1. Liming reduces nitrogen uptake from chemical fertilizer but increases that from straw in a double rice cropping system.
- Author
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Liao, Ping, Liu, Lei, Chen, Jin, Sun, Yanni, Huang, Shan, Zeng, Yongjun, and Jan van Groenigen, Kees
- Subjects
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DOUBLE cropping , *CROPPING systems , *LIMING of soils , *RICE straw , *SOIL acidification , *NITROGEN fertilizers , *PADDY fields - Abstract
Liming materials are widely applied to alleviate soil acidification and increase rice yield in acidic soils, but their effects on nitrogen (N) use efficiency are still unclear. Here, we conducted a field-, pot-, and micro-plot experiment to investigate how the application of slaked lime (i.e., Ca(OH) 2) affects the fate of chemical fertilizer-N and straw-N in a double rice cropping system. In the field experiment, liming increased grain yield and N uptake by an average of 9.0% and 10.6%, respectively. In contrast, CaCl 2 application did not affect rice yield and N uptake, suggesting that the effects of lime application were not related to the addition of Ca2+. Results from a 15N tracer experiment (i.e., 15N-labeled urea and straw) indicated that liming reduced N uptake from fertilizer (−5.7%), but increased N uptake from straw (+31.3%). Liming also reduced soil retention of both urea- and straw-N and increased their loss rates. Taken together, our results indicate that although liming increases rice yield and N uptake, it lowers the use efficiency of fertilizer N and facilitates N losses. In addition, our results emphasize the need for long-term studies on the impact of liming on soil N dynamics in paddy soils. • Liming of an acidic rice paddy soil increased both rice yield and N uptake. • Addition of Ca2+ did not affect rice yield and N uptake. • Liming reduced N uptake from fertilizer but increased that from straw. • Liming reduced soil retention of both urea- and straw-N and increased their loss rates. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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