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1.
Alternate partial root-zone irrigation (APRI) is a water-saving irrigation method but also can regulate crop physiological responses. This study investigated how water-use efficiency (WUE) and other physiological responses were regulated at different growth stages when maize plants were applied with APRI and how these responses were recovered to control levels when full irrigation was resumed. A pot experiment was carried out at two fertilization levels and with three irrigation methods at the jointing stage (29-38 days after sowing) or during the jointing and tasselling stages (29-77 days after sowing). The irrigation methods included the conventional irrigation (CI), APRI and fixed PRI (FPRI, watering was fixed to one side). Compared to the CI, APRI at the jointing stage for 10 days or during the jointing and tasselling stages for 49 days reduced water consumption by 10.6-12.9 and 31.7-32.4%, respectively, but did not reduce total dry mass accumulation significantly, thus increased canopy WUE by 10.4-13.6 and 41.2-41.8%, respectively. FPRI reduced the total dry mass significantly even though it also improved canopy WUE. APRI had slight effect on the leaf relative water content (RWC), chlorophyll (Chl), carotenoid (CAR), proline (Pro) and malondialdehyde (MDA) contents and superoxide dismutase (SOD) and peroxidase (POD) activities from jointing to tasselling stages but recovery to the levels of CI was rapid after receiving full watering. In comparison, FPRI treatment significantly reduced leaf RWC, Chl and CAR contents and SOD and POD activities and increased the Pro and MAD contents. After receiving full watering, the above-mentioned physiological indexes in FPRI could not recover fully to the levels of CI. High fertilization treatment only increased leaf Chl content significantly and contributed little to the total dry mass accumulation. Our result suggests that APRI can make plants use water and nutrients more efficiently with better drought tolerance.  相似文献   

2.
To investigate the dynamic change of plant nitrogen (N) absorption and accumulation from different root zones under the partial root-zone irrigation (PRI), maize plants were raised in split-root containers and irrigated on both halves of the container (conventional irrigation, CI), on one side only (fixed partial root-zone irrigation, FPRI), or alternatively on one of two sides (alternate partial root-zone irrigation, APRI). And the isotope-labeled 15N-(NH4)2SO4 was applied to one half of the container with (14NH4)2SO4 to the other half so that N inflow rates can be tracked. Results showed that APRI treatment increased root N absorption in the irrigated zone significantly when compared to that of CI treatment. The re-irrigated half resumed high N inflow rate within 5 days after irrigation in APRI, suggesting that APRI had significant compensatory effect on N uptake. The amount of N absorption from two root zones of APRI was equal after two rounds of alternative irrigation (20 days). The recovery rate, residual and loss percentages of fertilizer-N applied to two zones were similar. As for FPRI treatment, the N accumulation in plant was mainly from the irrigated root zone. The recovery rate and loss percentage of fertilizer-N applied to the irrigated zone was higher and the residual percentage of fertilizer-N in soil was lower if compared to those of the non-irrigated zone. The recovery rate of fertilizer-N in APRI treatment was higher than that of the non-irrigated zone but lower than that of the irrigated zone in FPRI treatment. In total, both FPRI and APRI treatments increased N and water use efficiencies but only consumed about 70% of the irrigated water when compared to CI treatment.  相似文献   

3.
Antioxidation responses of maize roots and leaves to water deficit and rewatering under partial root-zone irrigation (PRI) were investigated using a pot system. Plants were cultured using three irrigation methods, i.e. conventional irrigation (CI), alternate PRI (APRI) and fixed PRI (FPRI) with three different water regimes including W1 (70% field capacity, FC), W2 (50% FC) and W3 (35% FC). Compared to CI, root peroxidases (POD) activity was enhanced in the irrigated root zone of FPRI and both root zones of APRI during mild water deficit. After rewatering, POD activity was increased in the dry root zone under FPRI but reduced in the roots under APRI. Roots in the dry zone and leaves under FPRI remained high superoxide dismutase (SOD) activity after rewatering. In contrast, SOD activity decreased in the roots and leaves under CI and APRI. Malondialdehyde (MDA) contents were increased in leaves and two sub-roots under FPRI during water deficit and remained higher after rewatering compared to those under CI and APRI. MDA contents in the tissues under APRI showed similar levels to those under CI. Compared to CI, APRI showed the same biomass production, achieving significantly higher water use efficiency under mild water deficit. The results suggested that plants under APRI experienced less oxidative stress or damage induced by water deficit.  相似文献   

