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1.
Drought stress is an important factor limiting the yield potential of peanut. In order to determine the effect of different irrigation scenarios on peanut production, field experiments were conducted in 2011 and 2012 growing seasons using factorial design with three replicates. On the other hand, the crop simulation models can be useful to predict crop yields and to investigate the impact of drought stress on plant growth and development. In this study, the Cropping System Model–Crop Growth (CSM-CROPGRO)-Peanut model was employed for the simulation of seed yield, pod yield, biomass, soil water balance components and water productivity for peanut in Astaneh-Ashrafiyeh, Iran. Results showed that the model was able to reasonably simulate seed yield, pod yield and final biomass for different irrigation scenarios (RMSEn < 20%, R2 > 0.8 and d > 0.8). According to the results, irrigation depth and interval were important factors affecting yield and biomass. In general, model error increased as the amount of water applied decreased. The least amount of water applied (40 mm) resulted in yield reductions by 76%, 70% and 67% of the greatest amount of water applied (480 mm) for seed yield, pod yield and final biomass, respectively. For each irrigation interval, larger irrigation depth led to lower water productivity (WP) of irrigation (WPI), but higher WP based on evapotranspiration (WPET) and transpiration (WPT).The average amounts of WPI, WPET, WPT based on seed yield were 1.2, 0.63 and 1.01 kg m?3, respectively.  相似文献   

2.
Abstract

To investigate the effect of foliar application of nano-chelates of iron, zinc, and manganese subjected to different irrigation conditions on physiological traits, and yield of soybean (cultivar M9), a split plot experiment was conducted in a completely randomized block design with three replications in two crop years (2016–2017). The main plot included four levels of irrigation (I): full irrigation (I 1), irrigation withhold at flowering stage (I 2), irrigation withhold at podding stage (I 3), and irrigation withhold during the grain filling period (I 4). Also, the subplot included eight levels of foliar application with Fe, Zn, Mn, Fe?+?Zn, Fe?+?Mn, Zn?+?Mn, Fe?+?Zn?+?Mn nano-chelates, and distilled water (control). The results of combined analysis of variance suggested that the effect of irrigation and foliar application of nano-chelate was significant on all traits. Water deficit stress significantly reduced the grain yield. The minimum numbers of pods per plant, number of grains per plant, 100-seed weight per plant, leaf area index, leaf chlorophyll concentration, total dry weight of plant, and the grain yield were obtained by irrigation withhold at podding stage. Foliar application of combined nano-chelates increased the soybean resistance against water shortage more considerably than the separate consumption of these elements. Under drought stress in podding stage, the application of Fe?+?Zn led to the highest yield with a mean of 2613.84?kg ha?1 where this increase was 61.1% higher than control.  相似文献   

3.
为探明干热区芒果高效生产的灌溉施肥模式,应用微润灌溉施肥技术在西南干热区开展大田芒果试验。以7年生"贵妃芒"为试验材料,设置4种灌溉模式和3个施肥水平。4种灌溉模式为全生育期充分灌溉(FI,100%ETC)和3个生育阶段调亏灌溉(RDI),调亏阶段分别为开花期、膨大期和成熟期(RDIFS、RDIES和RDIMS),调亏阶段的灌水水平为50%ETC,非调亏阶段为100%ETC。3个施肥水平为高肥(FH)、中肥(FM)和低肥(FL)。研究不同水肥处理对芒果光合特性、产量和水肥利用效率的影响。结果表明:不同生育期RDI均可显著减小芒果净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr),而增大叶片瞬时水分利用效率(WUEi)。相同灌溉水平下,开花期和膨大期Pn、Gs和Tr随施肥量的增加而增加,WUEi随施肥量的增加先增后减,成熟期Pn、Tr和WUEi随施肥量的增加而增加。与FI处理相比,RDIFS减少芒果单果重量、产量和肥料偏生产力(PFP)分别为11.74%,23.43%,23.98%,RDIES分别减少为21.09%,20.29%,20.50%,RDIES和RDIMS分别提高灌溉水利用效率IWUE为11.87%和32.81%。与FM相比,FH减少产量和IWUE分别为4.17%和4.06%,FL分别减少6.75%和6.67%,PFP随着施肥量的增加而减少。与CK相比,除RDIMSFM处理增加产量6.36%和RDIMSFL增加不明显外,其余处理减少3.14%~31.76%,RDIMSFL处理下的PFP和RDIMSFM处理下的IWUE取得最大值,分别为363.93 kg/kg和15.80 kg/m3,与CK相比均显著增加。因此,综合考虑产量和IWUE等指标,RDIMSFM处理最优,是干热区芒果适宜的微润灌溉施肥模式。  相似文献   

