根系分区交替滴灌对苹果幼苗生理特性和水分利用效率的影响

以矮化红富士苹果幼苗为试验材料,采用交替滴灌(ADI)、固定滴灌(FDI)和常规滴灌(CDI)3种滴灌方式和3种灌水量对苹果幼苗的生理特性和水分利用效率进行了研究,以阐明根系分区交替灌溉下苹果幼苗生理特性和节水机理.结果表明:与CDI方式相比,当灌水定额由20 mm增大到30 mm时,ADI方式提高了苹果幼苗根干重、根系导水率、叶水势和净光合速率,降低了其蒸腾速率、棵间蒸发量和蒸散量,从而使得ADI方式下的叶片水分利用效率、总水分利用效率和灌溉水分利用效率较CDI方式大大提高;3种滴灌方式的根系导水率均存在显著的季节变化,并以8月份最大,12月份最小;与CDI方式相比, ADI和FDI方式在节水达33.3%时的平均根系导水率仅分别降低了5.81%和14.7%,但水分利用效率、灌溉水利用效率分别较CDI方式高出16.31%和14.48%、40.52%和27.65%.可见,局部根区灌溉方式能促进苹果幼苗生长和光合作用,并主要通过提高根系导水率的途径来提高水分利用效率.     

灌溉施肥深度对玉米同化物分配和水分利用效率的影响

 以夏玉米（Zea mays L.）（陕单9号）为供试材料,采用置于遮雨棚下的模拟土柱的方法,进行了不同灌溉施肥深度对夏玉米生长发育、地上与地下部分同化物分配、产量及水分利用效率的影响的试验研究。灌溉施肥深度分4个处理：表面灌施;20 cm 深度灌水施肥;30 cm 深度灌水施肥和40 cm深度灌水施肥。后3个处理为土表下灌施处理。4个重复。试验结果表明：土表下灌施抑制了玉米生育早期的地上部分生长,使根系向土壤中下层的分布加强,从而保证了作物中后期对水分养分的吸收利用,提高了水分利用效率。在本试验条件下,玉     

不同膜下滴灌方式对设施黄瓜生理特性及水分利用效率的影响

为了探明黄瓜膜下分根交替滴灌的节水效果,为设施黄瓜节水灌溉提供理论依据和技术参数,以‘津优3号’黄瓜为试材,采用随机区组设计,以土壤田间持水量的65%为灌水下限,田间持水量的90%为灌水上限,研究了分根交替滴灌(APDI)、固定1/2根区滴灌(FPDI)和传统滴灌(CDI)3种灌溉模式对黄瓜生长、生理特性、产量与品质及水分利用效率的影响,结果表明:(1)随灌溉处理时间的延长,3种灌溉模式的单株叶面积和株高的差异越来越显著,而茎粗和叶片数差异不显著;(2)与传统滴灌相比,分根交替滴灌模式下黄瓜叶片净光合速率略有下降而蒸腾速率显著降低,水分利用效率显著提高;(3)分根交替滴灌处理下黄瓜可溶性蛋白、可溶性糖含量与传统滴灌相比差异不显著,Vc含量却显著增加;(4)分根交替滴灌模式下黄瓜产量比传统滴灌下降1.5%,而灌水量减少17%,水分利用效率提高18.6%,节水效果显著。综上所述,分根交替滴灌可以在保证设施黄瓜产量没有显著下降的前提下,改善品质和显著提高水分利用效率,可作为设施节水提质增效的一种灌溉模式,推广应用前景广阔。     

根区交替地下滴灌对马铃薯产量及水分利用效率的影响

采用田间试验方法,研究了根区交替地下滴灌（APRI）对马铃薯生理指标、产量及水分利用效率的影响.结果表明：在马铃薯块茎生长期,与对照处理（CDI）相比,APRI处理的马铃薯叶片光合速率的降低不显著（4.7%）,而蒸腾速率和气孔导度则明显降低,降幅分别达15.8%和15.4%,CDI处理略高的光合速率是以消耗更多的水分为代价;与CDI处理相比,APRI处理的马铃薯产量仅降低5.4%,但灌溉水量却节省了25.8%,使灌溉水分利用效率和总水分利用效率分别提高了27.5%和15.3%.对于马铃薯来说,根区交替地下滴灌是一种切实可行的节水灌溉技术.     