4.
两种施肥水平下根区局部灌溉对甜玉米水分利用的效应   总被引：10，自引：0，他引：10  
根区局部灌溉如分根区交替灌溉和部分根干燥灌溉是新的高效节水技术。研究了两种施肥水平条件下根区局部灌溉对甜玉米叶片光合、叶面积、干物质积累和水分利用的影响。结果发现,与常规均匀灌水相比,根区局部灌溉高、低肥处理的蒸腾速率分别降低19．01％和17．50％．光合速率分别提高8．88％和18．34％,叶片水分利用效率分别提高34．69％和43．45％。随着甜玉米生育期的推进．各灌溉处理间的叶面积差异逐渐缩小;单株干物重分别下降15．14％和24．38％,蒸散量(即作物耗水量)分别下降31．28％和29．58％;冠层水分利用效率分别提高23．48％和7．40％。这表明较高肥条件下根区局部灌溉的冠层水分利用效率提高较多,因而根区局部灌溉技术的节水效应要与合理施肥相结合才能发挥更好的作用。  相似文献   

5.
为探讨玉米节水灌溉方式的理论依据,通过桶栽试验研究了分根区交替灌溉(APRI)方式下,不同生育期水分亏缺对夏玉米生长、干物质累积质量、籽粒产量、总耗水量和水分利用效率(WUE)的影响.结果表明:常规灌溉(CI)方式下,苗期和全生育期水分亏缺的株高、叶面积和总耗水量均显著低于充分灌溉,但苗期水分亏缺可以提高WUE.相同的灌水方式和亏缺时期,中度亏缺的根干物质质量、地上和总干物质质量以及籽粒产量均显著高于重度亏缺;相同的灌水方式和灌水水平,苗期水分亏缺的株高、叶面积、根干物质质量、地上和总干物质质量以及总耗水量均显著的低于灌浆期,但籽粒产量和WUE均显著高于灌浆期;相同的灌水水平和亏缺时期,APRI的根干物质质量和总耗水量均显著低于CI的,但APRI的籽粒产量和水分利用效率均显著高于CI的.本研究结果表明,APRI在苗期进行中度亏缺有利于营养生长的调控,并达到节水高产,提高WUE的目的.  相似文献   

6.
Carbon (C) sequestration through irrigation management is a potential strategy to reduce C emissions from agriculture. Two experiments (Exps. I and II) were conducted to investigate the effects of different irrigation strategies on C retention in the soil-plant system in order to evaluate their environmental impacts. Tomato plants (Lycopersicon esculentum L., var. Cedrico) were grown in split-root pots in a climate-controlled glasshouse and were subjected to full irrigation (FI), deficit irrigation (DI) and alternate partial root-zone irrigation (PRI) at early fruiting stage. In Exp. I, each plant received 2.0 g chemical nitrogen (N), while in Exp. II, 1.6 g chemical N and maize residue containing 0.4 g organic N were applied into the pot. The results showed that, in both experiments, the concentration and the amount of total C in the soil were lower in FI and PRI as compared to DI, presumably due to a greater microbial activity in the two treatments; particularly the PRI induced drying and wetting cycles of the soils may cause an increase of microbial activities and respiration rate, which could lead to more C losses from the soil. However, in both experiments the total C concentration in the PRI plants was the highest as compared with the FI and DI plants, and this was seemingly due to improved plant N nutrition under the PRI treatment. Consequently, the total amount of C retained in the soil-plant system was highest in the FI and was similar, but lower, for the PRI and DI. The different N input in the two experiments might have affected the C retention in the soil and in the plant biomass. Nevertheless, with a same degree of water saving, PRI was superior to DI in terms of enhancing C concentration in the plant biomass, which might have contributed to a better fruit quality in tomatoes as reported by [Zegbe et al., 2004] and [Zegbe et al., 2006].  相似文献   

