三種綠肥在浸水土壤可溶性有機碳的變化

The Changes of Dissoluble Organic Carbon in Submerged Soil Amended with Green Manures

林晉卿(C. C. Lin) ； 楊秋忠(C. C. Young) ； 林宏鋕(H. Z. Lin) ； 黃山內(S. N. Huang)

《臺南區農業改良場研究彙報》 47期 (2006/06) Pp. 17-30

https://doi.org/10.29558/XLZY.200606.0003

摘要

為瞭解南部地區三種常用綠肥作物（田菁、太陽麻及綠肥大豆台南4號）在浸水土壤有機質的分解情形，二氧化碳的釋放與可溶性有機碳的相關性。本實驗將三種綠肥分別加入兩種土壤（砂頁岩沖積土及紅壤）中，於浸水、25℃的孵育條件下，觀察之。實驗結果顯示，添加綠肥的處理確實造成土壤pH、有機質、二氧化碳的釋放速率及可溶性有機碳的濃度等性質的差異表現。不同處理兩種土壤的可溶性有機碳濃度的增加，均以孵育開始的前7天最快。綠肥處理的沖積土，土壤中累積可溶性有機碳濃度的最高點，出現略慢於二氧化碳釋放速度的高點，但綠肥處理的的紅壤，於土壤中累積可溶性有機碳的濃度已開始下降時，二氧化碳的釋放速率仍維持在高點。然大體觀之，二氧化碳釋放速率的高峰期出現在第2週至第5週，此與土壤累積可溶性有機碳的濃度有相似的趨勢，因此藉由監測土壤的二氧化碳釋放速率，應可推估土壤中累積可溶性有機碳的濃度出現的高峰期。

關鍵字

綠肥 ； 孵育 ； 二氧化碳的釋放 ； 可溶性有機碳

並列摘要

This study investigates the correlation between CO2 evolution and cumulative dissoluble organic carbon in terms of amending three kinds of green manures, namely sesbania, cratalaria, and soybean Tainan no. 4, which are commonly used in southern Taiwan, in two types of submerged soil, namely sandy alluvial and red soil under an incubating temperature of 25℃. Experimental results reveal that variation of chemical properties, e.g. soil pH, organic materials, CO2 evolution, cumulative dissoluble organic carbon, etc. was significantly influenced by addition of green manures. Acceleration of cumulative dissoluble organic carbon in both treated soils exhibits the fastest speed in the earliest seven days after incubation. For sandy alluvial treated with green manures, appearance of the highest concentration of cumulative dissoluble organic carbon is slower than the approaching point of the highest CO2 evolution rate. However, for red soil treated with green manures, CO2 evolution rate remains at the highest speed as the cumulative dissoluble organic carbon concentration is decreasing. In general, the highest CO2 evolution rate appears in the second to the fifth weeks, which reveals a similar tendency with the one of the cumulative dissoluble organic carbon concentration. Thus, monitoring the CO2 evolution rate in soil helps to identify the peak of cumulative dissoluble organic carbon concentration.

並列關鍵字

Green manure ； incubation ； CO2 evolution rate ； dissoluble organic carbon