A filtration system is crucial for recycling wastewater, with the filter as its core component. However, traditional filters struggle with rapid cleaning due to wastewater complexity, which challenges the sustainable operation of filtration systems. This study proposes a new method of mixed ultrasound assisted acid backwashing, however, the optimal cleaning parameters for this method are not yet clear. We evaluated the effects of various cleaning factors on filter cleaning parameters using single factor and response surface experiments. We evaluated the effects of ultrasound, acid washing, and backwashing, both individually and in combination, on filter performance, assessed by hydraulic performance recovery (HPR) and dirt removal rate (Drr). The results showed that backwashing yielded the best Drr (80.34 %), acid washing achieved the highest HPR (96.03 %) at low pH, and ultrasound demonstrated superior overall performance, improving HPR by 4.6 % over backwashing and Drr by 23.45 % over acid washing. The combined method enhanced cleaning efficiency, achieving complete recovery in some cases and increasing Drr by up to 28.44 %. Key cleaning parameters-ultrasonic duration, backwash time, and pH, were identified as most influential, and a response surface model was developed to optimise them. This study demonstrates the synergistic effect of ultrasound and acidic backwashing, providing a novel approach to improving filter cleaning and advancing the integration of acoustic energy in wastewater treatment systems.

Filters are essential components for maintaining the stability of drip irrigation systems, effectively reducing the risk of clogging. However, when applied to slurry drip irrigation systems, the complexity of slurry water quality makes it unclear how different filter types and their combinations affect the hydraulic performance of the system. This study provides a comprehensive performance evaluation of two common filter types and their combinations, considering various flow rates and biogas slurry-to-water ratios under drip irrigation conditions. The results revealed the following key findings: (1) In the application of biogas slurry drip irrigation, an increase in the concentration or flow rate of the slurry significantly affects the hydraulic performance of the filter, increasing the risk of clogging and shortening the operational lifespan. Notably, the impact of changes in slurry concentration on the hydraulic performance of the filter is much greater than that of the flow rate. Compared to mesh filters, disk filters offer better hydraulic performance, with the contaminant capacity of disk filters being approximately three times that of mesh filters. (2) In biogas slurry drip irrigation, the filter combination generally outperforms single filters in terms of hydraulic performance and contaminant removal capacity. Due to the unique nature of the water source in biogas slurry, a selection process for filter combinations was conducted. It was found that when a disk filter is used as the pre-filter and a mesh filter as the post-filter, the overall rate of head loss change is the smallest, and the clogging uniformity is the least. (3) In the entropy weight-TOPSIS comprehensive evaluation, the filter’s operating time and contaminant capacity are key factors affecting its overall performance. From the perspective of improving the operational stability of the biogas slurry drip irrigation system, it is recommended to use a disk filter + mesh filter combination. This study conducts practical measurements on the hydraulic performance, contaminant removal capacity, filtration accuracy, and other indicators of commonly used mesh and disk filters, aiming to provide useful references for the practical application of biogas slurry drip irrigation filters.

Identification of drought-tolerant maize varieties in the context of climate change is critical. Although many studies have reported that the coordination of stomatal and hydraulic conductance of plant leaves ensures the net photosynthetic rate, it is unclear whether the arrangement of these three parameters is consistent among maize varieties differing in drought tolerance. Therefore, in this study, gas exchange parameters, hydraulic properties, and stomatal structure of leaves from eight maize varieties under full and deficit irrigation (DI) were determined. Drought tolerance of varieties was assessed using principal component analysis, and the coordination of photosynthesis, stomatal and hydraulic conductance, as well as stomatal behavior was analyzed between drought-sensitive (DSVs) and drought-tolerant varieties (DTVs). Eight maize varieties were categorized into DSVs and DTVs based on the evaluation of these agronomic and physiological parameters. Significant variety-specific responses of physiological parameters to DI were found, with at least one parameter being significantly affected in each variety. Leaf net photosynthesis rate and stomatal conductance showed a tight coordination with hydraulic conductance among DSVs; however, this coordination was potentially absent among DTVs. Simulations of stomatal behavior based on Ball-Berry and Medlyn models showed that DI significantly reduced the model sensitivity parameters of m and g1 regardless of DSVs and DTVs. The study highlights the importance of physiological trait coordination in drought responses. The coordination between stomatal and hydraulic traits may be absent in DTVs, implying a potentially flexible adaptation strategy that could be exploited to improve maize drought tolerance.

