膜下滴灌条件下甜菜水分利用效率的研究

本试验在膜下滴灌条件下,研究不同灌水量对土壤水分、甜菜蒸腾效率及水分利用效率的影响,为半干旱地区甜菜丰产高糖、节水灌溉提供理论依据。结果表明,膜下滴灌条件下,甜菜营养生长时期主要消耗0～60cm土层的土壤水分;供水量为505．2mm时水分利用效率显著提高且对产量影响不显著。通过甜菜产量、蒸腾效率及水分利用效率综合分析,目标产量75咄／hm。时,全生育期最低耗水550．8mm,需供水445．4mm。     

不同滴灌制度对梨枣抗氧化活性的影响

目的：探讨不同滴灌制度对梨枣抗氧化成分及活性的影响,为节水高产优质梨枣生产提供科学依据。方法：以陕北7～8 年生矮化密植枣树所得枣果为材料,以无灌溉处理枣果为对照,比较3 种滴灌制度(不同灌水量和灌水次数)对枣果总酚、黄酮和VC 含量及酚类物质组成及抗氧化能力(抗亚油酸过氧化能力、还原力、DPPH 自由基清除率和ABTS+·清除率)的影响。结果：在研究设计的滴灌制度下,灌水次数和灌水量对梨枣总酚含量无显著性影响,但对梨枣黄酮和VC 含量有显著性影响;梨枣主要的多酚物质：儿茶素、表儿茶素和芦丁含量均受到滴灌制度的显著影响;梨枣的抗过氧化能力(4 种模型)在各处理之间均存在着显著性差异(P ＜ 0.05);抗氧化能力与黄酮含量有显著相关性,但二者并没有随着灌水次数和灌水量的增加而线性增加。结论：适时适量的灌溉制度,是节水高产优质梨枣生产的重要保证。     

灌水频次对强筋小麦蛋白质组分含量、粒度分布和品质的影响

研究了不同灌水频次对强筋小麦(济麦20和藁城8901)的蛋白质组分含量、粒度分布、品质及产量的影响,结果表明:灌水次数在0~2范围内,济麦20和藁城8901的籽粒产量随灌水次数增加而增加,在灌水次数增加到3次时,籽粒产量较灌2水处理显著下降。随灌水次数增加,济麦20和藁城8901的SDS可溶性谷蛋白含量、SDS不溶性谷蛋白含量、醇溶蛋白含量、HMW-GS含量和LMW-GS含量均呈上升趋势,SDS不溶性谷蛋白聚合体的算数平均直径、面团品质(形成时间和稳定时间)和面包品质(体积和总评分)亦均呈上升趋势。相关分析表明,SDS可溶性谷蛋白含量与面团和面包品质达到显著正相关;SDS不溶性谷蛋白含量与面团和面包品质相关不显著,但其算数平均直径与面团和面包品质呈显著正相关。     

覆膜灌溉技术在葡萄生产中的应用

以玫瑰香和赤霞珠为试材,利用覆膜灌溉技术,控制灌水次数,测定田间土壤含水量,调查葡萄产量及生长情况。结果表明,此项技术在达到节水效果的同时,能使果实提早成熟,未影响果实品质和产量。     

半干旱区甜菜高产高糖节水栽培模式的研究

采用Ｌ９（３）正交试验设计，分析品种、密度、肥料和灌水四因素及其不同水平对甜菜产量、含糖及产糖量的影响。研究结果表明，品种既是影响菜产量、也是影响甜菜含糖的主要因素。影响甜菜产糖量的主要是灌水。得出了半干亓区甜菜高糖节水最佳栽培模式：即品种为甜研３０３、密度为７５０００株／ｈｍ＾２，施肥为纯氮１１２．５ｋｇ／ｈｍ＾２，纯磷２２５ｋｇ／ｈｍ＾２，全生育期灌水三次，时间为６、７、９月，灌溉量为１８６１     

部分根域干燥栽培条件下藤稔葡萄灌水下限的研究

以3年生藤稔葡萄为材料,探讨了灌水下限对部分根域干燥栽培葡萄生长发育的影响.结果表明,部分根域干燥条件下,转色期之后设施葡萄灌水下限应该控制在-30kPa左右,即土壤饱和持水量的70%左右,此时叶面积生长量没有显著减少,果实产量、品质与双侧灌溉处理没有显著差异,但灌溉水利用效率显著提高.     

