共查询到19条相似文献，搜索用时 687 毫秒
1.
干旱胁迫对木薯苗生理特性影响研究 总被引：2，自引：0，他引：2
为探明木薯苗在干旱胁迫下的生理特性,以木薯品种新选048为材料,用桶栽方法人工模拟土壤干旱条件,设置供水量为土壤田间最大持水量的20%、40%、60%和80%4个水分处理水平,以不供水为对照,研究不同程度干旱胁迫对木薯苗生理特性的影响。结果表明:木薯株高、茎粗、叶片的总含水量、自由水的含量、自由水和束缚水的比值均随着供水量的增加而升高;叶片脯氨酸含量、可溶性糖含量、可溶性蛋白质含量、细胞膜透性、SOD酶活性、POD酶活性均随着供水量的增加而降低。可见,干旱胁迫越严重对木薯生长越不利,土壤含水量占田间最大持水量的80%时最有利于木薯苗的生长。 相似文献
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3.
经研究土壤持续干旱和不同淹水时间对苎麻生长发育的影响表明,在本试验条件下,土壤含水量在田间持水量的70%以上,苎麻能正常生长发育;65%左右为永久凋萎土壤含水量;60%以下为地上部开始死亡含水量,此时复水后,能恢复生长,当季(三麻)正常开花结实;50%以下3—4天就可使地上部分全部死亡,复水后,产生新的地上茎,当季(三麻)能开花结实;40%以下时间较长时,能使整个麻蔸死亡。淹水24小时对苎麻生长不造成太大的影响;48小时造成短期内生长缓慢;72小时使三分之一的中小地上茎死亡;以上三种淹水处理未死地上茎当季(三麻)能开花结实;96小时使地上部分全部死亡,但麻蔸仍保持有部分活力,新产生地上茎当季(三麻)未现蕾开花。严重干旱后,淹水48小时,整个麻蔸死亡。干旱和淹水均使蒸腾强度下降。 相似文献
4.
除草剂苄嘧磺隆对稻田土壤微生物活性和生物化学特性的影响 总被引：9，自引：0，他引：9
在室内培养试验条件下, 研究了不同剂量苄嘧磺隆（0~750 g/hm[sup]2[/sup])对淹水稻田土壤中微生物活性和生物化学特性的影响。结果表明,所有处理中土壤微生物生物量(磷脂含量)随培养期延长而缓慢减少,与对照相比,土壤微生物生物量(磷脂含量)随苄嘧磺隆增加而有所减少。所有处理中异养型细菌（富营养菌和贫营养菌）随培养期延长持续减少,与对照相比土壤中异养型细菌随苄嘧磺隆剂量增加而快速减少,尤其是苄嘧磺隆剂量较大（375和750 g/hm[sup]2[/sup]）的土壤中异养型细菌显著减少。土壤电子运输系统/脱氢酶活度在第1周内随培养时间延长持续下降,之后随培养时间延长而增强。与对照相比,土壤电子运输系统活度也随除草剂苄嘧磺隆施用剂量的升高而下降。第1周内土壤酚含量随培养时间延长持续增加,之后随培养时间延长而减少。 与对照相比,土壤酚含量随苄嘧磺隆施用剂量的增加而快速增加,尤其是苄嘧磺隆剂量较大（375和750 g/hm[sup]2[/sup]）的土壤中酚含量显著增加。在所有处理中,土壤中蛋白质含量随培养时间的延长缓慢减少,但不显著。土壤蛋白质含量随除草剂苄嘧磺隆剂量增加而略微增加,但不显著。 相似文献
5.
