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1.
在南疆枣园,设置了滴灌和漫灌两种灌溉方式、3种施氮量(102 kg/hm2、204 kg/hm2、306 kg/hm2)处理进行田间试验,通过测定各处理土壤总磷、有效磷及不同磷形态组分的含量,探讨了灌溉方式与氮肥施用量对土壤磷素形态组成及生物有效性的影响。结果表明:土壤总磷含量随滴灌土层深度的增加逐渐下降,而漫灌土层40 cm处的磷含量最高。滴灌处理的0~20 cm土壤有效磷含量显著高于漫灌;连续提取法测得的各处理生物活性磷占总磷的比例随土层深度增加逐渐降低,而滴灌有利于表层土壤生物活性磷的积累;漫灌土壤不同土层的NaHCO3-Po平均含量是滴灌的2.4~4.2倍,而滴灌处理的NaHCO3-Pi平均含量约为漫灌处理的2倍;生物活性磷含量随施氮量的增加而增加,氮肥施用量越高土壤中高生物活性磷含量越高。因此,滴灌和增施氮肥是提高磷素可利用性、降低磷流失风险的有效措施。  相似文献   

2.
调亏灌溉和灌溉方式对香梨树吸收根系重分布的影响   总被引:2,自引:0,他引:2  
武阳  赵智  王伟  黄兴法  马英杰 《农业机械学报》2017,48(5):244-250,257
于2009—2010年开展了田间试验,研究了调亏灌溉对成龄库尔勒香梨树吸收根系重分布的影响。灌溉方式为地表滴灌与漫灌,滴灌试验包括轻度与重度水分胁迫处理(在新梢及果实生长缓慢期分别按蒸发量的60%与40%灌溉,在其他生育期按蒸发量的80%灌溉),对照处理为充分灌溉,在整个生育期按蒸发量的80%灌溉。每年4—8月份,漫灌每月灌溉1次,灌水定额为300 mm。所有处理在2009年之前均为漫灌。研究结果表明,成龄库尔勒香梨树的吸收根系主要分布于地表以下20~60 cm。梨树需要2 a时间调整吸收根系的分布以适应灌溉方式由漫灌转为滴灌。土壤水分胁迫减小了梨树吸收根系的根长,抑制了梨树的营养生长,其后恢复充分灌溉可促进根系的生长。梨树新梢及果实生长缓慢期的土壤水分胁迫对根系生长的抑制效果超过了对新梢生长的抑制;但吸收根系的生长与果实产量之间并无显著的相关性。  相似文献   

3.
Water dynamics and salt distribution in the soil were studied under Fixed Partial Root zone Drying irrigation (FPRD) conditions in corn fields in Northern Greece. FPRD irrigation technique was applied without deficit treatment in two calcareous soils, a sandy clay loam and a sandy loam. Soil water content was recorded in the vertical profile of 0.6 m with the use of capacitance sensors in the row and interrow positions of plants. Salt built-up was monitored to the depth of the root zone, bi-weekly, by measuring electrical conductivity (ECe) and the concentrations of soluble cations Ca2+, Mg2+, Na+ and K+ of the saturation extract on irrigated and non irrigated interrow positions. Soil moisture distribution and salt built-up in soil were used to evaluate the potentials and constraints of FPRD efficiency to sustain plant growth and crop production as a low cost drip irrigation technique. The results indicated that FPRD application on both soils was capable of supplying sufficient amounts of water on plant row. Soil analyses showed that salts accumulated to high levels in the soil surface and decreased in depth at the non irrigated interrow positions. Spatial and temporal variability of salt movement and distribution in the soil profile of 0.6 m were ascribed to soil textural differences. The development and yield of corn plants for both soils reached the usual standards for the area with a minor decrease in the sandy loam soil.  相似文献   

