绿地精准灌溉控制系统设计与最优灌溉量分析

为了提高绿地精准灌溉控制系统中两点法测量土壤墒情的测量精度,通过对土壤水分传感器一体化的研究,设计了双层复合土壤水分传感器,相比于传统的两个传感器策略,使用该复合型土壤水分传感器测量结果更加精确,且降低了能耗。为了获得绿地作物的最优灌溉量,确保灌溉水不浪费且能满足作物正常生长的需求,以高羊茅为例,通过实验,在综合分析高羊茅生长需求、土壤墒情和部分气象资料的基础上,得出适合于高羊茅的最优灌溉量为12 mm。     

重力给水输水管路优化设计

在分析影响重力输水管渠设计的主要因素基础上，以输水管渠系统投资最小为目标函数，建立了优化设计的数学模型。并推导出计算公式，应用这一公式，确定地压管渠与有压管道最优长度和有压管道最优管径。     

干旱环境下春小麦最优调亏灌溉制度确定

以河西绿洲灌区春小麦调亏灌溉2年的平均产量、水分利用效率、供水效率和2年后的土壤养分综合指标4个单项参评因子为参数建立单因子评判矩阵,对干旱环境下春小麦调亏灌溉制度进行了综合评价。结果表明,调亏灌溉处理的综合评价指标以HFF处理最高,其次为MFM处理,而以LLL处理最低,但所有调亏灌溉处理综合评价指标均显著高于高水分处理FFF。因此,无论是从作物生产力、水资源利用效率还是水资源和土壤养分的可持续利用方面来说,HFF处理调亏灌溉模式均因其最高的作物生产力和水分利用效率、较高的供水效率(为最大值的96.3%)及较高的土壤养分综合指标(为最大值的97.7%)而具有最高的综合评价指标,成为试区推荐的春小麦全生育期最优调亏灌溉模式,即春小麦孕穗和抽穗期及灌浆—生理成熟期均高水分处理(65%~70%田持)而拔节期重度水分调亏(45%~50%田持),其灌溉定额为440 mm左右(包括晚秋季储水灌100 mm)。     

基于混合蛙跳算法的灌溉制度寻优应用研究

针对灌溉制度优化设计问题,以灌溉-产量灌溉制度模型为目标函数,随机生成灌溉制度,采用混合蛙跳算法对其进行优化,得到了最优灌溉制度。实例验证表明,混合蛙跳算法应用于灌溉制度寻优切实、可行,为灌溉制度寻优提供了一种新的方法。     

遗传算法在节水高效灌溉制度优化中的应用——以冬小麦为例

利用遗传算法对非充分灌溉条件下冬小麦的最优灌溉制度设计进行求解,并提出了与之对应的约束条件及处理方法。以我国华北地区某试验站为例来说明该算法及处理方法的可行性。结果表明,该方法能够实现对冬小麦整个生育期灌溉水量进行合理分配,使冬小麦在缺水敏感期内得到充分灌溉,从而达到节约灌溉用水,提高水分利用效率的目的。     

灌区引黄水和地下水联合运用的最优规划

开封市农业灌溉用水主要由引黄水和当地地下水供给,针对灌区多年年份的供水条件,在地下水削减的不同情况下,提出在全灌区地面水和地下水联合运用最优分配和最优用水量的问题.在提出的这一问题中,通过采用变量的一维搜索技术,并将非线性函数用分段线性函数来近似,将建立的被控对象的数学模型的非线性规划问题转化为线性规划问题.通过单纯性法计算,选择不同的决策变量和不同的参数,逐步逼近不同的供选方案,求得近似最优解.对研究开封农业水资源承载力分析有参考价值.     

