Fungus-fertilizer interactions can enhance agricultural productivity and effective resource utilization, however, the study of the effect of arbuscular mycorrhizal fungi (AMF) and phosphorus on soil fertility and nutrient uptake of soybeans under salinity stress is still unclear. In this study, a mixture of three AMFs (Funneliformis mosseae, Rhizophagus intraradices, and Diversispora epigaea) was inoculated into the salt-sensitive soybean (Glycine max (L.) Merr.) cultivar 'Wuxing No.2' in a pot experiment set up for inoculation, no inoculation and five levels of phosphorus (P2O5) supply (such as 0, 50, 100, 250, 500 mg P kg-1), bacterial phosphorus interactions totaling 10 treatments, each treatment 7 replications. Soil nutrient content and soybean nutrient uptake and translocation rates were determined at seasons of flowering pods, tympanic period and harvest period, respectively. Under low phosphorus (50 mg kg-1) conditions, the soil available phosphorus content at the seasons of flowering pods increased by 23.11% compared with the uninoculated group. The accumulation of nitrogen, phosphorus, and potassium in the plants increased significantly, with the phosphorus content in leaves reaching 4.72 mg·g-1, which was 98.50% higher than that in the high-phosphorus non-inoculated treatment. Meanwhile, it optimized nutrient partitioning, promoting the transfer of phosphorus to the stalks (with the phosphorus transport rate in stems being 37.27% in the + AMF P50 treatment) to support grain formation. In contrast, the uninoculated group required a higher phosphorus level (250 mg kg-1) to reach the peak of biomass, with the root fresh weight peaking at 13.71 g. The low phosphorus inoculation treatment can improve soil fertility and plant nutrient uptake and utilization, and promote the efficient use of agricultural resources.

Soil salinization is a major global challenge that limits crop productivity by inhibiting plant growth, nutritional quality and decreasing yields. This study examined the effect of foliar application of molybdenum (Mo) on two soybean varieties, HN517 (salt-sensitive) and DS118 (salt-tolerant) under saline-alkali soil conditions. Mo was applied via foliar spraying at four concentrations 0 (control), 70, 140, and 210 g ha−1 referred as CK, MO1, MO2, and MO3, respectively. These treatments were employed to investigate the influence of Mo on soybean physiological growth parameters, antioxidant defense mechanisms, osmotic regulation, ionic homeostasis, and nutrient accumulation. Results showed that foliar application of Mo treatment MO3 significantly improved plant height, root biomass, and total biomass by 39.24

【Objective】 Evaluating evapotranspiration and soil salinization is critical for soil and water management but challenging on large scales. This paper investigates the feasibility of using remote sensing technologies and meteorological data to estimate evapotranspiration and soil salinization in irrigated areas. 【Method】 The study was conducted in the Manasi River Basin in Northeastern China. It was based on the Surface Energy Balance System (SEBS) model, using the Landsat-8 remote sensing data and field sampling to estimate spatial distribution of both evapotranspiration and soil salinity in the studied area. 【Result】 ① The normalized vegetation index (R2 = 0.644 8), surface specific emissivity (R2 = 0.637 7), and surface temperature (R2 = 0.558 3) all showed a strong correlation with soil salinity, while surface albedo (R2 = 0.198 6) had a weaker correlation with soil salinity. ② Daily evapotranspiration (ET) in the Manasi River Basin ranged from 0.024 to 5.403 mm, with an average of 3.866 mm. ET decreased from the Southern irrigation area to the Northern Gobi region. ③ ET values less than 3.60 mm/d were associated with non-saline and moderate saline soils. For areas with ET between 3.60 mm/d and 4.05 mm/d, moderate soil salinity dominated. For areas with ET exceeding 4.05 mm/d, the proportion of severe soil salinity increased significantly. 【Conclusion】 Using remotely sensed satellite imagery, the SEBS model provides an accurate, high-resolution estimate of evapotranspiration in terrestrial systems. The evapotranspiration was positively correlated with soil salinity in the Manasi River Basin. These results can help improve land and water management in the region.