4.
Unlike annual crops where reclamation leaching of salts can be readily conducted between cropping, leaching of salts in permanent crops that are drip irrigated pose challenges. A need exists to formulate and test a management-type of salinity model for drip irrigation of table grapes. The model reported herein predicts the distribution of salts along the vine row and between the rows during the growing season, as affected by reactivity of salts of the applied irrigation water as well as rate and duration of drip application. The calibrated model reproduced the initial field salinity profiles after repeated irrigation cycles by adjusting only the routing factor α which is the ratio of horizontal to vertical water flow. After eight cycles the profiles stabilized and the calibrated horizontal to vertical flow routing ratio was 0.6. There is remarkable agreement between measured and simulated salinity. Corresponding soil moisture profiles show the expected high water content with depth at the emitter, the decrease in surface water content with radial distance and the increase with depth, at the distal end of the wedge. Although the model is location specific it can be applied knowing soil, initial and boundary conditions, as well as irrigation application quantity and quality and as such can be applied location by location in order to assess flow and quality of deep percolation recharging the groundwater system. With this capacity the model can predict soil water quantity and quality outcomes for possible land and water management scenarios.  相似文献   

5.
Florida is the largest producer of fresh-market tomatoes in the United States. Production areas are typically intensively managed with high inputs of fertilizer and irrigation. The objectives of this 3-year field study were to evaluate the interaction between N-fertilizer rates and irrigation scheduling on yield, irrigation water use efficiency (iWUE) and root distribution of tomato cultivated in a plastic mulched/drip irrigated production systems. Experimental treatments included three irrigation scheduling regimes and three N-rates (176, 220 and 230 kg ha−1). Irrigation treatments included were: (1) SUR (surface drip irrigation) both irrigation and fertigation line placed right underneath the plastic mulch; (2) SDI (subsurface drip irrigation) where the irrigation line was placed 0.15 m below the fertigation line which was located on top of the bed; and (3) TIME (conventional control) with irrigation and fertigation lines placed as in SUR and irrigation being applied once a day. Except for the “TIME” treatment all irrigation treatments were controlled by soil moisture sensor (SMS)-based irrigation set at 10% volumetric water content which was allotted five irrigation windows daily and bypassed events if the soil water content exceeded the established threshold. Average marketable fruit yields were 28, 56 and 79 Mg ha−1 for years 1-3, respectively. The SUR treatment required 15-51% less irrigation water when compared to TIME treatments, while the reductions in irrigation water use for SDI were 7-29%. Tomato yield was 11-80% higher for the SUR and SDI treatments than TIME where as N-rate did not affect yield. Root concentration was greatest in the vicinity of the irrigation and fertigation drip lines for all irrigation treatments. At the beginning of reproductive phase about 70-75% of the total root length density (RLD) was concentrated in the 0-15 cm soil layer while 15-20% of the roots were found in the 15-30 cm layer. Corresponding RLD distribution values during the reproductive phase were 68% and 22%, respectively. Root distribution in the soil profile thus appears to be mainly driven by development stage, soil moisture and nutrient availability. It is concluded that use of SDI and SMS-based systems consistently increased tomato yields while greatly improving irrigation water use efficiency and thereby reduced both irrigation water use and potential N leaching.  相似文献   

6.
水肥一体化下不同滴灌带配置对玉米产量的影响   总被引:1,自引:0,他引:1  
针对水肥一体化下不同滴灌带配置方式对作物产量的影响,结合实际探究了当铺设50 m长滴灌带、设置6种不同首部压力时,毛管首、中、尾部的土壤含水率、干物质质量积累量对作物产量的影响。结果表明:滴灌带类型差异使得土壤的平均含水率在生育期内变化规律有所差异,滴头采用内镶贴片式(N0. 30)时土壤含水率变化规律呈较明显的先下降后上升趋势,且随着滴头流量的增大,在全生育期土壤含水率变化越平缓;滴头采用侧翼迷宫式(L0. 15)时土壤含水率变化趋势平缓,且随着滴头流量的增大,在全生育期土壤含水率变化越显著。L0. 15下全生育期土壤含水率均满足作物生长的需求,可以为作物提供充足水分;流入滴灌带的肥液流速越低、长度越长,附着在管壁的肥料质量越多,尾部作物的肥料利用率越低,致使养分吸收少,作物产量降低。对不同处理下毛管的首、中、尾部产量均匀性进行分析表明,随着滴灌带长度的增加,N0. 30的作物产量均匀性逐渐降低,L0. 15的作物产量均匀性逐渐上升,故不同滴头流量对沿滴灌带长度方向的产量均匀性有一定影响。  相似文献   