4.
ABSTRACT

In the scheduling of nutrient supply programs, analysis of plant nutrient status has been found to be useful to prevent the deficiency or toxic effects of nutrients in any horticultural crop. So the present study was framed to assess the foliage nutrient content and vegetative growth under different irrigation and fertigation combination modules. Recently apple (Malus ×domestica) orchards in the state Himachal Pradesh of India have converted from the traditional royal delicious orchard at 6 × 6 m spacing with rainfed/basin irrigation to early spur varieties on dwarfing rootstock with drip irrigation, both with or without fertigation. An experimental field trial was started at the end of 2018 in a ‘Super Chief’/MM106 orchard at an experimental farm of the department of Soil Science & Water Management, Dr. YS Parmar University of Horticulture and Forestry, Nauni, Solan (HP). A factorial experiment with 16 treatment combinations of 4 irrigation levels viz. I1 – drip irrigation at 100% ETc, I2 – drip irrigation at 80% ETc, I3 – drip irrigation at 60% ETc, I4 – conventional irrigation, and four fertigation levels viz. F0 – No fertilizer application (absolute control), F1 – 100% of AD (NPK), F2 – 75% of AD (NPK) and F3 – 50% of AD (NPK) were replicated thrice with 3 plants in each replication. Vegetative growth parameters and leaf nutrient contents were affected by both fertilization and water rate. Irrigation and nutrient levels and their interactions exhibited significant effect on leaf N (3.10%), P (0.28%), K (1.77%), and S (0.44%) contents. Significantly maximum contents were observed in the irrigation level I1 (DI at 100% ETc). Among fertigation level, F1 [100% AD (NPK)] recorded highest contents of leaf N (3.17%), P (0.29%), K (1.80%), S (0.46%). Interaction I1F1 registered maximum leaf N (3.36%), P (0.36%), K (1.92%) and S (0.63%).

With an increase in the water volume and an increasing dose of NPK, vegetative growth parameters, i.e., tree height, plant spread, tree volume, trunk girth, and annual extension growth were noted to increase proportionately. Treatment DI at 100% ETc (I1), increased the tree height by 9.41, plant spread (EW by 32.0, NS by 16.3), tree volume by 61.36, trunk girth by 8.05, and annual extension growth by 14.22% over conventional irrigation (I4). Drip fertigated trees with F1 [100% AD (NPK)] reported the highest growth parameters. The results of two years apple trial suggested a positive effect of fertigation on enhanced effectiveness of fertilization and improved foliage nutrient content and vegetative growth.  相似文献   

5.
A pot experiment was conducted to investigate the effects of different water levels on water-use efficiency, yield and growth parameters of leek (Allium porrum L.) and was carried out in the practical research field of Ondokuz May?s University in Turkey. Different irrigation water levels were based on the weight changes of each pot and included 5 irrigation treatments [25% (I25), 50% (I50), 75% (I75), 100% (I100) and 118% (I118) times of consumed water]. Decreases in irrigation water resulted in decreases in plant height, stem diameter, leaf and stem fresh weights, leaf and stem dry weights and leaf area, but did not significantly affect leaf number or chlorophyll content. A yield-response factor of 1.26 was obtained, implying that the leek crop was sensitive to water stress caused by deficit irrigation. Comprehensive analysis of yield, water use efficiency, and evapotranspiration, the I75 treatment can be suggested for leek production in water-scarce regions.  相似文献   

