砂漠の土壌の下にある窒素の貯蔵庫
Michelle A Walvoord1, Fred M Phillips, David A Stonestrom
1U.S. Geological Survey, Lakewood, CO 80225, USA. walvoord@usgs.gov
まとめ
乾燥した地底に重要な窒素貯蔵庫が発見され,世界の窒素分布の推定に影響を与えています. この見過ごされた窒素の蓄積は,潜在的動員による地下水の汚染のリスクをもたらします.
科学分野:
- 環境科学 環境科学
- 土壌科学は,土壌科学である.
- 地質化学 地質化学
背景:
- グローバルな窒素分布モデルは,地下の大量の窒素貯蔵庫を無視しています.
- 乾燥地域では,地下地帯に生物学的利用可能な窒素を,主に窒素酸塩として蓄積します.
研究 の 目的:
- 乾燥した地下土における以前に過小評価されていた窒素貯蔵庫を定量化するために.
- この地下窒素が,世界および地域における窒素在庫に与える影響を評価する.
- 地下層の窒素蓄積が栄養素の動態と地下水の質に及ぼす影響を評価する.
主な方法:
- 乾燥地帯の地下地帯における窒素分布の分析.
- 地下蓄積を考慮したバドーゼゾーンの窒素在庫の推定.
- 窒素動員の可能性の評価.
主要な成果:
- 乾燥した地下には,生物利用可能な窒素の大きな貯蔵庫 (最大10^4 kg N/ha) が存在します.
- 地下窒素は,温暖な砂漠や乾燥した灌木地帯では,バドーゼゾーン窒素の推定量を14-71%増加させる.
- 地下窒素の蓄積は,長期にわたる土壌浸出に関連しています.
結論:
- 乾燥地域における地下窒素の蓄積は,世界の窒素循環の重要かつ見過ごされている要素である.
- この貯水池は,地域と世界の窒素予算に大きな影響を与えます.
- 地下窒素の潜在的動員は,土地利用や気候の変化による地下水の汚染を懸念しています.
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