不同饮水器保育猪用水总量及浪费水量对比试验

为寻求猪饮水时浪费水量少的节水饮水器或饮水方式,在舍内温度为20~25℃的条件下,选择60头体质量为20 kg的保育猪进行鸭嘴式饮水器、杯式饮水器和Swing饮水器的用水总量和浪费水量的比较研究。试验结果表明,3种饮水器的用水总量无显著性差异(P0.05)。每头猪浪费水量由小到大依次为:杯式饮水器(1.13 L/d)Swing饮水器(1.42L/d)鸭嘴式饮水器(1.93 L/d),其中,鸭嘴式饮水器浪费水量极显著高于Swing饮水器(P0.01),极显著高于杯式饮水器(P0.01),杯式饮水器和Swing饮水器浪费水量无显著差异(P0.05)。杯式饮水器浪费水量占用水总量百分比(15.17%)Swing饮水器(17.58%)鸭嘴式饮水器(25.10%),杯式饮水器和Swing饮水器浪费水量占用水总量百分比极显著低于鸭嘴式饮水器(P0.01),杯式饮水器和Swing饮水器浪费水量占用水总量百分比无显著差异(P0.05)。与鸭嘴式饮水器对比,杯式饮水器和Swing饮水器起到一定的节水作用。     

不同饲喂器和饮水器配置对育肥猪生产性能和节水的影响

为探究规模化养殖模式下不同饲喂器饮水器配置对育肥猪生产性能和节水的影响,试验比较了使用试验组饲喂器饮水器配置(带分隔条的不锈钢干湿料饲喂器,每组60头猪,提供4个采食位、2个杯式饮水器作为补充饮水器)和对照组饲喂器饮水器配置(商业猪场常用的饲喂器饮水器配置,不带分隔条的塑料斗干湿料饲喂器,每组60头猪,提供8～12个采食位、6个杯式饮水器作为补充饮水器)饲养育肥猪的生产性能和节水效果,每组各4个重复。结果表明,试验组和对照组育肥猪的日均耗料质量、日均体增质量和料质量体增质量比均没有显著性差异(P0.05)。试验组补充饮水器不供水而对照组补充饮水器均供水时,每头猪日均总耗水量分别为(8.62±2.21)、(22.89±3.55)L,差异极显著(P0.01);试验组与对照组补充饮水器均供水时,每头猪日均总耗水量分别为(24.03±3.11)、(28.66±4.92)L,差异不显著(P0.05)。在不考虑动物福利的条件下,试验组补充饮水器未供水时,饲喂器中饮水器的供水量可满足60头体质量为50.7～71.8kg的育肥猪的生理需求量。     

冉渡滩水库取用水合理性分析

冉渡滩水库工程主要以供水和灌溉为主,属中型水库。取用水合理性分析结果表明:设计总取水量9 400万m3/a,在保障城镇供水、工业园区用水、农村人畜饮水、农灌用水及水力发电用水情况下,水量利用系数为78.4%。水库取用水量适当,取水可靠性高,水源水量水质均有保障。     

猪舍内粪污废弃物和有害气体减量化工程技术研究

源头减量和过程控制是猪场废弃物综合治理的关键环节,而猪舍是废弃物产生的源头场所,该文针对猪舍内部污水和有害气体等养殖废弃物,从饮水系统、圈栏设计和清粪方式等3个方面,介绍分析了当前国内外在舍内废弃物减量化工程技术领域的研究进展。其中减少猪只饮水浪费水量是舍内污水减量的首要环节,通过优化饮水器选型、调整饮水器安装方式、选择适当水流速度等可以降低饮水浪费水量;合理的圈栏布置和地面类型可以促进猪只定点排泄,从而降低圈栏污染程度以及舍内有害气体浓度,配合适当的圈舍冲洗方式可以减少大量圈舍冲洗用水;不同的清粪方式会影响舍内空气环境、污水产生量及污染物浓度,与干清粪相比,水冲粪和水泡粪都存在耗水量大、污水产生量大及其污染物浓度高、舍内有害气体含量高等问题,从清洁生产的角度考虑,干清粪工艺是规模化猪场的必然选择。该文旨在为减少猪场废弃物总量、降低处理利用成本和实现清洁健康养殖提供工程技术支撑,促进中国生猪养殖业绿色转型升级。     