7.
The objective of this study was to investigate the comparative effects of alternative partial root-zone irrigation (PRI) and deficit irrigation (DI) on fertilizer-N use efficiency in tomato plants under mineral N and organic N fertilizations. The plants were grown in split-root pots in a climate-controlled glasshouse and were subjected to PRI and DI treatments during early fruiting stage. When analyzed across the N fertilizer treatments, PRI treatment led to significantly higher N yield, agronomic N use efficiency (ANUE), and apparent N recovery efficiency (ANRE) as compared with the DI treatment, indicating significantly higher fertilizer-N use efficiency and soil N availability as well as enhanced plant’s N acquisition ability in the PRI treatment. Analysis across the irrigation treatments showed that the mineral N fertilizer treatment (MinN) significantly increased N yield, ANUE and ANRE relative to the organic N fertilizer treatment (OrgN). Compared with DI, the rhizosphere and bulk soil mineral N content in the soil were significantly lowered in the PRI treatment, indicating the enhanced root N uptake efficiency. It is suggested that PRI-enhanced soil water dynamics may have increased soil nitrate mass/diffusive flow to the root surfaces and root N uptake efficiency in the wetting soil and stimulated soil N mineralization and plant N demand, contributing to the improved fertilizer-N use efficiency in the PRI relative to the DI treatment.  相似文献   

8.
通过盆栽试验研究了在2种施肥条件下,不同生育时期分根区交替灌溉(APRI)对烤烟生长、干物质积累与分配以及烟叶氮(N)、钾(K)含量的影响。结果表明,伸根期和成熟期APRI不但对烤烟植株有明显的增高作用,而且能显著提高烟叶中N、K含量。与常规灌溉(CI)相比,低肥时伸根期和成熟期APRI的株高、烟叶N含量、K含量分别提高5.19%、9.16%、6.42%和14.02%、28.03%、28.13%;高肥时分别提高9.11%、23.71%、18.75%和16.55%、38.57%、50.84%。可见在较高肥条件下,烤烟伸根期和成熟期进行分根区交替灌溉是烟叶适产优质生产中一种较好的水分调控方式。  相似文献   

9.
灌水方式与施钙水平对盆栽番茄产量和品质的影响   总被引：1，自引：0，他引：1  
分别在喷施氯化钙溶液质量分数为0%、0.3%、0.5%、0.8%、1.0%条件下进行3种不同灌水方式即常规全根灌溉(CI)、分根区固定灌溉(PRD)和分根区交替灌溉(APRI)的盆栽试验,测定番茄产量和品质.结果表明,分根区交替灌溉(APRI)番茄植株长势、果实产量和品质均显著优于分根区固定灌溉(PRD)和常规全根灌溉...  相似文献   

10.
Field experiments were conducted at the Luancheng Agro-Ecosystem Experimental Station of the Chinese Academy of Sciences during the winter wheat growing seasons in 2006-2007 and 2007-2008. Experiments involving winter wheat with 1, 2, and 3 irrigation applications at jointing, heading, or milking were conducted, and the total irrigation water supplied was maintained at 120 mm. The results indicated that irrigation during the later part of the winter wheat growing season and increase in irrigation frequency decreased the available soil water; this result was mainly due to the changes in the vertical distribution of root length density. In ≤30-cm-deep soil profiles, 3 times irrigation at jointing, heading, and milking increased the root length density, while in >30-cm-deep soil profiles, 1 time irrigation at jointing resulted in the highest root length density. With regard to evapotranspiration (ET), there was no significant (LSD, P < 0.05) difference between the regimes wherein irrigation was applied only once at jointing; 2 times at jointing and heading; and 3 times at jointing, heading, and milking. Compared with 1 and 3 times irrigation during the winter wheat growing season, 2 times irrigation increased grain yield and 2 times irrigation at jointing and heading produced the highest water-use efficiency (WUE). Combining the results obtained regarding grain yield and WUE, it can be concluded that irrigation at the jointing and heading stages results in high grain yield and WUE, which will offer a sound measurement for developing deficit irrigation regimes in North China.  相似文献   

