X, YANG W Y, XU J, WANG H L . Effect of long-term fertilizer application on distribution of aggregate-associated organic carbon in paddy doil. Acta Pedologica Sinica, 2015(4):828-838. (in Chinese)
[17]	陈晓芬, 李忠佩, 刘明, 江春玉 . 不同施肥处理对红壤水稻土团聚体有机碳、氮分布和微生物生物量的影响. 中国农业科学, 2013,46(5):950-960.
	CHEN X F, LI Z P, LIU M, JIANG C Y . Effects of different fertilizations on organic carbon and nitrogen contents in water-stable aggregates and microbial biomass content in paddy soil of Subtropical China. Scientia Agricultura Sinica, 2013,46(5):950-960. (in Chinese)
[18]	王欣欣, 符建荣, 邹平, 陈维, 叶静, 俞巧钢, 姜丽娜, 王强 . 长期植稻年限序列水稻土团聚体有机碳分布特征. 应用生态学报, 2013,24(3):719-724.
	WANG X X, FU J R, ZOU P, CHEN W, YE J, YU Q G, JIANG L N, WANG Q . Distribution characteristics of aggregates organic carbon in a paddy soil chronosequence. Chinese Journal of Applied Ecology, 2013,24(3):719-724. (in Chinese)
[19]	WANG H, GUAN D S, ZHANG R D, CHEN Y J, HU Y T, XIAO L . Soil aggregates and organic carbon affected by the land use change from rice paddy to vegetable field. Ecological Engineering, 2014,70:206-211.
[20]	徐文静, 丛耀辉, 张玉玲, 段鹏鹏, 范庆锋, 张玉龙 . 黑土区水稻土水稳性团聚体有机碳及其颗粒有机碳的分布特征. 水土保持学报, 2016,30(4):210-215.
	XU W J, CONG Y H, ZHANG Y L, DUAN P P, FAN Q F, ZHANG Y L . Distribution of organic carbon and partivulate organic carbon in water-stable aggregates of paddy soil in black soil area. Journal of Soil and Water Conversion, 2016,30(4):210-215. (in Chinese)
[21]	窦森, 张晋京 . 用δ ¹³C值研究土壤有机质周转的方法及其评价 . 吉林农业大学学报, 2001,23(2):64-67.
	DOU S, ZHANG J J . Introduction of a method for studying turnover of soil organic matter. Journal of Jilin Agricultural University, 2001,23(2):64-67. (in Chinese)
[22]	BAI E, BOUTTON T W, LIU F, WU X B, HALLMARK C T, ARCHER S R . Spatial variation of soil δ ¹³C and its relation to carbon input and soil texture in a subtropical lowland woodland . Soil Biology & Biochemistry, 2012,44(1):102-112.
[23]	PERI P L, LADD B, PEPPER D A, BONSER S P, LAFFAN S W, AMELUNG W . Carbon (δ ¹³C) and nitrogen (δ ¹⁵N) stable isotope composition in plant and soil in Southern Patagonia's Native Forests . Global Change Biology, 2012,18(1):311-321.
[24]	KULSAWAT W, PORNTEPKASEMSAN B, NOCHIT P . Paddy soil profile dstribution of δ ¹³C subjected to rice straw amendment and burning . Applied Mechanics and Materials, 2019,886:3-7.
[25]	GUNINA A, KUZYAKOV Y . Pathways of Litter C by Formation of aggregates and SOM density fractions: implications from ¹³C natural abundance . Soil Biology and Biochemistry, 2014,71:95-104.
[26]	LIM S S, KWAK J H, LEE K S, CHANG S X, YOON K S, KIM H Y, CHOI W J . Soil and plant nitrogen pools in paddy and upland ecosystems have contrasting δ ¹⁵N . Biology and Fertility of Soils, 2015,51(2):231-239.
[27]	LIU Y, LIU W Z, WU L H, LIU C, WANG L, CHEN F, LI Z G . Soil aggregate-associated organic carbon dynamics subjected to different types of land use: evidence from ¹³C natural abundance . Ecological Engineering, 2018,122:295-302.
[28]	SIX J, ELLIOTT E T, PAUSTIAN K, DORAN J W . Aggregation and soil organic matter accumulation in cultivated and native grassland soils. Soil Science Society of America Journal, 1998,62(5):1367-1377.
[29]	ZHAO J S, CHEN S, HU R G, LI Y L . Aggregate stability and size distribution of red soils under different land uses integrally regulated by soil organic matter, and iron and aluminum oxides. Soil and Tillage Research, 2017,167:73-79.
[30]	VAN VEEN A J, KUIKMAN P J . Soil structural aspects of decomposition of organic matter by micro-organisms. Biogeochemistry, 1990,11(3):213-223.
[31]	JIANG X J, XIE D T . Combining ridge with no-tillage in lowland rice-based cropping system: long-term effect on soil and rice yield. Pedosphere, 2009,19(4):515-522.
[32]	郝翔翔, 杨春葆, 苑亚茹 . 连续秸秆还田对黑土团聚体中有机碳含量及土壤肥力的影响. 中国农学通报, 2013,29(35):263-269.
	HAO X X, YANG C B, YUAN Y R . Effects of continuous straw returning on organic carbon content in aggregates and fertility of black soil. Chinese Agricultural Science Bulletin, 2013,29(35):263-269. (in Chinese)
[33]	徐虎, 张敬业, 蔡岸冬, 王小利, 张文菊 . 外源有机物料碳氮在红壤团聚体中的残留特征. 中国农业科学, 2015,48(23):4660-4668.
	XU H, ZHANG J Y, CAI A D, WANG X L, ZHANG W J . Retention characteristic of carbon and nitrogen from amendments in different size aggregates of red soil. Scientia Agricultura Sinica, 2015,48(23):4660-4668. (in Chinese)
[34]	RABBI S M F, WILSON B R, LOCKWOOD P V, DANIEL H, YOUNG I M . Aggregate hierarchy and carbon mineralization in two oxisols of new south wales, Australia. Soil and Tillage Research, 2015,146:193-203.
[35]	高崇升, 王建国 . 黑土农田土壤有机碳演变研究进展. 中国生态农业学报, 2011,19(6):1468-1474.
	GAO C S, WANG J G . A review of researches on evolution of soil organic carbon in mollisols farmland. Chinese Journal of Eco- Agriculture, 2011,19(6):1468-1474. (in Chinese)
[36]	CHEN Z D, TI J S, CHEN F . Soil aggregates response to tillage and residue management in a double paddy rice soil of the Southern China. Nutrient Cycling in Agroecosystems, 2017,109(9):1-12.
[37]	WANG B S, GAO L L, YU W S, WEI X Q, LI J, LI S P, SONG X J, LIANG G P, CAI D X, WU X P . Distribution of soil aggregates and organic carbon in deep soil under long-term conservation tillage with residual retention in dryland. Journal of Arid Land, 2019,11(2):241-254.
[38]	KÖGEL-KNABNER I, AMELUNG W, CAO Z H, FIEDLER S, FRENZEL P, JAHN R, KALBITZ K, KÖIBI A, SCHLOTER M . Biogeochemistry of paddy soils. Geoderma, 2010,157(1):1-14.
[39]	QIAN J, LIU J J, WANG P F, WANG C, HU J, LI K, LU B, TIAN X, GUAN W Y . Effects of riparian land use changes on soil aggregates and organic carbon. Ecological Engineering, 2018,112:82-88.
[40]	慈恩, 杨林章, 倪九派, 高明, 谢德体 . 不同区域水稻土的氮素分配及δ ¹⁵N特征 . 水土保持学报, 2009,23(2):103-108.
	CI E, YANG L Z, NI J P, GAO M, XIE D T . Distribution and δ ¹⁵N character of nitrogen in paddy soils located in different regions . Journal of Soil and Water Conservation, 2009,23(2):103-108. (in Chinese)
[41]	CHOI W J, RO H M . Differences in isotopic fractionation of nitrogen in water-saturated and unsaturated soils. Soil Biology and Biochemistry, 2003,35(3):483-486.

