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1.
可降解地膜对土壤、温度水分及玉米生长发育的影响 总被引：32，自引：8，他引：32
针对普通地膜覆盖导致的农田土壤污染现象,进行了可降解地膜、普通地膜覆盖及露地栽培玉米对比试验,探讨可降解地膜对土壤温度、土壤水分、玉米生长发育、产量及相关农艺性状的影响。结果表明,与露地栽培相比,可降解地膜覆盖能明显提高玉米播种后2个月的地表和地下10 cm的土壤温度,增加玉米播种至大喇叭口期0～20 cm、>20～40 cm的土壤水分含量,使玉米生育进程加快,出苗率和拔节期节根层数及条数增加,玉米不同生育时期株高、叶面积及地上部干物质积累量增加,玉米穗粒数增加9.6%,千粒质量增加20.9%,产量增加35.1%。可降解地膜和普通地膜间差异不显著。研究认为,以可降解地膜替代普通地膜应用于农业生产是可行的。 相似文献
2.
可降解地膜的降解性能及对土壤温度、水分和玉米生长的影响 总被引：46，自引：9，他引：37
针对生产中使用普通农用塑料地膜导致农田土壤污染的现状,进行了不同厚度可降解(光、生物降解)地膜、普通地膜和露地栽培玉米对比试验,探讨可降解地膜的降解性能及对土壤水分、温度和玉米生长的影响。结果表明,0.005mm厚可降解地膜的降解速度及强度均优于0.008mm厚膜,二者在覆膜后90d分别达降解5级、4级水平,地膜质量损失率达55.48%、39.99%。两种可降解地膜对土壤水分、温度和玉米生长的影响与普通地膜相当,均使0～20、>20～40cm土壤水分含量、地表及地下10cm土壤温度明显高于露地对照,使玉米出苗率提高,生育进程加快,株高、叶面积和地上部干物质积累量增加;其中0.008mm厚膜覆盖玉米效果优于0.005mm厚膜。研究认为,以可降解地膜替代普通地膜应用于农业生产具有可行性。 相似文献
3.
《南方农业》2016,(25)
普通农用地膜为"白色污染"污染源之一,对农田生态环境造成严重危害,可降解地膜而作为普通地膜的替代品,使用量逐渐加大。为了研究全生物可降解地膜对"土壤—植物"系统的影响,设计了9种全生物可降解地膜和普通地膜覆盖栽培玉米的田间试验。结果表明,可降解地膜与普通地膜相比,对玉米产量影响不大,减产3.0%~16.4%;从玉米大喇叭口期到玉米成熟期,地膜对土壤温度的影响不大,各种地膜覆盖土壤平均温度相差不到1℃;不同降解膜在降解速度、降解程度上存在差异,J3降解速度最快,从诱导期到大裂期仅30 d;覆膜150 d后,各种可降解地膜均未进入无膜期;由于降解膜易破裂、透光性好,在杂草控制上不及普通地膜效果好。杂草生物量由低到高的排序为:CKJ3J6J5=J7J1J2J4=J8J9,各处理杂草平均株高90 cm以上。 相似文献
4.
为了开发出一种安全高效的抗菌食品包装材料,添加不同质量分数(0～7%)的聚六亚甲基双胍盐酸盐(polyhexamethylene biguanidine hydrochloride,PHMB)抗菌母粒到聚乙烯基材中,制成PHMB抗菌膜,比较PHMB母粒添加量对抗菌食品包装薄膜的抗菌性和性能的影响。结果表明,随着PHMB母粒添加量的增大,薄膜抗菌性增强。PHMB母粒添加量为4%时,薄膜对大肠杆菌、金黄色葡萄球菌和杂菌样品的抗菌率分别为99.1%、99.2%和83.4%,且存放6个月后薄膜仍保持较强的抗菌作用;添加PHMB母粒后,薄膜的透光率、水蒸气透过率影响较小;薄膜的力学性能在PHMB母粒添加量为4%时最优;PHMB(4%)抗菌膜对实际试样(鳕鱼干)表现出良好的微生物抑制作用。因此,确定抗菌薄膜中PHMB母粒最佳添加量为4%,薄膜具备强抗菌作用和良好的性能。该研究为抗菌材料的研制提供了参考。 相似文献
5.
