전토양(田土壤) 무기태인산(無機態燐酸)의 조성(組成)과 유효인산 분석방법(分析方法)에 관(關)한 비교연구(比較硏究)

A study on composition of Inorganic Phosphours Forms and Comparison of Methods of Determining Available Phosphorus in Upland Soils

수종토양(數種土壤)에 2종(種)의 인산질비료(燐酸質肥料)를 시용(施用)한 후(後) 토양중(土壤中) 무기태인산(無機態燐酸)의 형태별(形態別) 함량변화(含量變化)와 수종침출액(數種浸出液)에 의한 유효인산침출량(有效燐酸浸出量)을 실내실험(室內實驗)으로 조사(調査)하여 비교(比較) 검토(檢討)한바 얻어진 결과(結果)는 다음과 같다. 1. Al-P 함량(含量)은 미경지(未耕地)에 비(比)해 기경전(旣耕田) 토양(土壤)에서 많고 Fe-P 함량(含量)은 사질(砂質)에 비(比)해 식질토양(埴質土壤)에서 많았다. 2. 시용(施用)된 중과석(重過石)의 인산(燐酸)은 토양중(土壤中)에서 주로 Al-P로, 용성인비(熔成燐肥)의 인산(燐酸)은 Al-P와 Ca-P로 변화(變化) 되었으며 Fe-P의 증가(增加)는 모두 아주 낮았다. 3. 유효 인산(燐酸)의 용출량(溶出量)은 침출액간(浸出液間)에 차이가 컸으며 대체(大體)로 중과석(重過石)을 시용(施用)한 토양(土壤)에서는 Bray No. 2>Lancaster${\fallingdotseq}$Bray No. 1>Truog>Olsen 침출액(浸出液)의 순(順)이었고 용린(熔燐)을 시용(施用)한 토양(土壤)에서는 Lancaster> Bray No. 2>Truog>Bray No. 1>Olsen 침출액(浸出液)의 순(順)이었다. 4. 모든 유효린산침출액(有效燐酸浸出液)의 무기린산형태별(無機燐酸形態別)에 대(對)한 침출액(浸出液)은 Al-P>Ca-P>Fe-P의 순(順)이었으나 이중 Bray No. 1과 Bray No. 2는 Fe-P에 대(對)한 침출능(浸出能)이 가장 낮았다. 5. Bray No. 2와 Bray No. 1 및 Olsen법(法)은 Ca-P의 침출능(浸出能)에 비(比)해 상대적(相對的)으로 Al-P에 대(對)한 용출능(溶出能)이 강(强)하니 Lancaster와 Truog법(法)은 Al-P에 비(比)해 Ca-P에 대(對)한 용출능(溶出能)이 더욱 큰 것으로 나타났다.

Laboratory experiment was conducted to investigate the changes in the amount of inorganic phosphorus forms in soils incubated by preaddition of two kinds of phosphorus fertilizer and to various methods of available soil P. The results are summarized as following. 1. The content of Al-P form was higher in cultivated upland soil than in noncultivated soil and that of Fe-P was higher in clayey soil than in sandy soil. 2. The amount of Al-P was increased greatly by addition of Triple superphosphate and Al-P and Ca-P were increased by addition of Fused phosphate but only a little amount of Fe-P was increased by both two fertilizers. 3. The magnitute of available soil P values of different methods was in order of Bray No. 2-P>Lancaster-P${\fallingdotseq}$Bray No. 1-P>Truog-P>Olsen-P in case of addition of Triple superphosphate, while it was Lancaster-P >Bray No. 2-P>Truog-P>Bray No.1-P>Olsen-P in case of addition of Fused phosphate. 4. Extractability of soil P by variouse extractants for determining avaliable soil p was in order of Al-P>Ca-P>Fe-P but the extractability of Fe-P by Bray No. 1 and Bray No. 2 methods was very slight. 5. Bray No. 1, Bray No. 2 and extractants was more Olsen extractable about Al-P in soil than Ca-P but Lancaster and Truog metho is was more extractable about Ca-P than Al-P.