为了研究同一区域内不同橡胶林对土壤容重及田间持水量的影响程度,以云南河口抗逆高产、胶木兼优和RRIM600作为研究对象,对土壤容重及田间持水量进行3年调查,结果表明：(1)橡胶林土壤容重为1.09～1.37 g/cm3,相同深度土壤容重相差较小,但随着土壤深度增加,土壤容重逐渐升高,表层土0～20 cm土壤容重显著低于20～40 cm土层;(2)胶木兼优、抗逆高产和RRIM600田间持水量平均值分别为36.92%、35.19%和34.90%,表现为胶木兼优＞抗逆高产＞ RRIM600,但三者田间持水量均随土壤深度增加逐渐降低,0～20 cm土层高于20～40 cm土层;(3)同一橡胶林下不同深度土壤之间,其土壤容重、田间持水量均存在非显著正相关,而相同深度土壤容重与田间持水量之间存在极显著负相关。 相似文献
6.
为筛选适宜北疆绿洲区滴灌春小麦高产栽培的水分管理模式,比较分析了耕层(0~40cm土层)不同墒度条件下滴灌春小麦旗叶SPAD值、灌浆期光合和荧光参数及产量的差异。结果表明,拔节至乳熟期土壤墒度过高或过低均会显著降低旗叶SPAD值(P0.05),乳熟期增加土壤墒度延缓了叶片衰老。在灌浆期,旗叶光合速率随土壤墒度的增加而显著提高;蒸腾速率在15∶00时T4处理(苗期-拔节、孕穗-乳熟和成熟-收获阶段耕层土壤平均含水量分别为田间持水量的75%、80%和65%)显著高于其他处理,高墒度处理T5(苗期-拔节、孕穗-乳熟和成熟-收获阶段耕层土壤平均含水量分别为田间持水量的80%、85%和70%)最低;气孔导度(Gs)在15∶00时显著降低后,在17∶00时又逐渐升高,且T4处理显著高于其他处理;胞间CO2浓度变化趋势同Gs一致;叶绿素荧光参数Fv/Fo、Fv/Fm、ΦPSⅡ等随土壤墒度升高而显著增加;土壤墒度较低处理的qP相对较低,NPQ较高;土壤墒度过高或过低均会降低小麦籽粒产量,产量构成中穗粒数对土壤墒度最敏感,千粒重次之。说明在本试验条件下,苗期-拔节、孕穗-乳熟和成熟期耕层土壤平均含水量分别占田间持水量的70%~75%、75%~80%和60%~65%是滴灌春小麦获得高产的最佳水分管理模式。 相似文献
7.
菌糠改良土壤田间持水量效果的研究 总被引：1，自引：0，他引：1
【目的】探讨食用菌菌糠做底肥对土壤田间持水量的改良效果。【方法】本试验以多种菌糠为底肥,以种植玉米土壤为研究对象,,设计了（0,5,10,15,20 kg/60 m2）5个处理,每个处理3次重复,在室内采用威尔克科斯法测定土壤的田间持水量。【结果】随着施用菌糠量的增加土壤的田间持水量容重由2.08%增加到2.50%,处理间F=13.40893具有显著性。【结论】通过对比可知菌糠在改良土壤的田间持水量的效果良好,并且玉米的产量明显的提高。 相似文献
8.
