Effects of Combined Application of Water Retaining Agents and Organic Materials on Water Holding Characteristics of Yellow Brown Soils in Hilly Areas

[Objective] The aim was to reduce fertilizer and water losses caused by surface runoffs in rainy season and provide scientific references for soil moisture in arid season. [Method] The application proportion of complex water-holding organic materials was determined by multi-factor mixture experiment and the curve changes of soil moisture characters were tested to analyze water-holding capacity and water availability of soils. [Result] The initial moisture content of soil with different mixture proportions improved in varying degrees. For example, when water-retention agents reached 0.4% and 0.6% of soil weight, soil moisture contents were 69.0% and70.5%, respectively, which showed significant differences with the control（S0.0）. Soil dehydration terms in different treatments all extended, prolonging in the range of4.6-14 d. [Conclusion] The applications of water-retention agent and organic material would improve water-holding capacity of hills and low mountains, and initial moisture content and dehydration cycle tend to be volatile upon mixture proportion. Therefore,it is necessary to adjust soil fertility, crop species, and irrigation to meet crop demands on fertilizer and water.

Potential Role of Feldspathic Sandstone as a Natural Water Retaining Agent in Mu Us Sandy Land,Northwest China

This paper analyzed the water-retention mechanism of feldspathic sandstone （fine-（〈 1 mm diam.） and gravel-sized （2-3 cm diam.） in Mu Us Sandy Land, Northwest China. The objective of this study is to study the effect of feldspathic sandstone amendment on water retention in sandy land. The results showed that as the proportion of fine feldspathic sandstone in the sandy land soil increased, the soil texture changed from sand to silt loam, the capillary po- rosity gradually increased from 26.3% to 44.9%, and the soil saturated hydraulic conductivity decreased from 7.10 ram/rain to 0.07 mm/min. Feldspathic sandstone gravel formed micro-reservoirs in the sandy land soil, playing the role of a ＇water absorbent＇ and ＇water retaining agent＇ in sandy land. Amendment with feldspathic sandstone can increase water retention in the arable layer of sandy land by 67%. This study provides a theoretical basis for the amelioration of sandy land on a large scale. It can be concluded that amendment with feldspathic sandstone can improve the physical properties of sandy land soil and increase soil water retention.

Effects of Water-Collecting and -Retaining Techniques on Photosynthetic Rates, Yield, and Water Use Efficiency of Millet Grown in a Semiarid Region

Field experiments were conducted in 2003 and 2004 to study the effects of plastic ridges and furrow film mulching （plastic film on sowing, as well as plastic film on flat soil and hole sowing） and chemicals （a drought resistant agent and a water- retaining agent） on growth, photosynthetic rate, yield, and water use efficiency （WUE） of spring millet （Setaria italica L.）. The experimental results showed that water-collecting and -retaining techniques can effectively increase soil moisture content, the leaf photosynthetic rate and crop growth. Due to increased soil moisture under the plastic-covered ridge and furrow water-collecting in July and August, dry matter and plant height had a increase at the booting stage （late growth advantage）. However, the plastic-covered flat soil and hole sowing reduced soil evaporation during early growth, the increase of dry matter and plant height appeared at the seedling stage （early growth advantage）. Plastic-covered ridge and furrow sowing supplemented with chemical reagents had significant positive effects on water collection and soil moisture retention. Improvement of soil moisture resulted into the increase of the photosynthetic rate, dry matter accumulation yield and WUE. The water-collecting and -retaining techniques can improve WUE and enhance crop yield. Correlation analysis demonstrated that the photosynthetic rate under the water-collecting and -retaining techniques was significantly associated with the soil moisture, but had no significant relationship with leaf chlorophyll content. Plastic- covered ridge and furrow sowing supplemented with chemical reagents increased the yield and WUE by 114% and 8.16 kg ha-1 mm-1, respectively, compared with the control; while without the chemical reagents the yield and WUE were 95% and 7.42 kg ha-1 mm-1 higher, respectively, than those of the control.