少污水排放垫料猪舍生产和环境效果

针对传统猪舍污水产生量大、处理费用高问题,该文设计并建造了一种基于减少育肥猪生产过程中污水排放的猪舍,为了检验少污水排放猪舍的饲养和环境控制效果,以规模化猪场常规育肥猪舍为对照舍,对其春季和夏季的生产效果和环境效果进行了研究。结果表明：试验舍与对照舍夏季平均温度分别为26.6℃、27.0℃,相对湿度分别为77%、71%,春季平均温度分别为18.9℃、21.0℃,相对湿度分别为50%,49%,试验舍和对照舍内育肥猪的平均日增质量、料质量比基本相同;但少污水排放型猪舍具有明显的节水效果,单头猪夏季减少用水量13.2 L/d,春季减少用水量1.4 L/d,夏季减少污水量16.5 L/d,春季减少污水量4.7 L/d,,少污水排放型猪舍不影响育肥猪生长性能,但能较大的减少生产过程中的用水量和污水排放量。     

水禽自动饮水装置研制与应用效果试验

为了满足水禽集约化饲养的饮水需要,该文选用PVC管、浮球等材料研制了一种水禽自动饮水装置,并以樱桃谷种鸭为对象进行了应用效果试验。当水位降低到一定程度时,水自动流出,浪费极少,种鸭单位饮水面积大（8.7cm2/只）,鸭饮水自如,能保持鸭嬉水的天性。比较了该自动饮水装置（第1组）与现存的乳头式饮水器（第2组）、普通水槽（第3组）和普拉松饮水器（第4组）的购置成本及折旧费,研究了同等饲养条件下4种饮水器的耗水量及对种鸭生产性能的影响。18684只父母代SM3樱桃谷种鸭随机分为4组,每组3个重复,每个重复1557只（母鸭1289只;公鸭268只）。试验期为25～75周龄。试验结果表明：第1组饮水器的购置成本最低,每只种鸭为0.59元,其它3个组分别为1.25、0.69、2.27元,第1组饮水器的折旧费也最低,每只种鸭每年0.13元,其它3个组分别为0.24、0.14、0.49元。第1组耗水量为1.72 kg/（只·d）,高于第2组的1.18 kg/（只·d）和第4组的1.48 kg/（只·d）,低于第3组的2.31 kg/（只·d）。第1组试验期内存活率为91.8%、产蛋率78.3%、种蛋合格率93.70%、受精率92.30%,均高于第2、3、4组。本文所研制的水禽自动饮水装置既能提高种鸭的生产性能,又比其它装置成本低,使用方便,极具推广前景。     

苏打碱土盐分水平冲洗模拟研究

通过模拟实验对苏打碱土盐分水平冲洗的效果进行了研究,分析了磷石膏对盐分冲洗效果的影响,探讨了应用水量与盐分冲洗总量和盐分冲洗效率的关系,并对一次性冲洗和少量多次性冲洗两种方案的盐分冲洗效果进行了比较.结果表明:水平冲洗能够有效排出土壤盐分,显著降低土壤盐度和碱度;3次冲洗后,1 L,2 L,3 L,4L,5 L应用水量分别使对照处理的土壤盐度从3.39 dS/m降低到了1.83,1.73,1.39,1.26,1.13 dS/m,使土壤碱度从98.27(mmolc/L)1/2下降到了15.33,19.14,17.96,15.73,15.04(mmolc/L)1/2;与对照相比,磷石膏使土壤盐度略有提高,但显著降低了土壤碱度;盐分冲洗总量随应用水量的增加而提高;盐分冲洗效率与应用水量间呈幂函数递减关系;在应用水量相同情况下,一次性冲洗和少量多次性冲洗两种方法的碱土改良效果无显著差异.     