土壤水分对玉米秸秆还田腐解率、土壤肥力及小麦籽粒蛋白质产量的影响 总被引：3，自引：0，他引：3
为提高玉米秸秆还田效果,通过防雨棚微区控水设施,研究了土壤水分对还田玉米秸秆腐解、土壤肥力及小麦籽粒蛋白质产量的影响,3个土壤水分水平分别为田间持水量的50%～55%(干旱)、60%～65%(轻旱)和70%～75%(适宜水分)。结果表明,小麦季还田玉米秸秆腐解速率表现为"快-慢-快"的变化趋势。随着土壤水分含量的增加,秸秆量减少率逐渐增加。秸秆腐解前期(0～70 d),干旱条件下秸秆量累计减少率、氮素释放率显著降低(P0.05);成熟期,不同土壤水分条件下秸秆量累计减少率及氮素释放率分别为66.50%～69.51%和75.88%～77.31%,不同土壤水分处理间差异不显著。与播前相比,成熟期不同处理0～25 cm耕层土壤有机质含量基本表现为降低趋势,但秸秆还田(RS)处理土壤有机质含量下降幅度较对照(CK)显著降低。与CK相比,RS处理0～25 cm耕层土壤有机质含量显著提高(16.1%～17.2%);不同生育时期土壤0～25 cm耕层的碱解氮含量显著提高(11.65%～23.10%);小麦籽粒蛋白质含量略有降低,籽粒蛋白质产量显著降低(4.63%)。在秸秆还田条件下,干旱处理的小麦籽粒蛋白质含量均显著高于轻旱和适宜水分处理。综上,还田玉米秸秆的腐解和氮素释放需要较好的土壤水分条件;土壤水分适宜时进行秸秆粉碎翻压还田有利于提高土壤有机质和碱解氮含量;干旱条件下秸秆还田导致小麦籽粒产量和蛋白质产量均显著降低。 相似文献
9.
目的研究栽培牛蒡田间持水量与光合作用的关系,为牛蒡栽培的水分管理提供理论依据。方法盆栽试验,用CI-340超轻型便携式光合测定仪进行光合参数的测定。结果 70%的田间持水量下牛蒡光合能力最强,在这一条件下,蒸腾速率和水分利用效率也较高。在70%和50%田间持水量条件下,净光合速率日变化均呈明显的双峰曲线,70%田间持水量的峰值出现在中午12时和下午16时,分别为6.3、6.2μmol/m2/s,有轻微的光合"午休"现象。结论栽培牛蒡以控制土壤水分含量为田间持水量的70%最佳。 相似文献
10.
初花期干旱对甘蓝型油菜生理和农艺性状的影响 总被引：2，自引：0，他引：2
初花期是油菜生殖生长的关键时期。为研究干旱对这一时期油菜的影响,在人工控水条件下(当土壤含水量为田间持水量的45%~50%时计为干旱胁迫开始,处理持续10d,然后复水;CK正常灌水,保持田间持水量在80%~85%),利用4个具有不同耐旱性的甘蓝型油菜品种浔油8号、阳光2009、浙油50和华油杂13号,研究生理特性、农艺性状和产量的变化。结果表明,在干旱胁迫10d后,耐旱性品种(浔油8号和阳光2009)的叶片SPAD值、可溶性蛋白质、MDA含量变幅不大,可溶性糖含量小幅下降,CAT酶活性小幅增加,游离脯氨酸含量显著增加(其中浔油8号和阳光2009分别比对照增加了4.1倍和2.9倍)。相比之下,敏感性品种(浙油50和华油杂13号)的叶片SPAD值、可溶性蛋白质和可溶性糖含量均显著减少,MDA含量显著增加,CAT酶活性变幅不大,游离脯氨酸含量显著增加,但增幅小于耐旱品种。初花期干旱影响油菜的主要农艺性状和产量,表现为敏感性品种的株高、一次分枝数、相对分枝高、主花序长、主花序角果数、角果长、单株角果数、角果粒数和单株产量均显著下降,而且降幅明显大于耐旱性品种。 相似文献
11.
