Changes in the Properties of Crimean Haplic Chernozems under the Impact of Forest Plantations

Eurasian Soil Science - The impact of 50-year-old forest plantations on the properties of postagrogenic segregational chernozems (postagrogenic Haplic Chernozems) in the steppe Crimea has been...     

Changes in the Plant Cover and Biological Properties of Chernozems in the Postagrogenic Period

Eurasian Soil Science - Changes in the soil cover and biological properties of ordinary chernozems in the natural succession on fallow lands differing in their age have been studied in Rostov...     

Influence of Land Use on the Physical Properties of Chernozems in the Forest-Steppe Zone of Western Siberia

Eurasian Soil Science - The land use type and agricultural practices significantly affect the aggregate state and many physical properties of soils. In this study, we provide a comparative...     

侵蚀型红壤植被恢复后土壤养分含量与物理性质的变化

为了解侵蚀型红壤植被恢复后土壤养分含量与物理性质的变化状况,采集了植被恢复17年和9年的两个定位试验点土壤样品。分析结果表明：侵蚀型红壤植被恢复后土壤养分含量明显增加。恢复17年的木荷、杉木林0～0．2m土层土壤全氮和有机质含量分别比对照增加了3．92倍、2．96倍、5．80倍和3．52倍,土壤有效养分中土壤有效磷含量增加幅度最大。植被恢复后土壤物理性质得到极大改善．表现在土壤容量明显降低,土壤总孔度、通气孔度增加和大于1mm大团聚体与大于0．25mm水稳性团聚体总量的增加。总的来看,恢复17年的木荷和恢复9年的黑麦草两处理．土壤物理性质改善最为明显．此两处理0～0．2m表层土壤容量比对照区降低了27．9％和20．41％,大于0．25mm水稳性团聚体总量分别比对照区增加了31．09％和29．96％,土壤总孔度和通气孔度分别是对照区的1．34倍、1．25倍、2．59倍和2．14倍。     

The Impact of No-Till,Conservation, and Conventional Tillage Systems on Erosion and Soil Properties in Lower Austria

Eurasian Soil Science - The effect of long-term (about 25 years) use of different farming practices on a set of soil properties and development of erosion in Lower Austria has been studied. Three...     

Assessment of the Influence of Pyrogenic Factors on the Biological Properties of Chernozems

Eurasian Soil Science - Changes in the biological properties of chernozems caused by several pyrogenic agents have been studied in simulation experiments with the low-temperature plasma, infrared...     

Optical Properties of the Extractable Organic Matter Fractions in Typical Chernozems of Long-Term Field Experiments

Eurasian Soil Science - The extractable fractions of organic matter (OM) differing in their mobility—water-extractable organic matter, labile humic substances, and humic substances—have...     

Assessing the Degree of Physical Degradation and Suitability of Chernozems for the Minimization of Basic Tillage

Results of studies performed in long-term stationary and short-term experiments on ordinary and leached chernozems in the Central Chernozemic Zone are presented. Agrophysical and physicomechanical parameters are proposed for assessing the degree of physical degradation of chernozemic soils. The scale of chernozem degradation has been improved. After the assessment of the agrophysical fertility parameters of old-arable soils, the limits of chernozem suitability for the minimization of basic tillage have been determined. Minimization of basic tillage is recommended for the nondegraded or slightly degraded soils resistant to compaction, with the soil bulk density of no more than 1.1–1.3 g/cm³, soil penetration resistance of 10–30 kg/cm², and the content of coarse blocky fraction of no more than 30%.     

等高植物篱模式下土壤物理性质变化与水土保持效果研究进展

等高植物篱模式就是在坡耕地上每隔4~8m的距离沿等高线将植物篱与作物种植带相间分布的一种农林复合经营模式,用于坡耕地的水土保持。已有的研究结果表明,等高植物篱技术用于坡耕地可有效地改善土壤物理性质和土壤水分状况,防治坡耕地水土流失效果显著,土壤水分的季节性再分配也有利于农作物的生长。但是该系统内植物篱和农作物相互之间的水分和养分关系有待深入研究。     

Changes in the Soil Cover under the Impact of Short-Term Climate Fluctuations

Eurasian Soil Science - The climate of the 1950s–1990s in the center of the Russian Plain was characterized by the alternation of cool–wet and warm–dry periods, which is confirmed...     