不同生育期玉米叶片光合特性及水分利用效率对水分胁迫的响应

利用大型移动防雨棚开展了玉米水分胁迫及复水试验,通过分析玉米叶片光合数据,揭示了不同生育期水分胁迫及复水对玉米光合特性及水分利用效率的影响。结果表明:水分胁迫导致玉米叶片整体光合速率、蒸腾速率和气孔导度下降以及光合速率日变化的峰值提前;水分胁迫后的玉米叶片蒸腾速率、光合速率和气孔导度为适应干旱缺水均较对照显著下降,从而提高了水分利用效率,缩小了与水分充足条件下玉米叶片的水分利用效率差值;在中度和重度水分胁迫条件下,玉米叶片的水分利用效率降幅低于光合速率、蒸腾速率和气孔导度的降幅, 有时甚至高于正常供水条件下的水分利用效率;适度的水分胁迫能提高玉米叶片的水分利用效率,从而增强叶片对水分的利用能力,抵御干旱的逆境;水分亏缺对玉米光合速率、蒸腾速率及水分利用效率的影响具有较明显滞后效应,干旱后复水,光合作用受抑制仍然持续;水分胁迫时间越长、胁迫程度越重,叶片的光合作用越呈不可逆性;拔节-吐丝期水分胁迫对玉米叶片光合作用的逆制比三叶-拔节期更难恢复。     

根区水肥空间耦合对冬小麦生长及产量的影响

利用管栽试验研究了根区不同湿润方式（整体湿润、上湿下干、上干下湿）、施肥方式（整体施肥、上层施肥、下层施肥）及其耦合对冬小麦不同生育期生长及产量的影响.结果表明：下层施肥方式显著降低了分蘖期冬小麦的株高和叶面积,而不同湿润方式对分蘖期株高和叶面积的影响不显著,拔节期水肥同区方式的株高大于水肥异区方式,表现出协同耦合效应.上干下湿方式和下层施肥方式显著降低了根系干物质量、地上部干物质量和总干物质量,上层施肥方式有利于增加冬小麦生物量,而上湿下干方式与施肥处理对地上部干物质量和总干物质量的耦合效应明显.水肥同区处理的根冠比高于水肥异区处理;上干下湿方式的水分利用效率显著高于整体湿润和上湿下干方式,水肥同区处理的水分利用效率高于水肥异区处理,但下层施肥方式的水分利用效率较低.与上干下湿方式相比,上湿下干和整体湿润方式的冬小麦单穗粒数分别增加了41.7%和61.9%,上层施肥和整体施肥方式的单穗粒数高于下层施肥方式,上湿下干方式与施肥处理对小麦产量及产量构成因素（除千粒重外）的水肥耦合效应明显.不同水肥处理主要通过影响单穗粒数来影响冬小麦产量.     

不同水肥条件下分根区交替灌溉对玉米生理特性和水分利用的影响

为探讨分根区交替灌溉(AI)条件下作物生理响应和水分利用情况,在不同水肥条件下,以常规灌溉为对照,研究了分根区交替灌溉(AI)对玉米总干物质量、水分利用和生理指标的影响以及这些指标在恢复正常灌水后的恢复补偿能力,以期为玉米实施分根区交替灌溉提供科学依据。盆栽试验包括2种氮磷(NP)肥水平,2种灌溉方式和不同亏水水平,即拔节前期至中期(18d)进行正常灌水(70%—80%θf,θf是田间持水量)、轻度亏水(60%—70%θf)和中度亏水(50%—60%θf),拔节前期至中期处理后拔节中期至抽雄期(18d)进行正常灌水(70%—80%θf)和轻度亏水(60%—70%θf)。结果表明:与常规灌溉相比,拔节前期至抽雄期AI不显著影响玉米叶片叶绿素、类胡萝卜素、可溶性糖和脯氨酸含量,总干物质量和水分利用效率;与正常灌水相比,拔节前期至抽雄期轻度亏水也不显著影响上述指标;拔节前期至中期中度亏水降低玉米叶绿素含量和总干物质量,提高可溶性糖和脯氨酸含量,但是该处理在拔节中期至抽雄期恢复正常灌水后这些指标均恢复到一直正常灌水的水平。此外,施肥水平对各项指标的影响也不显著。因此,轻度亏水、低肥和拔节前期至抽雄期分根区交替灌溉结合可以节约灌水量和施肥量。     

