Purpose

Liming is the most widely used agricultural practice for acidic paddy soils amelioration, which is usually applied before rice transplanting. Both liming and soil moisture can affect the generation of CO₂ and N₂O. This study aimed to investigate the optimal water management strategy after liming in paddy field under the consideration of greenhouse gas (GHG) mitigation.

Materials and methods

A 45-day incubation experiment was conducted to investigate the impact of dolomite application on the CO₂ and N₂O emissions in an acidic paddy soil under three soil moisture levels, including 50% (low, L), 90% (medium, M), and 130% (high, H) of water holding capacity.

Results and discussion

Dolomite application significantly increased CO₂ emissions in all moisture levels, with the highest emission in treatment M and the lowest in L. This result may be attributed to increases in soil pH and dissolved organic carbon (DOC) contents. Dolomite application decreased N₂O emission in all moisture levels, while the significant difference was only detected in treatment H. Dolomite application and soil moisture regulated N₂O fluxes through the alteration of the DOC and mineral nitrogen contents and their stoichiometry in treatments M and H. Dolomite application resulted in an optimal pH that considerably matches the target value (pH 6.50) and the lowest global warming potential in treatment L.

Conclusions

The present study suggests that the response of CO₂ and N₂O emissions to liming is moisture dependent in acidic paddy soil. This study also recommends that maintaining low soil moisture is the optimal water management strategy after dolomite application in the field to mitigate GHG emissions.

中文翻译：

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在酸性水稻土中，响应于白云石施用的CO 2和N 2 O排放取决于湿度

目的

石灰是酸性水稻土改良的最广泛使用的农业实践，通常在水稻移栽前应用。石灰和土壤水分均会影响CO ₂和N ₂ O的产生。本研究旨在研究在考虑温室气体（GHG）缓解的情况下，在稻田中进行石灰后最佳水管理策略。

材料和方法

进行了为期45天的温育实验，研究了在三种土壤水分含量（包括50％（低，L），90％（中，M）下，酸性稻田中白云石施用对CO ₂和N ₂ O排放的影响。）和130％（高H）的持水量。

结果和讨论

白云石的施用显着增加了所有水分含量下的CO ₂排放量，其中处理M的排放量最高，而L的排放量最低。该结果可能归因于土壤pH值和溶解有机碳（DOC）含量的增加。白云石施用降低了所有水分水平下的N ₂ O排放，而仅在处理H中发现了显着差异。白云石施用和土壤水分通过处理M和DOC中DOC和矿质氮含量及其化学计量的变化调节了N ₂ O通量。 H.白云石的使用导致最佳pH值与目标值（pH 6.50）充分匹配，并且处理L的全球变暖潜能最低。

结论

本研究表明，酸性稻田中CO ₂和N ₂ O排放对石灰的响应与湿度有关。这项研究还建议，在田间施用白云石以减少温室气体排放后，保持低土壤湿度是最佳的水管理策略。