Mechanical insights into the effect of fluctuation in soil moisture on nitrous oxide emissions from paddy soil 总被引：1，自引：0，他引：1
Paddy fields are subjected to fluctuating water regimes as a result of the alternate drying and wetting water management, which often incurs a sensitive change in N2O emissions from paddy soils. However, how the soil moisture regulates the emission of N2O from paddy soil remains uncertain. In this study, three incubation experiments were designed to study the effects of constant and fluctuating soil moisture on N2O emission and the sources of N2O emission from paddy soil. Results showed that the N2O emission from paddy soil at 100 % WHC (water-holding capacity) was higher than that at 40, 65, 80, 120, and 160 % WHC, indicating that 100 % WHC was the optimum soil moisture content for N2O emission under the incubation experiment. Small peak of N2O flux appeared when the soil moisture content from 250 % WHC decreased near to 100 % WHC, lower than that triggered by nitrogen (N) fertilization, which was mainly owing to the low NH4 + concentration at this period. Nitrification dominated the emissions of N2O from paddy soil at 250 % WHC (54.96 %), higher than that of nitrification-coupled denitrification (6.74 %) and denitrification (38.3 %). The contribution of denitrification to N2O emissions (44.10 %) was equivalent to that of nitrification (44.45 %) in soil at 100 % WHC, which was higher than that of 250 % WHC treatment. In conclusion, the finding suggested that the peak of N2O in paddy soils during midseason aeration could be attributed to the occurrence of optimum soil moisture under sufficient N availability, favorable for the production and accumulation of N2O. 相似文献
12.
《Plant Production Science》2013,16(3):276-279
AbstractDirect-seeding has been proposed as a water- and labor-saving method to grow irrigated rice. Our objective was to compare the effects of flooded and aerobic conditions on the yield stability of direct-seeded rice. We set up four trials in the field: aerobic, near-saturated and flooded soils with direct seeding, and flooded soil with transplanting. Grain yield of direct-seeded rice was comparable to that of transplanted under flooded conditions. However, the yield of direct-seeded rice under aerobic conditions was up to 21% lower than that under flooded conditions. This poor performance was associated with reduced leaf growth during the vegetative stage. Our results indicate that the yield stability of direct-seeded rice could be lowered by the water-saving irrigation, compared with the conventional flooded culture. In order to save irrigation water, physiological research on direct-seeded rice should target the vulnerability of rice to aerobic soils or to soil moisture fluctuations. 相似文献
13.
不同土壤N_2O排放的研究 总被引：1，自引：0，他引：1
以森林和蔬菜土壤作对照,采用实验室培养研究了高产、中产和低产等三种茶园土壤N2O的排放水平,试验设不加氮(对照)与加氮[200mg/kg,(NH4)2SO4]二处理,在25℃恒温培养0、1、3、7和14d时分别取样检测N2O释放量。另外,选择两种茶园土壤研究了土壤含水量与加氮对N2O排放影响的交互作用。结果表明,对于不加氮的对照土壤组,高产茶园具有较高的N2O排放量,14d内平均日排放量高达11.26mg/(kg·d)(以纯氮计),显著高于其它四种土壤;但对于加氮处理组,以菜园土壤的N2O排放水平最高,极显著高于茶园和林地土壤;所有五种土壤加氮后,N2O排放量均有明显提高。茶园土壤N2O排放水平随着土壤含水量的提高而增加,并与施氮存在显著的正交互作用,当土壤含水量较高时施氮具有刺激N2O排放的作用。文章根据土壤培养期间NH4+和NO3-含量的变化就N2O形成机理进行了讨论。 相似文献
14.
Soil slaking is an environment-friendly technique that is gaining importance in restoring saline soils. The objective of this
article is to evaluate the effect of initial water content (IWC) on saturated hydraulic conductivity (K
s) in desalinization with slaking and drying. Accordingly, a slaking test was carried out during February, 2009 for evaluating
the effects of slaking and drying on K
s, sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP) under various IWC. We prepared natural and air-dried
soils of paddy field in Kojima Bay Polder, Japan to give different pre-drying, air-dried, and not dried (natural). The air-dried
soils were resaturated. Each soil was well mixed, then dried to different initial moisture contents (60, 50, 40, 30, 20, and
10% by weight). The specimens were immersed into water in the pot for 24 h. The K
s was measured, and cations in slaked and unslaked soils were analyzed. The K
s was high under the water content below 30% in both the natural and the air-dried soils. But the effects were more pronounced
in the natural soil. The air-dried soil showed far smaller K
s than the natural soil. In outer solution, the highest SAR was noted at 30% in the natural and 30 and 20% in the air-dried
soils. Significant decrease in ESP of the soils (slaked + unslaked) was also observed at the same water content. Lower water
content was more effective in decreasing the soil ESP after desalinization from saline soil. The natural soil showed lower
ESP and higher porosity, which was considered as a reason for higher K
s of natural soil than that of air-dried soils. The results indicated that lower water content (10–30%) had no hazardous effect
on K
s by slaking and drying of soil. 相似文献
15.
