Conventionally the layers have been divided into A, B and C horizons. The A horizon is the upper layer, containing humus and is leached and,or eluviated of many minerals. The B horizon forms a zone of deposition and is enriched with clay minerals and iron,aluminium oxides from the A layer. The C layer is the parent material for the present soil and may be partially weathered rock, transported glacial or alluvial material or an earlier soil.

傳統(tǒng)上可將土壤分成A、B人人摸人人操人人干人人、C三層九一香蕉国产在线观看AV。A層是位於最上面的一層，含有腐殖質(zhì)偷拍一区1页，許多礦物質(zhì)在該層中瀝濾和淋溶av黄色网址。B層是個(gè)沉積區(qū)，富集了大量的來自A層的粘土礦物質(zhì)和鐵A级高清免费毛片av无码，鋁氧化物欧美日本亚洲国产另类。C層是現(xiàn)在土壤的母質(zhì)層，也可能是風(fēng)化的巖石A片黄网站、來自冰河或沖積層的物質(zhì)国产av的网站、或早期土壤遺留下來的大战黑人AV无码。

Horizon B, the subsoil, contains materials washed down from above and may be mottled with various colors depending on the iron compounds present.

B 水平層，是亞土層亚洲大吊，內(nèi)含從上層沖刷下來的物質(zhì)人人操人人干人人乐综合色站，而且這些物質(zhì)因?yàn)楹F量不同會呈現(xiàn)出斑駁的色彩。

Oxalic acid loading substantially stimulated soil P release from A1 horizon, showing a linear relationship; but its effect on B horizon soil was relatively negligible, especially at low oxalic acid concentrations mmol L^(-1. Oxalate solutions 0.5~20.0 mmol L^(-1 oxalic acid adjusted to pH 5.16 with 10.0 mmol L^(-1) NaOH had a much higher (1.51~2.98 times) soil-P-release effect than oxalic acid solution the same in oxalate concentration. Therefore, the mechanism of oxalic acid/oxalate triggering release of soil phosphorus is assumed to be dominated by ligand-exchange or complexing reactions of oxalate anionC2O(superscript 2- subscript 4 but not simply acid-dissolving effect. The effect of oxalate anion on soil phosphorus release was found to be somewhat cumulative, i.e. the amount of P released was primarily controlled by the cumulative oxalate loading rate, relatively independent of the manner of oxalate addition (one-time or sequential).

結(jié)果表明国产超级碰，草酸能顯著促進(jìn)暗棕壤A層磷的釋放操操操草草草，土壤磷溶出量隨草酸溶液濃度升高而線性增加；但對B層土壤磷的釋放效應(yīng)相對較弱91亚洲精品在线免费，草酸濃度低於5mmolL^(-1)時(shí)B層磷的釋放不明顯天天免费操一操。pH5.16草酸鈉溶液比相同濃度的草酸溶液具有更高的解磷效率，在設(shè)置二者濃度為0.5~20.0mmolL^(-1)時(shí)美女被操免费黄色网站，前者的解磷量是后者的1.51~2.98倍看黄的网页，推斷草酸鹽溶液或凋落物淋洗液中草酸類物質(zhì)促進(jìn)暗棕壤磷釋放的主要機(jī)理在於草酸陰離子C2O(上標(biāo) 2-下標(biāo) 4配位反應(yīng)。

illuvial horizon b：層

illusion 錯(cuò)覺 | illuvial horizon b層 | ilness 疾病

illuvial horizon b：層,淀積層

illuminating gas 可燃?xì)怏w | illuvial horizon B層,淀積層 | illuvial soil 淀積土

horizon b：淀積層

horizon 層 | horizon b 淀積層 | horizon refraction 水平折射