东辽河流域河流系统生态需水研究

河流系统的生态需水是指维持河流正常的生态结构和功能所需要的一定水质最小水量 ,具有明显的时空变化特征。河流系统的生态用水包括河道系统 (包括排沙生态用水和水面蒸发生态用水 )和洪泛地系统两大系统的生态用水。东辽河流域河道系统生态需水量占年均径流量的 44 .43%。洪泛地生态用水量为 16 .87亿 m3,占全流域年均降水量的 2 8.0 2 %。必需采取有效措施进行河流水资源开发的有效调控。     

简易式工厂化循环水对虾养殖系统构建及试验

为探索低换水量的对虾养殖生产方式,该研究构建了一种简易式工厂化对虾养殖系统,试验组利用自行研发的蛋白分离器和新型集污盘去除系统总悬浮颗粒物和老化微藻,对照组不设置蛋白分离器和集污盘,进行对虾养殖和水质调控试验,结果表明:试验组平均总氨氮浓度、平均亚硝氮浓度、平均TSS(Total Suspended Solids)浓度、平均副溶血弧菌数量分别为(0.4±0.16)、(0.53±0.23)、(68.33±39.72)mg/L和(140±113.83)cfu/mL,显著低于对照组(0.96±0.62)、(1.17±0.59)、(147.14±94.18)mg/L和(661.34±473.96)cfu/mL(P0.05);试验组成活率及单位产量分别为82.62%±5.64%和(3.44±0.85)kg/m~3,显著高于对照组18.29%±4.63%和(1.09±0.23)kg/m~3(P0.05)。该研究构建的简易式循环水工厂化系统,设置蛋白分离器流量10 m~3/h且不间断运行,养殖前45 d不换水、后55 d利用集污盘进行强排污保持日换水量5%的情况下能够有效调控对虾养殖水质。     

规模化猪场机械通风水冲粪式栏舍夏季氨日排放特征

选取长三角地区典型机械通风水冲粪模式养猪场,针对不同生长阶段的肥猪栏舍和不同类型的母猪栏舍排放口氨排放进行同时监测(其中,育肥猪按质量分保育(24 kg)、育肥-Ⅰ(24~60 kg)、育肥-Ⅱ(60~120 kg)3个阶段,母猪分为妊娠猪与分娩猪2种类型),估算各栏舍氨排放通量,分析各栏舍氨排放特征,探讨各生长阶段对氨排放贡献。研究结果表明,保育、育肥-Ⅰ、育肥-Ⅱ、妊娠、分娩栏舍氨质量浓度分别为(0.97±0.40)、(3.37±0.70)、(5.45±2.30)、(2.19±1.06)、(1.44±0.48)mg/m3;各栏舍氨排放具有显著的日变化过程,早晨氨排放呈波动增大趋势,午后开始降低,至夜间保持低值排放;小时氨排放速率与温度呈极显著正相关,与湿度呈显著负相关;各生长阶段氨排放存在差异,保育、育肥-Ⅰ、育肥-Ⅱ、妊娠、分娩栏舍日排放速率分别为0.85、6.53、8.20、10.39和13.86 g/(头·d);保育、育肥-Ⅰ和育肥-Ⅱ阶段对肥猪氨排放的贡献率分别为3.64%、26.11%和70.25%,妊娠猪与分娩猪对母猪氨的贡献率分别为75.32%和24.68%,母猪的氨排放速率是肥猪的1.87倍。     

PEAT WASTAGE IN THE EAST ANGLIAN FENS

Measurements of the decline in peat depth between 1941 and 1971 were taken at 14 sites across the East Anglian Fens. Rates of wastage in the period before 1955 and in the more recent period varied widely from site to site. Wastage rates were higher at all sites but one, in the period before 1955. The mean value for wastage rate over the entire period covered was 1.37 (± 0.78) cm/yr.     

