Changes in soil P pools during legume residue decomposition
Changes in soil P pools during legume residue decomposition
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DOI：
10.1016/j.soilbio.2012.01.031
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发表时间：
2012-06-01
影响因子：
9.7
通讯作者：
Marschner, Petra
中科院分区：
文献类型：
--
作者：
Alamgir, Md;McNeill, Ann;Marschner, Petra
在轮作中，豆类作物后的谷物往往比谷物后有更高的磷吸收，有人建议，豆类作物残留物可能发挥重要作用，在这种效果，通过动员土壤磷在豆类阶段和添加的P残留物。然而，很少有人知道在豆类残留物分解过程中磷库的变化。从蚕豆，白色羽扇豆或鹰嘴豆（芽或根）与不同的P浓度的残留物被添加到一个低有效P浓度的壤质砂土，和各种土壤P库的浓度进行了评估，通过土壤P分馏0，14，28和56天。秸秆还田显著提高了累积呼吸强度，且与秸秆还田时的碳量呈正相关（r = 0.54，p < 0.05），与C/P呈负相关（r =-0.58，p < 0.05）。磷库的大小随着时间的推移而变化，并受残留磷浓度和植物部分（根或地上部）。在前两周，低磷残留（0.6-1.8 mg kg（-1））时，微生物磷增加，树脂磷和NaHCO 3-Pi减少，而高磷残留（6.5-8.3 mg kg（-1））时则相反。在中磷残留物（2.9-33毫克千克（-1）），有一个平衡之间的矿化和固定。NaO-Po的下降发生早于低磷和中磷残留（d 0至d14）与高磷残留（d14-d28）。土壤残留磷含量随时间的增加而增加，表明部分矿化磷在14 d内转化为稳定态磷，但在后期（d28-d56），土壤残留磷含量急剧下降。在d28 ~ d56期间，NaOH-Po和HCI-P的含量均有所增加，表明磷净转化为稳定的有机磷和无机磷。NaOH-Po的浓度从d 0到d14增加，但随后从d14到d28下降，而根的情况则相反。这些变化一般在低磷比中磷残留更明显。研究表明，土壤磷库随时间的变化和转化取决于残留磷浓度和植物部位。(c)2012爱思唯尔有限公司保留所有权利。
In rotations, cereals after legumes often have higher P uptake than after cereals, and it has been suggested that legume residues may play an important role in this effect by mobilising soil P in the legume phase and by the P added with the residues. However, little is known about the changes in P pools during legume residue decomposition. Residues from faba bean, white lupin or chickpea (shoots or roots) with varying P concentrations were added to a loamy sand soil with a low available P concentration, and the concentration of various soil P pools were assessed by soil P fractionation on days 0, 14, 28 and 56. Residue addition significantly increased cumulative respiration which was positively correlated with amount of C added with residues (r = 0.54, p < 0.05), and negatively correlated with the C/P ratio (r = -0.58, p < 0.05). The size of the P pools changed over time and was affected by both residue P concentration and plant part (root or shoot). In the first two weeks, microbial P increased and resin P and NaHCO3-Pi decreased with low-P residues (0.6-1.8 mg kg(-1)) while the reverse was true for high-P residues (6.5-8.3 mg kg(-1)). In medium-P residues (2.9-33 mg kg(-1)), there was a balance between mineralisation and immobilisation. Decreases of NaO-Po occurred earlier with low-P and medium-P residues (d0 to d14) than with high-P residues (d14-d28). The increase in residual P with all residues indicated that part of mineralised P was converted into stable P within 14d; but later (d28-d56), the concentration of residual P strongly decreased. In the period from d28 to d56, there was an increase in NaOH-Po and HCI-P with all residues, indicating net conversion of P into stable organic and inorganic P. Changes in P pools between roots and shoots occurred mainly in the initial phase. The concentration of NaOH-Po increased from d0 to d14, but then decreased from d14 to d28 with addition of shoot residues whereas the reverse was found with roots. These changes were generally more pronounced in low-P than in medium-P residues. This study demonstrates that changes and transformations in soil P pools over time were dependant on residue P concentration and plant part. (c) 2012 Elsevier Ltd. All rights reserved.