引黄灌区水稻节水节肥最优组合方案研究

采用正交试验法,在砂性土壤上对控灌条件下的水稻水平畦田规格、灌水下限和施氮量三因素最优组合方案进行了试验研究。结果表明,三因素对水稻生长发育及产量影响的主次顺序为施氮量(主)-灌水下限-水平畦田规格(次)。在一定范围内,水稻产量随着水平畦田规格的增大产量逐渐减小;随着灌水下限和施氮量的增加产量逐渐增加。由三因素对水稻生理性状及产量的影响分析结果,得出水平畦田规格为0.134hm2、灌水下限为饱和含水率的80%~90%,施氮量为464.25kg/hm2为试验最优组合方案,为水稻节水节肥增产提供了技术依据。     

水稻节水控制灌溉经济效益投影寻踪评价模型

基于投影寻踪分类模型,以建三江大兴实验指标用水量、产量、水分生产率、生产成本、其他费用、耗电量、施肥量、农药用量及倒伏率为评价指标,对控制灌溉进行经济效益评价。结果表明,控灌Ⅰ投影值最佳,通过投影值得经济效益最优的处理为控制灌溉Ⅰ,控制灌溉Ⅱ与控制灌溉Ⅲ次之,然后是示范区及辐射区,最后是常规灌溉。同时控灌Ⅰ处理产量最高,达到10 400.55 kg/hm~2;控灌Ⅰ与常规灌溉相比,每公顷可节水899.85 m3,最高水分生产效率达2.397 kg/m3。研究成果为节水增产,为实际生产提供指导。     

井灌井排区机井运行的优化调度

根据宁夏井灌区机井运行费用高耐效率低的实际情况，运用动态规划原理，建立了以井灌区机井运行费用最小为目标的多阶段优化模型，可用于确定井区机井运行的最优井数和经济指标，从而提高现有井灌区的运行管理水平及经济效益。     

太阳辐射及影响环境因子与核桃灌溉平衡分析

为了探究太阳辐射、温度及相对湿度对于核桃灌溉需求的影响,确定最适宜核桃生长的灌溉量,设计了核桃灌溉平衡分析系统。结果表明:温度、相对湿度变化趋势滞于太阳辐射变化。同时,确定建立蒸腾作用模型参数,建立核桃蒸腾作用模型,进而建立蒸发蒸腾量和蒸腾量之间的关系,并采用经验公式,计算核桃耗水量。采用正交实验分析,以产量及出核率为指标,探究不同生长时期最优用水量及最重要时期。最后,综合产量及出核率分析结果,确定了核桃生长不同时期最优灌溉量。     

Performance assessment of irrigation water management of heterogeneous irrigation schemes: 2. A case study

The non-uniformity of soils, weather, fields, cropping pattern and canal systems in most surface irrigation schemes makes irrigation water management complex, but optimum performance is important particularly in irrigation schemes with limited water supply. This paper focuses on the performance of irrigation water management during the area and water allocation with a case study of an irrigation scheme in the semi-arid region of India. Often the irrigation managers or authorities of these heterogeneous irrigation schemes also need to deal with different allocation rules. The allocation plans and the corresponding water delivery schedules during the allocation process were estimated with the help of a simulation–optimisation model for different allocation rules based on cropping distributions (free and fixed), water distributions (free and fixed-area proportionate), irrigation depth (full, fixed depth and variable depth irrigation) and irrigation interval (from 14 to 35 days). The performance measures of productivity (in terms of net benefits and area irrigated), equity (in water distribution), adequacy and excess were assessed for these different allocation plans and schedules. These were further compared with the performance measures of the existing rule (fixed depth irrigation at a fixed interval). The analysis revealed that these performance measures are in some cases complimentary and in other cases conflicting with each other. Therefore, it would be appropriate for the irrigation managers to understand fully the nature of the variation in performance measures for different allocation rules prior to deciding the allocation plans for the irrigation scheme.     