Effect of Long-Term Drip Irrigation of Fruit Orchard on the Transformation of Properties of Chernozems

Eurasian Soil Science - The impact of long-term drip irrigation of apple plantations with low-saline water on the transformation of typical chernozems (Haplic Chernozems) on the Kuban Lowland...     

Nitrogen in Chernozems under Traditional and Direct Seeding Cropping Systems: A Review

Eurasian Soil Science - The functional role of nitrogen in the formation of crop yield on chernozems under conditions of traditional and direct seeding (DS) cropping systems is considered. In the...     

Assessment of the Impact of No-Till and Conventional Tillage Technologies on the Microbiome of Southern Agrochernozems

Eurasian Soil Science - Quantitative characteristics of microbial communities in southern agrochernozems of the Stavropol region managed with the use of no-till technology and moldboard plowing...     

降雨条件下云南红土理化特性对坡面侵蚀的影响研究

针对不同初始状态的云南红土,在一定雨强、坡度、坡长条件下,研究红土理化特性对坡面侵蚀的影响。采用人工模拟降雨方法进行试验研究,运用Excel分析试验数据。结果表明:(1)红土颗粒组成中黏粒含量对降雨作用下的红土坡面侵蚀影响显著,当黏粒含量增加8.1%时,其侵蚀模数则减小25.8g/(m~2·h);(2)红土初始含水率偏离最优含水率越远,红土侵蚀模数越大。当红土初始含水率从接近最优含水率的24.6%增加到36.5%时,侵蚀模数从110.4g/(m~2·h)增加到121.3g/(m~2·h);(3)在初始干密度为1.0,1.1,1.2,1.3,1.4g/cm~3条件下,红土侵蚀模数呈先增大后减小的二次曲线变化趋势(R~2=0.927)。初始干密度在1.1~1.2g/cm~3之间,红土侵蚀模数存在极大值[126g/(m~2·h)];(4)降雨作用使坡面红土铁铝氧化物含量减少,接近坡脚处Fe_2O_3含量从初始状态的8.591%减小到8.143%,Al_2O_3含量从初始状态的22.242%减小到20.967%;而坡内红土铁铝氧化物含量则随深度增加,坡体中段坡内的Fe_2O_3含量增加0.407%,Al_2O_3含量增加0.861%。降雨作用改变了红土理化特性,而红土理化特性的变化会对红土坡面侵蚀产生显著影响。     

多伦草原土壤理化性质在沙漠化过程中的变化

以典型生态脆弱区内蒙古多伦县为例,连续2 a进行了沙漠化对土壤理化性质的影响研究。结果表明,随着草原沙漠化的加剧,(1)土壤颗粒组成发生变化,黏粒含量趋于减少,砂粒增多。不同粒径对土壤团粒结构形成和保水保肥的贡献不同,黏粒的减少抑制了土壤的膨胀、可塑性及离子交换等物理性质。(2)土壤含水量下降。上层(0—20 cm)土壤含水量下降明显,随着沙漠化梯度的增加,表层土壤含水量下降速度加快,从而深层土壤含水量逐渐高于表层。(3)土壤容重呈上升趋势。容重的增加必然影响土壤中水分和空气的移动及植物根系的发育。不同深度的土壤容重与草原沙漠化也存在一定的关系,潜在阶段深土层(30—50 cm)的容重最小,而严重阶段表土层(0—5 cm)容重最小。(4)土壤有机质,C,N含量下降,方差分析显示各沙漠化梯度间均差异极显著。且土壤N的衰减要快于C。土壤C/N比呈增加趋势,说明伴随着土壤C,N的显著下降,质地变粗,植物N素供应不足更为突出。(5)土壤容重与土壤全N,C及黏粒含量的相关分析表明,细颗粒物多,有机质含量高,土壤容重即小,从而有助于提高土壤的稳定性,且5—10 cm土层的性质表现突出。(6)土壤的颗粒组成状况与土壤营养元素之间有着同增同减性,但黏粒与N的关系要密切于黏粒与C和C,N间的关系。因此土壤中细颗粒物的减少会导致N素的衰减十分明显,从而导致土壤稳定性降低。     

