非充分灌溉条件下泵站优化调度模型研究

研究了非充分灌溉条件下的泵站调度问题,在常规以灌区灌溉效益最大为目标模型的基础上,考虑了泵站的运行费用,建立了以全灌区净效益最大为优化目标的数学模型,并提出相应的求解方法和具体计算步骤,同时,阐明了非充分灌溉条件下泵站优化调度需要进一步考虑的问题.     

尾菜再生水不同灌溉处理对土壤理化性质及粪大肠菌群分布的影响

为探讨尾菜再生水与自来水不同灌溉处理对土壤理化性质和指示性病原菌分布的影响,采用室内土柱淋溶试验,设置充分灌溉(田间质量持水率的90%)和非充分灌溉(田间质量持水率的70%)2个灌水梯度,18 d为一个灌水周期,累计灌溉16期,分别在第72、144、216、288 d进行分层取样,研究再生水在不同灌溉条件下土壤质量的时空分布特征,为尾菜再生水农田回用提供理论依据及实践基础。结果表明,与自来水灌溉相比,再生水灌溉条件下,无论是充分灌溉还是非充分灌溉,均显著提高表层土壤可溶性盐(EC)含量和粪大肠菌群(FDC)数量,对土壤pH值无显著影响;提高土壤总氮(TN)、总磷(TP)、总钾(TK)和有机质(OM)含量,随着灌溉次数的增加,土壤营养元素在各土层表现出一定的累积效应,且有向深层土壤迁移的趋势;相关性分析表明,FDC与pH、EC、TN、TP、TK呈显著正相关(P<0.05),与OM呈正相关(P>0.05)。综上所述,尾菜再生水长期灌溉有利于土壤TN、TP、TK和OM含量的累积,一定程度上增加土壤养分,提高土壤肥力,但存在盐害和致病菌污染风险。     

再生水和清水不同灌水水平对土壤理化性质及病原菌分布的影响

【目的】探讨再生水和清水不同灌水水平对土壤理化性质和指示性病原菌粪大肠菌群数量分布的影响。【方法】采用室内土柱试验,研究了不同水质、不同灌水水平下土壤理化性质和粪大肠菌群的分布规律。【结果】相比清水灌溉,再生水灌溉下土壤有机质量(OM)、总氮量(TN)、总磷量(TP)、电导率(EC)显著提高,土壤p H值略微下降,且再生水充分灌溉处理的表层0~20 cm土壤有机质量(OM)、总氮量(TN)、总磷量(TP)均高于非充分灌溉处理,电导率(EC)则相反;再生水灌溉下,土壤中粪大肠菌群数量显著提高,各土层粪大肠菌群数量均显著高于清水灌溉,再生水充分灌溉下表层0~20 cm土壤粪大肠菌群数量显著高于非充分灌溉;土壤粪大肠菌群数量与OM、TN、TP量和EC均正相关,与土壤p H值、含水率负相关。【结论】再生水灌溉能够在一定程度上提高土壤肥力,合理控制再生水灌水水平可有效阻控土壤病原菌的污染;土壤养分量越高,越有利于粪大肠菌群的生长繁殖。     

河套灌区灌溉制度研究

根据河套灌区的气象、土壤、灌水等资料,利用ISAREG模型模拟了4种主要作物充分灌溉和非充分灌溉2种灌溉制度方案。根据模型的优化模拟结果分析,在作物产量比率仅略有下降的情况下,作物实施非充分灌溉将减少灌水次数和灌溉定额(平均下降45 mm),建议灌区把作物实施非充分灌溉作为一种节水措施之一。     

我国节水灌溉发展面积现状与宏观效益分析

对我国工程节水灌溉(防渗渠道输水灌溉、低压管道输水灌溉、喷灌、微灌、雨水集蓄工程节水灌溉)和非工程节水灌溉(水稻节水灌溉、坐水种等)面积发展状况作了简要总结，对其宏观效益作了扼要分析。     

基于改进NSGA-Ⅱ的作物灌水量与灌溉日期同步优化

在非充分灌溉条件下,基于农田水量平衡模拟模型和作物产量计算模型,以灌水日期和灌溉水量为决策变量,将作物相对产量最大和作物全生育期的总灌溉水量最小作为优化目标,建立了能够同时对灌水日期和灌溉水量进行优化的多目标优化模型.在模型求解方面,设计了适合于此类优化问题的染色体结构,在精英保留非劣排序遗传算法(NSGA-Ⅱ)的基础...     