Effects of Nano-carbon Humic Acid Water-retaining Fertilizer on Citrus Growth and the Soil Bacterial Community in Citrus Field

[Objective] In order to reveal the effects of reducing the amount of novel nano-carbon humic acid water-retaining fertilizer(CSF) on soil microbial community structure and citrus growth. [Method]In this study,conventional fertilization was as the control(KC1) in Wanzhou citrus orchard of Three Gorges Reservoir area. CSF reductions by 0%(KC2),10%(KC3),20%(KC4),30%(KC5) and 40%(KC6) were used to analyze the changes of soil bacterial community structure,citrus yield and quality. [Result]The results showed that the observed species,Shannon index,Chao1 index and PDwholetree of KC6 were higher than those of KC1,and were the same as KC2. The abundance of Xanthomonadaceae was the highest in KC5. Compared with KC1,the Xanthomonadaceae in KC3,KC4 and KC6 was significantly decreased,and the levels of Nitrosomonadaceae and Pseudomonasaceae were higher than that of KC1 after the treatment of KC6. Sphingomonas in different reduction treatments was lower than that of KC1,but Burkholderia and Pseudomonas were significantly higher than those of KC1. It was found that the similarity among treatments was small after bacterial community similarity clustering analysis,and citrus yield increased somewhat after CSF fertilization reduction.When CSF fertilization reduced by 30%,citrus yield increased by 4. 50%. When CSF fertilization reduced by 40%,citrus yield decreased by4. 14%. After CSF fertilization,citrus quality did not change significantly in CSF conventional fertilization and reduction of 10% and 40%,while significantly decreased in 20% and 30% of fertilization reduction. [Conclusion] CSF fertilization reduction changed the diversity of soil bacterial community structure and the yield and quality of citrus.

Ice-and cryogel-soil composites in water-retaining elements in embankment dams constructed in cold regions

There are a number of serious problems connected with building and repairing water-reining elements in embankment dams in cold regions. One of them is the difficulty in finding inexpensive clay materials with the necessary structural properties and using them in the winter. Another is the cracks that appear in the upper part of a dam when the core freezes to the banks, and leakage along the cracks threatens to desWoy the dam. Still another is the process of erosion at the bottom of the core which may occur through fissures in the rock foundation of a dam and in transport constructions. Also, the behaviour of water-retaining elements during eazthquakes is unreliable. All of these problems can be solved by using iceand cryogel-soil composites created by cryotropic gel formation （CGF）. Our laboratory investigations demonstrate that the materials proposed for water-retaining elements have the necessary permeable, plastic, thermophysical, and slrength properties to solve all of these problems. Certain consmactious of water-retaining elements which may prove to be both safe and cost-effective are proposed. However, these iceand cryogel-soil composites need to be field-validated before they are used in dams and transport structures in cold regions.

Effects of Nano-Carbon Water-Retaining Fertilizer on Yield and Nitrogen and Phosphorus Utilization Efficiency of Tuber Mustard

The effects of nano-carbon water-retaining fertilizer on yield,quality of tuber mustard,and fertilizer utilization efficiency were studied with the field experiments compared to the local tuber mustard fertilizer with equal amount of effective composition. The results showed that the yield of tuber mustard was 50 670-56 496 kg/ha in treatments of nano-carbon water-retaining fertilizer decreasing by 10%-40%,and compared with local tuber mustard fertilizer,the average yield was increased by 94. 8%. The yield increasing rate of tuber mustard was 93. 0%in treatment of nano-carbon water-retaining fertilizer decreasing by 30%. The average fertilizer utilization efficiency of nitrogen and phosphorus was 54% and 39. 7%,respectively,the average increment of fertilizer utilization efficiency was 36% and 37%,respectively compared with local tuber mustard fertilizer. Especially in treatment of reducing nano-carbon water-retaining fertilizer by 30%,the nitrogen and phosphorus fertilizer utilization efficiency was increased by 64% and 56%,respectively. By comprehensive comparison,it was found that nano-carbon waterretaining fertilizer and the treatment of 30% reduction could significantly improve the yield of tuber mustard and fertilizer utilization efficiency,and have popularization and application value in the Three Gorges Reservoir area.