灌溉量及滴灌管埋深对无膜地下滴灌棉花产量的影响

通过设置灌溉量和滴灌管埋深的二因素三水平田间小区试验,研究灌溉量和滴灌管埋深对无膜地下滴灌棉花产量的影响,以明确在无膜条件下地下滴灌棉田灌溉量和滴灌管埋深的最优指标。结果表明,无膜灌溉量为4 200m3/hm2,滴灌管埋深5cm时,产量最高,为最佳无膜覆盖滴灌量和滴灌管埋深设置,当灌溉量较低时,滴灌管要深埋,反之,则要浅埋。仅从经济效益来看棉花种植采用地膜覆盖更好,但无膜覆盖具有较好的社会效益和生态效益。     

温室西红柿滴灌灌水制度试验研究

对温室樱桃、西红柿进行了滴灌灌水制度的试验研究。结果表明 ,根据西红柿不同生育期的生理特性及其需水特征确定其相应适宜的土壤含水率范围 (占田间持水量的百分比 )为 :苗期55%～ 70 % ,开花坐果期 65%～ 85% ,结果期 70 %～ 90 %。不同生育期的灌水定额为 :苗期 10～15mm,开花坐果期 15～ 2 5mm,结果期 2 0～ 30 mm。     

玉米地下滴灌适宜出苗灌水定额试验研究

为探索解决地下滴灌玉米出苗难的问题,通过土箱试验,对内蒙古自治区具有典型代表性的3种土壤,开展了毛管铺设参数(滴头流量、埋深)和灌水定额对地下滴灌湿润半径的影响规律试验,结合玉米播种深度、水分向上及向下运移的距离及种子周围土壤含水量,研究了玉米适宜出苗灌水定额,以提高出苗率,指导实际生产.结果表明:按显著性水平0.05检验,土壤类型和灌水定额均对土壤湿润半径影响具有统计学意义,而滴头流量和埋深对湿润半径影响不具有统计学意义.在黏壤土中,玉米出苗灌水定额37.5~52.5 mm基本可满足毛管埋深25~35 cm的出苗要求;在壤土中,玉米出苗灌水定额37.5 mm左右基本可满足毛管埋深25~30 cm的出苗要求,灌水定额52.5 mm左右基本可满足埋深30~35 cm的出苗要求;在砂壤土中,灌水定额22.5~37.5 mm基本可满足毛管埋深约25 cm的玉米出苗要求,灌水定额52.5 mm基本可满足毛管埋深25~35 cm的玉米出苗要求.     

苜蓿田间地下滴灌效应试验研究

根据苜蓿地下滴灌土壤水分变化，并以常规沟灌为对照，对苜蓿田间地下滴灌的适宜埋深和灌水量进行了研究。结果表明，地下滴灌比常规沟灌的苜蓿，鲜草出草率高；滴灌带埋深35cm比埋深10cm的苜蓿长势好，鲜草产量高，并初步拟定了苜蓿地下滴灌的灌溉制度。因此，苜蓿田实施地下滴灌是可行的，在新疆具有推广应用价值和发展潜力。     

Effect of timing of first and last irrigation on the yield and water use efficiency in cotton

With increasing concern about declining water resources, there is increasing thrust in improving water management in farming systems to improve water use efficiency. The present investigation was undertaken to determine the optimum timing for the first and last irrigation of cotton on the basis of meteorological approach for scheduling irrigations. The experiment was conducted in a split plot design with three timings of first irrigation as main-plots and three timing of last irrigation as sub-plots. Delay of first irrigation from 28 days after sowing (DAS) to 42 DAS, irrespective of last irrigation, resulted in an increase of 8, 14 and 17% in seed cotton yield during first, second and third year, respectively. The corresponding increases due to delay in the last irrigation from 130 to 170 DAS were 14, 32 and 8%, respectively. On the basis of 3 years average, application of first and last irrigation at optimum time (after 42 and 170 days after sowing) resulted in an increase of 36% in seed cotton yield without involving any additional cost. Water expense efficiency (WEE) increased by 54%.     

