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穴灌坐水播种最大的难点就是种子与穴施水在播施过程中难以同位,提出了同步信号自动控制的穴施水机构,试验表明其种液同位合格率达97.8%,较好的解决了种液同位问题,但是作业过程中发现有施水飞溅现象,同时种子随穴灌水流在沟内运动随机,快速作业时更突出,影响了施水与播种质量。要解决这一问题、彰显穴灌坐水播种的优势就必须正确认识灌溉冲击水柱在沟内的水力特性,特别是灌溉水注对种沟沟底的冲击压力特性。针对以上问题,提出利用计算机直接测试装置对灌水冲击压力进行样本数据采集,给出了信号采集的方法及系统组成,并对信号采集过程中采样频率、采样次数等的确定及信号在时域、频域内的相关分析方法进行了研究。 相似文献
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微地形及沟断面形状变异性对沟灌性能影响的试验研究 总被引：1，自引：0，他引：1
针对沟灌,研究了沟底起伏状况和沟横断面形状的空间变异性对灌水质量的影响。通过分析在河北吴桥开展的棉花沟灌试验数据,描述了灌水沟断面形状和沟底高程二因素的空间分布特征。采用田面平整精度Sd值作为评价沟底高程变化程度的指标,确定其对灌水均匀度和灌水效率的影响;采用断面形状参数p2描述灌水沟断面形状,以p2的标准差反映其空间变异性对地表水流运动和灌水质量的影响。结果表明,灌水均匀度和灌水效率均随沟底高程标准差的增大而减小;水流推进速度随断面形状参数p2标准差的增大而降低,灌水均匀度和灌水效率随p2标准差的增大而减小。因此,微地形和灌水沟断面空间变异性,对灌水均匀度和灌水效率均有显著的影响。 相似文献
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抗旱节水播种机是把灌水设施与播种机结合的一种机械，用于土壤墒情不足时作物的播种，能在灌水的同时完成播种作业。该机的代表机型有单体播种机、施水硬茬播种机和抗旱灌水播种机。 相似文献
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抗旱节水型播种机
抗旱节水播种机是把灌水设施与播种机结合的一种机械,用于土壤墒情不足时作物的播种,能在灌水的同时完成播种作业.该机的代表机型有单体播种机、施水硬茬播种机和抗旱灌水播种机. 相似文献
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抗旱节水型播种机
抗旱节水播种机是把灌水设施与播种机结合的一种机械,用于土壤墒情不足时作物的播种,能在灌水的同时完成播种作业.该机的代表机型有单体播种机、施水硬茬播种机和抗旱灌水播种机.…… 相似文献
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沟,畦灌溉技术的完善与改进 总被引：2，自引：1，他引：1
赵竞成 《中国农村水利水电》1998,(3):6-9
改进沟、畦灌溉技术主要是围绕提高灌水均匀度这一基本指标进行的,灌水均匀度低就难以减小灌水定额;灌溉技术要素的合理确定是改进沟、畦灌溉技术的基础。文章对小畦灌溉、长畦短灌、细流沟灌、膜上灌溉、涌流灌溉等尺种灌溉方式的节水机理和适应情况以及各种灌溉方式技术要素的确定及组合进行了分析。对推广沟、畦灌溉技术的必要措施亦进行了阐述。 相似文献
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土壤入渗特性和田面糙率的变异性对沟灌性能的影响 总被引：2，自引：0，他引：2
以杨凌区粘壤土和砂壤土区域进行的大田沟灌试验为基础,在假定各灌水沟内部土壤入渗特性和糙率均一的条件下,重点分析各灌水沟之间土壤入渗参数和田面糙率的不同组合对沟灌水流运动过程和灌水质量的影响,结果表明土壤入渗特性的变异性对沟灌水流推进过程和灌水质量指标影响较大,在模拟时必须充分考虑;而田面糙率的变异性对沟灌水流推进过程和灌水质量指标影响较小,可采用田块糙率均值代替各灌水沟的糙率。经实例验证,水流推进过程相对误差为7.28%,灌水效率、灌水均匀度和储水效率模拟值与实测值误差分别为5.74%、6.18%和4.07%,结果表明其模拟效果较好。 相似文献
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干旱区垄膜沟灌条件下土壤水盐空间分布特征研究 总被引：1，自引：3，他引：1
研究了垄膜沟灌条件下,不同灌溉定额下土壤水盐空间分布特征。结果表明,土壤含水率的时空分布受灌水次数和灌水定额的影响。灌溉期,在垂直方向上沟底土壤含水率较垄顶明显增加。在非灌溉期,由于强烈的蒸发蒸腾作用,垄顶土壤含水率持续降低,含水率阶段性变化明显。土壤盐分空间分布随土壤含水率的变化而变化,在灌溉期,沟底土壤脱盐深度随灌溉定额的增加呈增加的趋势。在非灌溉期,垄顶在作物生育期均发生积盐现象,且垄顶表层土壤盐分累积量高于沟底表层土壤。 相似文献
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交替隔沟灌条件下夏玉米棵间蒸发研究 总被引：1，自引：0，他引：1
利用微型蒸发器观测了交替隔沟灌和常规沟灌条件下夏玉米的棵间蒸发量,分析了棵间蒸发、降雨量和参照腾发量的变化趋势以及不同土壤水分处理下隔沟灌和常规沟灌夏玉米棵间蒸发的日变化规律;探讨了相对蒸发强度与叶面积指数之间的关系,并拟合了棵间蒸发与叶面积指数之间的回归方程;最后指明了在充分供水条件下,相对蒸发强度与表层土壤含水量有极其敏感的关系.试验结果表明,交替隔沟灌条件下的棵间蒸发量小于相同水分处理的常规沟灌的棵间蒸发量,随着土壤水分下限值的增加,交替隔沟灌和常规沟灌间棵间蒸发量的差值越来越小;相对蒸发强度随着叶面积指数的增加而下降,随着表层土壤含水量的增加而增加. 相似文献
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不同沟灌条件下土壤入渗参数的估算 总被引：4，自引：5，他引：4
土壤入渗特性是决定沟灌灌水性能的重要参数之一。根据田间实测资料,采用水量平衡原理,利用In filt v5软件,对夏玉米田常规沟灌、固定隔沟灌和交替隔沟灌溉条件下田间土壤入渗参数的简易试验估算方法进行了研究。结果证明,用提出的方法估算不同沟灌方式下的土壤入渗参数简易可行,估算得到的水流推进曲线与利用实测资料拟合的曲线几乎完全重合;不同沟灌方式之间由于表层土壤干燥度及水平方向上的吸力梯度存在差异,估算得到的土壤入渗参数亦有所不同,表明沟灌方式不同对土壤入渗参数的确定会产生一定的影响。 相似文献