Clarifying the components and regulatory mechanisms of evapotranspiration is essential for irrigation scheduling. In this study, straw mulching and non-mulching treatments were set up in a maize field with drip irrigation, where the water use and related factors were determined in 2014 and 2015. Straw mulching slightly reduced evapotranspiration by 2.6% on average for the two years. However, transpiration of straw mulching increased by 10.0% and 9.0% and soil evaporation decreased by 36.0% and 31.1%, compared to the non-mulching treatment for 2014 and 2015, respectively. Straw mulching decreased the average crop coefficients of the entire growth period (from 1.03 to 1.01) while increasing them in the mid-growth period (from 1.20 to 1.22). The net radiation above the canopy for straw mulching was 92.3%-96.3% of that for non-mulching treatment, which could explain the lower evapotranspiration of the mulching treatment. The daytime canopy conductance of straw mulching was 30% higher than that of non-mulching treatment, which could potentially result in higher biomass. This study provided essential parameters for water management of drip irrigation maize fields with straw mulching in similar areas.

Biogas slurry drip irrigation can mitigate environmental pollution and reduce the use of chemical fertilizers to enable sustainable development. However, the stability of the biogas slurry drip irrigation system (BSDIS) is disrupted by emitter clogging; hence, it is essential to explore the flushing control strategy of BSDIS. By means of combining actual measurement and simulation, this study investigates the BSDIS stability based on the three technical parameters of the flushing control strategy. Appropriate flushing control strategies can improve system stability and cause spatial differences on the drip irrigation tape. Under various flushing control strategies, the system stability primarily undergoes delays, sensitivity, and ineffectiveness of flushing with time. Compared with the without flushing and emitter outlet downward-oriented treatment, the optimal flushing combination (the high frequency flushing + emitter outlet upward-oriented treatment) reduces the emitter clogging content by approximately 70.97% and increases system stability by 189.1%. In the internal hydrodynamics, the laying direction of emitters does not change the movement characteristics of water flow, although the clogging particles do not completely follow the water flow, with some particles settling owing to gravity, thereby clotting the emitters. When clogging occurs, the increase in flushing speed is conducive to the increase in turbulent kinetic energy on the inlet surface of the emitter, which facilitate the flushing of clogged substances. This study proposes optimal flushing strategy parameters along with a new management mode for the waste liquid represented by biogas slurry.

Drip irrigation is important for efficiently returning biogas slurry to fields. Elucidating the characteristics and components of clogging substances produced by labyrinth emitters in biogas slurry drip irrigation systems will help to develop various clogging substance-remediation strategies. However, previous studies were unable to characterize the clogging substances in emitters. Thus, we aimed to characterize and quantify the substances clogging emitters in a biogas slurry drip irrigation system and determine the micromorphology and dominance of microbial communities. Here, emitter discharge changes and the micromorphologies, phase compositions, and biological communities of clogging substances were studied via hydraulic performance tests, scanning electron microscopy-energy depressive spectra (SEM-EDS), and high-throughput sequencing. The degree of emitter-clogging increased over time (first quickly, then slowly) and was deeper at the end of the drip irrigation tape than at the head. The clogging substances were viscous agglomerations primarily comprising 0.3-1.5-μm particles. Their formation was affected by settlement with gravity, water pressure adhesion, and mobile biological adhesion. The dominant microbial communities in the clogging substances included Firmicutes (29.7%) and Proteobacteria (19%); the emitter-clogging substances primarily comprised water (85%) and composite dry matter. The water, dry matter, and extracellular polymer substance (EPS) weights in the clogging substances increased over time, but their relative proportions remained stable. In the composite dry matter, typical physical (organic carbon, Al2O3, and SiO2), chemical (CaCO3 and MgCO3), and biological (EPS) clogging substances accounted for >50, 9, and 5.62% of the total dry matter mass, respectively. This study provides a good foundation and reference idea and will be very helpful to propose targeted solutions for solving the clogging of biogas slurry drip irrigation system.