部分根域干燥栽培条件下藤稔葡萄灌水下限的研究

以3年生藤稔葡萄为材料，探讨了灌水下限对部分根域干燥栽培葡萄生长发育的影响。结果表明，部分根域干燥条件下，转色期之后设施葡萄灌水下限应该控制在-30kPa左右，即土壤饱和持水量的70％左右，此时叶面积生长量没有显著减少，果实产量、品质与双侧灌溉处理没有显著差异，但灌溉水利用效率显著提高。     

滴灌方式及定额对北疆冬灌棉田土壤水盐分布及次年棉花生长的影响

为探寻解决干旱区棉田冬季灌水问题,明晰北疆棉田不同冬灌方式及灌水定额对土壤水分、盐分分布以及翌年棉花生长及产量的影响,采用大田试验方法,以未冬灌大田作为对照(CK),设置滴灌和漫灌2种灌水方式下4个梯度的灌水定额(1 800、2 400、3 000、3 600、 3600 m3/hm²)共9个处理进行冬灌试验,分析了冬灌灌水后到播种前0~300 cm土层的水分、盐分的动态变化以及翌年各处理棉花的出苗率、群体生理指标(群体光合势、群体净同化率、叶面积指数)和产量数据。结果表明,冬灌对次年播前土壤水盐分布及含量的大小均具有一定的影响,无论漫灌还是滴灌方式进行冬灌,随灌水定额增加土壤水分和盐分的影响深度也随之加深,灌水定额达到3 000和3 600 m3/hm²时,冬灌对土壤水盐影响深度可达300 cm。冬灌可显著改变次年播前土壤盐分的自然分布状态,有效淋洗并降低上层土壤盐分含量;相对漫灌方式而言,滴灌冬灌方式土壤水分入渗更加均匀且规律明显。冬灌对次年滴灌棉花的生长发育及产量均具有重要影响,冬灌后次年棉花群体指标与未冬灌处理的差异随冬灌灌水定额的增加愈加显著,灌水定额3 000 m3/hm²滴灌冬灌处理的次年棉花群体光合势与叶面积指数较未冬灌处理分别提升34.30%和42.60%;冬灌有利于次年棉花产量的提高,滴灌冬灌灌水定额3 000、3 600 m3/hm²处理时的棉花产量相对未冬灌处理分别增产10.66%和12.36%。综合考虑冬灌方式及灌水定额对次年土壤水盐分布及棉花生长和产量的影响,研究认为滴灌条件下灌水定额3 000 m3/hm²的冬灌在试验条件下比较适宜,既可淋洗盐分至耕层以下300 cm处,亦可获得6 107.75 kg/hm²的较高产量。     

施氮量对旱地胡麻养分积累、转运及氮素利用率的影响

通过田间试验,研究不同施氮量对胡麻产量、氮素积累转运及氮肥利用率的影响。结果表明,在本试验土壤肥力条件下,无论施氮与否,胡麻各器官不同生育阶段氮素养分吸收、累积和转运规律的基本趋势一致,但其变化量与施氮量有极大关系。施氮量为55.2kg·hm-2时,叶和茎中的氮素向籽粒的转移量、转移率及对籽粒氮素的贡献率最大;叶中氮素向籽粒的转移量、转移率及贡献率要比茎高出89.18%、83.36%和86.36%。胡麻籽粒中47.10%-57.66%的氮素来源于叶,22.46%-30.94%的氮素来源于茎,21.00%-30.48%来自籽粒生长后期从土壤中吸收。施氮量为27.6、55.2、82.8 kg·hm-2时,胡麻籽粒产量分别比不施氮增加了10.21%、16.92%和15.55%。施氮量为27.6-55.2 kg·hm-2时,氮肥的表观利用率、偏生产力分别为51.10%-68.63%和51.54-97.16kg·kg-1。本试验条件下,综合考虑产量、氮肥利用率及生态环境,施氮量在27.6-55.2kg·hm-2为宜。     