供氮形态与部位对局部根区水分胁迫下玉米水分吸收与利用的影响

试验以玉米品种'金海五号'幼苗为材料,在分根条件下采用聚乙二醇(PEG-6000)模拟局部根区水分胁迫,设置3种供氮形态(硝态氮、铵态氮、两者各占50%的混合氮)和2种供氮部位(水氮同区,氮加入到无PEG侧;水氮异区,氮加入到含PEG侧),研究局部根区水分胁迫下氮形态与供应部位对玉米水分吸收和利用的调节与作用机制,为局部根区灌溉水分高效利用提供理论依据.结果发现:(1)同一氮形态下水氮同区供应的植株蒸腾速率、耗水量、木质部汁液流速和生物量较高,加有硝态氮源处理无PEG侧根系的导管数目及单一氮形态处理无PEG侧根系的导管直径较高,但木质部汁液、叶片中脱落酸(ABA)浓度以及水分利用效率均较低.(2)同一供氮部位下,植株的蒸腾速率、耗水量、木质部汁液流速和生物量的顺序均为混合氮>硝态氮>铵态氮依次,但单一铵态氮处理植株的ABA浓度较高,水分利用效率较高.研究表明,同一氮形态下水氮同区供应植株生长较好、水分吸收能力较强,但水氮异区供应下植株的水分利用效率较高;同一供氮部位下,植株生长和水分吸收能力的顺序为混合氮>硝态氮>铵态氮,但单供铵态氮植株的水分利用效率较高.     

不同沟灌模式对沙漠绿洲区葡萄生长和水分利用的效应

在甘肃河西荒漠绿洲区研究了覆膜与不覆膜条件下隔沟交替灌溉、常规沟灌对葡萄生长和水分利用的影响.结果表明,隔沟交替灌溉可以保证作物一部分根区处于比较湿润状态,另一部分根区处于相对干燥状态,湿润与干燥区域的交替出现可诱导葡萄的补偿生长效应.隔沟交替灌溉条件下葡萄叶片气孔开度减小,光合速率略有降低或下降不显著,而蒸腾速率明显下降,水分利用效率增大.光合作用日变化也表现出类似规律.隔沟交替灌溉与地膜覆盖技术相结合能显著提高水分利用效率,为在田间实施气孔最优化调控提供了一种有效途径.     

有机物沟埋还田模式与花后灌水量对玉米光合特性和产量的影响

有机物沟埋还田与花后灌水配合对增加玉米田保水供水能力,提高玉米花后光合性能、实现节水增产有重要意义.本试验以郑单958为供试材料,设置有机物沟埋还田和花后灌水量两个因素,有机物沟埋还田包括不还田(M₀)、秸秆单还田(M₁)和牛粪秸秆混合还田(M₂)3个还田类型,花后灌水量包括450 mm(W₁)和325 mm(W₂)2个水平,研究了其对玉米穗位叶光合性能、光系统Ⅱ(PSⅡ)效率和产量等的影响.结果表明:与秸秆单还田比较,牛粪秸秆混合还田有效提高了玉米花后光合能力和各器官的干物质积累量;与节水灌溉相比,正常灌溉加强了有机物还田对玉米光合能力的促进作用.牛粪秸秆混合还田与正常灌溉结合可显著提高玉米花后叶片的光合速率(P_n)、气孔导度(g_s)和蒸腾速率(T_r),降低胞间CO₂浓度(C_i);提高玉米花后叶片PSⅡ的最大光化学效率(φ_po)和捕获的激子将电子传递到电子传递链中Q_A下游的电子受体的概率(Ψ_o);改善花后叶片光能利用率,维持花后叶片较高的光合性能;同时增加花后玉米各器官干物质的量,提高干物质总积累量和转运能力,有利于花后同化物对籽粒的分配,最终获得高产.节水灌溉降低了叶片的光合性能,造成产量的下降;但配合牛粪秸秆混合还田与不还田处理相比,水分利用效率、籽粒增长速率和增产效果均优于正常灌水.这表明牛粪秸秆混合还田与正常灌溉结合可有效提高玉米花后光合性能,增加干物质积累量,促进玉米增产;牛粪秸秆混合还田与节水灌溉结合一定程度上降低了因减少灌溉量造成的减产.     