喷灌条件下冬小麦非充分灌溉试验研究

非充分灌溉是农业节水灌溉理论研究中的新课题，非充分灌溉的核心是节水高效。本文以喷灌条件下冬小麦为研究对象，采用数字模拟和田间试验相结合的方法，从田间水分转化规律出发，根据灌溉水量无效消耗最小原则，计算确定最优灌水定额，在此基础上根据土壤墒情、苗情制定出高效的非充分灌溉制度。该灌溉制度具有较强的可操作性、适用性、且定量化，经过5年9．33hm^2田间试验，平均每公顷产量6360kg，总耗水生产率达2kg/m^3。为非充分灌溉提供了理论依据和试验成果。     

不同滴灌灌溉制度对绿洲棉田土壤水热分布及产量的影响

【目的】探究不同滴灌灌溉制度对绿洲棉田土壤水热分布状况及对产量的影响。【方法】于2017年在策勒地区开展田间试验,设置了2种灌水模式:基于计算机模型的预报灌溉与基于土壤墒情的灌溉,每种灌水模式设置2种灌溉梯度:充分灌溉(100%)和非充分灌溉(75%的充分灌溉)。【结果】预报灌溉的土壤含水率和贮水量在花蕾与花铃期显著高于墒情灌溉;不同灌溉制度各剖面的土壤温度变化趋势一致,整个生育期的表层土壤平均温度表现为墒情亏缺最高,预报充分最低。作物产量在一定范围内随灌溉量的增加而增加,预报充分的产量较预报亏缺,墒情充分,墒情亏缺分别提高13.7%、12.1%、47.6%。水分利用效率表现为预报亏缺最高,且产量与预报充分的产量无显著差异。【结论】在策勒绿洲地区,预报亏缺灌溉可达到节水增产的目的。     

调亏灌溉对地下渗灌甘蓝产量、品质及水分利用效率的影响

为探究宁夏干旱气候地区地下渗灌甘蓝(Brassica oleracea L.)合理灌溉制度。在大田尺度上采用单因素随机试验设计,分别在甘蓝的莲座期、结球前期和结球中后期进行轻度(65%~75%FC)、重度(55%~65%FC)调亏灌溉,并以全生育期充分灌溉(75%~85%FC)为对照(分别记为T1、T2、T3、T4、T5、T6、T7(CK)),共7个处理,种植前施复合底肥400 kg/hm²(N>25%,P₂O₅>6%,K₂O>9%,总养分>40%),研究了不同调亏灌溉处理方案对甘蓝的干物质积累、产量、品质和水分利用效率的影响。结果表明:在甘蓝结球前期进行轻度调亏灌溉处理(T3),经济产量、单株球重、叶球纵径、中心柱长、可溶性糖含量和VC含量与充分灌水相比无显著性差异,但经济系数较充分灌溉(CK)提高了2.73%,叶球横径和帮叶比较充分灌溉(CK)降低了7.90%和5.37%,叶球紧实度较充分灌溉(CK)提高了24.60%,灌水量较充分灌溉(CK)减少了28.95%,水分利用效率较充分灌溉(CK)提高了31.43%。在甘蓝结球中后期进行轻度调亏灌溉处理(T5),地上部干物质量、经济产量、单株球重、叶球纵径、中心柱长、帮叶比与充分灌水相比无显著性差异,但经济系数和叶球紧实度较充分灌溉(CK)提高了3.25%和19.67%,可溶性糖含量和VC含量较充分灌溉(CK)提高了28.74%和13.81%,灌水量较充分灌溉(CK)减少了25.09%,水分利用效率较充分灌溉(CK)提高了27.78%;T3、T5的经济产量较充分灌溉(CK)分别降低了1.61%和1.22%。因此,T3和T5处理都能够达到节水稳产的目的。但是,T3处理更有利于提升宁夏干旱气候区地下渗灌甘蓝的物理品质,T5处理更有利于提升宁夏干旱气候区地下渗灌甘蓝的营养品质。     

干旱地区农作物有限水源灌溉系统优化算法

为了提高农业作物投入产出比,提出了一种适合干旱地区农业自动灌溉系统的优化控制方法。算法以带精英策略的非分支排序遗传算法(NSGA-II)为基础,以滴灌系统总费用最小和农业效益最大为目标函数,以灌溉系统和农作物需求为约束,基于不充分灌溉原理,实现了在总体供水不足的情况下节水灌溉的优化配置。伊犁地区水资源优化配置仿真表明,该算法是有效、可行的。     