Maize growth is limited by various environmental factors. There is a variation in response of different maize cultivars released in different years to environmental changes. The objective of this study was to investigate the drought resistance of two maize cultivars released in different years, Jingke 968 and Zhengdan 958, under two environmental factors viz. CO2 concentration and irrigation. Two CO2 concentrations, 400 and 600 μmol·mol−1, and three irrigation treatments, high, medium, and low, were considered. By analyzing the photosynthetic parameters and stomatal morphological parameters, it was concluded that higher CO2 improved the value of the water use efficiencies (WUE). Moreover, Jingke 968 showed 55.45% higher value of WUE in comparison to Zhengdan 958. As compared to other treatments, drought significantly improved the WUE. Additionally, higher CO2 reduced the value of the stomatal area and stomatal shape index. At 600 μmol·mol−1 CO2 concentration, when the light intensity range was 1200–1800 μmol·m−2·s−1, Jingke 968 showed slightly higher value of the WUE in comparison to Zhengdan 958, but, the WUE of Zhengdan 958 was not limited by light intensity. Therefore, the results showed that under 600 μmol·mol−1 CO2 concentration and a light intensity of 1800 μmol·m−2·s−1, Jingke 968 was the preferred maize cultivar because of its high WUE.

Soil salinization is a global problem that causes huge losses in agricultural production. Salt can interfere with crop absorption and metabolism of nutrients and water, affect plant physiological responses and reduce plant biomass. Maize, a very important economic crop, can adapt to a certain degree of saline-alkali soil. It is essential to understand the physiological indexes of response to soil salinity concentrations and explore the effects of different nitrogen fertilizer treatments on maize growth. In this study, three soil salinity gradients (S1, S2 and S3 were with soil salt concentration, Ssc, of 0, 0.1% and 0.25%, respectively) and two nitrogen application rates (N0 and N1 were without and with nitrogen applied (13.2 g per pot), respectively) were set up. Plant growth and photosynthetic parameters were measured. Whether nitrogen was applied or not, with the increase in Ssc, leaf area, plant height, stem diameter, SPAD, leaf water potential, RuBP carboxylase, and PEP carboxylase activities, photosynthetic rate (A), stomatal conductance (gs), the maximum stomatal conductance (gsmax), and the stomatal morphological parameters such as stomatal width and maximum stomatal area (amax), all showed a downward trend. Under the S1 and S2 treatments, compared with the N0, the N1 treatment alleviated the stress effect of the Ssc on these indicators. However, under S3 treatment, the stress degrees of leaf water potential, gs, gsmax and amax, were aggravated after nitrogen application. This indicated that under the high Ssc of S3, the interaction between nitrogen application and soil salinity should be considered. WUEin increased with the increase in Ssc. Moreover, under N1 treatments, the increase in WUEin with Ssc was greater than that with N0. With the increase in Ssc, whether nitrogen was applied or not, the dry weight of maize declined by 44.2% and 73.0%, respectively, for the S2 and S3 treatments. Under S2 treatment, N1 significantly improved the dry matter mass of maize compared with the N0 treatment. The results showed that soil salt stress can inhibit crop growth, physiology and dry matter accumulation, and that nitrogen application can alleviate this within a specific salinity range. Such results indicate that in saline-alkali areas, whether nitrogen fertilizer is applied or not should depend on the level of Ssc to improve plant growth.

