Variations in concentrations of N and P forms in leachates from dried soils rewetted at different rates
Variations in concentrations of N and P forms in leachates from dried soils rewetted at different rates
复制标题
DOI：
10.1007/s00374-012-0700-7
复制
发表时间：
2013-01-01
影响因子：
6.5
通讯作者：
Bol, Roland
中科院分区：
文献类型：
--
作者：
Blackwell, Martin S. A.;Carswell, Alison M.;Bol, Roland
干燥的土壤再湿润的速度会影响渗滤液中营养物质的数量和形式。两个对比草原土壤类型（粘土与棕壤）的干燥和潮湿的复制（n = 3）样品进行灌溉，在实验室实验中，相同的总水量，但在不同的速率，范围从0小时，增加30分钟的增量到4小时，另外一个24小时的再润湿率。两种土壤干燥样品的淋滤液中的总磷浓度一般随再湿速率的增加而降低，范围为2，923 +/- 589 μ g P L-1（0.5 h再湿润率）至731 +/- 46.0 μ g P L-1（24 h，粘性土）和1，588 +/- 45.1 μ g P L-1（0.5 h）至439 +/- 25.5 μ g P L-1（24 h棕壤）。类似的模式发生的浓度为活性磷（MRP），虽然浓度一般是一个数量级较低，表明大多数沥滤的P可能是有机的。潮湿的棕壤浸出相对较高浓度的MRP（最大值232 +/- 10.6 μ g P L-1，0.5 h），与潮湿的粘性土（最大值20.4 +/- 10.0 μ g P L-1，0 h）不同。渗滤液中的总氧化态氮浓度受回湿率的影响较小，虽然较长的回湿率导致两种土壤的干燥样品中的渗滤液浓度降低。两种土壤对再湿速率的响应差异可能是由于微生物生物量和土壤吸附性质的差异。结果表明，土壤水分可能是一个重要的因素，在调节养分流失和可用性，特别是在未来气候变化情景预测的降雨模式变化。
The rate at which dried soils are rewetted can affect the quantities and forms of nutrients in leachates. Both dried and moist replicated (n = 3) samples of two contrasting grassland soil types (clayey vs brown earth) were irrigated during laboratory experiments with identical total amounts of water, but at different rates, ranging from 0 h, increasing by 30-min increments up to 4 h, and additionally a 24-h rewetting rate. Total P concentrations in leachates from dried samples of both soils generally decreased as rewetting rate increased, ranging from 2,923 +/- 589 mu g P L-1 (0.5 h rewetting rate) to 731 +/- 46.0 mu g P L-1 (24 h, clayey soil) and 1,588 +/- 45.1 mu g P L-1 (0.5 h) to 439 +/- 25.5 mu g P L-1 (24 h brown earth). Similar patterns in concentrations occurred for molybdate reactive P (MRP), although concentrations were generally an order of magnitude lower, indicating that the majority of the leached P was probably organic. The moist brown earth leached relatively high concentrations of MRP (maximum 232 +/- 10.6 mu g P L-1, 0.5 h), unlike the moist clayey soil (maximum 20.4 +/- 10.0 mu g P L-1, 0 h). The total oxidised N concentrations in leachates were less affected by rewetting rate, although longer rewetting rates resulted in decreased concentrations in leachates from the dried samples of both soils. The difference in responses to rewetting rates of the two soils is probably due to differences in the fate of the microbial biomass and adsorption properties in the soils. Results show that soil moisture could be an important factor in regulating nutrient losses and availability, especially under changing patterns of rainfall predicted by future climate change scenarios.