An Overview of Recently Developed Coupled Simulation Optimization Approaches for Reliability Based Minimum Cost Design of Water Retaining Structures

This paper reviews several recently-developed techniques for the minimum-cost optimal design of water-retaining structures (WRSs), which integrate the effects of seepage. These include the incorporation of uncertainty in heterogeneous soil parameter estimates and quantification of reliability. This review is limited to methods based on coupled simulation-optimization (S-O) models. In this context, the design of WRSs is mainly affected by hydraulic design variables such as seepage quantities, which are difficult to determine from closed-form solutions or approximation theories. An S-O model is built by integrating numerical seepage modeling responses to an optimization algorithm based on efficient surrogate models. The surrogate models (meta-models) are trained on simulated data obtained from finite element numerical code solutions. The proposed methodology is applied using several machine learning techniques and optimization solvers to optimize the design of WRS by incorporating different design variables and boundary conditions. Additionally, the effects of several scenarios of flow domain hydraulic conductivity are integrated into the S-O model. Also, reliability based optimum design concepts are incorporated in the S-O model to quantify uncertainty in seepage quantities due to uncertainty in hydraulic conductivity estimates. We can conclude that the S-O model can efficiently optimize WRS designs. The ANN, SVM, and GPR machine learning technique-based surrogate models are efficiently and expeditiously incorporated into the S-O models to imitate the numerical responses of simulations of various problems.

Safe retaining pressures for pressurized tunnel face using nonlinear failure criterion and reliability theory

Based on the active failure mechanism and passive failure mechanism for a pressurized tunnel face, the analytical solutions of the minimum collapse pressure and maximum blowout pressure that could maintain the stability of pressurized tunnel faces were deduced using limit analysis in conjunction with nonlinear failure criterion under the condition of pore water pressure. Due to the objective existence of the parameter randomness of soil, the statistical properties of random variables were determined by the maximum entropy principle, and the Monte Carlo method was employed to calculate the failure probability of a pressurized tunnel. The results show that the randomness of soil parameters exerts great influence on the stability of a pressurized tunnel, which indicates that the research should be done on the topic of determination of statistical distribution for geotechnical parameters and the level of variability. For the failure probability of a pressurized tunnel under multiple failure modes, the corresponding safe retaining pressures and optimal range of safe retaining pressures are calculated by introducing allowable failure probability and minimum allowable failure probability. The results can provide practical use in the pressurized tunnel engineering.

Equilibrium sediment transport in lower Yellow River during later sediment-retaining period of Xiaolangdi Reservoir

The Xiaolangdi Reservoir has entered the later sediment-retaining period, and new sediment transport phenomena and channel re-estab- lishing behaviors are appearing. A physical model test was used to forecast the scouring and silting trends of the lower Yellow River. Based on water and sediment data from the lower Yellow River during the period from 1960 to 2012, and using a statistical method, this paper analyzed the sediment transport in sediment-laden flows with different discharges and sediment concentrations in the lower Yellow River. The results show that rational water-sediment regulation is necessary to avoid silting in the later sediment-retaining period. The combination of 3 000 m^3/s 〈 Q 〈 4 000 m^3/s and 20 kg/m^3 〈 S 〈 60 kg/m^3 （where Q is the discharge and S is the sediment concentration） at the Huayuankou section is considered an optimal combination for equilibrium sediment transport in the lower Yellow River over a long period of time.

水分胁迫下新型土壤保水剂对玉米苗期发育的影响

保水剂在土壤中降解能力低,会对土壤环境产生危害,利用聚天冬氨酸和膨润土为原料,制备了新型的可降解土壤保水剂。设置水分胁迫处理和正常灌溉处理2组水分处理,在2组水分处理下分别施用市售腐殖酸保水剂(TA)和12.5(TB1)、17.5(TB2)、22.5(TB3)、27.5(TB4)和32.5 kg·hm^(-2)(TB5)的新型土壤保水剂,以不施用保水剂为对照(CK),探讨其对玉米苗期生长发育的影响。结果表明,施用保水剂在玉米苗期可提高土壤含水量,当保水剂加入量为22.5 kg·hm^(-2)效果最好,保水剂用量为32.5 kg·hm^(-2)时对玉米出苗有显著抑制作用;在水分胁迫条件下,施用保水剂各处理的株高、茎粗、叶绿素含量和超氧化物歧化酶、过氧化物酶、过氧化氢酶活性均显著高于CK;同时施用保水剂能显著降低丙二醛和脯氨酸含量;其中,以保水剂用量为22.5 kg·hm^(-2)(TB3)效果最佳。以上结果表明,新型土壤保水剂效果明显,对我国的农业节水有一定的推进作用。