11.
A field study (1999-2000 to 2001-2002) was carried out to optimize the irrigation frequency and suitable water application methods for cauliflower with a view to increase curd yield (CY) and water use efficiency (WUE). Check Basin (CB), Each Furrow (EF) and Alternate Furrow (AF) methods were tested with three irrigation frequencies depending on the attainment of soil matric potential (Ψm) value at 0.2 m depth as: −0.03 MPa (F1), −0.05 MPa (F2) and −0.07 MPa (F3). Maximum CY was recorded under F1 and decreased by 10.4 and 31.4%, respectively under F2 and F3 frequencies. In contrast, WUE decreased by 9.3% from F3 to F1. Highest CY and WUE obtained under CB followed by EF and AF methods. Furrow application methods saved 12-24% irrigation water over CB method. Maximum soil water stress coefficient (Ks) recorded at curd development stage in comparison to other stages. Both seasonal evapotranspiration (ETa) and yield-moisture stress index (Kys) recorded positive linear relationships with CY. Present study shows a crop response factor of 0.822 for cauliflower. In this region, cauliflower should be irrigated with check basin method at an interval of 8-10 days.  相似文献   

12.
局部灌水方式下玉米根系对干旱及复水的生理生化响应   总被引：1，自引：0，他引：1  
采用分根装置,在均匀灌溉、固定灌溉和交替灌溉3种方式下,分区测定轻、中、重度3种胁迫条件下以及复水后玉米根系的丙二醛MDA含量、过氧化物酶POD和超氧化物歧化酶SOD活性。不同于以往的分根交替灌溉研究的内容,重点研究在局部灌水条件下玉米根系对干旱及复水的生理生化响应。研究结果表明,无论干旱还是复水后,固定灌水条件下,作物根系受活性氧伤害较之均匀灌水增大,而交替灌水使作物受活性氧的危害减小,这对交替灌溉的节水效应的进一步研究具有重要的意义。  相似文献   

13.
Carbon (C) and nitrogen (N) dynamics in agro-systems can be altered as a consequence of treated sewage effluent (TSE) irrigation. The present study evaluated the effects of TSE irrigation over 16 months on N concentrations in sugarcane (leaves, stalks and juice), total soil carbon (TC), total soil nitrogen (TN), NO3−-N in soil and nitrate (NO3−) and dissolved organic carbon (DOC) in soil solution. The soil was classified as an Oxisol and samplings were carried out during the first productive crop cycle, from February 2005 (before planting) to September 2006 (after sugarcane harvest and 16 months of TSE irrigation). The experiment was arranged in a complete block design with five treatments and four replicates. Irrigated plots received 50% of the recommended mineral N fertilization and 100% (T100), 125% (T125), 150% (T150) and 200% (T200) of crop water demand. No mineral N and irrigation were applied to the control plots. TSE irrigation enhanced sugarcane yield but resulted in total-N inputs (804-1622 kg N ha−1) greater than exported N (463-597 kg N ha−1). Hence, throughout the irrigation period, high NO3− concentrations (up to 388 mg L−1 at T200) and DOC (up to 142 mg L−1 at T100) were measured in soil solution below the root zone, indicating the potential of groundwater contamination. TSE irrigation did not change soil TC and TN.  相似文献   

14.
Improving irrigation water management is becoming important to produce a profitable crop in South Texas as the water supplies shrink. This study was conducted to investigate grain yield responses of corn (Zea mays) under irrigation management based on crop evapotranspiration (ETC) as well as a possibility to monitor plant water deficiencies using some of physiological and environmental factors. Three commercial corn cultivars were grown in a center-pivot-irrigated field with low energy precision application (LEPA) at Texas AgriLife Research Center in Uvalde, TX from 2002 to 2004. The field was treated with conventional and reduced tillage practices and irrigation regimes of 100%, 75%, and 50% ETC. Grain yield was increased as irrigation increased. There were significant differences between 100% and 50% ETC in volumetric water content (θ), leaf relative water content (RWC), and canopy temperature (TC). It is considered that irrigation management of corn at 75% ETC is feasible with 10% reduction of grain yield and with increased water use efficiency (WUE). The greatest WUE (1.6 g m−2 mm−1) achieved at 456 mm of water input while grain yield plateaued at less than 600 mm. The result demonstrates that ETC-based irrigation can be one of the efficient water delivery schemes. The results also demonstrate that grain yield reduction of corn is qualitatively describable using the variables of RWC and TC. Therefore, it appears that water status can be monitored with measurement of the variables, promising future development of real-time irrigation scheduling.  相似文献   

