Changes in Phosphorus Availability and Productivity of Strongly Acidic Red Clay Soil with Compost Application

施用堆肥對強酸性紅黏土壤生產力與磷有效性的影響

Babou Ousman Jobe ； 蔡秀隆(Shiow-Long Tsai) ； 許正一(Zeng-Yi Hseu)

《中華農學會報》 8卷4期 (2007/08) Pp. 275-296

https://doi.org/10.6730/JAAC.200708_8(4).0001

摘要

本研究採用未經耕作的極育土為試驗土壤，芥藍菜作為生物檢測的材料，探討施用堆肥及石灰對極育土中磷的吸附行為以及植物可利用性的影響。研究結果顯示，本參試土壤含高量的鋁與鐵，施用石灰反而加重對磷的吸附作用。以六種不同成分的堆肥混合土壤孵育試驗的結果得知，堆肥可以顯著的減少磷的吸附。低石灰潛勢（低質子消耗能力）的堆肥在減少磷吸附的效果最好，質子消耗能力與磷吸附作用之間呈現高的線性關係Y=0.09X+385, R^2=0.94(上標 **)同時全磷含量與Bray 1-磷含量之間呈現高的線性關係Y=6.41x+8.1, R^2=0.92(上標 **)，此意味著磷－礦化作用在磷有效性上擔負著舉足輕重的機制。具有高pH緩衝能力的堆肥，即使全磷含量不是最低，其在減少磷吸附的效果最差，此說明了鋁的水解與鋁氫氧化物的聚合作用形成新的吸附位置或是形成難溶的磷酸鋁化合物的可能性。堆肥的施用顯著改善植物對磷的利用效率，增加磷的吸收與乾物質產量。此乃由於堆肥的施用適當的提高pH值使得可交換的鋁沉澱、磷的釋放而增加磷的可溶性的結果。增加有關磷的釋放、pH緩衝能力與陰離子競爭作用之間的關係的知識，將可改善堆肥施用效率，以作為經營管理極育土壤的策略手段。

關鍵字

極育土 ； 有機質肥料 ； 石灰 ； 磷吸附 ； pH緩衝能力 ； 磷可利用性 ； 生產力

並列摘要

Experiments were conducted on an uncultivated strongly acidic clayey soil (Typic Hapludult) to evaluate the effects of compost on P sorption by laboratory incubation and on plant availability by bioassay in a green house, using kale as the assay crop. This soil contains high levels of Al and Fe and the addition of lime further exacerbates the P sorption problem. Results of the incubation study with six composts showed significant reduction in P sorption by compost. Composts with low lime potential (proton consumption capacity) were most effective in reducing P sorption as indicated by a strong positive linear relationship between proton consumption capacity of amendment and P sorption Y=0.09X+385, R^2=0.94(superscript **). The close positive linear relationship between total P and Bray 1P content Y=6.41x+8.1, R^2=0.92(superscript **) indicates P mineralization as the dominant mechanism in reducing P sorption. Composts with high pH buffer capacities or lime potentials, regardless of total P content, were the least effective. This suggests that like lime, these composts may induce Al hydrolysis and Al hydroxyl polymerization to generate new sorption sites or cause the precipitation P of into less soluble aluminum phosphate compounds. Addition of compost significantly improved plant fertilizer P use efficiency through increased plant P uptake and dry matter yield. This was a result of increased P solubility due to P release and precipitation of exchangeable Al by moderate increase in soil pH. Knowledge of the relative importance of compost-induced processes such as P release by compost, pH buffering and anion competition leading to reduction in P sorption would improve the effectiveness of compost as a strategic tool to manage Ultisols.

並列關鍵字

Ultisols ； Compost ； Lime ； P Sorption ； pH Buffer Capacity ； P Availability ； Productivity