Adults of Sitona lineatus (pea leaf weevil, PLW) feed on foliage of several Fabaceae species but larvae prefer to feed on nodules of Pisum sativum L. and Vicia faba L. Indirectly, through their feeding on rhizobia, weevils can reduce soil and plant available nitrogen (N). However, initial soil N can reduce nodulation and damage by the weevil and reduce control requirements. Understanding these interactions is necessary to make integrated pest management recommendations for PLW. We conducted a greenhouse study to quantify nodulation, soil and plant N content, and nodule damage by weevil larvae in relation to soil N amendment with urea, thiamethoxam insecticide seed coating and crop stage. PLWs reduced the number of older tumescent (multilobed) nodules and thiamethoxam addition increased them regardless of other factors. Nitrogen amendment significantly increased soil available N (>99% nitrate) as expected and PLW presence was associated with significantly lower levels of soil N. PLW decreased plant N content at early flower and thiamethoxam increased it, particularly at late flower. The study illustrated the complexity of interactions that determine insect herbivory effects on plant and soil nutrition for invertebrates that feed on N-fixing root nodules. We conclude that effects of PLW on nodulation and subsequent effects on plant nitrogen are more pronounced during the early growth stages of the plant. This suggests the importance of timing of PLW infestation and may explain the lack of yield depression in relation to this pest observed in many field studies. Also, pea crops in soils with high levels of soil N are unlikely to be affected by this herbivore and should not require insecticide inputs. 相似文献
16.
XIEXiao-mei LIAOMin LIUWei-ping SusanneKLOSE 《水稻科学》2004,11(3):140-146
Combined effects on soil microbial activity of nutrient and pesticide management in hybrid rice double annual cropping system were studied. Results of field experiment demonstrated significant changes in soil microbial biomass phospholipid contents, abundance of heterotrophic bacteria and proteolytic bacteria, electron transport system (ETS)/dehydrogenase activity, soil protein contents under different management practices and at various growth stages. Marked depletions in the soil microbial biomass phospholipid contents were found with the advancement of crop growth stages, while the incorporation of fertilizers and/or pesticides also induced slight changes, and the lowest microbial biomass phospholipid content was found with pesticides application alone. A decline in the bacterial abundance of heterotrophic bacteria and proteolytic bacteria was observed during the continuance of crop growth, while the lowest abundance of heterotrophic bacteria and proteolytic bacteria was found with pesticides application alone, which coincided with the decline of soil microbial biomass. A consistent increase in the electron transport system activity was measured during the different crop growth stages of rice. The use of fertilizers (NPK) alone or combined with pesticides increased it, while a decline was noticed with pesticides application alone as compared with the control. The soil protein content was found to be relatively stable with fertilizers and/or pesticides application at various growth stages in both crops undertaken, but notable changes were detected at different growth stages. 相似文献
17.