Biogas slurry drip irrigation (BSDI) can not only save water, but also reduce the use of chemical fertilizers. Determining the appropriate biogas slurry–water ratio (BSWR) and emitter types can ensure long-term stable operation of systems. Therefore, this study proposes an obtaining the BSWR suitable for crop irrigation conductivity method based on conductivity biogas slurry and clean water. The three conductivity levels（1.3, 2.3 and 3.3 mS/cm）are set based on their suitability for crop growth. The corresponding BSWR is determined using the proposed method, i.e.,1:20, 1:8, and 1:4. The clogging dynamic process, clogging location, and characteristic parameters are analyzed using a hydraulic test, an industrial camera and the ordered regression method for three common emitters under three BSWR. The results show that the proposed method relative error is approximately 10%, which is considered feasible. Over time, the discharge and uniformity of emitters decrease, and subsequently remain constant. As the slurry concentration increases, the emitters clog more rapidly, and internal patch emitters (IPEs) show the lowest adaptability to BSDI systems. The pressure compensation (PCEs) and single-wing labyrinth emitters (SWLEs) is better than IPEs on anti-clogging performance. Clogging mainly occurs at the inlet grid, and the SWLEs are clogged at the internal flow channel and outlet. Moreover, the inlet grid and pressure compensation are key characteristic parameters affecting clogging. The adaptability of emitters can be improved by changing the inlet grid layout, increasing the cross-sectional area of the flow channel, and/or reducing the pathway length. Based on irrigation uniformity and economic cost, large discharge SWLEs and PCEs are recommended for one-time field crops and multi-year cash crops respectively. Furthermore, the BSWR should be at least 1:4, and ratios of 1:8–1:20 are most conducive to stable operation. This study serves as a guideline for future development of BSDI systems.

生物炭在土壤应用过程,不可避免地会对与土壤之间接触的机械设备部分产生腐蚀作用.为探究生物炭应用于农业生产中对机械设备以及金属工具损耗的影响,采用分别在700、400和100 ℃温度下裂解制备的小麦秸秆生物炭(WB)、水稻秸秆生物炭(RB)和松木生物炭(PB)的生物炭对304不锈钢板材进行腐蚀处理,并测量其极化曲线和电化学阻抗谱和腐蚀表现.结果 表明:与空白组(CK)对比,相较于304不锈钢的腐蚀速率,在施入WB的土壤中,腐蚀速率会随着WB裂解温度的增大而增大;而加入RB的土壤会加剧不锈钢的腐蚀,其中在加入400℃RB的土壤中腐蚀速率达到最大;这是因为WB和RB的加入会提升土壤中的C1-含量至足以达到点蚀效应的程度加速了不锈钢板材的腐蚀.与此同时,发现100℃制备的PB生物炭可以抑制不锈钢的腐蚀.总而言之,不同生物质和制备温度的生物炭在土壤实际应用中表现出不同的腐蚀和抗腐蚀特性,因此深入研究这些方面将为其农业应用具有深远影响.