盐胁迫下葡萄光合特性的研究

对葡萄(8804品系)扦插苗进行不同程度的盐处理(0.2%,0.4%,0.6%),在一定时期对叶片的光合特性和叶绿素含量进行测定,结果表明:葡萄的净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)的变化规律与叶绿素a、b的含量变化规律基本一致,即在处理前期都持续下降,中期出现一段时间稳定甚至上升,后期又开始下降;细胞间CO2浓度(C i)前期几乎不变,后期则迅速下降。类胡萝卜素含量的变化幅度较小。     

Changes in the Ratio of Aggregate Fractions in Humus Horizons of Chernozems in Response to the Type of Their Use

Eurasian Soil Science - Data on the aggregate-size distribution (dry sifting method) in humus horizons of chernozems were processed by principal components analysis (PCA) with the centered logratio...     

Changes in Physical Properties of Soils with Land Use Time in the Brazilian Savanna Environment

Soils from central Brazil have been intensively used over the last decades because of the rapid conversion of savannas ( Cerrado ) into corn/soybean fields. The objective of this work is to study modifications in the physical properties of soils in the Rio Verde watershed, as a function of the land use time for agriculture, determined from classification of Landsat satellite images between 1980 and 2010. Soil samples were collected at surface (0–20 cm) and subsurface (20–40 cm) horizons for the different classes of land use time (<10, 10–20, 20–30, and >30 years). The following physical properties were measured: bulk density (BD), air permeability (K_a), penetration resistance (PR), microporosity (MI), macroporosity (MA), and total porosity (TP). Results showed a strong expansion with time of agriculture that occupied 35·3% (1980), 37·4% (1990), 51·3% (2000), and 60·9% (2010) of the watershed area. When properties were compared with those from the reference areas (preserved soils under native vegetation), significant differences were observed for all the physical attributes of soils for a land use time higher than 20 years. Overall, BD and PR increased with land use time, and the opposite was verified for K_a, MA, and TP. Some physical properties presented values (e.g., 1·54 g cm⁻³ for BD and 0.06 cm³ cm⁻³ for MA) close to the critical ones reported to affect crop development, but they were not still impacting on local soybean yield. Copyright © 2013 John Wiley & Sons, Ltd.     

Effects of Atmospheric CO2 Enrichment on Crop Nutrient Dynamics under No-Till Conditions

Increasing atmospheric CO₂ concentration could increase crop productivity and alter crop nutrient dynamics. This study was conducted (3 yrs) with two crops ([Glycine max (L.) Merr.] and grain sorghum [Sorghum bicolor (L.) Moench.]) grown under two CO₂ levels (ambient and twice ambient) using open top field chambers on a Blanton loamy sand under no-tillage. Macronutrient and micronutrient concentrations and contents were determined for grain, stover, and roots. Although elevated CO₂ tended to reduce nutrient concentrations, high CO₂ consistently increased nutrient content especially in grain tissue; this response pattern was more notable with macronutrients. The CO₂ effect was observed primarily in soybean. The consistent CO₂-induced increases in grain macronutrient contents favors reliable predictions of system outputs, however, predictions of crop nutrient inputs (i.e., stover and root contents) to the soil are less robust due to observed variability. Again, this is particularly true in regards to micronutrient dynamics in CO₂-enriched cropping systems.     

Impact of Desalination on Physical and Mechanical Properties of Lanzhou Loess

Soluble salt in soil has a significant influence on the physical and mechanical properties of the soil. We performed desalination experiments on Lanzhou loess, a typical sulfate saline soil, to study the effects of salt on the physical and mechanical properties of the loess and compare variations in the soil properties after desalination. The Atterberg limits of the soil increased after desalination as a result of changes in the soil particle composition and grain refinement. The shear and uniaxial compressive strength of the soil increased as a result of decreased calcitic cementation and other changes to the soil structure. Scanning electron microstructure (SEM) and mercury intrusion porosimetry (MIP) procedures revealed changes to the microstructure and pore-size distribution of the Lanzhou loess after desalination.