渗透各向异性土层中考虑挡墙厚度的基坑稳态渗流解析解

本文对考虑厚度挡墙支护下渗透各向异性土层中基坑的二维稳态渗流进行了解析研究。根据对称性取基坑半截面,将周围土层划分为5个规则区域,采用坐标变换将渗透各向异性土层转换成等效各向同性土层,对各区域利用叠加法和分离变量法推导得到二维稳态渗流场、挡墙上水压力以及坑底出逸比降的显式解析解。对比保角变换和积分变换方法,本文解渗流场计算结果连续且无奇异点,且基坑水头和挡墙两侧水压力分布情况与数值软件分析一致性较好,说明本文解析解的正确性和优越性。本文解与不同计算方法得到的挡墙水压力结果对比分析发现,挡墙厚度d、竖直与水平向渗透系数比α对挡墙上水压力的影响不可忽略。分析α、d对挡墙底部水压力及出逸比降的影响,随着α和d的增大,基坑外侧挡墙底部水压力增大,基坑内侧挡墙底部水压力减小;随着α和d的逐渐减小,坑底出逸比降不断增大;当α和d较小时,考虑一维渗流情况得到的出逸比降安全性较低,且随着α和d的减小与本文解析解差距越来越大。

充气式橡胶坝的模型试验及有限差分研究

橡胶坝的挡水性能优越,兼具实用性与景观性,被广泛用在城市河流挡水闸坝和溢流坝等领域。充气式橡胶坝相比充水橡胶坝,安装和拆卸更为方便,但目前充气式橡胶坝采用查表法进行粗略设计,过程复杂且存在误差。鉴于此,设计大比尺模型试验测试充气式橡胶坝在充气、挡水条件下的坝袋截面形状和袋体张拉力分布特点。基于有限差分软件建立充气式橡胶坝的力学模型,通过大比尺模型试验和现行设计规范验证了该模型的准确性。分析充气式橡胶坝在挡水过程中横截面几何形状及尺寸、张拉力与上游水位及内部气压之间的关系。结果表明:坝袋宽度B、接地宽度b随上游水位增大呈非线性增加;坝袋高度H、横截面面积A随上游水位增大呈非线性减小。设计工况下,坝袋高度H、横截面面积A随气压增加呈非线性增大,坝袋宽度B、接地宽度b随气压增大呈非线性减小;坝袋张拉力与气压呈正比关系。基于Chapman-Richard曲线模型对设计工况下的几何尺寸、张拉力与内部气压间的关系进行拟合,提出橡胶坝简化设计计算公式,可用于充气式橡胶坝的设计计算。

基于保水剂应用的高寒沙地土壤种子库激活效应

为探究保水剂对黄河上游高寒沙地土壤种子库的激活效应,以若尔盖天然草地、轻度沙地、中度沙地、重度沙地、极重度沙地为研究对象,分析其物种组成、生活型,通过围封(中度沙地、重度沙地、极重度沙地)样地,在样地上施加不同量保水剂,研究不同保水剂用量下萌发物种数、植株数量、植物生物量、群落盖度的变化。结果表明:(1)四川黄河上游高寒沙地共统计到植物种子26种,均为草本植物,表现出该区域种子的科、属、种较为集中、物种组成类型单一。(2)随着保水剂施用量的增加,中度沙化地生长的草本植物物种数、植株数量显著高于对照,施用0.25 kg·m^(-2)保水剂时达到最大萌发数量和最大萌发物种数;重度沙化地、极重度沙化地保水剂处理组植株数量显著高于对照,随着保水剂施用量增加植株数量总体呈先增加后降低的趋势,施用量为0.25 kg·m^(-2)时幼苗数量达到峰值。(3)就样地草本植物群落生物量和盖度而言,施用保水剂样地植物生物量、群落盖度总体上高于对照,除极重度沙化地外,中度沙地、重度沙地生物量和盖度在施用量0.25 kg·m^(-2)时达到最大,之后生物量、盖度逐渐降低。在高寒沙地土壤种子库激活实验中,保水剂用量为0.25 kg·m^(-2)时能满足植物种子的萌发与生长,进一步提高保水剂的施用量对植物生物量的增加无显著影响,反而有降低的可能。根据保水剂处理条件下土壤种子库物种萌发的情况,结合研究区原生植被情况,四川嵩草、赖草、羊茅、草地早熟禾、线叶嵩草可作为研究区生态恢复的参考物种。