为探究拔节期不同亏水-复水模式对冬小麦生长、生理及产量的影响,设置了拔节期不同程度土壤含水率和亏水时长,土壤含水率分别为Y1(55％～65％)θf、Y2(65％～75％)θf、Y3(75％～85％)θf(θf为田间持水量),亏水时长均为7 d,然后复水,另设全生育期充分灌水对照处理CK(85％～100％)θf,每个处理重复3次.复水7天后测定各处理冬小麦株高、叶绿素、净光合速率、荧光参数、产量及水分利用效率.结果表明:Y1、Y2、Y3各处理亏水7 d然后复水7 d后,与对照组CK相比,冬小麦株高分别提高了2.38％、9.52％、12.70％,叶绿素(SPAD)分别增长了0.67％、2.51％、3.85％,净光合速率分别降低了19.32％、14.02％、11.74％,Fv/Fm分别降低了9.64％、8.43％、6.02％,Fv/F0分别降低了9.00％、5.91％、4.63％,发现亏水-复水处理后的冬小麦表现出明显的生长补偿效应;纵向和自身相比,较亏水7 d刚结束时株高、叶绿素(SPAD)、净光合速率、Fv/Fm和Fv/F0分别提高了22.86％、25.96％、26.87％,17.46％、19.23％、21.73％,7.04％、6.61％、6.44％,16.30％、16.87％、16.84％,12.20％、11.67％、11.88％.最终产量结果为:Y1、Y2、Y3各处理比CK分别低18.84％、5.58％、0.79％,Y3处理的产量相较于Y1与Y2处理分别高22.24％与5.08％.Y3处理的水分利用效率值最大,分别较Y1、Y2、CK处理提高了8.29％、0.55％、2.77％.Y3为节水稳产适宜亏水模式.

为了提高作物水分生产效率,缓解农业用水危机,采用调亏灌溉模式,在西红柿开花坐果期干旱一定时间后进行复水,通过测定亏-复水前后的光合参数和叶绿素荧光,来分析干旱-复水模式下西红柿的生理性能、产量和水分利用效率的变化.设置对照、3种干旱周期、3种灌水梯度,共10个处理;对照组处理土壤含水率始终保持在田间持水量90％～100％,3种干旱周期分别为连续干旱7、14和21 d,然后复水;3种灌水梯度处理使土壤含水率分别保持在田持的80％、60％和40％;结果表明:在短期干旱7、14 d胁迫下,西红柿叶片的Fv/Fm、Fv/F0均随胁迫程度的增加而降低,复水后均有所恢复,除土壤含水率为田间持水量的80％～60％处理能基本恢复至对照水平,其余处理均不能恢复至干旱前的状态,而连续干旱21 d后的各处理受抑制更明显,复水后不能完全恢复.在短期干旱7、14 d胁迫过程中Ci逐渐降低,Gs下降,且复水后Ci迅速恢复,说明Pn降低主要是气孔限制引起的,在干旱21 d处理阶段,各调亏处理的Ci不同于Pn和Gs的下降,反而相比干旱14 d处理Ci升高,说明连续干旱21 d,会产生非气孔限制因素导致西红柿Pn降低.土壤含水率为田间持水量的80％、60％处理在干旱7 d后的WUE高于对照组4.44％和1.90％,表明在干旱7 d条件下,将土壤含水率控制在田持的60％～80％有利于提高西红柿水分利用效率.因此,适度干旱处理降低西红柿的光合性能,干旱后复水对西红柿的水分利用效率提高具有积极作用.

沼液是畜禽养殖过程中产生的废弃物,同时也是一种高效有机液态肥,实现沼液高效循环利用是实现农业绿色和生态循环发展的内在迫切需求,借助滴灌技术实施沼液水肥一体化施灌是解决沼液还田利用的重要技术手段,具有广阔的应用前景.文章综述分析了沼液滴灌在作物增产和提高作物品质方面的优异性,系统综述了沼液进入滴灌系统之前相关预处理技术效果,包括采用曝气、加酸、絮凝、沉降与过滤技术等,在沼液进入滴灌系统之前采用多种综合预处理技术是保障滴灌系统稳定高效运行的关键,综述最后提出了沼液滴灌后续研究应重点关注的内容.