7.
为探究西北半干旱地区适宜的膜下滴灌技术参数,以春玉米为试验对象,以甘肃省武威市民勤县为典型试验区,于2017年3—9月开展大田试验,分析了膜下滴灌灌水频率(P1∶5 d、P2∶7 d、P3∶9 d)及滴灌带间距(J1∶0.9 m、J2∶1.1 m、J3∶1.3 m)交互组合下对土壤水氮分布规律、春玉米生理特性指标、产量及水分利用效率等的影响。试验结果表明:当滴灌带间距相同时,灌水频率越高,湿润带宽度越小、各层土壤水氮含量波动幅度越小,同一土层深度处中低频处理平均土壤含水率较高;当灌水频率相同时,滴灌带间距较大的处理向土壤深层运移的水分较多。灌水频率相同时,滴灌带间距较小的处理产量及水分利用效率较高;滴灌带间距相同时,中高频处理产量及水分利用效率较高;P1J1处理产量最高,为16 485.25 kg/hm2,其次是P2J2处理,产量为16 292.21 kg/hm2,但P2J2处理水分利用效率最高,达到3.66 kg/m3。   相似文献   

8.
The study was undertaken in order to quantify the effect of 12-year irrigation by drip emitters placed on one side of the tree trunk on the rooting pattern of Gloster apple trees (Malus domestica Borkh) grafted on M26 rootstock under the conditions of south-west Poland. The orchard was established in 1994 and since 1995 was drip irrigated under three treatments: V0 - without irrigation (control), V1 - intensive irrigation, and V2 - economical irrigation. In March 2007, after 12 years of irrigation, a profile trench observation method was used to map the number and the location of root distribution in clay loam (Luvisol) soil.The root system architecture was largely affected by irrigation. In case of the trees irrigated intensively (V1), the study showed asymmetry in the distribution of roots of diameter <1 mm and 1-3 mm. In V1, shallow root system, concentrated in the wetted zone developed on the irrigated side of the tree, where on the side of the tree trunk opposite the emitter trees developed significantly larger numbers of roots, which penetrated deeper soil layers. There were no statistically significant differences in the number of roots between both sides of the tree trunk under the treatment with economical irrigation (V2). Moreover, spatial roots distribution over the entire soil profile was found to be the most uniform compared to the other experimental treatments (V0 and V1). Finally, the study examined the relationship between root system and yield. Obtained results showed that in the 3-year period less frequent water application (V2) resulted in the highest yield.  相似文献   

9.
为了探明灌水频率对小滴头滴灌土壤湿润区的影响,在实验室对沙土和中壤土进行了膜下间歇滴灌试验,滴头流量分别为0.3、0.5、0.7L/h;灌水频率分别为1、2、3、4次灌完。在灌水量相同的情况下观测了土壤的湿润区运移过程和含水率分布。结果表明,小滴头流量下改变滴水频率对土壤湿润体的大小影响很小;随着灌水频率的增加,土壤湿...  相似文献   

10.
滴灌水肥条件对樱桃产量、品质和土壤理化性质的影响   总被引:5,自引:0,他引:5  
以樱桃果树为研究对象,通过滴灌对植株进行灌溉施肥,设置9个不同水、肥量的试验处理,测定了樱桃果园土壤水分和理化性质,同时测定不同处理下樱桃果实产量和品质,综合分析了土壤养分各指标与樱桃果实微量元素之间的线性关系,引入Spearman秩相关系数法对土壤养分各指标与果实品质各指标作了敏感性分析。结果表明:不同水分处理下,在樱桃整个生育期内,土壤含水率呈下降趋势,在灌水时期,灌水越多,浅层土壤含水率越高,而对较深层次土壤含水率无明显影响。试验处理下的水肥条件能显著提高樱桃果实品质,较高施肥量能提高果实果径;适当灌水量能显著提高果实硬度;较高施肥量和较低灌水量能降低可滴定酸含量;较低灌水量和施肥量能提高可溶性固形物含量;中等施肥量和较低灌水量能提高粗蛋白的含量;较低灌水量和较低施肥量能提高果实内维生素C含量;适当灌水量以及较低施肥量能提高可溶性总糖含量。土壤中铵态氮与硝态氮含量处于不稳定状况,养分变化无明显规律;土壤各养分指标中,有机质含量与果实内全铁含量正相关;有效铵态氮含量与全氯含量呈正相关;有效硝态氮含量与果实内全钙、全锌、全氯含量呈正相关;有效磷含量与全铁含量正相关;速效钾含量与全钙含量呈负相关。土壤养分中,铵态氮、硝态氮含量与果实品质中的大多数指标有着密切联系。  相似文献   

