Effects of drip and flood irrigation on carbon dioxide exchange and crop growth in the maize ecosystem in the Hetao Irrigation District,China

Drip irrigation and flood irrigation are major irrigation methods for maize crops in the Hetao Irrigation District,Inner Mongolia Autonomous Region,China.This research delves into the effects of these irrigation methods on carbon dioxide(CO_(2))exchange and crop growth in this region.The experimental site was divided into drip and flood irrigation zones.The irrigation schedules of this study aligned with the local commonly used irrigation schedule.We employed a developed chamber system to measure the diurnal CO_(2)exchange of maize plants during various growth stages under both drip and flood irrigation methods.From May to September in 2020 and 2021,two sets of repeated experiments were conducted.In each experiment,a total of nine measurements of CO_(2)exchange were performed to obtain carbon exchange data at different growth stages of maize crop.During each CO_(2)exchange measurement event,CO_(2)flux data were collected every two hours over a day-long period to capture the diurnal variations in CO_(2)exchange.During each CO_(2)exchange measurement event,the biological parameters(aboveground biomass and crop growth rate)of maize and environmental parameters(including air humidity,air temperature,precipitation,soil water content,and photosynthetically active radiation)were measured.The results indicated a V-shaped trend in net ecosystem CO_(2)exchange in daytime,reducing slowly at night,while the net assimilation rate(net primary productivity)exhibited a contrasting trend.Notably,compared with flood irrigation,drip irrigation demonstrated significantly higher average daily soil CO_(2)emission and greater average daily CO_(2)absorption by maize plants.Consequently,within the maize ecosystem,drip irrigation appeared more conducive to absorbing atmospheric CO_(2).Furthermore,drip irrigation demonstrated a faster crop growth rate and increased aboveground biomass compared with flood irrigation.A strong linear relationship existed between leaf area index and light utilization efficiency,irrespective of the irrigation method.Notably,drip irrigation displayed superior light use efficiency compared with flood irrigation.The final yield results corroborated these findings,indicating that drip irrigation yielded higher harvest index and overall yield than flood irrigation.The results of this study provide a basis for the selection of optimal irrigation methods commonly used in the Hetao Irrigation District.This research also serves as a reference for future irrigation studies that consider measurements of both carbon emissions and yield simultaneously.

Genetic mechanism and main controlling factors of high-quality clastic rock reservoirs in deep and ultradeep layers:A case study of Oligocene Linhe Formation in Linhe Depression,Hetao Basin,NW China

Based on new data from cores,drilling and logging,combined with extensive rock and mineral testing analysis,a systematic analysis is conducted on the characteristics,diagenesis types,genesis and controlling factors of deep to ultra-deep abnormally high porosity clastic rock reservoirs in the Oligocene Linhe Formation in the Hetao Basin.The reservoir space of the deep to ultra-deep clastic rock reservoirs in the Linhe Formation is mainly primary pores,and the coupling of three favorable diagenetic elements,namely the rock fabric with strong compaction resistance,weak thermal compaction diagenetic dynamic field,and diagenetic environment with weak fluid compaction-weak cementation,is conducive to the preservation of primary pores.The Linhe Formation clastic rocks have a superior preexisting material composition,with an average total content of 90%for quartz,feldspar,and rigid rock fragments,and strong resistance to compaction.The geothermal gradient in Linhe Depression in the range of(2.0–2.6)°C/100 m is low,and together with the burial history of long-term shallow burial and late rapid deep burial,it forms a weak thermal compaction diagenetic dynamic field environment.The diagenetic environment of the saline lake basin is characterized by weak fluid compaction.At the same time,the paleosalinity has zoning characteristics,and weak cementation in low salinity areas is conducive to the preservation of primary pores.The hydrodynamic conditions of sedimentation,salinity differentiation of ancient water in saline lake basins,and sand body thickness jointly control the distribution of high-quality reservoirs in the Linhe Formation.