Inorganic cations' types are crucial to the formation of soil colloid aggregates. However, there are few studies on the effects of inorganic cations on the aggregation process of alkalized soil colloids. In this study, soil inorganic colloids with different alkalization degrees were prepared, and the effects of inorganic cations on soil colloid aggregation under different electrolyte concentrations were studied by the dynamic light scattering method. The results showed that for soil colloids with different alkalization degrees, when the electrolyte concentration was the same, the activation energy of Mg2+ involved in the reaction was significantly higher than that of Ca2+, indicating that the ion species had a significant effect on soil colloid aggregation under the same valence state. Most importantly, decreasing the electrolyte concentration increases the difference in activation energy (ΔE) between the same two cations (ΔEMg − ΔECa), and the increase in soil alkalinity increases the value of ΔEMg − ΔECa. This study provides a reference for understanding the aggregation and interaction of inorganic colloids in alkaline soil, and the development of agriculture in arid areas.

为探究秸秆还田对新疆盐渍化土壤降盐保水的作用,通过田间小区试验,设置6种处理:不还田(CK)、棉花秸秆还田(P1)、玉米秸秆还田(P2)、油菜秸秆还田(P3)、棉花秸秆还田+玉米秸秆还田(P12)、棉花秸秆+油菜秸秆还田(P13),分别测定各处理对棉花全生育期0～60 cm土层含水量、电导率、脱盐率、盐基离子含量以及棉花水分利用效率、产量的影响.结果显示:P12、P13处理较其他处理可增强土壤的蓄水能力,随着土壤深度的增加,含水量差异逐渐减小.相比CK处理,P12、P13处理土壤含水量分别提高了3.78%～15.03%、5.06%～18.23%.在棉花全生育期,P12、P13处理可提高0～20 cm土层的脱盐率,电导率较CK处理分别降低3.54%～39.27%、17.83%～40.01%.土壤盐基离子含量呈现出Na+>Ca2+>K+>Mg2+的规律,盐基离子中的Na+、K+、Mg2+含量具有表聚性.相关性分析显示,调控棉田土壤水盐环境(含水量、电导率、脱盐率)可以增加作物水分利用效率,提高产量.结果表明,P12、P13处理较其他处理更能显著增强棉花生育期内农田土壤持水能力并改善盐分分布状况,适合新疆地区盐渍土改良.

Inorganic cations' types are crucial to the formation of soil colloid aggregates. However, there are few studies on the effects of inorganic cations on the aggregation process of alkalized soil colloids. In this study, soil inorganic colloids with different alkalization degrees were prepared, and the effects of inorganic cations on soil colloid aggregation under different electrolyte concentrations were studied by the dynamic light scattering method. The results showed that for soil colloids with different alkalization degrees, when the electrolyte concentration was the same, the activation energy of Mg2+ involved in the reaction was significantly higher than that of Ca2+, indicating that the ion species had a significant effect on soil colloid aggregation under the same valence state. Most importantly, decreasing the electrolyte concentration increases the difference in activation energy (Delta E) between the same two cations (Delta E-Mg - Delta E-Ca), and the increase in soil alkalinity increases the value of Delta E-Mg - Delta E-Ca. This study provides a reference for understanding the aggregation and interaction of inorganic colloids in alkaline soil, and the development of agriculture in arid areas.

秸秆还田是西北地区普遍存在的一种改善土壤质量的农作措施之一.为明确秸秆不同还田方式对新疆盐碱土微观结构和理化性质的影响,于2020年进行田间试验,设置以不还田(CK)为对照,棉花秸秆翻压还田(H1)、油菜秸秆翻压还田(H2)、棉花秸秆覆盖还田(F1)、油菜秸秆覆盖还田(F2)共5个处理,分析0～20 cm土层电导率、含水量、有机质和团聚体粒径分布变化,并结合扫描电镜(SEM)探究其土壤微观结构变化.结果表明:较CK,H1、H2处理随着还田时间的增加电导率逐渐降低,含水量逐渐增加,效果优于F1、F2处理.第75 d,H1、H2处理电导率分别降低了5.30％和3.89％,含水量增加了8.93％和7.85％.相比CK,H1、H2处理土壤有机质分别增加了30.90％、29.80％.相比CK,H1、H2处理降低了土壤中小于0.053 mm团聚体比例,增加了0.25～2.00 mm团聚体的比例.秸秆翻压还田(H1、H2处理)相较于秸秆覆盖还田(F1、F2处理),土壤片状微观结构增多,颗粒之间由面与面接触转变为直接点接触,增加土壤孔隙数量.综上,秸秆翻压还田较覆盖还田更有利于改善土壤颗粒微观结构和土壤团聚体粒径组成,增强降盐保水的作用.为新疆地区秸秆还田提供理论支撑.