11.
Summary The effect of partial wetting of the root zone on yield and water use efficiency in a drip- and sprinkler-irrigated mature grapefruit grove was tested in a long-term experiment from 1976 to 1979. Three different percentages of the surface soil areas ( 30%, 40% and 70%) were wetted by the use of single and double drip laterals and sprinklers, respectively. Irrigation frequencies were 3 and 7 days for the drip treatments and 14 and 21 days for the sprinkler-irrigated plots.Two amounts of water, 80% and 100% of the total seasonal water application as previously determined from the soil moisture depletion data (ca. 630 and 800 mm), were applied at the different irrigation intervals for the drip- and sprinkler-irrigated treatments during the irrigation season (April–November). Soil moisture and salinity patterns were determined by the neutron scattering method and by gravimetric sampling. The partition of water extraction from the wet and dry zones in the drip-irrigated treatments was determined. About 86% of the total amount of water depletion was from the wet zone and 14% from the dry zone. Percolation losses in the irrigated treatments receiving 80% of the total seasonal water application decreased as compared with the 100% irrigated plots. Salts accumulated during the irrigation season were leached out by the winter rainfall.The effect of the reduction of irrigation application amount, first introduced in 1976, on the grapefruit yield was cumulative. The average yield (for the three years 1977, 1978, 1979) in the 80%, drip-irrigated plots at 3-day intervals, was 89 t/ha, compared with 98 t/ha in the 100% irrigated plots. The average yields obtained in the sprinkler and trickle irrigation treatments receiving 100% of the water application was 84 t/ha and 100 t/ha, respectively. Yield reductions in the plots receiving reduced water application of 80% were 11% for the drip treatments and 13% for the sprinkler treatment; the extent of the yield reduction varied according to the time interval between irrigations. The fruit quality was up to the required standards in all treatments. Water use efficiency was greater in the drip-irrigated plots than in the sprinkled ones, and also greater in the plots given the reduced water applications (80% of the maximum seasonal amount of the irrigation water applied), as compared with plots receiving the full amount of irrigation.Contribution from the Agricultural Research Organization, The Volcani Center, P.O.B. 6, Bet Dagan 50–250, Israel. No. 175-E, 1981 series  相似文献   

12.
【目的】确定南疆沙区红枣适宜的滴灌制度和滴灌方式。【方法】以7 a生矮化密植骏枣树为材料,设置枣树根部1个滴头灌水和多点滴灌灌水2种滴灌方式,每种方式设置3个灌水量(900、1 050、1 200 mm),进行了田间小区试验。【结果】多点滴灌方式下,不同灌水量土壤剖面水分分布有显著规律,表现为50 cm以上土层同层水平距离20 cm土壤含水率小于水平距离40 cm,50 cm以下土层则相反。110 cm土层以下单点滴灌土壤水分显著高于多点滴灌,110 cm以上土层单点滴灌土壤水分显著低于多点滴灌。受灌水量和滴灌方式的影响,同一处理不同土层土壤水分随时间推移其变化规律并不一致。【结论】单点滴灌与多点滴灌土壤水分分布规律差异显著,但耗水量无显著差异。  相似文献   