6.
ABSTRACT

The effect of deficit irrigation (DI) on wheat crop yield, soil physical parameters and on nitrate nitrogen movement in soil profile was evaluated under application of dairy manure and nitrogen fertilizer. Two levels of DI were taken as I0.6 (60% FC) and I0.8 (80% FC) along with two dairy manure levels (20 and 25 Mg ha?1) and three nitrogen levels (80, 100, and 120 kg ha?1). The grain yield was high under I0.8 than I0.6, whereas the irrigation level has no significant effect on soil organic carbon contents. Dairy manure, irrigation, and nitrogen indicated strong interaction with each other for all yield-related parameters during both years of study, however, results for 2nd year were highly positive. Soil nitrate nitrogen movement was significantly affected under I0.8 with high rate of dairy manure (25 Mg ha?1) and nitrogen fertilizer (120 kg ha?1). Results concluded that combined application of dairy manure (25 Mg ha?1) and nitrogen fertilizer (120 kg ha?1) under DI level I0.8 resulted in high grain yield. To overcome water scarce conditions, further experiments can be designed by addition of various organic matters in different combination that enhances the yield and soil health.  相似文献   

7.
Terminal drought stress (drought at reproductive growth stage) has been considered a severe environmental threat under changing climatic scenarios and undoubtedly inhibits sunflower production. A field study was conducted to explore the potential role of foliar applied boron (B) (0, 15, 30, 45 mg L?1) at late growth periods of sunflower in alleviating the adversities of terminal drought stress (75, 64, 53 mm DI) grown from inflorescence emergence to maturity stages. The plant water relations such as leaf relative water content (RWC), water potential (Ψw), osmotic potential (Ψs), and turgor pressure (Ψp) were increased significantly with B foliar sprays while exposed to terminal drought stress. Foliar B application considerably improved the nitrogen and B concentrations in leaf and seed tissues, and also chlorophyll a and b pigments under terminal drought stress conditions. Drought-induced proline accumulation prevented the damages caused by drought stress, nevertheless, B foliar spray increased its contents. Compared to well-watered conditions, terminal drought stress substantially declined the growth performance in terms of reduced leaf area index (LAI), crop growth rate (CGR), net assimilation rate (NAR), and total dry matter (TDM) production; however, foliar B supply (30 mg L?1) might be helpful for improving drought tolerance in sunflower with reduced growth losses.  相似文献   

8.
Water shortage is the most important factor constraining agricultural production all over the world. New irrigation strategies must be established to use the limited water resources more efficiently. This study was carried out in a completely randomized design with three replications under the greenhouse condition at Shahrekord University, Shahrekord, Iran. In this study, the physiological responses of pepper plant affected by irrigation water were investigated. Irrigation treatments included control [full irrigation (FI) level] and three deficit irrigation (DI) levels—80, 60, and 40% of the plant's water requirement called DI80, DI60, and DI40, respectively. A no plant cover treatment with three replications was also used to measure evaporation from the soil surface. Daily measurements of volumetric soil moisture (VSM) were made at each 10-cm intervals of the soil column, considered as a layer. The differences between the measured VSM and the VSM in the next day and evaporation rate at the soil surface at the same layer of the bare soil with no plant cover treatment were calculated. Eventually, by considering the applied and collected water in each treatment, evapotranspiration (ETC) and root water uptake in each layer per day were estimated. Furthermore, fruit number per plant, fresh fruit weight/day, root fresh/dry weights, shoot fresh/dry weights, root zone volume, root length and density, crop yield, and water use efficiency (WUE) were measured under different water treatments. The results showed that the maximum and minimum of all the studied parameters were found in the FI and DI40 treatments, respectively. ETC in the DI80, DI60, and DI40 treatments were reduced by 14.2, 37.4, and 52.2%, respectively. Furthermore, applying 80, 60, and 40% of the plant's water requirement led to the reduction in crop yield by 29.4, 52.7, and 69.5%, respectively. The averages of root water uptakes in the DI80, DI60, and DI40 treatments reduced by 17.08, 48.72, and 68.25%, respectively. WUE and crop yield also showed no significant difference in the FI and DI80 treatments. Moreover, in the DI80 treatment, the reduced rate of water uptake was less than the reduced rate of plant's applied water. According to these results, it can be concluded that 20% DI had no significant reduction on the yield of pepper, but above this threshold, there was an adverse effect on the growth and yield. Therefore, for water management in the regions with limited water resources, rate of plant's applied water can be decreased by around 20%.  相似文献   

