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.

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.

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.

The Impact of Water Pricing Policy on Local Environment-An Analysis of Three Irrigation Districts in China

As a high priority in dealing with the problem of water scarcity, the effect of water pricing policy remains a controversial issue, especially the environmental effect. Using household-level panel data of three irrigation districts （IDs） in the northern China, this paper probes the potential impact of water price rising on local environment. The examination shows that farmers will reduce the rice area as a response to the rising surface water prices. The changing cropping pattern will exert three-fold environmental impacts, including the dropping groundwater level resulting from the reduction of seepage and percolation of irrigated water and overexploitation of groundwater, the negative effect of non-point pollution from fertilizer and pesticide application, and the loss of field irrigation facilities. Water pricing is not a valid means of significantly reducing agricultural water consumption due to the substitution of groundwater for surface water, it will lead to negative environmental effect. It is an imperative task for Chinese government to improve the management efficiency at IDs.

Cause Analysis and Prediction of the Groundwater Level in Jinghuiqu Irrigation District

Groundwater environment evolution can comprehensively reflect groundwater dynamics. Based on the relationship between the groundwater system and the external environment in Jinghuiqu irrigation district, adopting the Principal Component Analysis method, variation characteristics of environmental factors including climate and human activity and their impact on groundwater were systematically analyzed. The results show that groundwater level in Jinghuiqu irrigation district has been significantly dropped in nearly 34 years;the reduction of surface water irrigation use, which reduced the amounts of groundwater recharge and destroyed the water balance, is considered as the most direct cause for falling of regional groundwater level. Besides, reduction in precipitation, increase of evaporation also accelerated the declining of the groundwater level at some extent. Finally, a predicting method of groundwater depth based on BP neural network is developed. The experimental results show that the predicting model can reasonablely predict the groundwater level in Jinghuiqu irrigation district with a high precision.

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.

The Analysis of Dominance Degree of Land Use in Irrigation District——A Case Study of Jinghuiqu Irrigation District in Shaanxi Province

According to the remote sensing interpretation data in study area, statistics and the data concerning agricultural land classification of Shaanxi Province, on the basis of degree of dominance of land use, taking Jinghuiqu Irrigation District as an example, this paper adopts benefit-cost analysis method and the method of degree of dominance of land resources per capita to conduct analysis on degree of dominance of land. The results show that in study area, the ratio of cost and benefit of farmland is 1.5, with relative big value, indicating that farmland is the dominant land resource in Jinghuiqu Irrigation District; the abundance of land resources in study area is 0.73, the combination index of land resources is 2.3, and degree of dominance of land resources per capita is 0.32, indicating that the combination index of land resources in study area is relatively big, while degree of dominance of land resources per capita is relatively small, which shows that in study area, the combination of all kinds of land resources is in a poor state, with poor supporting ability. In view of the status quo that the combination of all kinds of land resources is in a poor state, with poor supporting ability in Jinghuiqu Irrigation District, the corresponding policy suggestions are put forward as follows: first, strictly implement the central policy and protect farmland resources; second, adjust land use structure and strive to promote benefit; third, make rational planning of land resources and take the road of sustainable development; fourth, take the irrigation district as the unit and establish use class and price standard of land in irrigation district.

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.

Balance of Irrigation Water in Jinghui Canal Irrigation District of China

Jinghuiqu Canal Irrigation District is an old irrigation area with a long history.Due to natural and man-made factors,the inflow and rainfall of the irrigation area are decreasing,which seriously affects agricultural production water in the irrigation area and constantly threatens the safety of irrigation water in irrigation area.In this paper,natural and man-made factors of affecting irrigation water in irrigation area are analyzed,and it is proposed that main channels of solving safety of irrigation water are enhancing the utilization of canal water and optimizing the allocation of canals and wells.

Reducing water and nitrogen inputs combined with plastic mulched ridge-furrow irrigation improves soil water and salt status in arid saline areas,China

Plastic mulched ridge-furrow irrigation is a useful method to improve crop productivity and decrease salt accumulation in arid saline areas.However,inappropriate irrigation and fertilizer practices may result in ecological and environmental problems.In order to improve the resource use efficiency in these areas,we investigated the effects of different irrigation amounts(400(I1),300(I2)and 200(I3)mm)and nitrogen application rates(300(F1)and 150(F2)kg N/hm^(2))on water consumption,salt variation and resource use efficiency of spring maize(Zea mays L.)in the Hetao Irrigation District(HID)of Northwest China in 2017 and 2018.Result showed that soil water contents were 0.2%-8.9%and 13.9%-18.1%lower for I2 and I3 than for I1,respectively,but that was slightly higher for F2 than for F1.Soil salt contents were 7.8%-23.5%and 48.5%-48.9%lower for I2 than for I1 and I3,but that was 1.6%-5.5%higher for F1 than for F2.Less salt leaching at the early growth stage(from sowing to six-leaf stage)and higher salt accumulation at the peak growth stage(from six-leaf to tasseling stage and from grain-filling to maturity stage)resulted in a higher soil salt content for I3 than for I1 and I2.Grain yields for I1 and I2 were significantly higher than that for I3 and irrigation water use efficiency for I2 was 14.7%-34.0%higher than that for I1.Compared with F1,F2 increased the partial factor productivity(PFP)of nitrogen fertilizer by more than 80%.PFP was not significantly different between I1F2 and I2F2,but significantly higher than those of other treatments.Considering the goal of saving water and nitrogen resources,and ensuring food security,we recommended the combination of I2F2 to ensure the sustainable development of agriculture in the HID and other similar arid saline areas.