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Summary To determine if drip irrigation increases fertilizer requirements and/or the efficiency of utilization compared to furrow irrigation, growth and nitrogen uptake were measured in a four-year experiment comparing surface (SD) and buried (BD) methods of drip irrigation with furrow irrigation (F) of cotton. The soil was a slowly-permeable cracking grey clay (vertisol) at Narrabri, N.S.W Drip-irrigated treatments were maintained at a deficit of 45 mm below the fully-irrigated soil water content, while F was irrigated when the deficit reached about 90 mm. Nitrogen (N) fertilizer was applied weekly with drip irrigation to BD and SD over the first half of the season, and as a conventional single application to F before sowing. Leaf area index (LAI), dry matter and N uptake were influenced more by season than by method of irrigation. LAI during boll filling averaged 2.4 and was 10% greater in BD than in SD and F. Final dry matter averaged 988 g m–2 and was 10% greater in BD and SD than in F. The efficiency of conversion of solar radiation into dry matter averaged 0.55 g MJ–1; lint yield as a fraction of dry matter averaged 0.18; neither parameter was consistently influenced by the method of irrigation. Total N uptake ranged from 97 to 170 kg ha–1 and was influenced by irrigation method in one season only, when it was less in F than in SD and BD. N was often taken up later under drip irrigation than under F: there was up to 40% less N taken up by SD than F in the early flowering stage. The delay was associated with later application of N to BD and SD compared with F, and the application of N to the surface of alternate furrows of SD. Plant factors such as root ageing and competition between roots and bolls, were also implicated. We conclude that all of the N should be applied to drip-irrigated cotton on these soils by mid flowering, and that some of the N should be applied in the soil before sowing. 相似文献
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A 4-year field experiment was conducted in a semi-arid area to evaluate the response of each furrow and alternate furrow irrigation
in wheat-cotton system using irrigation waters of different qualities in a calcareous soil. Irrigation was applied to each
and alternate furrow of bed-planted wheat followed by ridge-planted cotton for comparison with standard check-basin method
of irrigation to both the crops. These methods of irrigation were evaluated under three water qualities namely good quality
canal water (CW), poor quality tube well water (TW) and pre-sowing irrigation to each crop with CW and all subsequent irrigations
with TW (CWpsi + TW). The pooled results over 4 years revealed that wheat grain yield was not affected significantly with
quality of irrigation water, but significant yield reduction was observed in alternate bed irrigation under canal water and
tube well water irrigations. In cotton, poor quality tube well water significantly reduced the seed cotton yield in all the
three methods of planting. The pre-sowing irrigation with canal water and all subsequent irrigations with tube well water
improved the seed cotton yield when compared with tube well water alone. However, this yield increase was significant only
in alternate furrow irrigation, and the yield obtained was on a par with yield under alternate furrow in CW. When compared
