长期增水处理对白刺灌丛沙堆土壤理化性质的影响

Effects of Long-term Water Addition on Soil Physical and Chemical Properties of Nitraria tangutorum Shrub

【目的】为揭示白刺灌丛沙堆下土壤理化性质对长期增水的响应,对不同增水处理乌兰布和沙漠白刺灌丛沙堆下土壤理化性质进行分析。【方法】在中国林业科学研究院沙漠林业实验中心第二实验场,以白刺灌丛沙堆下土壤为研究对象,以自然降雨量为对照,设置四个增水梯度(增水25%、增水50%、增水75%和增水100%),测定灌丛沙堆下土壤物理性质以及土壤养分含量。【结果】①除对照组土层深度为70~90 cm时有黏粒的分布,增水处理下各个土层均没有黏粒的分布。土层深度为50~70 cm时增水50%处理和增水100%处理较对照组土壤中砂粒含量分别显著增加15.06%和14.59%(P<0.05)。②土层深度为0~2 cm时,各处理组土壤电导率值均大于对照组,增水75%处理下电导率较对照组显著增加59%(P<0.05)。③土层深度为0~70 cm时,各增水处理土壤速效磷含量均高于对照组;土层深度为0~2 cm时,土壤中有机质含量为增水75%处理>增水100%处理>增水50%处理>增水25%处理。【结论】研究结果表明长期增水对白刺灌丛沙堆下土壤粒径、电导率以及土壤中氮、磷、钾含量具有一定程度的影响,但对土壤pH值影响不显著。结果可为预测未来降水变化环境下乌兰布和沙漠白刺灌丛沙堆下土壤理化性质变化提供理论依据。

【Objective】In order to reveal the response of soil physical and chemical properties under the Nitraria tangutorum shrub sandpile to long-term water addition,the soil physical and chemical properties under the Nitraria tangutorum shrub sandpile with different water addition treatments in Ulan Buh desert were analyzed.【Method】In the second experimental site of Experimental Center of Desert Forestry,Chinese Academy of Forestry,the soil under the Nitraria tangutorum shrub was studied with natural rainfall as the control,and four water addition gradients(25%,50%,75%and 100%water addition)were set;the physical properties and soil nutrient contents under the shrub were measured.【Result】①There was no distribution of clay particles in all soil layers under the water addition treatment,except for the control group where the soil layer depth was 70-90 cm.The sand content in the soil was significantly increased by 15.06%and 14.59%(P<0.05)in the 50%and 100%water addition treatments,respectively,compared with the control group at the soil depth of 50-70 cm.②Soil conductivity values were greater in all treatment groups than the control at soil depth of 0-2 cm,with a significant increase of 59%(P<0.05)in conductivity under the 75%water addition treatment compared to the control.③Soil quick-acting phosphorus content of each water augmentation treatment was higher than the control group when the soil depth was 0-70 cm;the organic matter content in the soil was 75%water addition treatment>100%water addition treatment>50%water addition treatment>25%water addition treatment when the soil depth was 0-2 cm.【Conclusion】The results showed that long-term water addition had a certain degree of effect on soil particle size,electrical conductivity,and soil N,P,and K contents under Nitraria tangutorum shrub,but it did not have a significant effect on soil pH value.The results can provide a theoretical basis for predicting the changes of soil physical and chemical properties under the Nitraria tangutorum shrub in Ulan Buh desert under the environment of future precipitation change.