不同有機質材在不同土壤水分與溫度條件下之碳與氮之礦化作用

Effects of Soil Moisture and Temperature on Mineralization of Carbon and Nitrogen of Different Organic Materials

莊作權(Tzo-Chuan Juang) ； 李英明(Ying-Ming Li) ； 陳鴻基(Horng-Ji Chen)

《土壤與環境》 1卷2期 (1998/06) Pp. 135-152

https://doi.org/10.30058/SE.199806.0005

摘要

室內孵育試驗，以1g有機質材（泥炭、堆肥、田菁和埃及三葉草）與200g土壤混合。於不同溫度、不同水分狀況下，測定不同時間CO2釋放速率連續變化情形，土壤pH及氮素的變化，並計算不同有機質材在土壤中不同溫度水份孵育後之短期碳及氮礦化潛能及礦化速率常數。室內孵育試驗結果顯示溫度愈高CO2釋放速率愈快。有機質材於半量田間容水量及田間容水量狀況下恆溫孵育，土壤中CO2釋放速率以35°C最大，25°C次之，15°C最小。而且初期（0至12天）有機質材在土壤中CO2釋放速率明顯大於後期。不同溫度及不同水分狀況下恆溫孵育，土壤中有效性氮淨礦化累積量以堆肥處理最大，埃及三葉草次之，泥炭幾無淨氮礦化累積量。田菁處理於田間容水量、半量田間容水量水分狀況下，15及25°C恆溫孵育出現淨氮生物固定化作用，於35°C恆溫孵育始出現淨氮礦化作用。田間容水量及半量田間容水量恆溫孵育，土壤pH值隨孵育期而下降。淹水3cm水分狀況下恆溫孵育，土壤pH值於孵育初期急遽上升，其後漸趨和緩而達到平衡。

關鍵字

有機質材 ； 土壤水分 ； 溫度 ； 碳礦化 ； 氮礦化

並列摘要

One gram of oven-dried organic materials (peat, compost, Sesbania and Egyptian clover) and 200 g of soil were mixed and then incubated under different temperature regimes and different moisture contents. The CO2 releasing rates of, soil pH, NH4^+ -N and NO3^- -N were determined on 4, 8, 16, 24, 32 and 56 d after incubation. The short-term C mineralization potential and mineralization rate constant of various organic materials were calculated after incubation at different temperature and soil moisture regimes: These incubation studies show ed that the CO2 releasing rate increased with increasing temperature. When organic materials were incubated under the moisture conditions of field capacity and half field capacity, the CO2 releasing rate was the highest at 35°C; 25°C the next; and 15°C the lowest. The CO2 releasing rate was found higher in early 0-12 days than that in the later days. The highest cumulative amount of net N mineralization was found in compost treatments, followed by Egptian clover and peat treatments. For the Sesbania treatment under the conditions of field capacity and half field capacity, the net N immobilization occurred at 15°C and 25°C, whereas the net N minerlization was appeared at 35°C. The soil pH rose in the early period and these dropped down during the incubation period. When incubated under flooded water (3 cm) condition, the soil pH increased quickly at the early period and then became smooth gradually.

並列關鍵字

Organic materials ； Soil moisture ； Temperature ； Carbon ； mineralization ； Nitrogen mineralization