Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2022-09-26 Cooperative journals: 《干旱区研究》
Abstract： Soil salinity aggregation will change soil acidity or alkalinity. As an important land resource reserve area in China, soil salinization and secondary salinization problems are frequent in Xinjiang, Therefore, accurately obtaining soil salinity information and effectively improving soil salinity is beneficial to regulating the contradiction between agricultural irrigation and freshwater resources. Such regulation is of considerable important to the sustainable development of agricultural production and ecological environment. In this study, the soil pH value of cotton fields in Alar Reclamation Area, southern Xinjiang, was taken as the research object, and the EM38-MK2 geodetic conductivity meter was used on the basis of electromagnetic induction technology to obtain soil apparent conductivity data of nine cotton fields in the Reclamation Area. In each cotton field, soil apparent conductivity thresholds were collected in accordance with cotton fields of 0- 0.375, 0.375- 0.75, 0.75- 1.00 m depth, 54 profile samples were collected from three soil layers, and 486 soil profile samples were collected from nine cotton fields. The linear regression model between soil pH and soil apparent conductivity was constructed using two ideas of the global and different regions and combined with geostatistical software to quantify in cotton fields in the Reclamation Area. The two-tailed test results revealed that the correlation coefficients between apparent conductivity and soil pH were 0.60-0.95 for the idea of different regions under the condition of P < 0.01; while those for the global regions were 0.28-0.46. Both findings were highly significant negative correlations, indicating that EM38- MK2 could be used for the determination of soil pH. Linear regression models between apparent conductivity data and soil pH were constructed using the global region and different regions. The zonal models 0.74 ≤ R2 ≤ 0.93 and 2.00 ≤ RPD ≤ 3.50, which have smaller RMSE, showed high accuracy, indicating that the accuracy of the different region model is better than that of the global region models. Meanwhile, the accuracy of the soil pH inversion model is also higher in areas with higher salinity. The Kriging interpolation results showed that the soil pH in the deep layer of cotton fields in the Reclamation Area was higher than that in the surface layer due to the influence of winter irrigation, cotton root system and cotton dead leaves. This study aims to provide ideas for the rapid determination of soil pH. Therefore, soil acid- base risk prediction can be accurate, and effective risk countermeasures can be formulated rationally
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-11 Cooperative journals: 《干旱区研究》
Abstract：以塔里木盆地胡杨、多枝柽柳、胀果甘草为研究对象，应用凋落袋法，研究叶凋落物分解动态，揭示3种植物叶凋落物在干旱生境下分解动态特征，结果表明：① 经过810 d分解，胡杨、胀果甘草叶凋落物质量残留率分别为48.93%、38.07%，经630 d分解多枝柽柳叶凋落物质量残留率为69.55%，分解时间对胡杨、胀果干草、多枝柽柳叶凋落物残留率均有极显著影响，处理(林窗、林下)对胡杨、胀果干草叶凋落物残留率有显著影响、极显著影响。② 处理对3种植物叶凋落物分解系数有显著影响(Pk林下，k胀果甘草>k胡杨>k多枝柽柳，经810 d分解胡杨、胀果甘草叶凋落物t0.95分别为9.15~9.48 a、6.75~7.03 a，经630 d分解多枝柽柳叶凋落物t0.95为13.82~15.05 a。③ 受植物种类的影响，分解时间、处理对C、N、P元素释放进程影响不同。3种植物C元素都表现出释放—富积—释放的变化过程，多枝柽柳、胀果甘草叶凋落物N元素在观测期内表现出释放—富积的过程，而胡杨林下则表现出富积—释放—富积的规律，观测期内P元素释放过程与N元素表现出相似的变化规律。④ 叶凋落物分解系数k值与分解时间、残留量、全氮、全磷、木质素、木质素比氮呈极显著相关(P<0.01)，土壤湿度、全碳、C/N均与k林窗、k林下存在极显著差异。干旱区微生境(林下、林窗)的变化对叶凋落物分解有显著影响，凋落物质量与土壤湿度对凋落物分解起主导作用。
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