直插式根灌技术的研究与应用

直插式根灌技术,是一种新型的节水灌溉技术,它结合了地面滴灌与地下渗灌的优点,能够把水直接灌溉到一定深度土壤层,起到对植物根系层,进行直接灌溉的目的;能有效减少表层土壤水分蒸发损失,提高灌水效率、提高灌溉水的有效利用率。过去的地埋式渗灌技术,有较好的灌水效果和抑制表层土壤水分蒸发损失作用,但其易堵塞、检修难的缺点,限制了地下渗灌技术的发展。地表滴灌技术成熟,但其表层土壤水分蒸发损失,影响滴灌水分的利用效率和灌水效率。为了结合滴灌与渗灌的优势,克服滴灌与渗灌的缺点;所以,开展对直插式根灌技术的研究,把地表滴灌的水分,直接引灌到一定深度的土壤层,实现土壤的越层灌溉,起到较好的灌水效果,根灌产品,安装简便,便于维护。     

棉花膜下滴灌灌溉制度试验研究

以田间试验为基础对棉花膜下滴灌的灌溉制度及其各因素的特点进行了分析研究。膜下滴灌技术采用局部灌水，男间地面蒸发量很小，另外，该技术为浅灌且可控性强，使灌水深度与棉花根系吸水深度相一致，避免深层渗漏，极大地提高了田间水分利用率。     

On-farm performance evaluation of improved traditional small-scale irrigation practices: A case study from Dire Dawa area, Ethiopia

Field evaluation of surface irrigation systems play a fundamental role to determine the efficiency of the system as it is being used and to identify management practices and system configurations that can be implemented to improve the irrigation efficiency. This study evaluated the performance of an ‘improved’ traditional small-scale irrigation practice at Adada, a representative small-scale irrigation practice in Dire Dawa Administrative Council, Eastern Ethiopia. In order to determine numerical values of performance measures, certain parameters were measured/observed before, during and after an irrigation event while farmers are performing their normal irrigation practice. These parameters include: irrigated crop, irrigation method, stream size, cutoff time, soil moisture deficiency, and field size, shape and spacing. The results showed that the irrigation water applied to a farmer's plot during an irrigation event/turn was generally higher than the required depth to be applied per event. Since the irrigation method used was end-dyked, the major cause of water loss was due to deep percolation. The deep percolation loss was 32% in sorghum, 57% in maize, and 70% in tomato and potato fields. The type of irrigation system used, the ridged irrigation practice and the poor irrigation scheduling in the study sites were the main problems identified in the management and operations of the schemes. The following corrective measures are recommended to improve the system: (1) farmers should regulate the depth of irrigation water they apply according to the type of crop and its growth stage, change the field irrigation system and/or configuration especially for shallow rooted row crops, to furrow system, (2) guidance and support to farmers in developing and introduction of appropriate irrigation scheduling, and (3) future development interventions towards improvement of traditional irrigation practices should also focus in improving the on farm irrigation systems in addition to improving physical infrastructure of the scheme.     

内蒙古河套灌区不同灌溉模式对土壤温度及盐分的影响

针对内蒙古河套灌区井渠结合膜下滴灌这一灌排发展趋势,分别选取了黄灌(H)、井灌(J)、滴灌(D)3种灌溉模式,研究了土壤温度时空变化规律和生育期盐分平衡状况。结果表明:玉米生育期内不同灌溉模式膜内膜外土壤温度月季下降明显,且膜内外土壤温度差异随着时间的推移越来越小;玉米需水旺季(6、7月)膜内5cm土壤日温度受灌水影响程度依次是滴灌井灌黄灌,平均温度黄灌较井灌高0.47℃,较滴灌高1.18℃;自6月下旬开始膜内5cm 10日平均土壤温度黄灌始终高于井灌0.35~1.53℃,滴灌基本小于井灌;30日平均温度黄灌较井灌温度始终高0.34~1.02℃,较滴灌高1.12~1.98℃。生育期黄灌、井灌、滴灌0~100、0~60cm土壤均积盐,膜外积盐率0~60cm远大于0~100cm。若地面灌溉一年一洗盐,滴灌0~100cm盐分累积至井灌土壤盐分水平需2年一次秋浇洗盐。