13.
The increasing demand for irrigation water to secure food for growing populations with limited water supply suggests re-thinking the use of non-conventional water resources. The latter includes saline drainage water, brackish groundwater and treated waste water. The effects of using saline drainage water (electrical conductivity of 4.2–4.8 dS m−1) to irrigate field-grown tomato (Lycopersicon esculentum Mill cv Floradade) using drip and furrow irrigation systems were evaluated, together with the distribution of soil moisture and salt. The saline water was either diluted to different salinity levels using fresh water (blended) or used cyclically with fresh water. The results of two seasons of study (2001 and 2002) showed that increasing salinity resulted in decreased leaf area index, plant dry weight, fruit total yield and individual fruit weight. In all cases, the growth parameters and yield as well as the water use efficiency were greater for drip irrigated tomato plants than furrow-irrigated plants. However, furrow irrigation produced higher individual fruit weight. The electrical conductivity of the soil solution (extracted 48 h after irrigation) showed greater fluctuations when cyclic water management was used compared to those plots irrigated with blended water. In both drip and furrow irrigation, measurements of soil moisture one day after irrigation, showed that soil moisture was higher at the top 20 cm layer and at the location of the irrigation water source; soil moisture was at a minimum in the root zone (20–40 cm layer), but showed a gradual increase at 40–60 and 60–90 cm and was stable at 90–120 cm depth. Soil water content decreased gradually as the distance from the irrigation water source increased. In addition, a few days after irrigation, the soil moisture content decreased, but the deficit was most pronounced in the surface layer. Soil salinity at the irrigation source was lower at a depth of 15 cm (surface layer) than that at 30 and 60 cm, and was minimal in deeper layers (i.e. 90 cm). Salinity increased as the distance from the irrigation source increased particularly in the surface layer. The results indicated that the salinity followed the water front. We concluded that the careful and efficient management of irrigation with saline water can leave the groundwater salinity levels unaffected and recommended the use of drip irrigation as the fruit yield per unit of water used was on average one-third higher than when using furrow irrigation.  相似文献   

14.
不同灌溉技术条件对冬小麦生产的影响   总被引:3,自引:0,他引:3  
为了研究并得到3种不同灌溉技术(滴灌、喷灌、漫灌)对冬小麦产量及其构成的影响,在中国农业大学吴桥实验站设计了滴灌、喷灌、漫灌的大田试验.3种灌溉技术条件下,其灌溉总量相同,漫灌和喷灌采用浇底墒水加浇两水,滴灌采用浇底墒水加浇四水的方式;从冬小麦整个生长期内的作物高度、叶面积指数、籽粒重等指标,考察不同灌溉技术对冬小麦生产及其构成的影响.结果表明:滴灌条件下,表层含水量下降速度最小,整个生长期,含水量高于喷灌和漫灌;滴灌处理的叶面积指数最高,其次是喷灌;在成熟期,滴灌条件下,作物高度比漫灌高12%,比喷灌高5%;滴灌和喷灌的条件下产量分别比漫灌高8.63%,7.75%;滴灌、喷灌、漫灌的籽粒千粒重分别为43.36,42.17和41.17 g,滴灌和喷灌籽粒重明显高于漫灌,且生物量分别比漫灌提高了6.9%,3%.这说明3种灌溉技术中,滴灌技术最有利于实现节水保墒、小麦增产,其次是喷灌.  相似文献   

15.
Experiments were conducted in summer of 2003 and 2004 to study the effect of withholding irrigation on tomato growth and yield in a drip irrigated, plasticulture system. Irrigation treatments were initiated at tomato planting (S0), after transplant establishment (S1), at first flower (S2), at first fruit (S3), or at fruit ripening (S4). An additional treatment received only enough water to apply fertigation (FT). Withholding drip irrigation for a short period (S2–S3) increased tomato marketable yield by 8–15%, fruit number by 12–14% while reducing amount of irrigation water by 20% compared to the S0 treatment. Withholding drip irrigation also increased irrigation water use efficiency (IWUE). Similar trends were observed in 2003 and 2004 despite large differences in rainfall, heat units, and tomato yield between years. This suggests that if soil moisture is adequate at transplanting, subsequent withholding of irrigation for 1–2 weeks after tomato transplanting may increase yield while reducing the amount of irrigation water.  相似文献   