梁北矿松软大采高工作面高水充填沿空留巷技术研究

以高水材料适应性研究为基础,通过分析梁北煤矿厚硬顶板大采高工作面沿空留巷围岩控制难点,提出“预裂切顶-高水充填-超前加固”沿空留巷技术。通过室内试验确定了高水充填材料最佳水灰比、早强剂掺量和用水温度;采用理论分析和工程类比确定了预裂切顶、超前加固和高水充填支护方案;采用数值模拟分析了沿空留巷方案的可行性。工程实践效果表明,围岩变形滞后工作面100~150 m趋于稳定,变形整体可控,留巷效果较好。

丙烯酸基高吸水性树脂的研究进展

介绍了高吸水性树脂的制备方法以及各种方法的优缺点。概述了不同的改性材料对高吸水性树脂吸水保水性能的影响,并给出了增加比表面积、分子量、活性基团数量、适当的中和度和交联度等方法来提高吸水保水能力。总结了高吸水性树脂在环境治理、建筑材料和农林业三个领域的应用。对高吸水性树脂性能的进一步改善进行了展望,开发低成本、可降解的高吸水性树脂仍是亟需解决的难题。

高寒矿区蛇纹石渣土配制及其改良种植基质的试验——以青海威斯特铜矿为例

针对青藏高原高寒矿区“客土”资源缺乏、土壤结构质量差和植被建造困难等问题,研究蛇纹石渣土与当地原土配制和改良,为植被建造提供种植基质。以青海威斯特铜矿为例,通过土壤模拟、盆栽种植和田间小区试验方法,对矿区蛇纹石渣土与当地原土进行种植基质配制,并通过改良试验确定种植基质的改良方案。蛇纹石渣土与原土不同比例配制极大影响基质的理化性能。蛇纹石渣土与原土配制比例6∶4时,种植基质土壤密度、pH和土壤电导率分别与纯蛇纹石渣土对照(CK)降低2.20%、7.95%和19.88%,土壤毛管孔隙度、田间持水量,以及有效磷、速效钾、全氮和水解性氮的质量分数分别显著增加15.12%、7.02%、75.23%、328.88%、117.65%和32.38%,达到绿化基质基本要求;盆栽种植表明,蛇纹石渣土与原土配制比例6∶4时,单种植披碱草和混种6种草籽等牧草的出苗数较对照CK提高10.34%和25%,披碱草株高、地上生物量、地下生物量分别较对照CK提高7.25%、87.00%和246.95%;田间小区种植试验表明,蛇纹石渣土与原土配制比例为6∶4且添加TG改良剂1 kg/m^(2)、KM 3005保水剂12 g/m^(2)和羊板粪3.12 kg/m^(2)时,羊板粪和TG改良剂梯度试验出苗株高和生物量分别较对照提高38.30%和200.43%、21.43%和358.02%,并得到工程示范应用。蛇纹石渣土与原土按照6∶4配制并通过TG改良剂、保水剂和羊板粪改良后,能达到矿区生态修复的植物种植的基质要求,试验结果对促进青海高寒矿区的生态修复具有重要参考。

新型复合保水剂对植烟土壤性质及烤烟有机酸含量的影响

本研究采用大田小区试验,以不施保水剂为对照(CK),设置市售保水剂T1、自制聚乙烯醇保水剂(PVA/AA)T2、自制生物炭复合保水剂(PVA/AA/B)T3和自制腐植酸钾复合保水剂(PVA/AA/HAK)T4共5个处理,研究不同类型保水剂对植烟土壤理化性质、烤后烟叶有机酸含量和经济效益的影响。结果表明,T4处理(PVA/AA/HAK保水剂)效果较好,其T3处理次之,土壤理化性状均明显改善,均较对照显著提高烤烟的产量和产值;T4处理全生育期土壤含水率和速效磷、速效钾、碱解氮、有机质含量较CK分别增加16.98%~29.78%、16.44%~18.11%、9.59%~18.08%、15.16%~25.00%、10.45%~15.98%;土壤脲酶、蔗糖酶活性分别提高15.72%~19.93%、10.10%~13.80%。PVA/AA/HAK保水剂显著提高烟叶非挥发性有机酸总量,其中苹果酸、柠檬酸含量较对照分别提高53.68%和68.29%。相关性分析结果表明,烤烟苹果酸含量与土壤碱解氮含量呈显著正相关;草酸含量与土壤脲酶活性呈极显著正相关,与土壤含水率呈显著正相关。综上所述,施用新型生物炭及腐植酸钾复合保水剂明显改善了土壤质量,提高了烟叶非挥发性有机酸总量和经济效益。