中国可降解膜覆盖对玉米产量效应的Meta分析 总被引：2，自引：1，他引：1
可降解膜是解决农业生产中地膜残留污染的有效措施,但覆盖可降解膜的作物产量效应仍存在较大分歧.该研究以玉米为研究对象,分别以不覆盖和覆盖普通地膜作为覆盖可降解膜的对照,通过检索已发表的相关田间试验数据,利用Meta分析方法定量研究覆盖可降解膜对玉米的产量效应和影响因素.结果表明,在可降解膜和不覆盖组合中,覆盖可降解膜的玉米产量较不覆盖平均提高17.8%(95%置信区间14.8%~20.9%);该组合不存在发表偏倚和极端值.可降解膜和普通地膜组合存在发表偏倚,校正前覆盖可降解膜的玉米产量显著低于覆盖普通地膜(平均相差1.8%),校正后二者差异不显著(置信区间-0.9%~2.7%);该组合也不存在极端值.与不覆盖和覆盖普通地膜相比,覆盖可降解膜的累计平均产量效应均随时间趋于稳定.近5 a来,覆盖可降解膜与覆盖普通地膜的玉米产量差异和变幅均较2000—2010年有所减小.在高海拔、低气温区域,平作和使用0.008 mm厚度降解膜时,更有利于提高可降解膜的增产效应.该研究可为降解膜的大规模推广应用和开发研制提供依据. 相似文献
6.
基于改进AquaCrop模型的覆膜栽培玉米水分利用过程模拟与验证 总被引：4，自引：6，他引：4
为应用AquaCrop模型模拟覆膜玉米水分利用与产量形成过程,该文根据玉米发育阶段生长度日恒定原理,利用地积温对气积温的补偿效应,改进AquaCrop模型对覆膜玉米的气温计算方法,并根据2011年的生育期、耗水量和产量实测数据对改进模型参数进行校正,依据2012年与2013年的冠层覆盖度、土体贮水量、产量与水分利用效率试验数据对改进模型验证。结果表明,玉米地膜覆盖地积温对气积温的量化补偿系数（Cm）：播种-出苗为1.356,出苗-抽雄前为0.635;校正改进的AquaCrop模型能够较好地模拟覆膜与裸地玉米生育天数、作物耗水量、籽粒产量,相对误差（Pe）、模型效率（CE）、残差系数（CRM）变幅分别为：-4%0.88,CE>0.87,0.09相似文献
7.
内蒙古通辽膜下滴灌玉米棵间蒸发量SIMDual_Kc模型模拟 总被引：2，自引：1，他引：1
为明确内蒙古东北部地区玉米膜下滴灌棵间蒸发的变化规律,探索玉米膜下滴灌节水增产机制,在田间试验的基础上,采用经过参数率定与验证的双作物系数SIMDual_Kc模型,模拟分析了土壤含水率、土壤棵间蒸发及作物系数的变化规律,结果表明:1)双作物系数SIMDual_Kc模型模拟内蒙古东北部地区滴灌玉米土壤含水率与实测值具有很好的一致性;2)利用双作物系数SIMDual_Kc模型估算出该地区覆膜玉米生育初期、中期和后期作物系数分别为0.15、1.05、0.4,无膜滴灌玉米初期、中期和后期作物系数分别为0.15、1与0.4;3)根据双作物系数模型SIMDual_Kc模拟了2014和2015年滴灌玉米棵间蒸发量占作物蒸散发的比例,覆膜滴灌较无膜滴灌少,说明覆膜能有效降低作物棵间蒸发量,具有降低作物耗水量的潜在优势。研究结果可以为内蒙古东北部地区玉米滴灌生产实践提供科学依据。 相似文献
8.
基于新陈代谢GM(1,1)模型的玉米叶长动态预测 总被引：1，自引：1，他引：0
为实现虚拟玉米生长动态预测,本文以玉米棒三叶为对象,采用新陈代谢 GM(1,1)模型分析了不同施氮水平(150、300和450 kg/hm2)下玉米叶片长度的生长动态,结果表明:各组数据序列所建模型的均方差比值均小于0.0811,平均相对误差均小于0.0471,模型精度优于二级,具有较高的准确性,表明新陈代谢GM(1,1)模型能有效模拟玉米叶长动态变化,具有一定的可行性,研究结果可为玉米生长过程中的动态变化模拟提供参考. 相似文献
9.
