季节性冻融期不同水氮量组合下土壤水分的时空变化特征

发布时间：2018-03-19 09:27

本文选题：水氮量组合　切入点：冻融阶段　出处：《节水灌溉》2017年03期 　论文类型：期刊论文

【摘要】：以季节性冻融期系列田间试验资料为基础,探求不同水肥耦合下非饱和冻融土壤介质中含水率的时空变化特征。结果表明:封冻前N_0W_0含水率较灌水地块低。快速冻结阶段水分运移主要受冻结作用形成的附加基质势驱动,土壤聚墒区为20~50 cm,N_(500)W_(750)和N_(300)W_(375)处理峰值聚墒量高于其他处理。稳定冻结期土壤聚墒区范围延伸至60 cm处,含水率峰值下移至50 cm,由大到小为:N_(300)W_(750)、N_(300)W_(375)、N_(500)W_(750)、N_0W_0、N_(500)W_(375)、N_(100)W_(750)、N_(100)W_(375)。解冻后N_(300)和N_(500)地块0~60 cm土层略高于自然储水量;封冻前后表土层(0~20 cm)灌溉效应衰减随深度增加而延迟。N_(500)W_(750)和N_(300)W_(375)地块10~20 cm冻结含水峰值呈现时间比N_0W_0提前7 d。灌水后30~40 cm含水率峰值高于N_0W_0,冻结聚墒峰值出现时间随肥量的增加而缩短,消融期N_(500)W_(750)和N_(300)W_(375)处理对水分的吸持作用更强。N_(300)W_(750)和N_(300)W_(375)处理50~60 cm的含水率峰值较高,消融期增幅最为明显,分别为2.00%和0.9%。冻融期各处理土壤含水率与N_0W_0绝对关联度整体随深度增加而减小,说明水氮量组合对冻融期0~60 cm含水率时程动态的影响随深度增加而递减。
[Abstract]:Based on the data of seasonal freezing and thawing season field experiments, The temporal and spatial variation characteristics of moisture content in unsaturated frozen and thawed soil media under different coupling of water and fertilizer were studied. The results showed that the moisture content of N0W _ 0 was lower than that of irrigated land before freezing, and the water migration in rapid freezing stage was mainly driven by the additional matrix potential formed by freezing action. The soil moisture accumulation in the soil moisture accumulation area was 20 ~ (50 cm) and the peak value of soil moisture accumulation was higher than that in other treatments. The range of soil moisture accumulation was extended to 60 cm during the stable freezing period, and the peak value of soil moisture accumulation was increased to 60 cm during the freezing period, and the peak value of soil moisture accumulation was higher than that of other treatments. The peak of water content moved down to 50 cm, and the maximum water content was moved down to 50 cm, and from 1: Ns to 300 S / W / S / W / S / C / C / C / C / C / C / C / C / C / C / C / C / N / C / C / C / N / C / C / C / C / C / C / N / S / C / N / S / C / N / S / C / C / C / N / S / C / N / S / C / N / S / C / N / S / T / N / S / C / C / N / S / S / C / N / S / C / N / S / C / C / N / S / S / N / S / C / N / S / S / C / N / S / C. Before and after freezing, the attenuation of irrigation effect was delayed with the increase of depth, and the attenuation of irrigation effect was delayed with the increase of depth. The peak time of 1020 cm freezing water content in the 1020 cm structure of the stack was 7 days earlier than that of N0W0. The peak water content of 3040 cm after irrigation was higher than that of N0W0, and the time of the peak value of freezing accumulated moisture appeared with the time of the peak value of freezing water accumulation. The amount of fertilizer increased and shortened, The water absorption effect of the treatment is stronger. The absolute correlation degree between soil moisture content and NSCW _ 0 in freezing and thawing period decreased with the increase of depth, which indicated that the effect of combination of water and nitrogen on the time history of water content in 0 ~ 60 cm during freezing and thawing period decreased with the increase of depth.
【作者单位】：太原理工大学水利科学与工程学院;
【基金】：国家自然科学基金资助项目(41572239) 教育部博士点基金资助项目(20131402110008) 山西省自然科学基金资助项目(2015021169)
【分类号】：S152.7

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