氮素营养对小麦产量和籽粒蛋白质及组分含量的影响

研究了不同施氮量和施氮时期对小麦籽粒蛋白质及组分含量和产量的影响。试验结果表明 ,随施氮时期后移 ,小麦籽粒蛋白质及不同组分含量呈递增趋势 ,其中谷蛋白和清蛋白含量随施氮期推迟而递增 ,以孕穗期施氮达最高 ,醇溶蛋白和球蛋白含量以拔节期施氮为最高 ;随施氮量增加 ,小麦籽粒蛋白质含量明显提高 ,二者呈显著正相关。施氮量与籽粒产量和蛋白质产量间呈二次曲线关系 ,籽粒最高蛋白质产量施氮量高于其最高产量施氮量     

Impacts of crop level,soil and irrigation management in grape berries of cv ‘Trincadeira’ (Vitis vinifera L.)

Berry size and crop yield are widely recognized as important factors that contribute to wine quality. The final berry size indirectly affects the phenolic concentration of the wine due to skin surface-to-berry volume ratio. The effects of different irrigation levels, soil management and plant crop level on growth of ‘Trincadeira’ berries were studied. In order to test the influence of different irrigation levels (rainfed, pre-veraison and post-veraison), different soil management (tillage and natural cover crops) and different plant crop levels (8 and 16 clusters per vine), leaf water potential, skin anthocyanin, polyphenols, berry skin and seed fresh weight were measured in fruits. The segregation of berries into three different berry classes: small, medium and large, allowed to identify different levels of contribution of soil management and irrigation level into berry, skin and seeds ratios. As expected, higher water availability due to irrigation and soil tillage management during berry development induced an increase in berry flesh weight and this was more evident in larger berries; however, berry skin and seed fresh weight remained unchanged. Also, anthocyanins did not show significant differences.     

Assessment of root activity of perennial ryegrass and white clover measured using 32phosphorus as influenced by method of isotope placement,irrigation and method of defoliation

Two methods of placement of ³²P in soil were used to investigate the root activity in perennial ryegrass and mixed ryegrass–white clover swards. The placement of isotope by either horizontal or vertical insertion in the mixed sward had no significant effect on the distribution of root activity with depth, the total dry-matter yield of herbage or its distribution between ryegrass and clover. At least 90% of the root activity to a depth of 35 cm for both grass and clover occurred within the upper 12.5 cm of the soil profile. Irrigation resulted in a more even distribution of root activity with depth and increased the lateral exploitation of soil P. In the irrigated plot, the root activity of both grass and clover above the line of isotope placement accounted for 40–50% of the total activity at depths to 18.8 cm in contrast to 70–100% in the absence of irrigation. The method of defoliation (cutting versus grazing) had no significant effect on the vertical or lateral distribution of root activity. In unirrigated mixed swards, the root activity of grass in the upper 12.5 cm of the soil profile was greater by a factor of 1.5 to 2 than the contribution of grass to the yield of herbage. With irrigation, however, the distribution of root activity between grass and clover was similar to the contribution of each to the yield of herbage.     

覆膜滴灌对日光温室甜瓜土壤环境及产量的影响

为探明不同覆膜滴灌条件下,大棚甜瓜土壤水、热等环境因素变化对脲酶及甜瓜产量的影响,该文采用正交试验设计,研究了日光温室内不同覆膜方式(全覆膜、半覆膜、无膜)、灌水下限(田间持水量的60%、70%、80%)、滴灌毛管密度(1管1行、3管4行、1管2行)以及3种因素的交互作用下的土壤水、热、pH值等的变化,以及对甜瓜土壤脲酶活性及甜瓜产量的影响。结果发现,半膜覆盖、80%田间持水量的灌水下限、1管2行滴灌毛管密度等的甜瓜根区土壤水分分布均匀、土壤温度较高、pH值较低,可显著提高土壤脲酶活性;60%田间持水量下限处理脲酶活性在果实膨大期和成熟期高,70%田间持水量下限处理在苗期高,80%田间持水量下限处理在各个生育阶段都最高;半膜覆盖、1管2行和80% 田间持水量下限组合和半膜覆盖、3管4行和70%田间持水量下限组合的甜瓜产量分别为34.46、31.27 t/hm²,显著高于全膜覆盖、1管1行和80% 田间持水量下限组合的28.02 t/hm²;半膜覆盖、1管2行和80% 田间持水量下限组合甜瓜的可溶性糖和可溶性固形物含量高,有机酸含量低。在陕西关中地区的日光温室栽培甜瓜,建议采取半膜覆盖,1管2行的滴灌管密度,灌水量下限分别为苗期70%、开花坐果期80%、果实膨大期80%和成熟期60%田间持水量。     