9.
Better irrigation and nitrogen (N) scheduling and more efficient management of crop production require modeling of plant growth and crop yield. Models become more applicable if they are simple and require less and accessible inputs. The objective of this study was to use simple equations of soil water budget, evapotranspiration (ET), leaf area index (LAI), yield, and harvest index (HI)–transpiration function to develop a model for the prediction of growth and yield of maize under various water and N rates. The model was calibrated based on given data under sprinkler irrigation and verified based on independent data under furrow irrigation. The comparison between predicted and measured values of different crop parameters did not show any significant difference and the model was able to estimate LAI, ET, soil water content, HI, dry matter, and grain yield properly. Furthermore, an equation was presented to predict daily dry matter accumulation by a logistic curve for different water and N applications. It was concluded that the presented simple model was able to predict crop yield quite well and hence could be used for farm irrigation and N scheduling and management of both. Furthermore, the relationship between LAI and ET may be different in various environmental conditions that should be considered in using the model.  相似文献   

10.
张寒  王琳  陈刚 《水土保持学报》2021,35(4):88-95,105
蒸散发(ET)在农业灌溉和水资源管理中起着重要作用。ET可通过FAO-Penman-Monteith方法(ET_(FPM))进行准确估算,ET_(FPM)方法是ET估算的标准参考方法,此方法需要提供更为详实的气象数据。对于ET的估算,需要寻找使用较少的输入数据,而不会影响预测准确性的替代方法。研究运用5个基于辐射的模型,包括Makkink(ET_(MAK))、Priestley和Taylor(ET_(PT))、Abtew(ET_(ABT))、Jensen-Haise(ET_(JH))、McGuinness和Bordne(ET_(MB)),3个基于温度的模型,包括Hargreaves and Samani(ET_(HS))、Hamon(ET_(HAM))和Linacre(ET_(LIN)),以及1个基于空气动力学的模型Penman(ET_(PEN)),通过使用韩仓河流域周边6个气象水文站的长期数据,将选取的模型与ET_(FPM)模型在月尺度和生长季节尺度上进行比较评价。结果表明,ET_(JH)、ET_(HAM)分别是67%,33%研究区域每月ET的最佳预测方法。在研究区域中,基于辐射的方法优于基于温度的方法。植被生长季节ET累积值表明,Jensen-Haise和Hamon方法在暖季和秋冬季生长期表现最佳,而春季生长期最佳预测方法仅包括Jensen-Haise方法。最佳替代方法和ET_(FPM)方法之间的差异表明,最佳替代方法在某些地区的估算可信度不高,因此在使用之前应考虑ET模型可预测性能的时空变化。  相似文献   

11.
土壤熏蒸剂对土壤硝化、反硝化作用的影响   总被引：4，自引：0，他引：4       下载免费PDF全文
采用化学分析和变性梯度凝胶电泳(DGGE)技术,以大田威百亩、棉隆、溴甲烷、硫酰氟熏蒸100 d土壤为研究对象,探究土壤熏蒸对土壤硝化活性、反硝化活性及amoA基因型硝化型细菌、nirS基因型反硝化细菌群落结构影响。研究表明,威百亩、棉隆、硫酰氟熏蒸剂处理下,土壤硝化活性与对照无显著差异;而溴甲烷处理的硝化活性比对照降低13.19%,差异显著(P0.05);熏蒸剂之间土壤硝化活性无显著差异。4种熏蒸剂之间以及与对照之间土壤反硝化活性无显著差异。4种熏蒸剂中溴甲烷处理土样amoA型硝化细菌多样性指数、均匀度显著低于对照土样和其他3种熏蒸剂处理土样;而丰富度指数无显著差异。威百亩、棉隆和硫酰氟熏蒸土样之间及与对照之间amoA型硝化细菌3种生态指数无明显差异。4种熏蒸剂处理土壤nirS型反硝化细菌多样性指数、均匀度与对照无显著差异(P0.05);熏蒸剂之间存在显著差异(P0.05)。研究表明,溴甲烷对土壤硝化活性的抑制是通过抑制amoA型硝化细菌的多样性而实现,其他3种熏蒸剂对土壤硝化活性无显著影响。4种熏蒸剂对土壤反硝化活性无显著影响。  相似文献   