Root distribution following spatial separation of water and nitrogen supply in furrow irrigated corn

Proper management of water and fertilizer placement in irrigated corn (Zea mays L.) has the potential to reduce nitrate leaching into the groundwater. Potential management practices tested in a two year field experiment included row or furrow fertilizer placement combined with every or alternate furrow irrigation. To understand how fertilizer availability to plants could be affected by these management practices, root growth and distribution in a Ulm clay loam soil were examined. Spring rains were greater than normal in both years providing adequate moisture for early root growth in both irrigated and non-irrigated furrows. As the non-irrigated furrow began to dry, root biomass increased as much as 126% compared with the irrigated furrow. The greatest increase was at lower depths, however, where moisture was still plentiful. When early season moisture was available, roots proliferated throughout the soil profile and quickly became available to take up fertilizer N in both irrigated and non-irrigated furrows. Root growth responded positively to fertilizer placement in the furrow in 1996 but not in 1995. Excessive N leaching in 1995 may have limited the response to fertilizer N.     

Benefits of alternate partial root-zone irrigation on growth, water and nitrogen use efficiencies modified by fertilization and soil water status in maize

Alternate partial root-zone irrigation (APRI) is a new water-saving technique and may improve crop water use efficiency without much yield reduction. We investigated if the benefits of APRI on biomass accumulation, water and nitrogen use efficiencies could be modified by different soil fertilization and watering levels in pot-grown maize (Zea mays L. cv. super-sweet No 28, a local variety). Three irrigation methods, i.e. conventional irrigation (CI), alternate partial root-zone irrigation (APRI, alternate watering on both sides of the pot) and fixed partial root-zone irrigation (FPRI, fixed watering on one side of the pot), two watering levels, i.e. water deficit (W₁, 45–55% of field capacity) and well-watered (W₂, 70–80% of field capacity), and two N fertilization levels, i.e. no fertilization and fertilization, were designed. Results showed that APRI and FPRI methods led to more reduction in transpiration than in photosynthesis, and thus increased leaf water use efficiency (leaf WUE, i.e. the ratio of leaf net photosynthetic rate to transpiration rate). Compared to the CI treatment, APRI and FPRI increased leaf WUE by 7.7% and 8.1% before the jointing stage and 3.6% and 4.2% during the jointing stage, respectively. Under the fertilization and well-watered conditions, APRI treatment saved irrigation water by 38.4% and reduced shoot and total dry masses by 5.9% and 6.7%, respectively if compared to the CI treatment. APRI also enhanced canopy WUE (defined as the amount of total biomass per unit water used) and nitrogen (N) apparent recovery fraction (Nr, defined as the ratio of the increased N uptake to N applied) by 24.3% and 16.4%, respectively, indicating that effect of APRI can be better materialized under appropriate fertilization and water supply. Responsible Editor: Rana E. Munns     

Evaluating the Effects of Sustainable Chemical and Organic Fertilizers with Water Saving Practice on Corn Production and Soil Characteristics

The rapidly growing world population, water shortage, and food security are promising problems for sustainable agriculture. Farmers adopt higher irrigation and fertilizer applications to increase crop production resulting in environmental pollution. This study aimed to identify the long-term effects of intelligent water and fertilizers used in corn yield and soil nutrient status. A series of field experiments were conducted for six years with treatments as: farmer accustomed to fertilization used as control (CON), fertilizer decrement (KF), fertilizer decrement + water-saving irrigation (BMP1); combined application of organic and inorganic fertilizer + water-saving irrigation (BMP2), and combined application of controlled-release fertilizer (BMP3). A significant improvement was observed in soil organic matter (14.9%), nitrate nitrogen (106.7%), total phosphorus (23.9%), available phosphorus (26.2%), straw yield (44.8%), and grain yield (54.7%) with BMP2 treatment as compared to CON. The study concludes that integrating chemical and organic fertilizers with water-saving irrigation (BMP2) is a good approach to increasing corn productivity, ensuring water safety and improving soil health. The limitations of the current study include the identification of fertilizer type and its optimum dose, irrigation water type, and geographical position.