Petroleum geological features and hydrocarbon enrichment of Linhe Depression in Hetao Basin, NW China

Based on paleogeomorphology, drilling and seismic data, this paper systematically studies the structural and sedimentary evolution, source rock characteristics, reservoir characteristics and formation mechanism, hydrocarbon accumulation model and enrichment law in the Linhe Depression of the Hetao Basin, NW China. The Hetao Basin mainly experienced three stages of evolution, namely, weak extensional fault depression, strong extensional fault depression and strike-slip transformation, giving rise to four positive structural belts(Jilantai, Shabu, Nalinhu and Xinglong), which are favorable areas for oil and gas accumulation. The two main saline lacustrine source rocks, Lower Cretaceous Guyang Formation and Oligocene Linhe Formation, are characterized by high sulfur content, rich algae, early maturity, early expulsion, and wide oil generation window. The large structural transition belt in the intermountain area around the Hetao Basin controls the formation of large-scale braided river delta deposits, which are characterized by high quartz content(50%-76%), long-term shallow burial and weak compaction, low cement content, and good reservoir properties in delta front sandbody. The burial depth of the effective Paleogene reservoirs is predicted to reach 8000 m. Three hydrocarbon accumulation models, nose-uplift near sag, buried hill surrounding sag, fault nose near source rock, are constructed. The law of hydrocarbon accumulation in the Linhe Depression is finally clarified as follows: near-source around the depression is the foundation, high-quality thick reservoir is the premise, good tectonic setting and trap conditions are the key.

Impacts of Sulfur and Microalgae Co-fertilization on Saline-alkaline Soil of Sunflower Field in Hetao Irrigation District

[Objectives]To evaluate the impacts of the elemental sulfur(S 0)and micro-algae(MA)co-fertilization on saline-alkaline soil of sunflower field in the Hetao Irrigation District(HID).[Methods]The greenhouse pot experiment was conducted with four treatments:control(CK),single S 0 fertilization(S),single MA fertilization(A),and S 0 and MA co-fertilization(SA)for comparing the selected soil properties and sunflower plant heights and weights in different treatments.[Results]The results showed that the mean soil organic matter(SOM)under the SA(25.08 g/kg)was significantly higher than that for the CK(20.59 g/kg),S(22.47 g/kg),and A(22.95 g/kg).The mean pH under the SA(7.75)was significantly lower than that for the CK(8.14),S(7.82),and A(7.96).The mean soil exchangeable Na+concentration under the SA was significantly lower than that for the S.The mean soil electrical conductivity(EC)under the SA was 9.76%lower than that for the S.The means of Cl-(1.22 g/kg)and SO 2-4(1.90 g/kg)in soil under the SA were lower than that for the S(1.30,2.06 g/kg)and A(1.31,1.97 g/kg),respectively.For plant height 3 at the late stage of plant growth,the mean plant height 3 under the SA(89.00 cm)was higher than that of the CK(69.60 cm)and A(74.33 cm).The total weights of the fresh sunflower heads,fresh stems,and dry seeds under the SA were higher than that for the CK,S,and A.[Conclusions]In conclusion,the S 0 and MA co-fertilization had positive effects on improving saline-alkaline soils,the soil under the S 0 and MA co-fertilization could be better conditions for promoting sunflower growth than that for the S,Z,and CK,and thereby the S 0 and MA co-fertilization could be a new idea to improve saline-alkaline soil in the cold and arid regions.

采后河套蜜瓜(Cucumis melo cv.Hetao)软化的生理生化研究

采后河套蜜瓜贮存中，呼吸强度和内源乙烯含量均发生跃变，并都在采后６ｄ达到最大值，分别为７６．６ｍｇＣｏ２ｋｇ－１ｈ－１和１８．５５ｎｍｏｌｍｌ－１．可溶性固形物在采后４ｄ达到最大值１２．８％，至采后６ｄ前基本维持这一含量，表明此时果实品质最佳．对直接软化因素细胞膜透性、淀粉含量及淀粉酶活力、组织含水量、果胶层降解酶ＰＧ及β－半乳糖苷酶活力等的研究表明，ＰＧ和β－半乳糖苷酶对细胞壁果胶层的破坏及组织含水量降低引起膨压降低，是河套蜜瓜采后软化的重要因素．组织膜透性变化，对采后８ｄ前果实软化影响较小；

Applying a salinity response function and zoning saline land for three fi eld crops: a case study in the Hetao Irrigation District, Inner Mongolia, China