基于DNDC模型的东北地区春玉米农田固碳减排措施研究 总被引：6，自引：1，他引：5
春玉米是我国东北地区主要粮食作物,但由于连年耕作和氮肥的高投入,春玉米农田也可能成为重要的温室气体排放源。因此,通过优化田间管理措施在保证作物产量的同时实现固碳减排,对于春玉米种植系统的可持续发展具有重要意义。过程模型（Denitrification Decomposition, DNDC）是评估固碳减排措施的有效工具,本研究在对DNDC模型进行验证的基础上,应用模型研究不同施氮和秸秆还田措施对东北地区春玉米农田固碳和氧化亚氮（N2O）排放的长期综合影响。模型验证结果表明,DNDC模拟的不同处理下土壤呼吸季节总量、 N2O排放季节总量和春玉米产量与田间观测结果较一致;同时模型也能较好地模拟不同处理下土壤呼吸和N2O排放季节变化动态。这表明DNDC模型能较理想地模拟不同施氮和秸秆还田措施对春玉米农田土壤呼吸、 N2O排放和作物产量的影响。利用模型综合分析不同管理情景对产量和土壤固碳减排的长期影响,结果表明: 1）与当地农民习惯施肥相比,优化施氮措施不会明显影响作物产量,能减少N2O排放,且对土壤固碳影响很小,因而能降低温室气体净排放,但净排放降低幅度有限（8%~13%）; 2）在优化施氮措施的同时秸秆还田能在保障供试农田春玉米产量的同时大幅度减少春玉米种植系统温室气体净排放,甚至可能将供试农田由温室气体排放源转变为温室气体吸收汇。本研究结果可为优化管理措施实现春玉米种植系统固碳减排提供科学依据。 相似文献
10.
基于水分供需关系的冬小麦夏玉米节水灌溉模式研究 总被引：1，自引：0，他引：1
节水灌溉是解决水资源短缺问题的重要途径之一。在长期田间试验的基础上, 运用Hydrus-1D模型对研究区冬小麦 夏玉米轮作条件下的田间水分运移过程进行了模拟分析, 探讨适宜的节水灌溉模式。结果表明, 表征土壤水分实测值与模拟值精度关系的Nash-Suttcliff效率系数Ens为0.652~0.903, 均大于0.5, 模型效果良好; 在灌水量为520 mm的传统灌溉模式下, 1.6 m土层深层土壤水分无效渗漏量为189 mm, 占地表总入渗补给水量的22.3%, 土壤水分无效渗漏大, 且与降雨和灌溉关系密切; 根据作物水分供需状况及土壤水分状况得出夏玉米、冬小麦季的灌溉量分别为50 mm、320 mm, 比传统灌溉模式共节水100 mm。改进后的灌溉模式对于土壤水分渗漏具有良好的控制作用, 土壤水分渗漏峰值明显降低, 根据作物供需与土壤水分状况提出的节水灌溉模式能减少土壤水分渗漏, 提高灌溉水利用效率。 相似文献
11.
Corn gluten meal (CGM) was studied to investigate the effect plasticizers and water have on its melt processing, and how this melting affects its mechanical properties. GCM containing varying amounts of water were mixed with 23% (w/w) plasticizers; (glycerol, triethylene glycol (TEG), dibutyl tartrate, and octanoic acid in a Haake bowl mixer at 80°C. The amount of water in the CGM affected the amount of torque produced in the Haake mixer. This increase in torque was correlated with how well the CGM melted in the mixer. SEM images of CGM melted in the mixer showed a more uniform homogenous structure when processed at its optimum moisture content. Glycerol, TEG, and dibutyl tartrate produced the greatest torque when the CGM contained <1% water. Octanoic acid produced the greatest torque when the CGM was processed at 8% moisture. CGM plasticized with TEG and octanoic acid were mixed at either their optimum moisture or at 9.6% moisture and then compression molded into tensile bars. The tensile strengths of the bars that were mixed at their optimum moisture content were significantly greater than the bars mixed at 9.6% moisture. The tensile properties of the CGM samples were affected by relative humidity (rh). The tensile strength decreased and elongation increased as relative humidity increased. CGM plasticized with TEG saw a greater changes in its tensile properties due to relative humidity than did octanoic acid plasticized CGM. 相似文献
12.
The glass transition temperature and rheological moduli of plasticized corn gluten meal (CGM) were determined with dynamic mechanical thermal analysis (DMTA). The tested plasticizers were water, glycerol, polyethylene glycols (PEG) 300 and 600, glucose, urea, diethanolamine, and triethanolamine, at concentrations of 10–30% (dwb). The glass transition temperature (Tg) of CGM, measured at 188°C when unplasticized, was lowered by >100°C at 30% plasticizer content, except by PEG 600 and glucose, which showed limited compatibility with CGM proteins. The highest plasticizing efficiency, on a molar basis, was measured with PEG 300 and was attributed to the large number of hydrophilic groups and the high miscibility of this compound with CGM proteins. The change in Tg due to the plasticizing effect was modeled with the Gordon and Taylor equation, but a better fit of the experimental data was obtained with the Kwei equation. 相似文献
13.