     

灌溉和种植方式对冬小麦生育后期旗叶光合特性及产量的影响

于2009—2011年通过田间试验,以高产中筋冬小麦品种济麦22为材料,设等行距平作、宽窄行平作、沟播3种种植方式,每种种植方式下设不灌水(W₀)、灌拔节水(W₁)、灌拔节水+开花水(W₂)、灌拔节水+开花水+灌浆水(W₃)4种灌溉处理(每次灌水量为60 mm),研究不同灌溉和种植方式对冬小麦生育后期旗叶光合特性和产量的影响.结果表明: 随冬小麦灌水量的增加,3种种植方式下小麦花后旗叶叶面积和光合速率均增加,光系统Ⅱ最大光化学效率和实际光化学效率也增加;与W₀处理相比,各灌水处理提高了小麦籽粒产量,但水分利用效率(WUE)降低.同一灌溉条件下,与其他两种种植方式相比,沟播方式小麦花后旗叶光合速率、光系统Ⅱ最大光能转化效率和实际光化学效率均较高,且W₂处理籽粒产量显著高于其他处理.统筹考虑冬小麦的籽粒产量和WUE,沟播结合灌拔节水+开花水是华北平原冬麦区较适宜的节水种植方式.     

Nitrogen uptake and partitioning under alternate- and every-furrow irrigation

Alternate-furrow irrigation, combined with fertilizer placement in the non-irrigated furrow, has the potential to reduce fertilizer leaching in irrigated corn (Zea mays L.). The potential also exists, however, for reduced N uptake under alternate-furrow irrigation. This study examined the effects of fertilizer placement and irrigation treatment on N uptake, rootashootroot circulation, and partitioning between reproductive and vegetative tissues. Rainfall was above average in both years of the study, especially during May and June, so that root growth beneath the non-irrigated furrow was equal to root production beneath the irrigated furrow. Under those conditions, soil NO₃ concentration in the fertilized furrow during late-vegetative and reproductive growth was greater in the alternate-furrow compared with the every-furrow treatment, resulting in increased fertilizer N uptake during reproductive growth and increased N partitioning to reproductive tissues under alternate-furrow irrigation. About 80% of the fertilizer N found in roots had first been translocated to the shoot and then returned via the phloem to the root system. Nitrogen cycling from root to shoot to root was not affected by irrigation treatment. Alternate-furrow irrigation successfully increased N uptake and reduced the potential for NO₃leaching when environmental conditions allowed adequate root development in the non-irrigated furrow, and when the growing season was long enough to allow the crop to reach physiological maturity.     

不同沟灌方式棉花的水氮耦合效应

研究了交替隔沟灌溉（AFI）、常规沟灌（CFI）、固定隔沟灌溉（FFI)下棉花的水氮耦合效应,施氮量和灌水量采用二次通用旋转组合设计,进行大田小区沟灌试验.结果表明：在施氮量56.2～95.2 kg N·hm^-2范围内,棉花产量与施氮量呈显著正相关,在施氮量95.2～134.2 kg N·hm^-2范围内变化不明显;在灌水量37.52～160.00 mm范围内,棉花产量与灌水量呈显著正相关,在灌水量160.00～218.48 mm范围内变化不明显;不同施氮量和灌水量情况下,AFI与CFI的产量差异不显著,CFI平均比FFI高9.15%.在56.2～122.8 kg N·hm^-2范围内,棉花水分利用效率(WUE)与施氮量呈显著正相关,在122.8～134.2 kg N·hm^-2范围内变化不明显;在灌水量37.52～160.00 mm范围内,棉花WUE与灌水量呈显著负相关,在灌水量160.00～218.48 mm范围内,棉花WUE无明显变化;不同施氮量和灌水量情况下,CFI与AFI的WUE差异不显著,CFI平均比FFI高9.01%.施氮量56.2～134.2 kg N·hm^-2范围内,棉花氮素利用效率(NUE)与施氮量呈显著负相关;在灌水量37.52～160.00 mm范围内,棉花NUE与灌水量呈显著正相关,在160.00～218.48 mm范围内变化明显;不同施氮量和灌水量情况下,AFI与CFI的NUE差异不显著,FFI则平均比CFI低6.34%.根据大田沟灌棉花的水氮耦合效应,以棉花产量、WUE、NUE的优化管理为目标,提出了不同沟灌方式水氮高效利用策略.     