现代化数字灌区建设主体功能及主要应用结构体系探讨

基于对物理灌区的现代化和模拟灌区的数字化认知,分析总结了现代化数字灌区建设应着力完成的“灌区识别”“立体感知”“精准控制”“信息交互”“管理调度”等“五大主体功能”结构体系;基于智慧水利建设和灌区高效运管需求,高效地模拟渠系水流,系统梳理了以“节点流量过程”为输入和输出的灌区概化图,研究提出了现代化数字灌区建设主要业务应用结构体系,即构建以“数据库”为载体,“数学模型”为支撑,基于“灌区一张图”基础之上的“组织管理、工程管理、安全管理、泵站管理、农业节水与供用水管理、经济管理、信息化管理、公共服务”等“九大业务应用”为交互的的整体架构,以期有效提升灌溉供水服务的安全性、公平性、可靠性和灵活性。

淠史杭灌区干旱推演及抗旱预案调控研究

水资源干旱是限制灌区可持续发展的关键因素。为提高灌区的干旱防治能力,使其更好的发挥其在节水、减灾方面的作用,以淠史杭灌区为研究区,通过划分水资源配置子单元和设置调蓄节点,采用公平性最优和供水缺水率最小作为目标函数,总量控制、供水能力、分质供水等作为约束条件,采用基于精英策略的非支配遗传改进算法求解,构建区域General Water Allocation and Simulation Model(GWAS)模型;以2022年为现状基准年,与2023规划年组合,分为连续干旱与不连续干旱两大类,基于灌区水资源“应急干旱三次平衡”调控思想,分析灌区水资源在不同干旱情景下缺水的基础上,展开水资源抗旱配置研究,推演分析不同抗旱方案下水资源供需平衡情况。结果表明:连续干旱年中,灌区2023规划年在情景Ⅰ(P=90%)、情景Ⅱ(P=80%)来水频率下,各乡镇配置单元均存在不同程度的缺水情况,区域总缺水率分别为35.1%、20.8%;不连续干旱年中,2023规划年在情景Ⅲ(P=50%)来水频率下,模型基准配置水量基本可以满足区域各乡镇水量需求,区域总缺水率为5.9%。经不同抗旱方案尾部泵站补水、调整作物种植结构及外调水的优化配置后,三种情景下区域总缺水率最终都降为0%,优化后各配置单元供水改善效果显著。研究成果可为淠史杭灌区未来在应对不同干旱类型情景下水资源的合理调整提供技术支撑,并且可为实现该区域水资源统一管理和水量的统一调配提供理论依据。

漳河水库灌区水效领跑者引领行动的实践与评价

开展灌区水效领跑者引领行动及评价,是强化、规范农业灌溉用水管理的重要措施。基于有关部门印发的《灌区水效领跑者引领行动实际细则》和漳河水库灌区实践情况,采用层次分析方法(AHP),建立了漳河水库灌区水效领跑者引领行动的评价指标体系和评价阈值,分析了节水技术评价、节水管理评价和鼓励性评价等敏感指标,并对其进行评价,结果表明漳河水库灌区水效领跑者引领行动综合评价值0.94与实际情况吻合。

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。

智慧水利理论体系与数字孪生流域虚拟模型研究成果述要

智慧水利是水利高质量发展的显著标志之一。围绕智慧水利理论体系不完善、流域映射精准度不高、模型精度不高、决策支撑程度低等问题,建立了由智慧流域基础理论、数字孪生流域基础理论和智能水网理论框架组成的智慧水利理论体系,研究了由数字孪生感知节点模型、数字孪生降水遥感模型、数字孪生蒸散发遥感模型、数字孪生土壤水遥感模型、数字孪生水体遥感模型、数字孪生地下水遥感模型、数字孪生水质遥感模型组成的数字孪生流域感知模型,构建了由数字孪生流域水文模型、数字孪生水动力水质模型、数字孪生动态调控模型、数字孪生虚拟仿真模型、数字孪生协同决策模型、数字孪生并行组合模型等组成的数字孪生流域虚拟模型。研究成果可为我国智慧水利建设提供理论基础和技术支撑。