Salinity is one of the major abiotic factors affecting the growth and productivity of crops in Hetao Irrigation District, China. In this study, the salinity tolerances of three local crops, wheat （Triticum aestinum L.）, maize （Zea mays L.） and sunflower （Helianthus annuus L.）, growing in 76 farm fields are evaluated with modified discount function. Salinity ecological zones appropriate for these local crops are characterized and a case study is presented for crop salinity ecological zoning. The results show that the yield reductions of wheat, maize and sunflower when grown in saline soils are attributed primarily to a reduction in spikelet number, 1 000-grain weight and seed number per head, respectively. Sunflower is the most tolerant crop among the three which had a salinity tolerance index （ST-index） of 12.24, followed by spring maize and spring wheat with ST-Indices of 9.00 and 7.43, respectively. According to the crop salinity tolerance results, the arable land in the Heping Village of this district was subdivided into four salinity ecological zones： the most suitable, suitable, sub-suitable and unsuitable zones. The area proportion of the most suitable zone for wheat, maize and sunflower within the Heping Village was 27.5, 46.5 and 77.5%, respectively. Most of the most suitable zone occurred in the western part of the village. The results of this study provide the scientific basis for optimizing the local major crop distribution and improving cultural practices management in Hetao Irrigation District.

Analysis of Spatial and Temporal Variation Characteristics of the bvalue in the Hetao Seismic Belt

Focusing on the b-value as the research target and under the theoretical framework that the b-value is determined by stress state and medium properties, the variation characteristics of the b-value in the Hetao seismic belt are analyzed. Earthquakes with ML≥1. 5,which have occurred in the Hetao seismic belt since 1970 are selected to conduct the quantitative detection of the non-uniform temporal change of Mcusing the EMR method. Based on the actual situation of seismic activity,the lower limit magnitude is set as ML2. 0 to calculate the b-value. The temporal variation of the b-value is calculated and scanned using the least square method. The results show that there is a good corresponding relationship between the temporal variation of the b-value,strong earthquake activity,network distribution and aftershock deletion. We also calculate and scan the spatial variation of the b-value by using maximum likelihood. The results show that the spatial difference is possibly caused by stress state and crustal medium properties. The tectonic dependence of the b-value is obvious. In addition,the sufficient earthquakes samples in each magnitude interval are still a key step to improve the calculation accuracy of the b-value.

Characteristics and Development of Agricultural Soil in Hetao Irrigation District,Inner Mongolia

Hetao Irrigation District is located in the cold and arid region of Hetao Plain,Inner Mongolia,where the agricultural soil has unique characteristics.Although the agricultural soil properties in Hetao Irrigation Districts have been reported,the overall characteristics remain unclear.Through literature review and investigation,the overall characteristics,development patterns,and related reasons were explored,consequently providing theoretical support for enhancing soil utilization and formulating sustainable soil development strategies.The results showed that the agricultural soil in Hetao Irrigation District originated from the sedimentary layer and anthropogenic mellowing produced by the diversions of the Yellow River.The soil has periodic secondary salinization characteristics,accompanied by a slightly increasing pH value over time.It has low soil organic contents with a stable changing trend,low nitrogen,and phosphorus contents but high potassium and sulfur content,uneven nutrient distribution,diverse production performance,weak but stable ecological performance,and heterogeneous soil quality with a stable change trend.These findings indicate that this kind of soil can be used to plant diverse crops tolerant to different saline-alkali and requiring various nutrients.This agricultural soil is sustainable,but it is also faced with the problems of increased saline-alkali,nutrient loss,and pollution.

LAND UTILIZATION COUNTERMEASURES AND CURRENT SITUATION OF HETAO IRRIGATION REGION IN INNER MONGOLIA

Hetao irrigation region is situated in the western part of Inner Mongolia. It stands bythe Yin·Shan mountain in the north, leans against the Yellow River in the south, nears theeastern side of Ulanbuhe Desert in the west and borders on Baotou in the east. It is 280kilometers in length from east to west. and 45-90 kilometers in width from north to south.