我国盐碱地分布广、面积大.在盐碱地选种有饲料价值的作物,实现种养循环,对推动我国草食畜牧业的发展及盐碱地改良具有重要意义.本研究分别在天津滨海盐碱地(NaCl型)和新疆西北内陆盐碱地(Na2SO4-NaHCO3型)选取盐碱度差异大的地块,种植具有饲料价值的玉米、高粱、小麦、谷子、大豆、油菜等大田作物,测定生物学产量、植株粗蛋白含量、钠离子、钾离子含量等指标.结果表明,在NaCl型和Na2SO4-NaHCO3型盐碱地,当其含盐量分别低于1.82 g kg–1和2.00 g kg–1时,各作物生物学及蛋白质产量均与常规耕地接近,可作为饲料生产基地加以利用;当Na2SO4-NaHCO3型盐碱地含盐量达2.49 g kg–1时,油菜生物学及蛋白质产量均显著高于其他作物,因此可种植油菜作饲料开发利用;当NaCl型和Na2SO4-NaHCO3型盐碱地含盐量分别达3.63 g kg–1和4.42 g kg–1时,各作物生物学及蛋白质产量均低于常规耕地的51.72％,利用价值低,建议改良后利用.在两试验点的不同地块,油菜对土壤Na+的富集量均显著高于其他作物(P<0.05),同时也显著降低了土壤全盐量和Na+含量.本试验中,在含盐量分别为1.82、2.00、2.49 g kg–1的地块中,油菜富集Na+效果最为明显,油菜对土壤Na+的富集量分别为39.45、102.24、57.19 kg hm–2,分别占0～20 cm耕层土壤Na+的13.02％、15.99％、8.94％,盐碱地改良效果显著.上述结果为利用我国盐碱地进行草食饲料原料生产,促进草食畜牧业发展及盐碱地改良提供了参考.

[目的]改善土壤磷素状况、土壤无机磷组分,提高磷肥利用效率.[方法]于2019―2020年在新疆昌吉进行2 a的田间试验,设置4个处理,分别为DF1:底肥全部基施(追肥以氨基酸水溶肥为主);DF2:底肥全部基施(追肥以微生物复合肥为主);NF 1:底肥全部追施(追肥以氨基酸水溶肥为主);NF 2:底肥全部追施(追肥以微生物复合肥为主).分别在棉花蕾期、花铃期、吐絮期和收获期采集土壤样品,测定了土壤有效磷、微生物量磷、无机磷组分和棉花产量.[结果]与DF1、DF2处理相比,NF1、NF2处理能够显著提高棉花花铃期、吐絮期、收获期0～20 cm土层的有效磷和微生物量磷.NF1、NF2处理的Ca2-P分别在棉花花铃期均达到最高,Ca10-P、AL-P在棉花花铃期达到最低,Ca 8-P在蕾期至吐絮期增加,但在收获期降低.土壤有效磷与Ca 2-P显著正相关,与Ca 10-P和AL-P显著负相关.底肥全部追施的施肥方式可显著提高土壤中直接磷源的量,降低向缓效磷源的转化量,从而提高了土壤中磷的有效性.相比底肥全部基施的施肥方式,底肥全部追施的施肥方式可使棉花产量平均增加7.5％.[结论]通过减少底肥的施入量,根据作物需肥规律精准定量施入磷肥可增加土壤有效磷,减少土壤磷素向无效磷源的转化,增加作物产量.