明确不同品种玉米生长和光合特性对CO2浓度和水分处理双因子的响应规律可为变化环境下品种选育提供参考.采用盆栽试验,分析了两个品种玉米拔节期的株高、茎粗和叶面积以及净光合速率(A)、气孔导度(Gs)和蒸腾速率(E).结果表明:低水处理使两个品种玉米的茎粗及"京科968"的叶面积显著降低,并使两品种玉米的A和Gs显著降低;除"郑单958"低水处理的株高显著降低外,CO2浓度升高并未导致两品种玉米的株高、茎粗、叶面积和SPAD显著变化;所有水分处理下,CO2浓度升高并未造成A显著变化,而两品种玉米的E和Gs均有不同程度的显著降低;CO2浓度升高使所有水分处理下"京科968"和"郑单958"的Gs降低的均值分别为39.99％和21.10％.CO2浓度升高显著提高了"京科968"的叶片水分利用效率(WUE),而对郑单958的WUE无明显影响.CO2浓度400μmol/mol下,各水分处理的"京科968"的Gs均高于"郑单958",而600μmol/mol时,"京科968"的Gs则由于降低更多而低于"郑单958",且具有较高的WUE.表明不同品种玉米应对CO2浓度升高表现不同,而"京科968"在未来CO2浓度升高环境下因其较低的GS可能具有更好的抗旱能力.

In order to quantitatively analyze the serious non-point source pollution caused by the excessive use of fertilizer in agriculture in Hebei Province,the temporal and spatial variation of growing process grey water footprint of 4 main crops including winter wheat,summer maize,vegetables,fruits in each city of Hebei province were analyzed and evaluated by using grey water footprint theory and evaluation method.The results showed that the growing process grey water footprint of winter wheat and fruits showed a downtrend during 2005 to 2014,that of summer maize decreased during 10 years in all cities except for Qinhuangdao,Cangzhou,Langfang,Hengshui,that of vegetables in all cities decreased during 2005 to 2014 except for Hengshui rised 1.02%;nitrogen fertilizer per hectare of each city did not show decreasing trend during 2005 to 2014,so production increasing was the main cause that led to the decline of growing process grey water footprint of 4 crops.During the past ten years,Tangshan had the maximum growing process grey water footprint of winter wheat(2005),which was 1.076 m+3/kg;Hengshui had the minimum growing process grey water footprint of winter wheat(2014),which was 0.526 m+3/kg;Tangshan had the maximum growing process grey water footprint of summer maize(2005),which was 0.727 m+3/kg;Zhangjiakou had the minimum growing process grey water footprint of summer maize(2012),which was 0.251 m+3/kg;Handan had the maximum growing process grey water footprint of vegetable(2005),which was 0.125 m+3/kg;Zhangjiakou had the minimum growing process grey water footprint of vegetable(2012),which was 0.029 m+3/kg;Zhangjiakou had the maximum growing process grey water footprint of fruits(2005),which was 1.24 m+3/kg;Henshui had the minimum growing process grey water footprint of fruits(2014),which was 0.298 m+3/kg.Finally,the solution measures to reduce the nitrogen application rate and the growing process grey water footprint of crop were proposed from the two perspectives of technology and policy.

In order to ascertain the effect of different moistube buried depth on soil water infiltration and crops root growth under moistube-irrigation conditions， the laboratory soil infiltration and greenhouse pakchoi cultivation experiment were carried out respectively. Three treatments of buried depth which were 10 cm， 15 cm and 20cm were set up， correspondingly marked as T1， T2 and T3. Cumulative infiltration of soil water and movement of soil wetting front of each treatment were observed during laboratory soil infiltration experiment. Taproot length， taproot diameter， root volume and the number of primary lateral root which diameter was greater than 2mm of each treatment were observed during pakchoi cultivation experiment in greenhouse. The laboratory soil infiltration experiment results show that the cumulative infiltration per unit length of moistube of each treatment linearly increased over time， the infiltration rate of T2 was maximum， T3 was minimum， and the infiltration rate of T1 and T2 were 43.48% and 67.55% greater than T3 respectively. The wetting front movement law of each treatment towards the left was the same as towards the right in horizontal direction， diffusion rate of T1 and T2 was much greater than T3， and diffusion rate of T1 was greater than T2. The law of wetting front moving upward was basically the same as downward in vertical direction before the wetting front reached the land surface， the effect of gravity was not obvious， the order of diffusion rate was T1＞T2＞T3. The shape of T1s wetting front was an ellipse， and in the beginning， the length of vertical direction was greater than horizontal direction， then gradually， the length of horizontal direction was greater than vertical direction. The shape of T2s wetting front was an ellipse with the length of vertical direction being greater than horizontal direction. The shape of T3s wetting front was an ellipse， and in the beginning， the length of horizontal direction was greater than vertical direction， then gradually， the length of vertical direction was greater than horizontal direction. The greenhouse pakchoi cultivation experiment results show that root indexes of moistube-irrigation treatment such as taproot length， taproot diameter， root volume and the number of primary lateral root which diameter was greater than 2 mm were better than those of flood irrigation treatment except for the taproot length of T1. When the moistube buried depth was 15 cm， the root system was the best. The conclusion can provide support for related productive practice.