Green Control Measures of Weeds in Wheat Fields in Hetao Irrigation Area along the Yellow River

This study was conducted to solve the problem of green weed control in wheat fields in Hetao irrigation area among the Yellow River.Based on the observation of the competition between wheat and weeds in areas where weeds occurred seriously in wheat fields in Hetao irrigation area among the Yellow River,we measured the effects of green weed control measures and wheat yield using different wheat varieties,planting densities,different organic fertilizers,different ploughing times,and different mulching methods.The results showed that the emergence of weeds in wheat fields dominated by Chenopodiaceae weeds,grain amaranth and barnyard grass was more than 10 d later than wheat.Weeds were mainly distributed between rows(holes),and the number of plants accounted for 66.6%(drill seeding)and 97.6%(hole seeding),respectively.And the growth of weeds in rows(holes)was weaker,and the fresh weight of individual plants was 39.3%-41.9%lower than that between rows(holes).The ecological weed inhibitory effect was significant in the early stage of wheat growth;and among the green weed control measures,except that different varieties and planting densities caused no significant difference in weed control effect,other measures had obvious weed control effects.Comprehensive comparison showed that the control effects of plant number in black film full-covered hole seeding,conventional film-covered hole seeding,increasing ploughing times,and applying organic fertilizer free of weed seed pollution were 82.3%,71.7%,22.0%,and 8.6%,respectively;the fresh weight control effects of black film full-covered hole seeding,conventional film-covered hole seeding,increasing ploughing times,and applying organic fertilizer free of weed seed pollution were 98.0%,97.1%,23.9%,and 9.6%,respectively;and the fresh weight control effects of black film full-covered hole seeding,conventional film-covered hole seeding and increasing ploughing times increased wheat yield by 69.4%,56.4%and 21.1%,respectively.The technologies in this study can realize the purposes of mechanized green weed control in organic wheat production and low-cost,high-yield,large-scale production.

An Empirical Framework of Washing Salinity by Irrigation to Maintain Soil Quality in Hetao Irrigation District

[Objectives] To summarize the characteristics of washing salinity by irrigation in Hetao Irrigation District, and propose the empirical framework of washing salinity by irrigation to maintain soil quality, and provide a theoretical basis for maintaining the sustainable development of soil in Hetao Irrigation District. [Methods] The methods of experiment, questionnaire, on-the-spot investigation and literature review were used. [Results] This study proposed the empirical framework of washing salinity by irrigation to maintain soil quality in Hetao Irrigation District. Seven factors of the framework, including flood irrigation, land leveling, plastic film mulching, fertilization, soil organic matter, pH and salinity, and their relationships were determined. The characteristics of these factors in Hetao Irrigation District were investigated(flooding irrigation with a large amount of irrigation water, high amount of fertilizer application, low organic matter, high pH, large variation of salinity, etc.). The mechanisms and effects of various factors affecting soil quality in Hetao Irrigation District were analyzed(the mean soil organic matter(SOM) and pH were kept in the range of 10.9-13.9 g/kg and 8.0-8.15 in recent 35 years, respectively, and increased slightly, etc.). [Conclusions] The empirical framework can be used as a theoretical norm for evaluating soil quality under the condition of washing salinity by irrigation. Under the condition of washing salinity by irrigation, the agricultural soil quality in Hetao Irrigation District showed a stable trend over time. Using this framework, we can find soil problems, and adjust some unbalanced factors to maintain the stability of soil quality in Hetao Irrigation District, and can also provide a reference for other areas.

河套蜜瓜(Cucumis melo cv.Hetao)静电法保鲜的试验研究

河套蜜瓜是内蒙古的名优特产,深受国内外顾客的欢迎.但其产期集中,贮存困难,为了开拓销售市场,极待解决其贮藏保鲜的问题.本文报道了利用静电保鲜法贮存河套蜜瓜的试验结果.将河套蜜瓜存放在连续发生气体放电的环境中,由于臭氧、空间电荷及电场的作用,贮存30天,好瓜率达80%,而对照瓜仅存放7天,坏烂瓜竞高达70%.同时静电保鲜法还具有设备简单,费用低,操作方便,无残留物等优点,是一种很有发展前途的保鲜新方法.