滴灌压差施肥系统灌水与施肥均匀性综合评价

为优化滴灌压差施肥系统的设计与运行,通过田间试验综合评价了施肥罐两端压差(0.05、0.10、0.15、0.20和0.25 MPa)和管道布置方式(纵向一端、纵向中间、横向一端和横向中间供水)对系统灌水与施肥均匀性的影响。结果表明,施肥罐两端压差与管网布置方式对灌水均匀性的影响均不显著,但管道布置方式对灌水均匀性的影响强于施肥罐两端压差。对于纵向一端和纵向中间供水,施肥罐两端压差对施肥均匀性的影响达到显著水平(P0.05),而横向一段和横向中间供水时施肥罐两端压差对施肥均匀性影响不显著。总体而言,滴灌压差施肥系统灌水均匀性优于施肥均匀性,横向供水方式均匀性高于纵向供水方式。为了同时保证滴灌压差施肥系统灌水与施肥的均匀性,建议优先采用横向供水管道布置方式,同时尽量降低施肥罐两端差压,延长系统施肥时间。     

全射流喷头喷洒水滴动能分布规律

喷灌动能是评价喷头水力性能优劣的重要指标之一。该文在0.15、0.20、0.25、0.30和0.35 MPa工作压力下,采用激光雨滴谱仪测量技术(laser precipitation monitor,LPM)对全射流喷头的水滴直径、速度和水量分布等参数进行试验,研究了单个水滴动能、单位体积水滴动能、动能强度分布规律及动能强度均匀性系数与组合间距之间的关系。结果表明:全射流喷头的单个水滴动能分布与水滴直径之间的关系与该文所建立的模型拟合较好,呈幂函数关系;单位体积水滴动能沿径向呈一次函数关系增大,与压力的-0.556次方呈正比关系;动能强度沿径向逐渐增大,而在射程末端迅速减小至0,随压力增大而减小,且沿径向距离的增大而动能强度减小程度越大;在各工作压力下,全射流喷头的矩形最佳组合间距分别为1.2、1.0、1.1、1.0、1.1倍喷头射程;所对应的动能强度均匀性系数分别为56.6%、71.1%、76.2%、77.2%、72.9%。该结果对研究喷头外特性、优化喷头结构、喷灌系统优化配置提供了一定的理论价值。     

不同喷洒浓度沙蒿胶固沙效果试验

为了探究沙蒿胶的固沙效果,采用不同质量分数(0、0.02%、0.05%、0.10%、0.20%和0.50%)的沙蒿胶喷洒试验,对固沙试样的固结层厚度、抗压强度、抗风蚀能力、团聚体水稳定性、渗透性、保水性和沙蒿胶对植物种子萌发及幼苗生长的影响进行测定。结果表明:1)喷洒沙蒿胶后,固沙试样的固结层厚度和抗压强度显著增加,抗风蚀能力明显增强,质量分数0.10%的沙蒿胶处理,其起沙风速均在20 m/s以上;2)沙粒在沙蒿胶的作用下相互胶结,微团聚体质量百分数显著降低,大团聚体百分数显著增加;3)团聚体平均质量直径显著增加,表明沙蒿胶提高了沙样的水稳定性;4)沙面形成的固结层具有良好的渗透性,利于水分的入渗,沙蒿胶良好的吸水性和保水性,能够促进虫实(Corispermum puberulum)和沙蒿(Artemisia sphaerocephala Krasch.)2种固沙先锋植物种子的萌发及幼苗的生长。可见,沙蒿胶具有良好的固沙效果,且固沙成本低,可以作为一种环境友好型固沙剂,与生物固沙结合用于治沙,沙蒿胶喷洒质量分数以0.20%为宜。研究可为沙蒿胶的固沙应用提供理论依据。     

Long-term influence of different production systems on potassium buffering capacity of Typic Ustochrept soil