The strength of films extruded from powder blends of corn zein or corn gluten meal (CGM) with low‐density polyethylene was investigated. Tensile strength, percent elongation at break, and elastic modulus of the extruded films were measured. The tensile strength decreased from 13 MPa to ≈10.5 MPa with zein addition, while CGM addition resulted in tensile strength of ≈6 MPa. The higher the level of biological material (CGM or zein) in the films the lower the tensile properties. Films containing CGM exhibited significantly lower tensile properties than those containing zein. Extrusion processing of biological films is a step toward commercial viability. 相似文献
14.
Homogeneous blends of corn gluten meal (CGM) and "polar" plasticizers (water, glycerol) or "amphiphilic" plasticizers [octanoic and palmitic acids, dibutyl tartrate and phthalate, and diacetyl tartaric acid ester of mono-diglycerides (DATEM)] were obtained by a hot-mixing procedure. The glass transition temperature (T(g)) of the blends was measured by modulated differential scanning calorimetry and dynamic mechanical thermal analysis, as a function of plasticizer type and content (0-30%, dwb). The plasticizing efficiency (i.e., decrease of T(g)) at equal molar content was found to be proportional to the molecular weight and inversely proportional to the percent of hydrophilic groups of the plasticizer. The migration rate of the plasticizers in the polymer was related to their physicochemical characteristics. It was assumed that polar substances interacted with readily accessible polar amino acids, whereas amphiphilic ones interacted with nonpolar zones, which are buried and accessible with difficulty. The temperature at which a thermoplastic resin of plasticized CGM could be formed was closely connected to the T(g) of the blend. 相似文献
15.
Aline Pissinatti Patricia Helena Santoro 《Communications in Soil Science and Plant Analysis》2018,49(13):1660-1670
The aim of this experiment was to test on-farm growing after composting the mixture of following legume plants Crotalaria juncea, Cajanus cajan, Mucuna aterrima with the grass Sorghum bicolor. The treatments were compared to commercial growing medium (CGM) and CGM+NPK to produce bedding plants of lettuce, broccoli, kale, and cabbage. The nutrient contents in CGM and CGM+NPK were higher than the values found in the mixture of the legumes plants with the grass. The pH was higher in the growing media from legume plants as well as the electrical conductivity in the combination CroSor and CajSor. The water retention capacity was higher in the treatments MucSor and CGM. The chemical attributes indicated that CroSor, CajSor, MucSor and CGM+NPK were better than CGM. The growing media from the mixture of legume with grass are an affordable alternative to produce bedding plants of lettuce, broccoli, kale and cabbage under organic agriculture system. 相似文献
16.
Production of corn gluten meal (CGM), a high‐protein coproduct from wet milling of corn, is increasing as production of fuel ethanol from corn increases. Unpleasant taste and odor have limited the use of CGM in human food. Adjustment of pH and extraction with water have been reported to reduce the off‐flavor of CGM but the improvement is not enough for substantial addition of CGM to the human diet. More study of CGM is needed. In this study, volatile compounds released under different conditions of pH, water extraction, and temperature were identified and compared using solid‐phase microextraction‐gas chromatography‐mass spectrometry (SPME‐GC‐MS). The water‐extractable portion, which improves the taste of CGM by its absence, was dried and analyzed by SPME‐GC‐MS. In addition, materials extractable from CGM with methylene chloride were identified by gas chromatography‐mass spectrometry (GC‐MS). Further, the spontaneous generation of a CGM‐like odor accompanied by a change in physical appearance of the CGM sample was described. Flavors and odors known to be associated with the identified CGM compounds were listed. Some possible origins of the volatiles, from degradation of corn constituents or as fermentation products of the corn steeping process, were noted. 相似文献
17.
Xi‐Qun Zheng Xiao‐Lan Liu Shi‐Feng Yu Xiao‐Jie Wang Yan‐Qiu Ma Shuang Yang Shan‐Shan Jing 《Cereal Chemistry》2014,91(5):496-501
In this study, the structure and selected properties of zeins extracted from corn gluten meal (CGM) pretreated by extrusion and removal of starch were investigated. The structure and properties of the zeins from pretreated CGM changed significantly. Pretreatments can decrease the extraction yields of zeins and change the granule shape and size of zein aggregates. The studies indicated that extrusion and removal of starch can significantly decrease the thermal enthalpy (ΔH1 and ΔH2) of zein from 1.94 ± 0.20 to 0.19 ± 0.10 and from 107.20 ± 0.80 to 78.62 ± 2.30 and J/g, respectively. The SDS‐PAGE results confirmed that the molecular weight of zeins from CGM was 24,000 and 27,000, and the molecular weight of zeins did not change with the pretreatment. On the other hand, the circular dichroism spectroscopy results showed that the processing of extrusion and removal of starch can change the secondary structure content of β‐sheets and β‐turns; these results indicated that extrusion and removal of starch can significantly break the secondary structure of zeins. Furthermore, extrusion and removal of starch can change the sulfhydryl content of zeins. The obtained results provided some fundamental information that is useful for further modification of CGM to improve its functional properties and industrial applications. 相似文献
18.