Effects of deficit irrigation scheduling on yields and soil water balance of irrigated maize

This paper presents the findings of the effect of some selected deficit irrigation scheduling practices on irrigated maize crop in a sub-catchment in south western part of Tanzania. Field experiments, in which maize (TMV1-ST) variety was planted under total irrigation, were conducted during the dry seasons of 2004 and 2005. Surface irrigation method was used and the crop was planted in basins. The seasonal water applied ranged from 400 to 750 mm. Soil moisture content from both cropped and bare soils, leaf area index, dry matter, and grain yields were measured. The dry matter yield ranged between 6,966 and 12,672 kg/ha, and grain yields obtained were between 1,625 and 4,349 kg/ha. The results showed that deficit irrigation at any crop growth stage of the maize crop led to decrease in dry matter and grain yields, seasonal evapotranspiration and deep percolation. Deficit irrigation in any one growth stage of the maize crop only seems to affect grain production and no significant effect on biomass production, but deficit irrigation that spanned across two or more growth stages affect both biomass and grain production drastically. Crop water use efficiency (WUE) and Irrigation water use efficiency (IWUE) were strongly influenced by the number of growth stages in which deficit irrigations were applied and how critical the growth stages were to moisture stress rather than the amount of irrigation water applied. While maximum WUE was obtained under full irrigation, maximum IWUE was obtained in the deficit irrigation treatment at vegetative growth stage, which suggest that IWUE may be improved upon by practicing deficit irrigation at the vegetative growth stage of the maize crop.     

不同生育期水分亏缺对春青稞水分利用和产量的影响

对不同生育期水分亏缺程度对春青稞(Hordeum vulgare)水分利用效率和产量的影响进行了桶栽试验研究。试验处理设充分灌溉处理(2个水分控制下限和秸秆覆盖)以及在全生育期和5个不同生育期的4个水分亏缺程度(轻度、中度、重度和极度)处理,共27个处理。结果表明,在充分灌溉条件下,75%田间持水率水分下限控制处理的春青稞收获指数、籽粒产量和作物水分利用效率大于80%水分处理;秸秆覆盖处理的籽粒产量和水分利用效率在所有试验处理中最大。在全生育期水分亏缺条件下,春青稞籽粒产量均小于充分灌溉处理,且随着水分亏缺程度的增大而显著减小;轻度至重度水分亏缺处理可获得更大的作物收获指数和水分利用效率,但极度水分亏缺却导致最低的籽粒产量、收获指数和水分利用效率。除成熟期水分亏缺处理外,不同生育期水分亏缺处理条件下,春青稞籽粒产量和作物水分利用效率基本随着水分亏缺程度的增大而减小;拔节期、分蘖期和灌浆期水分亏缺对籽粒产量的不利影响较大。地表秸秆覆盖或全生育期轻度至重度水分亏缺处理可提高春青稞水分利用效率。     

A new stochastic optimization model for deficit irrigation

Deficit irrigation has been suggested as a way to increase system benefits, at the cost of individual benefits, by decreasing the crop water allocation and increasing the total irrigated land. Deterministic methods are common for determining optimal irrigation schedules with deficit irrigation because considering the inherent uncertainty in crop water demands while including the lower and upper bounds on soil moisture availability is a hard problem. To deal with this, a constraint state formulation for stochastic control of the weekly deficit irrigation strategy is proposed. This stochastic formulation is based on the first and second moment analysis of the stochastic soil moisture state variable, considering soil moisture as bounded between a maximum value and a minimum value. As a result, an optimal deficit irrigation scheduling is determined using this explicit stochastic model that does not require discretization of system variables. According to the results, if irrigation strategy is based on deterministic predictions, achievement of high, long-term expected relative net benefits by decreased crop water allocation and increased irrigated land may have a higher failure probability.     

Yield and size of deficit irrigated potatoes

Controlled deficit irrigation (CDI) has been studied in a potato crop cultivated in a semi-arid zone (Albacete, Spain). Ten drip irrigation treatments were differentiated by the level of fulfilment of the water requirements. The effect of deficit irrigation at three crop stages (growth, tuber bulking and ripening) has been studied. Tuber yield and its components were highly influenced by the total volume of irrigation water. The treatments with deficit during the last part of the cycle have had the lowest productions. The larger potatoes were obtained in the treatments which had not undergone deficit in the ripening period. Against this, the smallest potatoes were obtained in the treatments with deficit in growth period due to a higher number of tubers per plant. The effect of water on tuber size relies on the combination of deficits during the growth and the ripening stages, through the influence of the number of tubers per plant. The mathematical function that better fits the production obtained with the water volume received is a second-degree polynomial. The irrigation regime that leads to moderate deficit in the beginning of the season (growth and tuber bulking periods) can achieve production results of the order of those obtained by the test treatment, well irrigated along the whole cycle, it being a clearly advisable regime. On the other hand, the least advisable regimes are those that lead to deficit in the ripening stage as well as at growth or tuber bulking.     