黏性细尾砂料浆流变特性初步研究

为探究黏性细尾砂料浆流变特性,以某金矿细尾砂料浆为研究对象,借助流变仪、pH计、ICP-OES、Zeta电位仪多种手段开展料浆保水性、触变性研究,分析了金矿细尾砂料浆流变特性,探讨了料浆从层流到紊流的转变及扩展度与流变参数的关系。结果表明:①细尾砂的黏土矿物成分含量高和比表面积大的特点是影响料浆保水性、触变性、流动性以及层流—紊流转变的重要内因;②黏土矿物溶出碱阳离子使电动电位下降引起吸附水膜厚度降低,但共用吸附水膜的细尾砂颗粒间吸引力也因此增强,促进絮网结构形成和发展,使絮网结构强度提高,絮网内包裹水量因此增加,再加上较大比表面积使水膜面积增加,导致料浆吸附水量增加;③细尾砂黏土矿物成分越多,比表面积越大,被破坏的絮网结构恢复重建越困难,触变性越明显,通过增加剪切速度和降低料浆浓度可弱化触变性;④细尾砂料浆属于宾汉塑性体,黏土矿物和较大比表面积有助于使料浆维持层流,使料浆屈服应力、刚度系数增加和扩展度降低,扩展度同时受屈服应力和刚度系数控制且遵循负幂函数关系。

玉米芯纤维素基保水保肥材料的制备及性能研究

使用玉米芯纤维素结合羧甲基化修饰制备高吸水性水凝胶,引入氨氮吸附功能,制备出一种高效保水保肥材料CCH/Z,通过SEM、FTIR、接触角等测试对其微观结构、官能团组成、亲水性进行了分析,并通过吸水溶胀实验和氨氮吸附实验,测试了合成材料的保水保肥性能。结果表明,CCH/Z保水率可达到452.49%,在保肥方面,当CCH/Z用量为0.15 g时,在100 mg/L氨氮溶液中,吸附率可达41.4%,准一级动力学模型、准二级动力学模型均可以描述吸附氨氮行为,热力学分析表明,CCH/Z的吸附行为符合Freundlich模型。

硼肥和保水剂配施对甜菜硼吸收利用的影响

以甜菜品种‘Beta 796’和‘ST 13092’为试验材料,采用裂区设计,以施硼量为主区[包括施硼量0 kg·hm^(-2)(M0)、1.2 kg·hm^(-2)(M1)、2.4 kg·hm^(-2)(M2)、4.8 kg·hm^(-2)(M3)],保水剂为副区[包括保水剂施用量0 kg·hm^(-2)(Z0)、75 kg·hm^(-2)(Z1)],研究硼肥和保水剂配施对滴灌甜菜硼养分吸收和产量的影响。结果表明:甜菜硼含量随施硼量的增加呈现先增加后降低的趋势,在M2处理达到最大。甜菜不同器官硼含量表现为叶片>叶柄>块根,其中M2处理条件下甜菜叶片、叶柄和块根硼含量较其他处理分别提高6.09%~54.55%、7.17%~49.68%和11.08%~73.70%。与叶丛期相比,收获期甜菜叶片和叶柄硼积累量占比分别降低8%~19%和3%~7%,块根硼积累量占比提高14%~24%。施用保水剂后,甜菜叶片、叶柄和块根硼含量较不施用保水剂处理分别提高10.56%~32.73%、3.66%~25.04%和20.11%~57.38%。相同处理条件下,‘Beta 796’叶片、叶柄和块根硼积累量比‘ST 13092’提高0.45%~15.64%、0.89%~13.72%和1.15%~15.79%。‘Beta 796’和‘ST 13092’品种的硼肥表观利用率分别为42.43%和37.89%。因此,将3.1~3.5 kg·hm^(-2)硼肥和75 kg·hm^(-2)保水剂在叶丛期随水滴施能够实现甜菜增产增效,为新疆甜菜可持续生产管理提供了案例支撑。