12.
Controlled‐release urea (CRU) is a new type of urea, which may increase crop nitrogen (N)‐use efficiency compared with conventional urea (CU), but the conditions where it outperforms urea are not well defined. A field experiment assessing responses of plant growth and grain yield of maize to CRU and irrigation was conducted on a typical agricultural farm in Shandong, China. Five treatments of the two types of urea (75, 150 kg N ha–1, 0 kg N ha–1) were applied as basal fertilizer when sowing maize, and two water treatments (W0 and W1) were used 23 d after anthesis. Net photosynthetic rate (PN) and chlorophyll concentration as well as leaf‐area index (LAI) increased significantly by both CRU and CU application, with the increases being larger in CRU‐treated plants than in CU‐treated plants at grain filling and maturing stages. CRU significantly enhanced the maximum photochemical efficiency (Fv / Fm), PSII coefficient of photochemical fluorescence quenching (qP), and actual quantum yield of PSII electron transformation (ΦPSII) but decreased the nonphotochemical quenching (NPQ). Cob‐leaf N concentration of CRU‐treated plants was significantly higher than that of CU‐treated plants under no irrigation, but not in the irrigation treatment 30 d after anthesis. Significant positive correlations were found between cob‐leaf N concentration and PN both with and without irrigation. Grain yield of maize was significantly higher in the CRU treatment than in the CU treatment under both irrigation conditions. In conclusion, CRU as a basal application appeared to increase the N‐use efficiency for maize relative to CU especially by maintaining N supply after anthesis.  相似文献   

13.
ABSTRACT

In arid zones, farmers are obligated to reduce water amounts used in irrigating their lands. Consequently, reduction in final yields is realized. Thus, dealing with such a case became a decisive act. We tried to investigate the acceptable degree of lowering irrigation water with sustaining the productivity of groundnut as a way for managing drought conditions. Therefore, in summer seasons of 2016 and 2017 at the Experimental Research and Production Station, National Research Centre, Egypt, field trials were conducted with growing groundnut plants under three irrigation levels, i.e., 50%, 75%, and 100% of crop evapotranspiration (ETc), denoted as I50, I75, and I100, respectively. N, P, and K contents in seed and shoot and their yields in addition to harvest and partitioning indices were estimated. In spite of irrigating groundnut plants by normal water amounts, I100, caused the maximum weight of seed biomass yield ha?1 and seed N and P contents, I75 was similar to I100 for producing shoot biomass yield ha?1 and seed K content. Moreover, N and P yields (for shoots and seeds) and k yield (for seeds) showed the maximum values with I100. Differences in all nutrient harvest indices (NHI, PHI, and KHI) between I100 and I75 were not significant. Furthermore, I75 statistically leveled with I100 in nutrient partitioning indices, viz., NPI, PPI, and KPI. In conclusion, groundnut straw residues produced by 25% less water supply than normal may share in managing drought stress by releasing nutrients and saving irrigation water in arid areas.  相似文献   

14.
为了明确分层施肥在不同灌水条件下对冬小麦产量、耗水特性和水分利用效率的影响,为黄淮海地区小麦高产高效生产实践提供理论依据。结合当地冬小麦灌溉制度采用水肥2因素裂区试验,水分为主区,施肥方式为副区,设置3个灌溉处理:春季不灌水(W_0)、春季拔节期灌水(W_1)、春季拔节期灌水+开花期灌水(W_2),灌水量90 mm/次;2种施肥方式处理:常规施肥处理(F_1)和分层施肥处理(F_2),分析了不同灌水与施肥模式下冬小麦产量、耗水特性和水分利用效率的特点。结果表明:与F_1相比,F_2处理40—120 cm土层土壤贮水消耗量、冬小麦拔节期—开花期耗水强度和农田耗水量显著增加,其中以W_2F_2处理农田耗水量最高。分层施肥处理冬小麦水分利用效率较常规施肥提升14.2%～3.0%,其中以W_1F_2处理水分利用效率最高。在3种灌水条件下,分层施肥处理较常规施肥显者增加了冬小麦的单位面积穗数,产量增加19.8%～6.4%,其中W_(2 )F_2产量最高。因此,建议在水分充足地区,采取小麦春季灌溉拔节水和开花水结合底肥分层施用的管理方式;在水资源短缺地区,采取小麦春季灌溉拔节水结合底肥分层施用的管理方式。  相似文献   