旱地改稻田年限 Years of the conversion from upland to paddy field (a)	地理坐标 Geographic coordinate	土层 Soil depth (cm)	有机碳 Soil organic carbon (g·kg^-1)	δ¹³C (‰)	全氮 Total nitrogen (g·kg^-1)	δ¹⁵N (‰)	C/N	pH
0	127.533° E, 47.005° N	0—20	28.60	-24.72	2.34	9.25	12.25	5.99
		20—40	22.25	-24.51	1.71	10.43	12.97	5.97
		40—60	15.34	-24.35	1.26	10.82	12.12	5.82
3	127.518° E, 47.001° N	0—20	16.23	-24.04	1.39	6.63	11.64	6.07
		20—40	14.78	-23.67	1.24	7.84	11.98	5.95
		40—60	13.25	-23.52	1.12	8.07	11.69	5.99
5	127.520° E, 47.002° N	0—20	24.09	-24.78	1.99	6.71	12.13	5.79
		20—40	24.50	-24.58	1.94	7.31	12.62	6.23
		40—60	21.63	-23.52	1.78	7.28	12.15	6.10
10	127.528° E, 46.990° N	0—20	23.93	-24.99	1.83	6.05	13.28	5.88
		20—40	22.88	-24.57	1.76	7.50	12.95	5.54
		40—60	22.02	-24.41	1.68	6.52	11.33	5.49
17	127.537° E, 46.997° N	0—20	29.39	-24.91	2.35	6.93	10.95	6.11
		20—40	28.90	-24.58	2.24	6.48	12.86	5.93
		40—60	25.01	-24.62	2.00	6.44	12.53	5.73
20	127.519° E, 46.999° N	0—20	31.61	-25.23	2.49	4.69	12.69	6.26
		20—40	26.08	-24.53	2.04	4.59	12.76	6.27
		40—60	25.71	-24.73	1.99	4.98	12.94	6.07
25	127.538° E, 46.995° N	0—20	36.36	-25.25	2.74	7.06	13.46	6.03
		20—40	28.20	-25.10	2.12	7.08	13.28	6.28
		40—60	19.56	-24.66	2.08	7.80	9.72	6.34

土层 Soil depth (cm)	>2 mm	2-0.25 mm	0.25-0.053 mm	<0.053 mm
0-20	0.984^**	0.485	-0.908^**	-0.854^*
20-40	0.992^**	0.337	-0.920^**	-0.852^*
40-60	0.930^**	0.772^*	-0.827^*	-0.915^**

土层 Soil depth (cm)	>2 mm		2-0.25 mm		0.25-0.053 mm		<0.053 mm
土层 Soil depth (cm)	OC	TN	OC	TN	OC	TN	OC	TN
0-20	0.933^**	0.969^**	0.788^*	0.882^**	0.454	0.460	0.483	0.602
20-40	0.988^**	0.853^*	0.681	0.626	-0.010	-0.087	0.706	0.821^*
40-60	0.868^*	0.885^**	0.267	0.285	0.913^**	0.732	0.709	0.843^*