稻田控制排水对高邮灌区河道洪水过程的影响

以高邮灌区为例,采用水文-水动力模型,研究稻田控制排水措施对河道洪峰流量、水位和洪水过程的影响。结果表明,雨前通过控制灌溉适当降低田间水位可减轻稻田出流峰值,随着稻田控制水位的增加,稻田径流峰值逐渐降低。通过稻田控制排水,可降低田间出口峰值流量,改变灌区河道洪水过程,降低河道洪峰流量和水位,减轻灌区内部以及附近河道的防洪压力。

基于主成分及信息熵的额敏灌区农业用水特征

以额敏灌区农业灌溉用水为研究对象,采用主成分分析、信息熵分析方法,选取10个指标对灌区2009—2021年进行主成分分析。结果表明:影响灌区农业用水的主要驱动因子为衬砌防渗渠道长度、灌溉面积、农作物播种面积、节水灌溉面积、灌溉水量、农业人口数等6个指标;时间上,2009—2022年额敏灌区用水构成以农业灌溉用水为主,耕地、园地、林地、牧草地灌溉用水量分别占农业灌溉用水量的90.25%、3.12%、5.05%、1.58%,农业灌溉用水量于2010—2020年呈现逐年下降趋势;空间上,灌区东北部农业用水以地表水为主,中部与西部地表水和地下水占比基本一致。2009—2022年信息熵值与均衡度在灌区不同地理位置表现为:西部>东北部>中部,东北、中、西部信息熵分别为0.36、0.32、0.56 Nat,东北、中、西部均衡度均值分别为0.26、0.23、0.40。分析成果可为灌区农业灌溉用水现状及用水管理提供理论参考。

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。

氮肥与生物质炭配施对春小麦生长、产量及品质的影响

为了解氮肥和生物质炭配施对北疆灌区春小麦生长、产量及品质的影响,采用随机区组试验设计,以春小麦品种新春37号为供试材料,设置3个氮肥水平[不施氮肥(N0:0 kg·hm^(-2))、常规施氮(N1:300 kg·hm^(-2))、减量施氮(N2:255 kg·hm^(-2))]和4个生物质炭水平[不施生物质炭(B0:0 kg·hm^(-2))、低量生物质炭(B1:10×10^(3)kg·hm^(-2))、中量生物质炭(B2:20×10^(3)kg·hm^(-2))、高量生物质炭(B3:30×10^(3)kg·hm^(-2))],分析了不同处理下春小麦干物质积累与转运特性、籽粒产量及品质指标的差异。结果表明,生物质炭与氮肥配施可增加春小麦单株干物质积累量,提高花前同化物转运量、转运效率和对籽粒产量的贡献率,促进籽粒灌浆和产量形成,改善加工、营养品质。对小麦生长、品质及产量指标进行综合分析,减量施氮配施中量生物质炭(N2B2)处理综合表现最好,且该处理下成熟期单株干物质积累量最高,达5.12 g·株^(-1),花前同化物转运量、转运效率和对籽粒产量的贡献率分别为0.46 g·株^(-1)、15.32%、17.41%,产量较单施氮肥(N1B0)处理提高22.12%,蛋白质(干基)含量、淀粉(湿基)含量、面筋(湿基)含量、Zeleny沉降值和硬度分别为16.59%、62.12%、31.31%、46.95 mL和63.79。综上所述,在本试验条件下,减量氮肥配施中量生物质炭(N2B2)有利于北疆灌区春小麦高产优质生产。

春汇/夏浇灌溉制度对盐碱土壤水盐运移及向日葵水分利用的影响

【目的】确定河套灌区向日葵适宜的节水控盐春汇—夏浇灌溉制度,提高灌区农业灌溉水资源利用效率。【方法】设置非生育期畦灌(春汇S,灌溉定额135、95mm)和作物生育期滴灌(夏浇W,灌溉定额135、100、68 mm)田间小区试验,研究了不同春汇/夏浇条件下的向日葵农田土壤水盐分布规律、盐分淋洗效果、作物生长特征及水分利用效率。【结果】S135W135处理下的整个生育期内平均土壤含水率较高,为17.10%,为饱和含水率的75.53%;S95W135处理下的土壤含水率变异系数最小,为22.40%。S135、S95处理下的土壤脱盐率分别介于50.50%~32.64%、38.87%~21.87%,春汇后S135和S95处理下的0~80 cm土层的土壤盐分量无显著差异;S135W100、S95W135处理下的灌溉水淋洗深度较高,脱盐效果较好,土壤脱盐率均显著高于除S135W135处理以外的其他处理,0~80 cm土层脱盐率为40.77%和33.37%,较S135W135处理分别提高68.39%、37.86%。S95W135、S135W100处理下的地上部干物质量显著大于其他处理,相比S135W135处理增加10.55%和9.94%。S135W100处理的作物水分利用效率最高(21.59%),较S135W135处理显著增加13.03%。【结论】常规春汇水量减少30%(95mm)与夏浇滴灌(135 mm)是河套灌区向日葵农田适宜的灌溉制度。