15.
The increasing scarcity of water for irrigation is becoming the most important problem for producing forage in all arid and semi-arid regions. Pearl millet is a key crop in these regions which needs relatively less water than other crops. In this research, a field study was conducted to identify the best combination of irrigation and nitrogen (N) management to achieve acceptable pearl millet forage both in quantity and quality aspects. Pearl millet was subjected to four irrigation treatments with interaction of N fertilizer (0, 75, 150 and 225 kg ha−1). The irrigation treatments were 40%, 60%, 80% and 100% of total available soil water (I40, I60, I80 and I100, respectively). The results showed that increasing moisture stress (from I40 to I100) resulted in progressively less total dry matter (TDM), leaf area index (LAI), and nitrogen utilization efficiency (NUzE), while water use efficiency (WUE) and the percentage of crude protein (CP%) increased. The highest TDM and LAI were found to be 21.45 t ha−1 and 8.65, in I40 treatment, respectively. TDM, WUE, CP% and profit responses to N rates were positive. The maximum WUE of 4.19 kg DM/m3 was achieved at I100 with 150 kg N ha−1. The results of this research indicate that the maximum profit of forage production was obtained in plots which were fully irrigated (I40) and received 225 kg N ha−1. However, in the situation which water is often limited and not available, application of 150 kg N ha−1 can produce high forage quality and guaranty acceptable benefits for farmers.  相似文献   

16.
Precision irrigation management and scheduling, as well as developing site- and cultivar-specific crop coefficient (Kc), and yield response factor to water deficit (ky) are very important parameters for efficient use of limited water resources. This study investigated the effect of deficit irrigation, applied at different growth stages of peanut with sprinkler irrigation in sandy soil, on field peanut evapotranspiration (ETc), yield and yield components, and water use efficiencies (IWUE and WUE). Also, yield response factor to water deficit (ky), and site- and cultivar-specific Kc were developed. Four treatments were imposed to deficit irrigation during late vegetative and early flowering, late flowering and early pegging, pegging, and pod formation growth stages of peanut, and compared with full irrigation in the course of the season (control). A soil water balance equation was used to estimate crop evapotranspiration (ETc). The results revealed that maximum seasonal ETc was 488 mm recorded with full irrigation treatment. The maximum value of Kc (0.96) occurred at the fifth week after sowing, this value was less than the generic values listed in FAO-33 and -56 (1.03 and 1.15), respectively. Dry kernels yield among treatments differed by 41.4%. Deficit irrigation significantly affected yields, where kernels yield decreased by 28, 39, 36, and 41% in deficit-irrigated late vegetative and early flowering, late flowering and early pegging, pegging, and pod formation growth stages, respectively, compared with full irrigation treatment. Peanut yields increased linearly with seasonal ETc (R2 = 0.94) and ETc/ETp (R2 = 0.92) (ETp = ETc with no water stress). The yield response factor (ky), which indicates the relative reduction in yield to relative reduction in ETc, averaged 2.9, was higher than the 0.7 value reported by Doorenbos and Kassam [Doorenbos, J., Kassam, A.H., 1979. Yield response to water. FAO Irrigation and Drainage Paper 33, Rome, Italy, 193 pp.], the high ky value reflects the great sensitivity of peanut (cv. Giza 5) to water deficit. WUE values varied considerably with deficit irrigation treatments, averaging 6.1 and 4.5 kg ha−1 mm−1 (dry-mass basis) for pods and kernels, respectively. Differences in WUE between the driest and wettest treatment were 31.3 and 31.3% for pods and kernels, respectively. Deficit irrigation treatments, however, impacted IWUE much more than WUE. Differences in IWUE between the driest and wettest treatment were 33.9 and 33.9% for pods and kernels, respectively. The results revealed that better management of available soil water in the root zone in the course of the season, as well as daily and seasonal accurate estimation of ETc can be an effective way for best irrigation scheduling and water allocation, maximizing yield, and optimizing economic return.  相似文献   