Combined effects on soil microbial activity of nutrient and pesticide management in hybrid rice double annual cropping system were studied. Results of field experiment demonstrated significant changes in soil microbial biomass phospholipid contents,abundance of heterotrophic bacteria and proteolytic bacteria, electron transport system (ETS)/dehydrogenase activity, soil protein contents under different management practices and at various growth stages. Marked depletions in the soil microbial biomass phospholipid contents were found with the advancement of crop growth stages, while the incorporation of fertilizers and/or pesticides also induced slight changes, and the lowest microbial biomass phospholipid content was found with pesticides application alone. A decline in the bacterial abundance of heterotrophic bacteria and proteolytic bacteria was observed during the continuance of crop growth, while the lowest abundance of heterotrophic bacteria and proteolytic bacteria was found with pesticides application alone, which coincided with the decline of soil microbial biomass. A consistent increase in the electron transport system activity was measured during the different crop growth stages of rice. The use of fertilizers (NPK) alone or combined with pesticides increased it, while a decline was noticed with pesticides application alone as compared with the control.The soil protein content was found to be relatively stable with fertilizers and/or pesticides application at various growth stages in both crops undertaken, but notable changes were detected at different growth stages. 相似文献
18.
茶园土壤酸化是制约茶树可持续生产的重要因素,通过田间小区试验分析比较几种措施对茶园土壤的改良效果,以期为茶园酸化土壤改良提供科学依据。试验设置7个处理：全量化肥（常规施肥,NPK）、全量化肥+10 t•hm-2生物质炭（NPK+BC10）、有机肥替代50%化肥（OM50）、有机肥替代50%化肥+2 t•hm-2生石灰（OM50+Lime）、有机肥替代50%化肥+10 t•hm-2生物质炭（OM50+BC10）、有机肥替代50%化肥+20 t•hm-2生物质炭（OM50+BC20）、有机肥替代50%化肥+40 t•hm-2生物质炭（OM50+BC40）。连续施用2年后,对茶园土壤酸度、养分和微生物群落进行测定。与NPK相比,OM50+Lime、OM50+BC20和OM50+BC40处理土壤pH分别显著提高1.10、0.49和0.68,盐基饱和度分别显著提高114.01%、55.92%和58.62%。OM50+BC10、OM50+BC20和OM50+BC40处理的土壤有机碳含量分别比NPK处理显著增加了29.68%、41.04%和59.37%。不同处理对土壤硝态氮含量无显著影响,OM50、OM50+BC20和OM50+BC40处理的铵态氮含量比NPK处理分别显著提高了40.27%、44.77%和41.77%。NPK+BC10、OM50+BC10、OM50+BC20和OM50+BC40处理能显著提高土壤微生物活性、微生物群落物种丰富度、多样性和均一性。OM50+BC10、OM50+BC20和OM50+BC40处理显著降低了真菌/细菌比例,表明这3个处理短期内增加了红壤茶园土壤生态系统稳定性,但OM50+Lime处理的革兰氏阴性菌/革兰氏阳性菌比例显著低于对照处理,表明施用生石灰处理的土壤微生物受到的环境胁迫程度高于其他处理。总之,OM50+Lime、OM50+BC20和OM50+BC40处理对酸化茶园土壤有较好的改良效果,OM50+BC20和OM50+BC40处理对土壤微生物群落性质方面的改良效果更佳。综合考虑改良效应及成本,OM50+BC20为最佳改良方案。 相似文献
19.
马铃薯块茎产量淀粉与土壤质地含水量的关系 总被引：1，自引：0，他引：1
试验在1992年同时安排在河北坝上、山西大同和内蒙呼盟进行。每个地区选用3个品种（系）种植在当地典型沙土和粘土，并施以“常干旱”和“常湿润”两个处理以观察土壤质地和水分含量对马铃薯淀粉含量的影响。试验结果表明：“常湿润”处理的马铃薯的产量显著高于“常干旱”的处理，而两者的淀粉含量没有明显差别。综合分析，沙土地的产量在“常干旱”情况下低于粘土地的产量，而在“常湿润”条件下则高于粘土地的产量。块茎的淀粉含量总的来分析，沙土地的要等于和高于粘土地，最多可高出2％以上。马铃薯品种不同，其淀粉含量多寡对土壤沙粘的水分含量的要求也不相同。品系“坝318”淀粉含量在“常干旱”处理条件下常高于“常湿润”处理，而“晋薯2号”则正相反。 相似文献