to check-basin irrigation, each furrow and alternate furrow irrigation resulted in a saving of 30 and 49% of irrigation water
in bed-planted wheat, whereas the corresponding savings in ridge-planted cotton were 20 and 42%, respectively. Reduced use
of irrigation water under alternate furrow, without any significant reduction in yield, resulted in 28.1, 23.9 and 43.2% higher
water use efficiency in wheat under CW, TW and CWpsi + TW, respectively. The corresponding increase under cotton was 8.2,
2.1 and 19.5%. The implementation of alternate furrow irrigation improved the water use efficiency without any loss in yield,
thus reduced use of irrigation water especially under poor quality irrigation water with pre-sowing irrigation with canal
water reduced the deteriorating effects on yield and soil under these calcareous soils. 相似文献
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宁夏引黄灌区单种玉米的水分利用效率研究 总被引：1，自引：0，他引：1
针对宁夏引黄灌区严峻的缺水问题，利用玉米的宽窄行种植方式。结合起垄、覆膜、中耕等节水措施，探讨了4种单种玉米种植方式的节水效果和玉米前期推迟灌水的可行性及后期水分胁迫条件下的保水效果。结果表明：垄作沟灌和隔行沟灌可节水34％～35％；覆膜具有较好的增温保水效果。增产幅度在25．4％左右。收支相减，仍有增产效果；隔行沟灌较常规栽培增产幅度在11．8％左右。达到了既增产又节水的目的。在控水条件下，分析了垄背与垄沟、膜内与膜外、宽沟与窄沟的土壤水分差异，提出了玉米推迟灌头水的土壤水分指标，并阐述了后期控水对单种玉米产量及土壤水分的影响。 相似文献
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Ahmad Yar Ranjha Richard C. Peralta Antonio Maria Requena Howard M. Deer Majid Ehteshami Robert W. Hill Wynn R. Walker 《Irrigation Science》1992,13(1):9-14
Summary Effects of furrow irrigation designs, water management practices (irrigation scheduling, etc.), soil types and pesticide parameters on pesticide leaching were simulated. A hydraulic kinematic-wave irrigation model was used to estimate water infiltration for alternative furrow lengths and inflow rates. A one-dimensional simulation model then simulated the movement of pesticides through soils following furrow irrigation. Potential ground-water contamination by pesticides can be reduced by an integrated use of the best management practices (BMPs) such as careful selection and use of pesticides, efficient furrow irrigation designs and improved water management techniques (irrigation scheduling, etc.). Procedures for designing an appropriate furrow irrigation system for a particular site and pesticide, and selecting pesticides for a particular site, crop and furrow irrigation system are illustrated. These procedures are being used to develop decision support computer models for developing different BMPs for pesticide-agricultural management decisions. 相似文献
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保护地蔬菜栽培不同灌水方法对表层土壤盐分含量的影响 总被引：12，自引：0，他引：12
通过 3年连续保护地栽培蔬菜小区试验 ,对滴灌、渗灌、沟灌 3种灌水方法的土壤盐分积累状况进行了比较研究。试验后 0～ 2 0 cm土层土壤全盐含量以沟灌最高 ,渗灌次之 ,滴灌最低 ;滴灌土壤 p H下降幅度明显低于渗灌和沟灌土壤。在 0～ 2 0 cm土层内全盐含量呈幂指数形式分布 ,即地表处含量最高 ,随深度增加逐渐下降 ;而土壤 p H则随深度增加而直线上升。另外 ,土壤中可溶性盐的阴离以 NO-3 为主 ,阳离子以 Ca2 + 为主。这说明选择合理灌水方法 ,是防止土壤退化、提高保护地作物产量和质量的有效途径。 相似文献
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为探明扶埂开沟膜下灌条件对作物土壤水分分布以及经济效益的影响,以温室番茄为研究对象,采用完全随机试验设计方法,通过时域反射仪进行水分观测,研究扶埂开沟膜下灌条件下土壤水分分布规律,以及该灌溉方式对温室番茄经济效益的影响.结果表明:扶埂开沟膜下灌,垄背的土壤剖面达到最大含水量时间迟于垄沟以及垄坡,垄背剖面观测点在灌水后184 h;在扶埂开沟膜下灌条件下,温室番茄在苗期内进行缺水灌溉的IWUE最大达到34.925 kg/(hm2·mm-1), 产量与商果率均较高,综合产生的净收入最高,经济效益达到最大值. 相似文献