Late Quaternary tectonic uplift and Yellow River evolution create high arsenic aquifers in the Hetao Basin,China

High arsenic(As)groundwater is a global problem primarily originating from As-enriched sediments.The provenance(source)and release mechanisms(sinks)of high As sediment have been identified,but the source-sink transfer is poorly understood,especially the influence of geological and surface processes.In this study,we explore the roles of tectonic movement and Yellow River evolution in provenance formation processes and evaluate the combined effects of provenance and sediment age on the As content of aquifer sediments in the northern Hetao Basin of Inner Mongolia.Based on optically stimulated luminescence(OSL)and 14C dating and detrital zircon U-Pb,As content,and lithological analyses of a 400 m core,we reconstructed As changes over the last 160 ka.Our results show clay deposited in a paleo-lake during the Gonghe movement period in the late Pleistocene(∼100 ka B.P.)is enriched in As(31.8μg/g)due to significant provenance contributions of the As-bearing Langshan Group under tectonic uplift and mountain erosion.In contrast,clay deposited in the middle Pleistocene(∼160 ka B.P.)has lower As content(7.3μg/g)due to the Yellow River as the primary provenance.Accordingly,the provenance of basin As forced by tectonic uplift and Yellow River evolution determines the background As of aquifer sediments.After deposition,sediment As content decays over time,with higher decay rates in coarse-grained sands than fine-grained.Overall,both provenance formation and sediment age,representing initial and dynamic states of solid phase As,jointly determine the As content of aquifer sediments.More solid phase As provided by younger sediments from the proximal orogenic provenance and reducing conditions due to frequent river-lake transitions,jointly lead to higher As concentrations in shallow groundwater.The study highlights the potential for using a combined analysis of the tectonic movement-surface processes-environment system to improve understanding of geogenic high As groundwater over global large sedimentary basins in the proximity of young orogenic belts.

青藏高原东缘及邻区强震构造:专辑序言

青藏高原东缘由多个次级构造单元组成了独特的“多层次挤出-旋转活动构造体系”,是调节高原物质向东挤出的构造转换带,发育了高密度的活动断裂,强震频度高且强度大,而且地质地貌复杂,成为我国地震灾害问题最为突出的地区之一。近年来,伴随全国地震灾害风险普查、城市活断层探测、地震科学实验场建设、工程场地的地震安全性评价以及重大工程与城镇区的活断层鉴定与地壳稳定性评价等工作的深入开展,高精度遥感、构造地貌、古地震和第四纪年代学等方法的广泛应用,显著提升了青藏高原东缘及邻区强震构造的调查研究程度。为了及时交流这方面的最新研究成果,支撑区域防震减灾及重要工程和基础设施建设的地质安全评价等工作,《地震科学进展》编辑部组织了“青藏高原东缘及邻区强震构造”成果专辑,征集了活断层与地震、甘肃积石山地震以及相关领域的研究综述等代表性学术论文20余篇,本期《青藏高原东缘及邻区强震构造专辑Ⅰ》优选了10篇论文,后续还将推出《青藏高原东缘及邻区强震构造专辑Ⅱ》,希望这些成果可提升对区域强震活动特征与孕震构造机制的理解,并为区域强震危险性分析和有效防范强震灾害风险提供科学依据。

不同改良剂对河套灌区盐渍土理化性质及向日葵生长的影响研究

本研究旨在为内蒙古河套灌区的不同程度盐渍化土壤选择适宜的改良产品。选取了具有代表性的腐植酸和新型土壤改良产品,并通过田间试验评估了施用这些改良产品后土壤盐分含量、pH值、有机质含量、阳离子交换量(CEC)以及对向日葵株高和产量的影响。试验结果表明,5种土壤改良产品均能改善表层土壤的理化性质。其中,益百稼土壤调理剂对轻度和中度盐渍土具有明显的改良效果,而克碱土壤修复剂对轻度、中度、重度盐渍土均表现出良好的改良优势。在不同程度盐渍化土壤中,腐植酸对作物增产效果仅次于克碱土壤修复剂和益百稼土壤调理剂。因此,克碱土壤修复剂和益百稼土壤调理剂是该试验区较为适宜的改良产品。