土壤盐分的准确监测是干旱、半干旱地区农业可持续发展的前提,气候变化、不合理灌溉等因素使土壤盐渍化问题逐渐显现.文中以新疆玛纳斯河流域为例,采用多光谱遥感影像和野外实测土壤盐分数据相结合的方法,选取对土壤盐渍化影响较大的归一化差异水体指数及其它具有代表性的多光谱遥感指数与土壤盐分构建反演模型,探讨研究区内土壤盐渍化的空间分布特征.结果表明:与土壤盐分相关性最高且具有代表性的多光谱遥感指数是NDWI、NDVI和DVI,相关系数分别为0.841、-0.787、-0.768,达到极显著水平(P＜0.01),均可以用于构建土壤盐分反演模型.最优光谱参数与土壤盐分构建的模型建模精度均在80％以上,达到极显著水平,可以较为准确的预测出研究区内盐渍化状况.在玛纳斯河流域绿洲区土壤盐渍化以中度、重度盐渍化为主,其中石河子灌区盐渍化程度最为严重,莫索湾灌区盐渍化程度较轻,与实地调查结果一致.基于多光谱影像提取的土壤归一化差异水体指数作为构建土壤盐分反演模型的基础,可以获得较好的土壤盐分空间分布.土壤盐渍化遥感反演为新疆玛纳斯河流域土壤盐渍化治理和土地资源可持续利用提供理论依据.

The objective of this study was to evaluate bacterial community structure and diversity in soil aggregate fractions when salinized farmland was reclaimed after >27 years of abandonment and then farmed again for 1, 5, 10, and 15 years. Illumina MiSeq high-throughput sequencing was performed to characterize the soil bacterial communities in 5 aggregate size classes in each treatment. The results indicated that reclamation significantly increased macro-aggregation (>0.25 mm), as well as soil organic C, available N, and available P. The 10-year field had the largest proportion (93.9%) of soil in the macro-aggregate size classes (i.e., >0.25 mm) and the highest soil electrical conductivity. The 5 most dominant phyla in the soil samples were Proteobacteria, Actinobacteria, Gemmatimonadetes, Acidobacteria, and Bacteroidetes. The phylogenetic diversity, Chao1, and Shannon indices increased after the abandoned land was reclaimed for farming, reaching maximums in the 15-year field. Among aggregate size classes, the 1-0.25 mm aggregates generally had the highest phylogenetic diversity, Chao1, and Shannon indices. Soil organic C and soil electrical conductivity were the main environmental factors affecting the soil bacterial communities. The composition and structure of the bacterial communities also varied significantly depending on soil aggregate size and time since reclamation.

玛纳斯河流域作为新疆最大的绿洲农耕区,近年来随着农业用地开发强度加大,水资源不合理利用等因素使土壤盐渍化和土壤退化问题逐渐显现,从而带来一系列生态环境问题并制约着农业生产和社会经济发展.以石河子垦区为研究区域,针对区域内存在的土壤盐渍化问题等土壤质量问题,选取土壤养分、土壤质地及盐碱化程度为评价指标,利用层次分析法对垦区土壤质量做出综合评价.结果表明:根据综合评价结果可以将区域土壤质量划分为4个等级,其中一级地质量最好且占总面积的14.92％,二至四级分别占比23.14％ 、36.54％ 、25.40％.垦区内土壤质量总体偏低,土壤养分亏缺严重,且异质性较大.土壤普遍呈微碱化,小部分区域遭受到盐碱危害,大部分区域受到潜在盐碱化威胁,土壤质量有待进一步提高.应通过多种措施相结合,因地制宜地制定科学合理的措施以减轻盐碱化,提高土壤肥力,增强农业生态系统稳定性,保障绿洲区农业可持续发展和土壤生态安全.