Analysis of deficit irrigation strategies for corn using crop growth simulation

Summary Corn yields for full irrigation and 4 different levels of deficit irrigation were simulated using a model developed by Stockle and Campbell (1985). Different irrigation levels were obtained by holding the application depth constant and allowing the irrigation interval to vary from 1 to 5 days. Silt loam and loamy sand soils, two root depths, two water contents at planting time, total pumping heads ranging from 0 to 800 m, four ratios of energy cost to commodity price and climatic data for the 1974 growing season at Davis, California were examined. The different variable combinations resulted in a wide range of crop water deficit and yield. Results indicated that, for given combinations, slight deficit (ratios of actual to potential transpiration larger than 0.89) provided higher net benefit than full irrigation. Larger deficits were never advantageous across the diverse range of conditions examined, indicating that potential benefits are associated with only a narrow range of irrigation deficits. This result illustrates the risk involved when deficit irrigation is practiced. Large soil water holding capacity, high soil water contents at planting and deep root exploration were found important for successful implementation of deficit irrigation. Total pumping head and the ratio of energy cost to commodity price were important factors in determining the feasibility of deficit irrigation for the conditions examined. It was also found that the level of irrigation which maximized net benefits tended to be lower for situations where the quantity of water available for irrigation was fixed and the amount of land which could be irrigated was unlimited than when there was sufficient water to fully irrigate the entire farm. Situations where deficit irrigation is a more effective way of reducing energy cost than reducing system operating pressure were ob served.Scientific Paper No. 7571 Project 0634, College of Agriculture and Home Economics, Washington State University, Pullman, WA 99164-6120, USA     

干旱缺水地区春小麦经济灌溉定额的确定

根据水资源与耕地资源配置不协调的情况,以农田灌溉试验成果为基础,并考虑作物种植的投入与产出,用数学分析的方法,给出了一种能够充分发挥水资源和耕地资源综合效益的经济灌溉定额的求解方法。     

温室番茄结果期产量和品质对水分亏缺的响应

试验以甘肃武威市凉州区传统灌水量为对照(CK),设计3个灌水量水平CK、2/3CK、1/2CK,在番茄结果期研究亏缺灌溉对日光温室番茄累计产量及平均单果质量、品质、干物质分配及水分利用效率的影响。结果表明,随着灌水量的减少,水分利用率显著提高,番茄果实中的可溶性固形物、可溶性蛋白、有机酸和Vc含量均增加,果实的累计采收...     

冬小麦节水高效优化灌溉制度模型应用研究

根据霍泉灌区田间试验资料,考虑水分亏缺的后效性,以冠层叶面积指数修正后的作物-水模型作为目标函数,建立二雏动态规划模型,计算冬小麦节水高效优化灌溉制度。结果显示,该模型充分反映了灌水时间、灌水定额和灌溉水量产生的冬小麦的产量效应,所建模型和参数确定较合理,在实践中更有实用性。     

调亏灌溉条件下紫花苜蓿生长、作物系数和水分利用效率试验研究

为了探讨西北旱区饲草作物节水灌溉新途径,在石羊河流域下游民勤干旱荒漠绿洲区大田进行了不同调亏灌溉模式下紫花苜蓿生长、作物系数及水分利用效率试验研究。结果表明,第一茬不同调亏处理最终株高差异不显著,而返青期、分枝期土壤水分下限为55%田间持水量(θf)的水分亏缺有利于增加分枝数,而茎粗随灌水量增加而增加。不同处理的耗水强度总体趋势是随着供水量的增加而递增。作物系数(Kc)第一茬随生育阶段逐渐增大,全年Kc随茬次递减。第一茬土壤水分下限55%θf的控水处理,有利于后继茬次生长,保证全年总产量最高。在石羊河流域水资源严重不足的情况下,调亏灌溉是一种有效的灌溉方式,在民勤干旱缺水地区苜蓿第一茬土壤水分下限不应低于55%θf,第二、三茬土壤水分下限保持(55%~70%)θf可以获得较高的产量和水分利用效率。