In order to find the suitable moistube''s buried depth for tomato growth, yield and quality, three different kinds of moistube buried depth treatments incuding T1 (10 cm), T2 (15 cm), T3 (20 cm are) are set up, and surface gravity irrigation is set up as control.The effect of various treatments on growth indexes such as plant height, stem diameter, leaf area and physiological indicators such as photosynthetic rate, transpiration rate, chlorophyll content, and yield and comprehensive quality of tomato are investigated.Results are given as follows: ①As entering flowering and fruit enlargement period, the growth indexes of all moistube buried treatment are higher than CK treatment except for the leaf area of T1 less than CK, all growth indexes of T2 treatment are maximum.The order of photosynthetic rate are T2>T1>CK>T3.The order of transpiration rate are T2>T3>T1>CK.The order of stomatal conductance are: T2> T3> T1> CK.The order of intercellular carbon dioxide concentration is T1>T3>CK>T2.②The individual fruit mass of all moistube buried treatment are higher than CK treatment, T2 treatment has a maximum yield.③ The order of comprehensive quality evaluation value is T2> T3> T1> CK.Our study concludes that 15 cm is the appropriate moistube''s buried depth when tomato is planted.

为了定量分析河北省农业过量施用化肥造成的严重面源污染,应用灰水足迹理论与评价方法,对河北省2005～2014年期间的冬小麦、夏玉米、蔬菜、水果4种主要农作物总灰水足迹及生长过程灰水足迹变化进行了分析评价,结果表明:2005 ～2014年期间,河北省冬小麦总灰水足迹总体呈下降趋势;夏玉米总灰水足迹总体呈增加趋势;蔬菜总灰水足迹总体呈增加趋势;水果总灰水足迹总体呈下降趋势.2005 ～2014年期间,河北省冬小麦、夏玉米、蔬菜、水果生长过程灰水足迹均呈下降趋势.4种作物每公顷施肥量没有表现出下降趋势,产量增加是导致4种作物生长过程灰水足迹下降的主要原因.最后从技术和政策两方面提出了降低氮肥施量和作物生长过程灰水足迹的措施.

为考察不同调亏灌溉模式对冬小麦产量形成的影响,进行了防雨棚下的人工控水试验.结果表明,与不亏水处理CK相比,所有调亏处理均使得籽粒灌浆期显著缩短,达到最大灌浆速度的时间提前,最大灌浆速率和平均灌浆速率增加.拔节期亏水降低有效穗数,拔节期重度亏水有效穗数最小;抽穗期及灌浆成熟期亏水降低千粒质量,灌浆成熟期重度亏水千粒质量最小;拔节期亏水减少穗粒数,拔节期重度亏水穗粒数最小.综合本文研究结果,冬小麦产量较高的适宜调亏模式依次为:返青期轻度亏水、返青期重度亏水、灌浆成熟期轻度亏水、抽穗期轻度亏水、拔节期轻度亏水、拔节期重度亏水.研究结果可以为相关区域冬小麦高产栽培水分调控提供参考.