[1]ZHAO Fa-zhu,HAN Xin-hui,YANG Gai-he,et al.Change Characteristics of Density of Soil Organic Carbon and Nitrogen under Land Shifted into Forestland in Hilly Loess Region[J].Research of Soil and Water Conservation,2012,19(04):43-47,52.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
19
Number of periods:
2012 04
Page number:
43-47,52
Column:
Public date:
2012-08-20
- Title:
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Change Characteristics of Density of Soil Organic Carbon and Nitrogen under Land Shifted into Forestland in Hilly Loess Region
- Author(s):
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ZHAO Fa-zhu1,2, HAN Xin-hui2,3, YANG Gai-he2,3, TONG Xiao-gang4, KANG Le1, DU Yue-han2,3
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1. College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China;
2. The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling, Shaanxi 712100, China;
3. College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China;
4. College Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
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- Keywords:
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conversion of cropland to forestland; soil organic carbon; soil nitrogen; Hilly Loess Region
- CLC:
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Q948.113
- DOI:
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- Abstract:
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This study was conducted to determine the change characteristics of the density of soil organic carbon and total nitrogen and distribution in soil layers of 0-60 cm with 10-40 years of conversion of cropland to forest in Hilly Loess Region. The results showed that: compared different soil layers in forestland shifted from cropland for 10-40 years, the average organic carbon density in 0-20 cm soil layer of caragana, orientalis and robinia was 4.20, 6.87, 4.46 Mg/hm2, which was higher than that in 20-60 cm soil layer in caragana, orientalis and robinia forest land, respectively, and average nitrogen density was increased 0.08, 0.02, 0.07 Mg/hm2, which was higher than that in 20-60 cm soil layer, respectively. Compared with slope farmland, the organic carbon sequestration rate in 0-20 cm soil layer within 30 years of conversion of cropland to forestland follow the order of orientalis (0.33 Mg·hm-2·a-1)>robinia (0.28 Mg·hm-2·a-1)>caragana (0.17 Mg·hm-2·a-1), and nitrogen sequestration rate follow the order of robinia (0.03 Mg·hm-2·a-1)>orientalis (0.02 Mg·hm-2·a-1)>caragana (0.01 Mg·hm-2·a-1). The carbon and nitrogen sequestration rate of 0-20 cm soil layer was higher than that in deep soil layer. Average 57% of increased soil organic carbon and 51% of increased nitrogen were contributed by 0-20 cm soil during 10-30 years of conversion of cropland to forest. The ratio of C/N decreased with soil depth under all lands of conversion of cropland to forest. In conclusion, conversion of cropland to forestland could significantly increase soil carbon and nitrogen stocks, and orientalis was better for carbon sequestration and robinia was better for nitrogen sequestration.