15.
[目的]研究阿克苏河灌区作物的理论需水量的时空变化特征,为该区水资源科学管理、高效利用提供理论依据。[方法]基于灌区内1972—2014年6个气象台站的逐日气象观测数据,采用FAO修正的Penman-Monteith模型,计算参考作物蒸发蒸腾量(ET0),进行空间数据的插值分析,对阿克苏河灌区作物的理论需水量特征分别在空间和时间两个维度上进行探讨。[结果](1)阿克苏河灌区多年平均ET0介于1 118~1 241mm之间,呈现中部以北地区较低,西南部、南部地区较高的规律;(2)春季和夏季的ET0最高,5,6,7月的月均ET0合计为533mm,是作物最需要水分补给的重要时段;(3)自20世纪70年代至今,作物年均蒸发蒸腾量呈现逐渐降低的趋势,2010年以后的变化趋势较为显著;(4)灌区各季节及全年的ET0变化均呈现S形曲线分布,至2014年已接近波谷并有抬升趋势。[结论]在气候变化背景下,阿克苏河灌区作物的理论需水量随时间变化显著,春夏季受蒸腾作用影响是需要补水的关键时期,年际变化呈波动抬升趋势;在空间上亦呈现明显地带分异特点,呈南高北低的特征。  相似文献   

16.
灌溉方式与施肥水平对超级稻光合生理的影响   总被引：2，自引：0，他引：2  
为研究不同施肥水平下节水灌溉方式对超级稻光合生理的影响,通过盆栽试验研究了3种施肥水平(不施肥、低肥和高肥)和3种灌溉方式[常规灌溉(FIR)、控制灌溉(CIR)和间歇灌溉(IIR)]对"中浙优1号"拔节期、抽穗期和乳熟期叶片净光合速率(Pn)、胞间CO2浓度(Ci)、光合光响应曲线和光合色素含量的影响,以及光合速率与光合色素的关系。结果表明,与FIR处理相比,CIR和IIR处理提高了3个生育期"中浙优1号"的Pn,而Ci提高不明显;分别使拔节期、抽穗期"中浙优1号"的光饱和点增加9.2%~36.8%和3个生育期表观量子效率增加6.7%~31.5%,但使拔节期、抽穗期和乳熟期光补偿点降低3.2%~12.8%。与FIR相比,CIR分别增加拔节期、抽穗期和乳熟期叶绿素a、叶绿素b、类胡萝卜素和总叶绿素含量19.1%~76.3%、44.5%~98.5%、31.5%~117.4%和45.4%~145.0%;IIR处理分别提高3个生育期类胡萝卜素和总叶绿素含量4.2%~45.8%和31.5%~117.4%。不同灌溉方式下,施肥处理"中浙优1号"光合生理指标和光合色素含量均高于不施肥处理,高肥处理又高于低肥处理。通过"中浙优1号"光合速率与光合色素含量的相关分析发现,其Pn与同期光合色素含量存在显著相关性,并受到生育时期的影响。因此,CIR和IIR处理能提高"中浙优1号"的光合能力,提高其对强光的光合能力和弱光条件下的适应性,提高了光饱和点,进而增加光能利用率,并提高了功能叶光合色素含量,有效改善其叶片光响应特征。同时,在节水灌溉条件下,在一定范围内增施肥料均能明显提高"中浙优1号"的光合机能。  相似文献   

