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1.
为探讨土壤有机质对两种常用的土壤交换性酸测定方法(BaCl_2-TEA提取法和KCl淋溶法)结果的影响,选取了85个不同有机质质量分数的酸性土壤并采用BaCl_2-TEA提取法和KCl淋溶法测定其交换性酸含量.结果表明,BaCl_2-TEA提取法测得的土壤交换性酸含量远大于KCl淋溶法的测定结果.KCl淋溶法测得的土壤交换性酸含量与土壤pH值间的负相关性极有统计学意义(r=-0.79**),而BaCl_2-TEA提取法测得的土壤交换性酸含量与土壤pH值间的相关性无统计学意义(r=-0.08).但BaCl_2-TEA提取法测得的土壤交换性酸含量却与土壤有机质质量分数间的正相关性极有统计学意义(r=0.94**).此外,由KCl淋溶法测得的土壤交换性酸进一步计算得到的盐基饱和度与土壤pH值间的相关性(r=0.69**)也大于BaCl_2-TEA提取法(r=0.25*).通常土壤酸化越严重,土壤pH值越低,交换性酸含量越高,盐基饱和度越低.可以得出,土壤有机质会使BaCl_2-TEA提取法的测定结果产生较大的正误差,而对KCl淋溶法的影响较小.由于土壤有机质中的腐殖酸会与BaCl_2-TEA提取法中的有机弱碱TEA发生反应,增加TEA用量,从而使计算得到的土壤交换性酸的结果偏高.因此,对于高有机质质量分数的酸性土壤,不宜采用BaCl_2-TEA提取法测定其交换性酸含量.但在KCl淋溶法中,由于K~+对Al~(3+)的交换能力较弱,使得该方法测得的土壤交换性酸含量偏低.因此,可乘以1.5左右的校正系数,以便能真实地反映出土壤交换性酸含量.  相似文献   
2.
Soils comprise a critical interface between the atmosphere, lithosphere, hydrosphere and biosphere, and play a major role in the cycling of nitrogen (N), an element crucial to plant growth. Isotope techniques constitute a powerful tool to study the origin and fate of N compounds (e.g. NO3) within the environment including soils. The objective of our study was to test the usefulness of the isotope composition of soil NO3 extracted with 2 M KCl (soil NO3) as a tool to investigate the origin and fate of NO3 in the environment. Specifically issues related to repeat extractions, crop type, length of fertilization, and soil depth were addressed. Soils from four contrasting agricultural management regimes were sampled. Within the relatively confined study area (4 ha), the isotopic compositions of soil NO3 differed markedly due to management treatments (up to 6 and 17‰ for δ15N and δ18O, respectively), but were repeatable among replicate plots (±1‰). Differences in both δ15N and δ18O values were observed between legume and non-legume treatments, as well as fertilized versus non-fertilized treatments, which were larger than the variability observed between replicate plots. Differences in the isotopic composition of extractable soil nitrate were not limited to the surface layer, but also occurred within deeper soil layers. This study indicates that the analysis of the natural abundance stable isotope composition of soil NO3 may provide a promising additional tool for tracing the origin and fate of NO3 in the soil zone.  相似文献   
3.
A laboratory incubation experiment using soil columns was conducted to study the effects of monocalcium phosphate (MCP) and potassium chloride (KCl) on soil pH changes in fertilizer microsites with two Chinese soils. Mixtures of two fertilizers at two rates (0 and 0.26 g per column) were added to the surface of soil cylinders. The results shown that both fertilizers significantly decreased soil pH after 7 d and 28 d, which declined with time and distance from fertilizer site. Compared with KCl alone, the soil pH decrease close to the fertilizer site induced by applied KCl was slowed down in the acidic red soil by MCP addition but was promoted in the calcareous soil. Compared with MCP alone, the application of KCl with MCP had greater effects of reducing pH in both soils. The magnitude and extent of soil pH changes were mostly contributed by KCl in the KCl plus MCP treatment.  相似文献   
4.
2010年余庆县开展了氯化钾肥料施用量的田间试验工作,结果表明:氯化钾施用量为45.0~60.0 kg/hm2范围内,能显著提高烟叶产量和经济效益,烟叶外观质量、内在质量明显改善,化学成分较为协调,评吸质量较优。  相似文献   
5.