覆膜滴灌对日光温室甜瓜土壤环境及产量的影响

为探明不同覆膜滴灌条件下,大棚甜瓜土壤水、热等环境因素变化对脲酶及甜瓜产量的影响,该文采用正交试验设计,研究了日光温室内不同覆膜方式(全覆膜、半覆膜、无膜)、灌水下限(田间持水量的60%、70%、80%)、滴灌毛管密度(1管1行、3管4行、1管2行)以及3种因素的交互作用下的土壤水、热、pH值等的变化,以及对甜瓜土壤脲酶活性及甜瓜产量的影响。结果发现,半膜覆盖、80%田间持水量的灌水下限、1管2行滴灌毛管密度等的甜瓜根区土壤水分分布均匀、土壤温度较高、pH值较低,可显著提高土壤脲酶活性;60%田间持水量下限处理脲酶活性在果实膨大期和成熟期高,70%田间持水量下限处理在苗期高,80%田间持水量下限处理在各个生育阶段都最高;半膜覆盖、1管2行和80% 田间持水量下限组合和半膜覆盖、3管4行和70%田间持水量下限组合的甜瓜产量分别为34.46、31.27 t/hm²,显著高于全膜覆盖、1管1行和80% 田间持水量下限组合的28.02 t/hm²;半膜覆盖、1管2行和80% 田间持水量下限组合甜瓜的可溶性糖和可溶性固形物含量高,有机酸含量低。在陕西关中地区的日光温室栽培甜瓜,建议采取半膜覆盖,1管2行的滴灌管密度,灌水量下限分别为苗期70%、开花坐果期80%、果实膨大期80%和成熟期60%田间持水量。     

覆膜滴灌对日光温室甜瓜土壤环境及产量的影响

为探明不同覆膜滴灌条件下,大棚甜瓜土壤水、热等环境因素变化对脲酶及甜瓜产量的影响,该文采用正交试验设计,研究了日光温室内不同覆膜方式(全覆膜、半覆膜、无膜)、灌水下限(田间持水量的60%、70%、80%)、滴灌毛管密度(1管1行、3管4行、1管2行)以及3种因素的交互作用下的土壤水、热、pH值等的变化,以及对甜瓜土壤脲酶活性及甜瓜产量的影响。结果发现,半膜覆盖、80%田间持水量的灌水下限、1管2行滴灌毛管密度等的甜瓜根区土壤水分分布均匀、土壤温度较高、pH值较低,可显著提高土壤脲酶活性;60%田间持水量下限处理脲酶活性在果实膨大期和成熟期高,70%田间持水量下限处理在苗期高,80%田间持水量下限处理在各个生育阶段都最高;半膜覆盖、1管2行和80% 田间持水量下限组合和半膜覆盖、3管4行和70%田间持水量下限组合的甜瓜产量分别为34.46、31.27 t/hm²,显著高于全膜覆盖、1管1行和80% 田间持水量下限组合的28.02 t/hm²;半膜覆盖、1管2行和80% 田间持水量下限组合甜瓜的可溶性糖和可溶性固形物含量高,有机酸含量低。在陕西关中地区的日光温室栽培甜瓜,建议采取半膜覆盖,1管2行的滴灌管密度,灌水量下限分别为苗期70%、开花坐果期80%、果实膨大期80%和成熟期60%田间持水量。     