17.
【目的】提高夏玉米用水效率。【方法】2018—2019年设置4个微喷补灌处理,分别以0～10(W10)、0～20(W20)、0～30(W30)和0～40(W40)cm为目标湿润土层,补灌的目标土壤含水率为相应土层的田间持水率,补灌时期均为夏玉米播种时、拔节期开始时和抽雄期开始时;以传统畦灌模式(CK)为对照,研究了不同微喷补灌方案对夏玉米形态发育指标、产量构成、耗水量和水分利用效率(WUE)的影响。【结果】随着补灌目标湿润土层深度的增加,夏玉米株高、叶面积指数(LAI)、地上部干物质量和籽粒产量等指标呈逐渐增大或先增大后减小的趋势,当目标湿润土层达到20cm后,继续增加灌水量对夏玉米生长的促进效应减小,W20处理的各项指标均能获得较高值。耗水量和WUE受补灌目标湿润土层深度影响显著,其中,耗水量随目标湿润土层深度的增加而增大,WUE则与之相反。W20处理与CK和高水分(W40)处理相比,籽粒产量无显著差异,但灌溉用水量减少47.33%～54.73%,耗水量显著降低9.86%～13.85%,WUE显著提高11.48%～19.26%。【结论】建议试验区夏玉米微喷补灌的目标湿润土层为0～20 cm,目标含水率为田间持水率。  相似文献   

18.
肥料施入土壤后,会对酶活性产生一定的影响,进而影响土壤的生态和土壤质量。以河北平山片麻岩及花岗岩山地贫瘠土壤为研究对象,通过施用3种新型肥料后探究土壤各种酶活性在不同肥料之间差异性。结果显示,土壤蔗糖酶、过氧化氢酶、酸性磷酸酶、中性磷酸酶活性均有所提高,脲酶活性降低,其中生物有机肥对脲酶的抑制作用最强,微生物菌肥对脲酶的抑制最弱。  相似文献   

19.
Excessive amounts of irrigation water and fertilizers are often utilized for early potato cultivation in the Mediterranean basin. Given that water is expensive and limited in the semi-arid areas and that fertilizers above a threshold level often prove inefficacious for production purposes but still risk nitrate and phosphorous pollution of groundwater, it is crucial to provide an adequate irrigation and fertilization management. With the aim of achieving an appropriate combination of irrigation water and nutrient application in cultivation management of a potato crop in a Mediterranean environment, a 2-year experiment was conducted in Sicily (South Italy). The combined effects of 3 levels of irrigation (irrigation only at plant emergence, 50% and 100% of the maximum evapotranspiration - ETM) and 3 levels of mineral fertilization (low: 50, 25 and 75 kg ha−1, medium: 100, 50 and 150 kg ha−1 and high: 300, 100 and 450 kg ha−1 of N, P2O5 and K2O) were studied on the tuber yield and yield components, on both water irrigation and fertilizer productivity and on the plant source/sink (canopy/tubers dry weight) ratio. The results show a marked interaction between level of irrigation and level of fertilization on tuber yield, on Irrigation Water Productivity and on fertilizer productivity of the potato crop. We found that the treatments based on 50% ETM and a medium level of fertilization represent a valid compromise in early potato cultivation management. Compared to the high combination levels of irrigation and fertilization, this treatment entails a negligible reduction in tuber yield to save 90 mm ha−1 year−1 of irrigation water and 200, 50 and 300 kg ha−1 year−1 of N, P2O5 and K2O, respectively, with notable economic savings for farmers compared to the spendings that are usually made.  相似文献   

20.
A field experiment was carried out over 2 years to investigate the effect of partial root-zone irrigation applied using drip irrigation on the water use and yield of cotton (Gossypium hirsutum) in oasis fields of arid north-west China. Two irrigation treatments, i.e., conventional drip irrigation (CDI, both sides of plant row watered) or alternate drip irrigation (ADI, both sides of plant row alternatively watered) were applied under plastic mulch. Three irrigation levels (i.e., 15, 22.5, 30 mm during 2004 and 12, 18, 24 mm during 2005) were applied at each irrigation. Monitoring of soil water contents in the ADI treatment indicated a change in root-zone uptake in response to the irrigation method, although there existed some lateral soil water movement from the wetted side to the dry side after each watering. Stomatal conductance in ADI was lower than that of CDI when compared at the same irrigation level. Reduced stomatal conductance and water loss resulted in higher water use efficiency (WUE) in the ADI treatment. About 31-33% less total irrigation water was applied using the ADI method when compared to that of the CDI treatment with a similar seed cotton yield. ADI also yielded 11% more pre-frost seed cotton than CDI in 2005, indicating a better lint quality and higher price. These results suggest that ADI should be a useful water-saving irrigation method in arid oasis fields where cotton production is heavily dependent on irrigation and water resources are scarce.  相似文献   

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