We systematically examined past spatiotemporal changes in climate variability to gain some cross-regional insights into South Asia's vulnerability to extreme conditions. Gridded Asian Precipitation-Highly-Resolved Observational Data Integration Towards Evaluation (APHRODITE) precipitation and Princeton Global Meteorological Forcing Dataset (PRINCETON) temperature data from 1975-2004 were used to derive a suite of annual extreme indices. Long-term mean and decadal variations of these indices were mapped. Long-term change tendencies were also detected from a suite of 'slope' maps composed by the 30 yr change trend at each grid cell in the region. Most precipitation indices indicated a tendency towards drier conditions, whereas all temperature indices marked a steady coherent warming trend. The extremely wet day precipitation index exhibited the largest change, indicating an increase in heavy precipitation in South Asia. The highest maximum temperature extreme showed increases, indicating more unbearable heatwaves in the region. These trends present a previously unrecognised regional picture of the patterns and trends in historical climate extremes, with each grid cell representing spatiotemporal characteristics of changes. The present study is superior to most studies that only summarise an averaged regional trend from tendencies over large areas, and therefore will improve trans-boundary understanding of extreme climates in South Asia. Our study also exemplifies the application of existing gridded regional/global data sets. It provides valuable means of cross-regional information for bridging gaps where gauging observations are unavailable, particularly in data-poor developing countries.

SUMMARYA field experiment was conducted to quantify changes in soil aggregation and aggregate-associated soil organic carbon (SOC) concentration 1, 3, 5 and 10 years after abandoned, salinized land in the Manasi River Basin was reclaimed for cotton (Gossypium hirsutum L.). Results showed that reclamation significantly increased SOC concentrations and SOC stocks. Specifically, 10 years of cotton production increased SOC concentrations by 45% in the 0–60 cm depth and SOC stocks by 35%. The SOC concentrations and stocks decreased as soil depth increased. Reclamation time, season and soil depth had significant interaction effects on SOC. The SOC concentrations were significantly and positively correlated with available soil nitrogen and available soil phosphorus. Compared with abandoned farmland, macro-aggregate-associated (>250 µm) SOC concentrations in the 0–60 cm depth increased by 47% after 5 years of cotton production and by 53% after 10 years of cotton production. The contribution of macro-aggregate-associated SOC to total SOC in the 0–60 cm depth increased by 87% after 5 years of cotton production and by 69% after 10 years of cotton production. The findings indicate that soil aggregates were more stable after abandoned, salinized farmland was reclaimed for cotton production. Furthermore, cotton production can increase SOC concentrations and sequester C in this arid area.

温室气体大量排放使得全球变暖已成为世界公认的热点问题之一.农田生态系统在全球碳循环与碳平衡中扮演着重要的角色.文中运用开路式涡度相关测量系统进行定点定位观测,研究干旱区农田生态系统/大气间净交换量(Net Ecosystem Exchange),分析农田生态系统中碳源/汇功能的关系.结果表明:新疆棉田生态系统在现蕾期、开花期与铃期CO2通量日变化呈现出单峰型的"U"型曲线,现蕾期、开花期和铃期CO2通量最高点在凌晨3:00、4:00和1:00,分别为9.45、8.78和7.68umol·m-2·s-1,CO2通量最低点在正午14:00、15:00和15:00,依次为-19.35、-21.73和-20.51 umol·m-2·s-1.不同生育期夜晚NEE值均负值,表明棉田生态系统夜间处于碳排放过程;白天正值,棉田生态系统为碳吸收过程.棉花不同生育期均为碳储存,且开花期碳储量最大,平均值为-7.26g·m-2·d-1,其次是现蕾期,平均值为-6.31g·m-2·d-1,铃期平均值为-5.37g·m-2·d-1.温度和降雨对棉田生态系统碳储量影响显著.研究结果表明干旱区高产棉田生态系统有着较好的碳储量,是一个碳汇过程.

蒸散量的变化是地表热量和水量平衡中直接受气候变化影响的重要一项,文中采用Penman-Monteith公式计算潜在蒸散量,利用小波分析、Mann-Kendall法等多种统计方法对新疆干旱区玛纳斯河流域近60年蒸散量进行了定量分析.结果表明:玛纳斯河流域多年平均蒸散量为1521.43mm,年蒸散量的增加幅度为15.8mm/10年,在近60年呈现增多-减少-增多-减少的变化趋势,2005年为突变点,18年为蒸散量变化的震荡主周期,通过降水量、温度、风速和蒸散量的相关性分析表明,温度升高是蒸散量增加的主要原因,气温和风速是影响玛纳斯河流域潜在蒸散量的主要因素,降水量对蒸散量的影响最小.