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京郊有机肥料的质量状况分析 总被引：9，自引：2，他引：7
调查分析了北京市125个有代表性的商品有机肥和传统有机肥样品的养分状况、重金属含量及部分微生物学指标.结果表明,目前北京地区有机肥品质并不理想.商品有机肥中,有73.7%的样品有机质含量低于标准,44.7%的样品养分含量不符合标准,73.7%的样品pH值、39.5%的样品含水量不符合标准.传统有机肥的有机质、全氮、全磷含量均高于商品有机肥,但含水量超过商品有机肥1.29倍.商品有机肥中重金属Cd、Cr、Pb、As、Hg的含量变异较大,平均分别为0.678、36.1、17.2、5.26、0.679 mg/kg.商品有机肥和传统有机肥中蛔虫卵死亡率均符合标准,传统有机肥中部分样品大肠杆菌值超标. 相似文献
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Yunqing Luo Shujie Zhao Jingyao Tang He Zhu Wei Cui 《Journal of plant nutrition》2020,43(19):2876-2884
Abstract Fast urbanization and population increase resulted in the demand for ornamental seedling supply in a high efficiency under the culture of continuous artificial lighting. Light emitting diode (LED) can be considered as the replacement of high-pressure sodium (HPS) lamps by providing lights with specific wavelengths for plant growth at low energy cost. In this study, nutrient use efficiency was detected in Podocarpus macrophyllus seedlings under lighting spectra generated by white light-emitting diodes (LEDs) (red (R)/green (G)/blue (B)=8.4:75:16.6) and high-pressure sodium (HPS) lamps (R/G/B/=4.3:69.3:26.5). Compared to seedlings under the HPS spectrum, those under white LED spectrum had better growth, greater biomass accumulation, higher photosynthesis and gas exchange. In contrast, LED-spectrum treated seedlings had greater nitrogen (N) and phosphorus (P) contents than HPS-spectrum treated ones. The LED spectrum promoted nutrient use index for both N and P in seedlings compared to the HPS spectrum. The LED spectrum induced steady-state uptake of P but resulted in the dilution of N. In conclusion, white LED can be considered to replace the usage of HPS lamps for the culture of tree seedlings due to the spectrum effect on N utilization, P uptake and the use efficiencies of N and P. 相似文献
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低钾逆境下根结线虫感染所诱导的番茄根巨型细胞的组织病理学反应 总被引：1，自引：0，他引：1
Comparison of histopathological response and quantitative measurement of giant cell(GC) induced by Meloidogyne javanica in tomato root were studied under potassium-deficient(0.2 mmol/L K+) and replete conditions(control,6.0 mmol/L K+).K+-deficient stress did not impede the formation and maintenance of GC.The mean number of GC per feeding site as well as the mean diameter of GC did not differ between the treatments.However,the thickness of cell wall including components resulted from the accumulated polysaccharide and the length of cell-wall ingrowth increased 5-25 d after inoculation in K+-deficient as compared with K+-replete conditions.An increase of cell-wall ingrowth suggested a kind of compensational response to the potassium stress. 相似文献
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Ahmad Sher Abdul Sattar Abdul Qayyum Muhammad Ijaz Ahmad Nawaz Abdul Manaf 《Journal of plant nutrition》2019,42(13):1556-1565
The production of oil from the conventional oilseed seed crops (viz. mustard, rapeseed) is not sufficient to meet the demands of Pakistani people. Due to this reason, a surplus quantity of oil is imported every year from different countries to fulfill the domestic demands of the cooking oil. This 2-year study was aimed to optimize the dose of NPK for profitable production of white mustard. Nitrogen (0, 60, 90?kg ha?1), phosphorous (0, 30, 60?kg ha?1) and potassium (0, 75, 100?kg ha?1) were applied in various combinations. The results indicated that highest seed yield and profitability was recorded with NPK at 90–60–100?kg ha?1, which was attributed to improvement in crop growth. In crux, application of NPK at pre-optimized rate might be a viable option to improve the growth, yield, oil quality, and economics of white mustard production under arid climates in Pakistan. According to the results, a balanced use of NPK fertilization is a key management strategy for white mustard growing farmers of arid region. 相似文献
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在我国东南6省(市)选择代表性区域(自然村),采用ASI和地统计学等方法对耕作土壤的pH值、有机质、有效氮、磷和钾的空间变异性与合理取样数量进行了研究。结果表明,①pH值和有机质是相对稳定的土壤属性,在整个研究区域其变异较小,近似于正态分布;施肥元素的变异则较大,表现出明显的负偏峰分布特征。②尽管某些土壤属性或大量元素的总体变异性相似,但在各研究区域,其实际半方差结构并不相同。③对于明显偏峰分布的土壤养分来说,建议采用最适分配法确定合理取样数量。纯随机合理取样数量可在一定程度作为参考。 相似文献
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