17.
Accurate estimation of reference evapotranspiration (ETo) is essential for water resources management and irrigation systems scheduling, especially in arid and semiarid regions such as Iran. In the present research, constant coefficients of Hargreaves–Samani (CH–S) and Priestley–Taylor (CP–T) equations were locally calibrated to estimate the ETo based on the FAO–Penmen–Monteith (PM) method as standard method. For this purpose, meteorological data of eight synoptic stations located in the northwest of Iran were used during the period of 1997–2008. The outcomes showed that the values of CH–S and CP–T were 0.0026 (instead of 0.0023) and 1.68 (instead of 1.26), respectively. Also, at stations with high wind speed, the values of calibrated coefficients of CH–S and CP–T were maximum. Then, the estimated ETo values using adjusted CH–S and CP–T coefficients were compared to the obtained actual ETo values by PM method using root mean square error and mean bias error indices. The results indicated that the new calibrated H–S and P–T equations have good agreement with the PM method for estimation of the ETo. Moreover, the equation of Ravazzani et al. was calibrated in the studied region. It was concluded that in general, the mentioned equation was shown better performance than original H–S equation.  相似文献   

18.
为探究省力化栽培模式下库尔勒香梨园适宜的灌溉制度，依据4种灌溉定额(3 750,5 250,6 750,8 250 m3/hm2)条件下2年香梨的田间试验数据，通过冠层覆盖度、土壤含水量和蒸散强度(ETa)和产量指标，确定AquaCrop模型参数。设置不同灌水场景，综合考虑产量、水分利用效率和灌溉水利用效率，利用AquaCrop模型优化香梨灌溉制度。结果表明：Y2W3处理产量高出其余处理3.87%～16.86%,Y2W1处理水分利用效率高出其余处理2.88%～27.20%;AquaCrop模型模拟与试验地实测结果的决定系数(R2)、均方根误差(RMSE)、标准均方根误差(NRMSE)、拟合度指数(d)和Nash效率系数(NSE)评价指标表明，冠层覆盖度R2变化范围为0.89～0.93,土壤含水量d为0.92～0.98,ETa的RMSE为1.06～1.61 mm/d; AquaCrop模型预测15种不同场景，灌溉定额7 200 m3/h...  相似文献   

19.
The model ORYZA2000 simulates the growth and development of rice under conditions of potential production and water and nitrogen (N) limitations. Crop simulation models could provide an alternative, less time-consuming, and inexpensive means of determining the optimum crop N and irrigation requirements under varied irrigation and nitrogen conditions. Water productivity (WP) is a concept of partial productivity and denotes the amount or value of product over volume or value of water used. For the evaluated ORYZA2000 model in Iran, a study was carried out in a randomized complete block design between 2005 and 2007, with three replications at the Rice Research Institute of Iran, Rasht. Irrigation management (three regimes) was the main plot and N application (four levels) was the subplot. In this study, simulation modeling was used to quantify water productivity and water balance components of water and nitrogen interactions in rice. Evaluation simulated and measured total aboveground biomass and yield, by adjusted coefficient of correlation, T test of means, and absolute and normalized root mean square errors (RMSE). Results showed that with normalized root mean square errors (RMSEn) of 5–28%, ORYZA2000 satisfactorily simulated crop biomass and yield that strongly varied among irrigation and nitrogen fertilizer conditions. Yield was simulated with an RMSE of 237–443 kg ha?1 and a normalized RMSE of 5–11%. Results showed that the significant (28–56%) share of evaporation into evapotranspiration, using the actual yield (measured) and simulated water balance (ORYZA2000), the calculated average WPET was significantly lower than the average WPT: 37%. The average WPI, WPI+R, WPET, WPT, and WPETQ were 1.4, 1.07, 1.07, 1.57, and 0.82 kg m?3. Results also showed that irrigation with 8-day intervals and 60 kg N ha?1, nitrogen level was the optimum irrigation regime and nitrogen level.  相似文献   

20.
本文回顾了中国科学院栾城农业生态系统试验站(以下简称栾城试验站)建站初期20 世纪80 年代以来在农田节水方面开展的研究。20 世纪80 年代以作物优化灌溉制度为研究重点, 解决生产实际问题; 20 世纪90 年代围绕土壤-植物-大气系统水分传输和界面调控开展了系统研究, 为农田节水措施的形成提供理论基础和技术途径; 近10 年来进一步深化了农田节水生理生态研究, 并根据多年研究积累, 形成了综合节水技术模式, 进行推广应用。未来栾城试验站农田节水工作将更加突出多学科渗透交叉, 以提高农田水分利用效率和效益为目标, 加强基础研究和节水技术的示范应用。  相似文献   

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