干旱胁迫对不同施氮水平麻疯树幼苗光合特性及生长的影响

采用盆栽控水的方法,研究了干旱胁迫（连续干旱0 d,5 d,10 d,…,45 d）对不同施氮水平(对照 0 kg N·hm^-2、低氮 96 kg N·hm^-2、中氮 288 kg N·hm^-2、高氮 480 kg N·hm^-2)麻疯树幼苗光合特性及其生长的影响.结果表明: 随干旱胁迫强度的增加,各施氮水平麻疯树幼苗叶片相对含水量、苗高生长量、地径生长量、叶面积、净光合速率、蒸腾速率和气孔导度均降低,且各水分处理间差异极显著(P<0.01);随干旱时间的延长,叶绿素含量和水分利用效率表现出先升高后降低的趋势,而胞间CO₂浓度呈先降低后升高的趋势.正常供水时,施氮处理均不同程度提高了麻疯树幼苗的光合能力,促进了麻疯树幼苗的生长,且施氮量越高效果越好;干旱条件下,氮素营养对植株光合能力和生长的影响与干旱程度和施氮水平有关.轻度干旱时,提高施氮水平对植株光合能力和生长具有明显的促进作用;中度干旱时,中氮的促进作用明显高于其他施氮水平;严重干旱时,低氮的促进效果最好,高氮的促进作用减弱并逐渐转向抑制.     

分根区干湿交替对玉米光合速率及蒸腾效率的影响

以玉米为材料研究了分根区干湿交替对叶片光合速度及蒸腾效率的影响,结果发现控制１／２根区交替供水和固定１／２根区供水在减少用水量的同时,叶片蒸腾速度明显下降,而光合速度不明显,蒸腾效率提高;控制１／２根区交替供水比固定１／２根区供水在光合维持高水平稳定时所要求的土壤含水量低,其蒸腾效率较高。干湿交替能够增加根冠比、根干重和根九。证明控制性分根交灌溉可提高玉米腾效率达到节水的目的。     

不同水氮条件下灌溉方式对玉米干物质量和氮钾利用的影响

由于作物需水随生育期的变化,分根区交替灌溉(AI)的节水效果也会随生育期而发生变化,探明不同生育期分根区交替灌溉对玉米生长和水分养分利用的影响,以期为分根区交替灌溉的实施和充分发挥其节水节肥效果奠定理论基础。通过盆栽试验,在2种灌水水平(正常灌水和轻度缺水)和2种有机无机氮比例(100%无机氮和70%无机氮+30%有机氮)下,以常规灌溉(CI)为对照,分别研究苗期—灌浆初期、苗期—拔节期以及拔节期—抽雄期进行AI对玉米干物质量、氮钾含量和吸收量以及土壤碱解氮和速效钾含量的影响。结果表明,在轻度缺水和有机无机氮肥配施下,与CI相比,拔节期—抽雄期分根区交替灌溉玉米地上部和总干物质量分别增加29.6%和27.4%,地上部和总N吸收量增加50.7%和50.4%。与单施无机氮肥相比,有机无机氮肥配施会在不同程度上增加地上部和总N吸收量,但是一般降低土壤碱解氮和速效钾含量,这说明在轻度缺水和有机无机N肥配施下,拔节期—抽雄期进行分根区交替灌溉提高玉米总干物质量和N吸收量。