基于MWatNet模型的河套灌区解放闸灌域灌溉水体提取

为提高灌溉农田中灌溉水体的识别精度,以河套灌区解放闸灌域作为研究区,基于Sentinel-2遥感影像,结合灌区实际情况对地表水体提取模型(WatNet)进行改进,得到MWatNet模型并提取灌溉水体。采用总体精度(Overall accuracy,OA)、平均交并比(Mean intersection over union,MIoU)、F1值等水体提取精度指标进行综合评价。结果表明:改进后的地表水体提取模型(MWatNet)在解放闸灌域农田灌溉水体的提取上具有较好的识别精度,模型总体精度达到96%,平均交并比达到83%,F1值为80%,实地调研验证准确度为85.7%;对比原WatNet、水体语义分割模型(Deeplabv3_plus)和水体提取模型(Deepwatermapv2),MWatNet在灌溉水体提取的连结性、剔除道路和城镇干扰等方面,均表现出更好的效果和模型运行效率。利用该模型可以实现灌溉水体定量化表征,为灌溉用水调度提供了数据支撑。

关于黄河与河套古湖河湖关系演变的假说性分析——兼论对黄河内蒙古段生态治理的启示

黄河曾经在流经河套盆地过程中形成吉兰泰、乌兰布和、巴彦淖尔、呼包4个古湖,且在高湖面时期连成统一的“河套古大湖”,其后4湖分离并分别演绎了自己的河湖关系。在研习前人相关成果基础上,通过建立整体假说性解释框架,试图按照历史顺序与逻辑顺序统一的要求对该河段河湖关系的演变过程进行重建,并为与之相关的生态系统的治理提供借鉴。研究认为:主河道构建是黄河主动实施填湖、建堤、造槽并“甩湖”的过程与结果;冲积扇是黄河填湖的主要模式,而冲积扇顶附近凸起则是湖口淤塞、移动并最终筑成黄河自然堤的主要原因;巴彦木仁与磴口两地控制点对形成鄂尔多斯一侧黄河主河道起到了关键性作用;黄河西派在高湖面期间从巴彦木仁湖口注入吉兰泰-乌兰布和古湖,与从北面入湖的黄河水共同促成贺日木西尼古砂嘴及其延伸砂脊生长,并在低湖面期将这两个湖分离。基于对所述黄河历史过往的认识,须尽可能立足高效集成利用有限水资源这一观念,将减灾与适度重造沿河湖泊和绿洲结合,营建可持续的内蒙古段黄河生态体系。

河套灌区不同播期向日葵生长状况评述

[目的]明确河套灌区向日葵的适宜播期。[方法]以内蒙古三瑞农业科技股份有限公司自主中熟杂交向日葵品种SH363为参试品种,通过不同播种期试验结合生育期气象条件,并综合商品性、产量等因素进行了分析。[结果]5月29日至6月5日为河套灌区向日葵SH363最佳播种期。[结论]结果为河套灌区向日葵提质增效提供了依据。

河套灌区盐渍土壤原核生物群落特征及其潜在功能研究

辨明盐渍土原核生物群落特征及潜在功能对盐渍化程度和土地利用类型的响应,对理解盐渍土壤元素循环与植物互馈效应、构建良性循环农田生态系统具有重要意义。以河套灌区不同盐渍化程度的农田和荒地为研究对象,结合土壤基本理化性质分析与原核生物高通量测序方法,探究盐渍化土壤中原核生物的群落组成特征、环境驱动要素及其潜在功能。结果表明,农田土壤盐渍化程度显著低于荒地,其原核生物多样性更高,尤其是富集了大量农田特有的ASV(扩增子序列变体,amplicon sequence variant);原核生物的群落组成在农田和荒地间差异最大,并主要受到土壤电导率(EC)、pH和有机质(SOM)等环境因子的驱动。基于群落组成和功能预测的差异分析结果表明,盐渍化农田中具有较高丰度的氮循环相关微生物以及潜在的植物促生菌,如亚硝化球菌(Nitrososphaeraceae)、亚硝化单胞菌(Nitrososmonadaceae)、诺卡氏菌(Nocardioidaceae)和鞘氨醇单胞菌(Sphingomonadaceae)等;而盐碱荒地富集了以盐杆菌(Halobacterota)为代表的古菌和具有烃类化合物分解功能的原核生物类群。本研究对于明晰北方灌区盐渍土原核生物群落特征与土壤微环境的互馈关系、揭示土壤养分周转对提升土壤-植物-微生物跨域有益协同具有指导意义。