KCl+S-3307对绿豆下胚轴和离体黄瓜子叶生根的影响   总被引:2,自引:0,他引:2  
1.34 mmol/L KCl与 0 .0 0 34~ 0 .0 34 2 mmol/L的 S- 330 7混用能促进绿豆下胚轴生根 ,根长增加 ,也能促进黄瓜子叶生根 ,根长和根鲜重增加。KCl还具有逆转 S- 330 7抑制离体黄瓜子叶和绿豆下胚轴根伸长的作用  相似文献   
6.
通过向营养液中分别添加NaCl和KCl,在2种EC值(4.0、8.0 mS/cm)和3种处理时间(10、20、30 d)下,对比研究2种盐胁迫对番茄产量和果实品质的影响。结果表明:NaCl比KCl处理更能提高番茄果实的VC含量,其中EC值为4.0 mS/cm的NaCl处理30 d与EC值为8.0 mS/cm的NaCl处理10 d的2种处理的果实中VC含量最高;可溶性固形物的含量在处理后都有不同程度的提高,在EC值为4.0 mS/cm情况下,NaCl处理和KCl处理的提升率差异不明显,当EC值增大至8.0 mS/cm后,KCl处理比NaCl处理的提升率更大;盐胁迫降低了果实的糖酸比,在相同处理下,除EC值为4.0 mS/cm、时间为30 d的处理外,KCl处理的下降率大于NaCl处理;盐胁迫使得番茄的单株产量减少,NaCl处理和KCl处理下降幅度最小都发生在EC值为4.0 mS/cm、处理时间为10 d时,分别为33.8%和5.5%;另外,相同处理条件下,NaCl处理的单株产量下降率明显大于KCl处理。为了改善番茄果实品质,建议采用EC值为4.0 mS/cm的NaCl或KCl营养液对番茄在开花后进行盐胁迫处理10 d。  相似文献   
7.
研究了KCl处理对盐生植物毕氏海蓬子生长和抗氧化酶活性的变化.结果表明,低浓度KCI(0,1和6mmol·-1)处理显著促进了海蓬子生长和抗氧化酶系统中的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性.而高浓度的KCI(50和100mmol·L-1)却明显抑制了海蓬子的生长,SOD、POD和CAT的活性也受到抑制,超氧阴离子(O2-)和丙二醛(MDA)含量增加程度明显高于低浓度的KCI处理.高浓度KCI处理伤害海蓬子的原因之一是抗氧化酶活性降低,不能及时将活性氧类清除,从而导致活性氧及MDA积累,引起质膜伤害,使海蓬子生长量降低.  相似文献   
8.
KCl诱导虾夷马粪海胆幼体变态的研究   总被引:1,自引:0,他引:1  
研究了不同浓度的KCl对于虾夷马粪海胆幼体变态的诱导作用及对变态后个体生长的影响。试验结果表明,KCl对虾夷马粪海胆是一种极好的变态诱导剂,0.05 mol/L的KCl作用5~10 h诱导效果最佳,在提高变态率的同时,大大地降低了死亡率。  相似文献   
9.
The effect of NaCl plus 3% chitosan on the systolic blood pressure of spontaneously hypertensive rats (SHR) were evaluated and compared with NaCl plus KCl (NaCl, 49.36% + KCl 49.36%) and chitosan or NaCl treatment alone. In SHR, administration of NaCl plus chitosan (44 mM Na/day) for two months significantly decreased the systolic blood pressure greater than of NaCl plus KCl and NaCl alone. NaCl plus chitosan resulted, though not statistically significant, in decreased urinary Na+ excretion and decreased blood urea nitrogen levels. Urinary creatinine of NaCl plus chitosan was slightly decreased compared to 3 treated groups. Serum electrolytes levels, however, remained unchanged. The combination of NaCl and chitosan may be superior to the conventional use of NaCl plus KCl or NaCl alone in the prevention of hypertension. Even though these supplementary diets have demonstrated potential anti-hypertensive effects in the experimental animal model, further research is needed before any recommendations can be made.  相似文献   
10.
KC1对中间球海胆幼虫变态的诱导效果   总被引:1,自引:1,他引:0  
中间球海胆(Strongylocentrotus intermedius)八腕后期幼虫,在KC1添加浓度100mmol/L海水中,分别处理5,10,15min后,均变态为正常稚海胆,中间试验及生产应用结果表明,经KC1处理,幼虫的附着时间缩短了36h,附着率则分别增加了40.4%,27.75%。  相似文献   
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