Journal of Integrative Agriculture ›› 2015, Vol. 14 ›› Issue (12): 2405-2416.DOI: 10.1016/S2095-3119(15)61205-9

• 论文 • 上一篇    下一篇

Soil aggregation and aggregate associated organic carbon and total nitrogen under long-term contrasting soil management regimes in loess soil

 XIE Jun-yu, XU Ming-gang, Qiangjiu Ciren, YANG Yang, ZHANG Shu-lan, SUN Ben-hua, YANG Xue-yun   

  1. 1、College of Resources and Environment, Northwest A&F University, Yangling 712100, P.R.China
    2、Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Northwest A&F University,
    Yangling 712100, P.R.China
    3、National Engineering Laboratory for Improving Quality of Arable Land, Institute of Agricultural Resources and Regional Planning,
    Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China
    4、Agriculture and Animal Husbandry in Cona County, Shannan 856700, P.R.China
    5、Department of Agronomy, Hetao College, Bayannur 015000, P.R.China
  • 收稿日期:2015-04-27 出版日期:2015-12-01 发布日期:2015-12-16
  • 通讯作者: ZHANG Shu-lan, E-mail: zhangshulan@nwsuaf.edu.cn; YANG Xue-yun, Tel/Fax: +86-29-87088120,E-mail: xueyunyang@hotmail.com
  • 基金资助:

    This study was financially supported by the Special Fund for Agro-scientific Research in the Public Interest of China (201203030) and the Agricultural Scientific Research Talent and Team Program of China.

Soil aggregation and aggregate associated organic carbon and total nitrogen under long-term contrasting soil management regimes in loess soil

 XIE Jun-yu, XU Ming-gang, Qiangjiu Ciren, YANG Yang, ZHANG Shu-lan, SUN Ben-hua, YANG Xue-yun   

  1. 1、College of Resources and Environment, Northwest A&F University, Yangling 712100, P.R.China
    2、Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Northwest A&F University,
    Yangling 712100, P.R.China
    3、National Engineering Laboratory for Improving Quality of Arable Land, Institute of Agricultural Resources and Regional Planning,
    Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China
    4、Agriculture and Animal Husbandry in Cona County, Shannan 856700, P.R.China
    5、Department of Agronomy, Hetao College, Bayannur 015000, P.R.China
  • Received:2015-04-27 Online:2015-12-01 Published:2015-12-16
  • Contact: ZHANG Shu-lan, E-mail: zhangshulan@nwsuaf.edu.cn; YANG Xue-yun, Tel/Fax: +86-29-87088120,E-mail: xueyunyang@hotmail.com
  • Supported by:

    This study was financially supported by the Special Fund for Agro-scientific Research in the Public Interest of China (201203030) and the Agricultural Scientific Research Talent and Team Program of China.

摘要: This study investigated the effects of three contrasting soil management regimes and different nutrient treatments on the distribution of water-stable aggregates (>2, 1–2, 0.5–1, 0.25–0.5, and <0.25 mm) and associated soil organic carbon (SOC) and total nitrogen (TN) content in loess soil. A 21-yr long-term experiment was performed, in which soil management regimes include cropland abandonment (Abandonment), bare fallow (Fallow) and wheat-fallow cropping (Cropping). Under Cropping, the following nutrient treatments were employed: control (CK, no nutrient input), nitrogen only (N), nitrogen and potassium (NK), phosphorus and potassium (PK), NP, NPK, and manure (M) plus NPK (MNPK). Results demonstrated that Abandonment significantly increased the content of soil macro-aggregates (>0.25 mm) and mean weight diameter (MWD) at 0–10 and 10–20 cm soil horizons compared with Cropping, whereas Fallow yielded lower values of above two parameters. Abandonment increased SOC and TN contents in all aggregate sizes by 17–62% and 6–60%, respectively, at 0–10 cm soil layer compared with Cropping. Conversely, Fallow decreased SOC and TN contents in all aggregates by 7–27% and 7–25%, respectively. Nevertheless, the three soil management regimes presented similar SOC contents in all aggregates at 10–20 cm soil horizon. Only Cropping showed higher TN content in >0.5 mm aggregates than the two other regimes. Consequently, Abandonment enhanced the partitioning proportions of SOC and TN in >1 mm macro-aggregates, and Fallow promoted these proportions in micro-aggregates compared with Cropping. Under Cropping, long-term fertilization did not affect the distribution of aggregates and MWD values compared with those under CK, except for NPK treatment. Fertilizer treatments enhanced SOC and TN contents in aggregates at all tested soil depths. However, fertilization did not affect the partitioning proportions of SOC and TN contents in all aggregates compared with CK. Comprehensive results showed that different soil management regimes generated varied patterns of SOC and TN sequestration in loess soil. Abandonment enhanced soil aggregation and sequestered high amounts of SOC and TN in macro-aggregates. Long-term amendment of organic manure integrated with NPK maintained soil aggregate stability and improved SOC and TN sequestration in all aggregates in loess soil subjected to dryland farming.

关键词: cropland abandonment , bare fallow , wheat-fallow , water-stable aggregate , aggregate stability

Abstract: This study investigated the effects of three contrasting soil management regimes and different nutrient treatments on the distribution of water-stable aggregates (>2, 1–2, 0.5–1, 0.25–0.5, and <0.25 mm) and associated soil organic carbon (SOC) and total nitrogen (TN) content in loess soil. A 21-yr long-term experiment was performed, in which soil management regimes include cropland abandonment (Abandonment), bare fallow (Fallow) and wheat-fallow cropping (Cropping). Under Cropping, the following nutrient treatments were employed: control (CK, no nutrient input), nitrogen only (N), nitrogen and potassium (NK), phosphorus and potassium (PK), NP, NPK, and manure (M) plus NPK (MNPK). Results demonstrated that Abandonment significantly increased the content of soil macro-aggregates (>0.25 mm) and mean weight diameter (MWD) at 0–10 and 10–20 cm soil horizons compared with Cropping, whereas Fallow yielded lower values of above two parameters. Abandonment increased SOC and TN contents in all aggregate sizes by 17–62% and 6–60%, respectively, at 0–10 cm soil layer compared with Cropping. Conversely, Fallow decreased SOC and TN contents in all aggregates by 7–27% and 7–25%, respectively. Nevertheless, the three soil management regimes presented similar SOC contents in all aggregates at 10–20 cm soil horizon. Only Cropping showed higher TN content in >0.5 mm aggregates than the two other regimes. Consequently, Abandonment enhanced the partitioning proportions of SOC and TN in >1 mm macro-aggregates, and Fallow promoted these proportions in micro-aggregates compared with Cropping. Under Cropping, long-term fertilization did not affect the distribution of aggregates and MWD values compared with those under CK, except for NPK treatment. Fertilizer treatments enhanced SOC and TN contents in aggregates at all tested soil depths. However, fertilization did not affect the partitioning proportions of SOC and TN contents in all aggregates compared with CK. Comprehensive results showed that different soil management regimes generated varied patterns of SOC and TN sequestration in loess soil. Abandonment enhanced soil aggregation and sequestered high amounts of SOC and TN in macro-aggregates. Long-term amendment of organic manure integrated with NPK maintained soil aggregate stability and improved SOC and TN sequestration in all aggregates in loess soil subjected to dryland farming.

Key words: cropland abandonment , bare fallow , wheat-fallow , water-stable aggregate , aggregate stability