鉱質土と黒ボク土における添加有機物と化学肥料の窒素,イオウおよびリンの利用率の比較

Comparison of the Recovery Rates of N, S and P in Added Organic Matter and Chemical Fertilizer in Regosols and Andosols

Kouno Kenji

Ogata Shoitsu

Marumoto Kazuki

日本土壌肥料學雜誌

有機物の無機化に伴う草類への窒素 (N), リン (P), イオウ (S) 供給を添加有機物の N, P, S 利用率の有機物間,要素間差異とその化学肥料対照区 (対照区) に対する割合から解析するため,N, P, S 含量および炭素 (C)/N 比の著しく異なる,鶏糞堆肥,牛糞堆肥,イタリアンライグラス残根 (残根) を残積性未熟土 (鉱質土) と黒ボク土に添加し,シコクビエ (Eleusine coracana G_<AERTN>) を栽培し,シコクビエによる N, P, S 吸収量から添加有機物の N, P, S 利用率を算出した.また,添加有機物中の N, P, S 量に相当する各要素量を試薬で添加した化学肥料対照区を設け,同様の方法で N, P, S 利用率を算定し,比較検討した.その結果,1) 添加有機物の N 利用率は鶏糞堆肥と牛糞堆肥で 9.1%, 残根で -0.2% と残根で著しく低かったのに対して,対照区の N 利用率はいずれの有機物でも1回刈りで約 60% ,その後 80% 前後と同程度に上昇した.したがって,添加有機物の N 利用率の対照区に対する割合は 12% 以下と著しく低く,その有機物間差異は添加有機物の利用率の場合と同様の傾向を示した.2) 添加有機物の S 利用率は鶏糞堆肥,牛糞堆肥,残根でおのおの 23, 9, 9% と鶏糞堆肥で高く,牛糞堆肥と残根で低かった.また,対照区の S 利用率は2回刈りで 40% 程度,4回刈りでも残根では 95% と高かったが,鶏糞堆肥,牛糞堆肥では約 60% と低く,鶏糞堆肥,牛糞堆肥では S 利用率が N の場合よりも過小評価されやすい.この場合,添加有機物のS 利用率の対照区に対する割合が重要となり,その値は鶏糞堆肥と牛糞堆肥でおのおの 36, 14% とN利用率よりも高かった.3) 鉱質土に有機物を添加した場合の添加有機物のP利用率は,鶏糞堆肥,牛糞堆肥,残根でおのおの 35, 58, 44% であり,対照区ではおのおの 23, 51

Comparative study was performed to estimate and compare the recovery rates of N, S and P in added organic matter or chemical fertilizer source in a greenhouse experiment. Fermented poultry manure, cattle manure compost and root residue of Italian ryegrass (Lolium multiflorum L. cv. Waseyutaka) were used as the organic matter source, while ammonium nitrate, potassium phosphate and potassium sulfate served as chemical source for N, S and P respectively. Treatments consisted of two soil types (regosols and andosols), three kinds of organic matter sources. chemical fertilizer source in a factorial experiment. Wagner pots of size (1/5,000 a) were filled with soil and organic matter or equivalent chemical contents provided as fertilizer and the control which contained soil and other mineral nutrients, except for the element under investigation. Depending on the source, the concentrations of N, S, P and C/N ratio of organic matter varied considerably. African millet (Eleusine coracana G_<AERTN>, Snow Brand) was used as an estimate of the mineral recovery. 1) The recovery rates of N and S in added organic matter, especially in root residue which had high C/N ratio were extremely lower than those of the chemical fertilizer. Furthermore it was observed that application of organic matter with a high C/N ratio, such as root residue may result in N and S deficiency in grasses. 2) Generally, the recovery rates of P in organic manure application, especially poultry manure, were higher than that of chemical fertilizer. This was more pronounced in the andosols which have low pH and high phosphate absorption coefficient.

家畜排泄物コンポスト

鶏糞堆肥

窒素

イオウ

リン利用率

cattle manure compost

poultry manure

recovery rate of N,S and P

Agriculture [ 610 ]

jpn

社団法人日本土壌肥料学会

Copyright (c) 1992 社団法人日本土壌肥料学会

本文データは学協会の許諾に基づきCiNiiから複製したものである

[ISSN] 0029-0610

[NCID] AN00195767

[NAID] 110001747798 isVersionOf