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Temporal variations of crop residue effects on soil N transformation depend on soil properties as well as residue qualities.
- Source :
- Biology & Fertility of Soils; Jul2018, Vol. 54 Issue 5, p659-669, 11p
- Publication Year :
- 2018
-
Abstract
- Purple soils (Eutric Regosols) are widely distributed in humid subtropical Southwest China. They are characterized by high nitrification activities, with risks of severe NO<subscript>3</subscript><superscript>−</superscript> leaching. Incorporation of crop residues is considered an effective method to reduce NO<subscript>3</subscript><superscript>−</superscript> loss. In the present study, we compared the effects of alfalfa, rice straw, and sugarcane bagasse on gross N transformation turnover in a purple soil (purple soil, pH 7.62) compared with those in an acid soil (acid soil, pH 5.26), at 12 h, 3 months, and 6 months after residue incorporation. The gross N transformation rates were determined by <superscript>15</superscript>N tracing. All tested crop residues stimulated the gross N mineralization rates, but reduced the net mineralization rates in both soils at 12 h after residue incorporation; however, the extent of the effect varied with the crop residue qualities, with rice straw having the strongest effects. Crop residues reduced net nitrification rates by depressing gross autotrophic nitrification rates and stimulating NO<subscript>3</subscript><superscript>−</superscript> immobilization rates in the purple soil, particularly after rice straw incorporation (net nitrification rate decreased from 16.72 mg N kg<superscript>−1</superscript> d<superscript>−1</superscript> in the control to − 29.42 mg N kg<superscript>−1</superscript> d<superscript>−1</superscript> at 12 h of residue incorporation); however, crop residues did not affect the gross autotrophic nitrification rates in the acid soil. Crop residue effects subsided almost completely within 6 months, with sugarcane bagasse showing the longest lasting effects. The results indicated that crop residues affected the N transformation rates in a temporal manner, dependent on soil properties and residue qualities. [ABSTRACT FROM AUTHOR]
- Subjects :
- REGOSOLS
CROP residues
ACIDITY
SOILS
PLANT residues
Subjects
Details
- Language :
- English
- ISSN :
- 01782762
- Volume :
- 54
- Issue :
- 5
- Database :
- Complementary Index
- Journal :
- Biology & Fertility of Soils
- Publication Type :
- Academic Journal
- Accession number :
- 130103630
- Full Text :
- https://doi.org/10.1007/s00374-018-1291-8