覆膜滴灌对日光温室甜瓜土壤环境及产量的影响

为探明不同覆膜滴灌条件下,大棚甜瓜土壤水、热等环境因素变化对脲酶及甜瓜产量的影响,该文采用正交试验设计,研究了日光温室内不同覆膜方式(全覆膜、半覆膜、无膜)、灌水下限(田间持水量的60%、70%、80%)、滴灌毛管密度(1管1行、3管4行、1管2行)以及3种因素的交互作用下的土壤水、热、pH值等的变化,以及对甜瓜土壤脲酶活性及甜瓜产量的影响。结果发现,半膜覆盖、80%田间持水量的灌水下限、1管2行滴灌毛管密度等的甜瓜根区土壤水分分布均匀、土壤温度较高、pH值较低,可显著提高土壤脲酶活性；60%田间持水量下限处理脲酶活性在果实膨大期和成熟期高,70%田间持水量下限处理在苗期高,80%田间持水量下限处理在各个生育阶段都最高；半膜覆盖、1管2行和80% 田间持水量下限组合和半膜覆盖、3管4行和70%田间持水量下限组合的甜瓜产量分别为34.46、31.27 t/hm²,显著高于全膜覆盖、1管1行和80% 田间持水量下限组合的28.02 t/hm²；半膜覆盖、1管2行和80% 田间持水量下限组合甜瓜的可溶性糖和可溶性固形物含量高,有机酸含量低。在陕西关中地区的日光温室栽培甜瓜,建议采取半膜覆盖,1管2行的滴灌管密度,灌水量下限分别为苗期70%、开花坐果期80%、果实膨大期80%和成熟期60%田间持水量。     

Persistence of enterohemorrhagic Escherichia coli O157:H7 in soil and on leaf lettuce and parsley grown in fields treated with contaminated manure composts or irrigation water

Outbreaks of enterohemorrhagic Escherichia coli O157:H7 infections associated with lettuce and other leaf crops have occurred with increasing frequency in recent years. Contaminated manure and polluted irrigation water are probable vehicles for the pathogen in many outbreaks. In this study, the occurrence and persistence of E. coli O157:H7 in soil fertilized with contaminated poultry or bovine manure composts or treated with contaminated irrigation water and on lettuce and parsley grown on these soils under natural environmental conditions was determined. Twenty-five plots, each 1.8 by 4.6 m, were used for each crop, with five treatments (one without compost, three with each of the three composts, and one without compost but treated with contaminated water) and five replication plots for each treatment. Three different types of compost, PM-5 (poultry manure compost), 338 (dairy manure compost), and NVIRO-4 (alkaline-stabilized dairy manure compost), and irrigation water were inoculated with an avirulent strain of E. coli O157:H7. Pathogen concentrations were 10(7) CFU/g of compost and 10(5) CFU/ml of water. Contaminated compost was applied to soil in the field as a strip at 4.5 metric tons per hectare on the day before lettuce and parsley seedlings were transplanted in late October 2002. Contaminated irrigation water was applied only once on the plants as a treatment in five plots for each crop at the rate of 2 liters per plot 3 weeks after the seedlings were transplanted. E. coli O157:H7 persisted for 154 to 217 days in soils amended with contaminated composts and was detected on lettuce and parsley for up to 77 and 177 days, respectively, after seedlings were planted. Very little difference was observed in E. coli O157:H7 persistence based on compost type alone. E. coli O157:H7 persisted longer (by > 60 days) in soil covered with parsley plants than in soil from lettuce plots, which were bare after lettuce was harvested. In all cases, E. coli O157:H7 in soil, regardless of source or crop type, persisted for > 5 months after application of contaminated compost or irrigation water.     

Effects of direct drilling and ploughing on root distribution in spring barley,and on the concentrations of extractable phosphate and potassium in the upper horizons of a clay soil

A comparison was made between the effects of three consecutive years of either direct drilling or ploughing, on the distribution of extractable soil phosphate and potassium, and the distribution of roots of a spring barley crop in the upper 20 cm of the soil. Samples were collected from a clay soil (Evesham series) in June 1975 when the crop was mid-way through the phase of stem extension (Feeke's growth stage 7–8). With ploughing, the concentration of nutrients was approximately uniform to the maximum depth of cultivation (20 cm). With direct drilling there were markedly higher concentrations of phosphate and potassium in the upper 5 cm of the soil, but at depths between 10 and 20 cm the concentrations of potassium, and particularly phosphate, were lower than with ploughing. Root weight and length, per unit soil volume, in the upper 5 cm, were also greater with direct drilling than with ploughing. However, the more superficial distribution of phosphate and of roots with direct drilling did not restrict phosphate uptake by the crop, despite the dry summer. The results are discussed in relation to factors contributing to differences in the distribution of nutrients and roots in land receiving contrasting cultivations, and possible consequences for crop growth are indicated.