16.
阿拉尔灌区微咸水滴灌对土壤水盐分布影响的试验研究   总被引:3,自引:0,他引:3  
利用不同矿化度微咸水对试验地进行灌溉,同时采用滴灌的灌水方式,分析了灌溉前后土壤水盐运移及盐分离子的分布状况。研究结果表明:微咸水灌溉对含盐土壤具有淋洗作用,这一作用随着灌溉水矿化度的提高而上升,这为干旱区节水农业技术提供了依据。  相似文献   

17.
荔枝园智能灌溉决策系统模糊控制器设计与优化   总被引:2,自引:0,他引:2  
为解决荔枝园灌溉中水资源浪费严重的问题,根据现有装备条件,设计了基于无线传感器网的模糊专家决策系统,并对系统的模糊控制器进行优化以提升系统整体性能。该系统通过网关节点实时接收来自传感器节点采集的荔枝园环境信息,选择土壤实测含水率与预设土壤最佳含水率的误差及其变化率作为决策因子,得出预测灌溉值等决策结果。通过Matlab仿真并进行果园实地试验,分析该系统的有效性。仿真结果表明,该智能灌溉系统能结合荔枝园土壤含水率情况进行适时、适量灌溉,有效实现了经济灌溉,并且优化后的模糊灌溉系统实现了更高的暂态性能、控制精度及抗干扰性,系统响应时间更快。试验结果表明,基于模糊控制器的智能灌溉系统能有效地对荔枝园灌溉进行控制,使荔枝园土壤含水率维持在17.8%左右,符合荔枝树的生长环境;同时,基于优化后的模糊控制器的智能灌溉系统将荔枝园土壤含水率平均值控制在17.6%,更接近系统预设的荔枝园土壤最佳含水率17%,并且具有更高的控制精度、更强的抗干扰性与实用性。  相似文献   

18.
研究了华北半湿润区滴灌条件下不同土壤基质势对露地栽培豇豆产量和灌溉水利用效率的影响。试验共有5个处理,分别控制滴头正下方0.2 m深度处土壤基质势下限高于-10、-20、-30、-40和-50 kPa。研究分析发现,土壤基质势对豇豆的产量没有明显的影响,并且随着土壤基质势控制的降低,豇豆整个生育期的灌水量明显降低,灌溉水利用效率显著升高。因此,在华北半湿润区,在保证豇豆安全度过苗期之后,可以通过控制滴头正下方0.2 m深度处土壤基质势下限高于-50 kPa来制定豇豆的滴灌灌溉计划。  相似文献   

19.
干旱区玉米滴灌需水规律的田间试验研究   总被引:16,自引:0,他引:16  
在内蒙古干旱区的一种砂土及砂质壤土上 ,对玉米滴灌需水规律进行了田间试验研究。试验设置高灌水定额 ( 3 0~ 40 mm)、中灌水定额 ( 2 0~ 3 0 mm)和低灌水定额 ( 1 5~ 2 5 mm ) 3个处理 ,灌水周期相同 ,在需水高峰期为 3 d,其它时间为 4~ 7d。试验结果表明 ,中灌水定额处理的株高、叶面积和产量均明显高于低灌水定额处理 ,而高灌水定额与低灌水定额处理之间差异很小。因此对所研究土壤来说 ,建议采用灌水定额 2 0~3 0 mm,灌水周期 3~ 5 d的灌溉制度。这种情况下 ,玉米生育期需水量为 466mm (生育期有效降雨 1 0 1 .1mm)。对滴灌玉米作物系数的计算方法进行比较后发现 ,双作物系数法可以较好地描述灌水或降雨后地表蒸发对作物腾发的影响 ;在作物生育中期 ,分段单值平均法、双作物系数法的计算结果与实测值吻合良好。  相似文献   

20.
在滴灌方式下,通过覆盖地膜的栽培方式研究了库尔勒香梨生长特性以及果实品质和产量。结果表明,地膜滴灌(MD)显著提高了香梨根际区土壤水分含量,0~60cm土层土壤含水率显著高于未覆盖滴灌(ND)和漫灌(CK),该土层土壤含水率与叶片含水率之间的相关性显著高于60~100cm土层。土壤含水率的增加促进了叶片含水率和叶绿素含...  相似文献   

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