Imbalanced application of nutrients in the intensively cropped areas results in deterioration of soil fertility. Application of recommended dose of potassium (K) is essential for improving the use efficiency of other nutrients. To assess the buffering capacity of soil, three composite soil samples were collected from the surface soil (0–30?cm) during 2015 from 3 production systems viz., organic, inorganic and integrated which was maintained from 2004 with basmati rice–wheat–Sesbania system under Network Project on Organic Farming at ICAR-Indian Institute of Farming Systems Research, Modipuram. Fractionation of potassium (K) was achieved by sequential extraction of soil samples with distilled water, ammonium acetate and nitric acid in the same order. The relationship between the adsorbed and equilibrium potassium concentration, quantity was determined by plotting Freundlich adsorption isotherms. This was used to determine the buffering capacity and the concentration levels of potassium adsorbed on un-specific sites in the soil. The suitability of the adsorption equation was determined by applying the least square regression analysis. The results revealed that available potassium in the soils ranged from 119.51 to 135.01?mg/kg with 126.02?±?5.24?mg/kg as mean (ammonium acetate method) while water soluble and nitric acid extracted potassium ranged from 28.51 to 29.05?mg/kg and 2594.49?±?19.33?mg/kg (mean) in various production systems. The mean free energy of replacement was found to be ?1998.01?±?28.38?cal/mol indicating that soils have comparatively higher potassium supply under organic system. The potassium buffering capacity of the soils was found to be 0.7462?±?0.16?mg/kg, 0.6295?±?0.20?mg/kg and 0.6774?±?0.09?mg/kg in organic, integrated and inorganic systems, respectively. The amount of potassium adsorbed on un-specific sites of the organic, integrated and inorganic systems was found to be 7.4730?±?1.81, 15.11?±?2.40 and 11.6 89?±?3.58?mg/kg, respectively. It can be concluded that long-term organic production system improves K⁺ buffering capacity of Typic Ustochrept soil as compare to the integrated as well as inorganic production systems.     

Kinetic properties and stability of potato acid phosphatase immobilized on Ca-polygalacturonate

 Acid phosphatase from potato was adsorbed and immobilized on a pre-formed network of Ca-polygalacturonate, a substrate which has a composition and morphology similar to the mucigel present at the root-soil interface. The influence of different types of organic buffers on enzyme adsorption and activity was investigated. The highest enzyme activity, for free and adsorbed enzyme, was obtained with Na-maleate buffer at pH 6.0, which was used for all subsequent experiments. The Michaelis-Menten kinetic parameters, V_max and K_m, were determined for free and adsorbed phosphatase. V_max showed a 60% decrease upon adsorption (2.09±0.30 U/mg, for the soluble form and 0.84±0.15 U/mg, for the adsorbed enzyme), whereas K_m increased from 0.49±0.15 mM for the free enzyme to 0.99±0.20 mM for adsorbed phosphatase. Phosphatase adsorption decreased as the concentration of NaCl increased, indicating that the enzyme is bound to the carrier gel through coulombic interactions. Adsorption increased stability of the enzyme as compared with the free enzyme (t _1/2 of the activity was 9.4 days and 5.8 days, respectively), but increased thermal and proteolytic inactivation. The pH/activity profile revealed no change in terms of shape or optimum pH (4.5) upon adsorption of the enzyme. These results indicate that adsorption of acid phosphatase on Ca-polygalacturonate induces changes in the kinetic properties and stability of the enzyme, and the same type of response can be extrapolated from these results for acid phosphatases of the rhizosphere. Received: 1 July 1997     

Response of Chamecytisus palmensis to drought stress induced by polyethylene glycol during germination

Abstract

Seed germination and subsequent changes in Chamecytisus palmensis were studied under water limiting conditions, imposed by increasing concentrations of polyethylene glycol (PEG-6000) (0, 5, 10, 15, 20, 25, and 30%). Six water stress conditions (C. palmensis. Seed germination was completely inhibited under the drought stress of 30% (?1.20?MPa). Similar to the seed germination, the growth of radicles and hypocotyls after seed germination was also restricted by PEG-simulated drought stress, especially when water potential was lower than ?0.12?MPa (25%). In the same way, the ratio of radicles and hypocotyls significantly decreased with the increase of PEG concentrations, demonstrating strong adaptability to drought stress. Moreover, the decline of radicles and hypocotyls lead to a decrease in the number of root hairs. This would seriously affect the water absorption ability of the young roots. It was concluded that drought stress might be one of the causes for obstructed natural regeneration of C. palmensis plantations on sandy land.