Glenn GM Klamczynski AK Holtman KM Shey J Chiou BS Berrios J Wood D Orts WJ Imam SH 《Journal of agricultural and food chemistry》2007,55(10):3936-3943
A heat expansion process similar to that used for expanded bead polystyrene was used to expand starch-based compositions. Foam beads made by solvent extraction had the appearance of polystyrene beads but did not expand when heated due to an open-cell structure. Nonporous beads, pellets, or particles were made by extrusion or by drying and milling cooked starch slurries. The samples expanded into a low-density foam by heating 190-210 degrees C for more than 20 s at ambient pressures. Formulations containing starch (50-85%), sorbitol (5-15%), glycerol (4-12%), ethylene vinyl alcohol (EVAL, 5-15%), and water (10-20%) were studied. The bulk density was negatively correlated to sorbitol, glycerol, and water content. Increasing the EVAL content increased the bulk density, especially at concentrations higher than 15%. Poly(vinyl alcohol) (PVAL) increased the bulk density more than EVAL. The bulk density was lowest in samples made of wheat and potato starch as compared to corn starch. The expansion temperature for the starch pellets decreased more than 20 degrees C as the moisture content was increased from 10 to 25%. The addition of EVAL in the formulations decreased the equilibrium moisture content of the foam and reduced the water absorption during a 1 h soaking period. 相似文献
19.
Zeins were isolated from corn ethanol coproduct distiller's dried grains (DDG) and fractionated into α- and β γ-rich fractions. The effects of the ethanol production process, such as fermentation type, protease addition, and DDG drying temperature on zein recovery, were evaluated. Yield, purity, and molecular properties of recovered zein fractions were determined and compared with zein isolated from corn gluten meal (CGM). Around 29-34% of the total zein was recovered from DDG, whereas 83% of total zein was recovered from CGM. Process variations of cooked and raw starch hydrolysis and fermentation did not affect the recovery, purity, and molecular profile of the isolated zeins; however, zein isolated from DDG of raw starch fermentation showed superior solubility and film forming characteristics to those from conventional 2-stage cooked fermentation DDG. Protease addition during fermentation also did not affect the zein yield or molecular profile. The high drying temperature of DDG decreased the purity of isolated zein. SDS-PAGE indicated that all the isolated α-zein fractions contained α-zein of high purity (92%) and trace amounts of β and γ-zeins cross-contamination. Circular dichroism (CD) spectra confirmed notable changes in the secondary structure of α-zeins of DDG produced from cooked and raw starch fermentation; however, all the α-zeins isolated from DDG and CGM showed a remarkably high order of α-helix structure. Compared to the α-zein of CGM, the α-zein of DDG showed lower recovery and purity but retained its solubility, structure, and film forming characteristics, indicating the potential of producing functional zein from a low-value coproduct for uses as industrial biobased product. 相似文献
20.
John W. Lawton 《Cereal Chemistry》2006,83(5):565-568
Traditionally, zein is isolated and recovered from corn gluten meal (GCM) using aqueous alcohol as the solvent. Recovery of zein from this solvent is inconvenient and costly. Zein is insoluble in 100% ethanol at room temperature, but it is soluble at 120°C in ethanol. Absolute ethanol effectively extracted zein from CGM, distillers dried grains (DDG), and ground corn. Zein was extracted from CGM with absolute ethanol in a high‐pressure reactor at 130°C. After extracting at 130°C for 45 min, the solution was pumped out of the extractor and allowed to cool. Upon cooling, the zein precipitated from solution. The precipitate was removed from the solution and air‐dried, resulting in 14% recovery of the starting material. The recovered precipitate had an average protein content of >90% on a dry basis, accounting for ≈20% of the CGM protein and recovered ≈35% of its zein. No differences were seen in the amount of zein extracted from CGM samples that were hand‐collected off the dewatering screen and gently dried, versus commercial CGM samples. The commercial CGM did produce a greater amount of solubles. The extraction procedure also worked at temperatures as low as 90°C. The lower temperature did produce lower yields of extracted zein. The zein extracted at the lower temperatures was less brown, but zein extracted at either temperature was almost fully soluble in traditional zein solvents. 相似文献