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1.
用营养液培养方法研究了铁和两种形态氮素(NO3--N和NH4+-N)对玉米植株吸收氮、磷、钾等大量元素和钙、镁等中量元素及其在体内分布的影响。结果表明:与NO3--N相比,供应NH4+-N促进了玉米对氮的吸收,在缺铁条件下,降低了对磷、钾、钙及镁的吸收。铁和NH4+-N都显著提高了玉米植株各器官中氮的含量。与NH4+-N处理相比,NO3--N处理的新叶中磷含量显著增加,但铁的供应对植物体内磷的含量无显著影响。使用NO3--N显著提高了玉米新叶和老叶中钾的含量,根和茎中钾的含量无明显影响。铁的供应降低了新叶和老叶中钾的含量。供铁时,NH4+-N处理的玉米新叶中钙和镁的含量显著低于NO3--N处理,而在缺铁时则无显著差异。  相似文献   

2.
Abstract

Tomato plants were grown in sand culture with NH+ 4, and NO? 3, forms of N and three levels of light. Plants supplied with NH+ 4, nutrition under high light intensity had symptoms of stunting, leaf roll, wilting, interveinal chlorosis of the older leaves, and one third the dry weight of N03‐fed plants. In contrast, growth of plants receiving NH+ 4, nutrition under shade appeared normal although dry weight was reduced. NH4‐N nutrition suppressed K, Ca and Mg accumulation in tissues and increased P contents as compared to NO3‐N nutrition.  相似文献   

3.
影响菜豆体内铁再利用效率的因素及其机理   总被引:5,自引:0,他引:5       下载免费PDF全文
本文在人工气候室中,用营养液培养方法,并结合同位素示踪技术研究了铁的供应状况,两种形态氮素(NO^-3-N和NH^+4-N)及叶处遮光对菜豆体内铁再利用效率的影响,并对其有关机理进行了深入的研究。结果表明,铁的缺乏有利于累积在根和初生叶中的铁身新生组织中转移,铁的再利用效率明显提高。无论有缺铁还供铁条件下,NH^+4-N的供应使得菜豆新叶中活性铁含量、新叶叶绿素含量及体内铁的再利用效率都明显高于N  相似文献   

4.
Abstract

A sandy soil was amended with various rates (20 – 320 g air-dry weight basis of the amendments per kg of air-dry soil) of chicken manure (CM), sewage sludge (SS), and incinerated sewage sludge (ISS) and incubated for 100 days in a greenhouse at 15% (wt/wt) soil water content. At the beginning of incubation, NH4-N concentrations varied from 50 – 280 mg kg?1 in the CM amended soil with negligible amounts of NO3-N. Subsequently, the concentration of NH4-N decreased while that of NO3-N increased rapidly. In soil amended with SS at 20 – 80 g kg?1 rates, the NO3-N concentration increased sharply during the first 20 days, followed by a slow rate of increase over the rest of the incubation period. However, at a 160 g kg?1 SS rate, there were three distinct phases of NO3-N release which lasted for160 days. In the ISS amended soil, the nitrification process was completed during the initial 30 days, and the concentrations of NH4-N and NO3-N were lower than those for the other treatments. The mineralized N across different rates accounted for 20 – 36%, 16 – 40%, and 26 – 50% of the total N applied as CM, SS, and ISS, respectively.  相似文献   

5.
氮素形态对巨峰葡萄果实品质的影响   总被引:3,自引:0,他引:3  
为了探讨氮素形态对巨峰葡萄果实品质性状的影响,设置了尿素T1(酰胺态)、全硝T2(硝铵比为100/0)、混合氮T3、T4、T5(硝铵比为70/30、50/50、30/70)及全铵处理T6(硝铵比为0/100)和清水对照CK,于生长季节进行叶面喷施试验。结果表明,不同处理均提高了果实的营养品质,喷尿素的总糖量、糖酸比最大,其次是混合氮处理,全铵处理最小;果实的Vc含量以混合氮处理较高,全铵处理的最低;果实中花青素的含量顺序为:全硝尿素混合氮全铵CK。果实硝酸盐含量从高到低依次为:全硝混合氮全铵尿素CK;硝态氮促进了果实生长,各处理平均单果重为全硝混合氮全铵尿素CK。综上结果,尿素及适当的硝态氮配比有利于巨峰葡萄果实品质的提高。  相似文献   

6.
Aerobic incubations to estimate net nitrogen (N) mineralization typically involve periodic leaching of soil with 0.01 M calcium chloride (CaCl2), so as to remove mineral N that would otherwise be subject to immobilization. A study was conducted to evaluate the accuracy of leaching for analysis of exchangeable ammonium (NH4+)-N and nitrate + nitrite (NO3?+ NO2)-N, relative to conventional extractions using 2 M potassium chloride (KCl). Ten air-dried soils were used, five each from Illinois and Brazil, that had been amended with NH4+-N (1 g kg?1) and NO3-N (0.6 g kg?1). Both methods were in good agreement for inorganic N analysis of the Brazilian Oxisols, whereas leaching was significantly lower by 12–48% in recovering exchangeable NH4+-N from Illinois Alfisols, Mollisols, and Histosols. The potential for underestimating net N mineralization was confirmed by a 12-wk incubation experiment showing 9–86% of mineral N recoveries from three temperate soils as exchangeable NH4+.  相似文献   

7.
Optimal fertilizer nitrogen (N) rates result in economic yield levels and reduced pollution. A soil test for determining optimal fertilizer N rates for wheat has not been developed for Quebec, Canada, or many other parts of the world. Therefore, the objectives were to determine: 1) the relationship among soil nitrate (NO? 3)- N, soil ammonium (NH + 4)- N and N fertilizer on wheat yields; and 2) the soil sampling times and depths most highly correlated with yield response to soil NO? 3-N and NH + 4-N. In a three year research work, wet and dried soil samples of 0- to 30- and 30- to 60-cm depths from 20 wheat fields that received four rates of N fertilizer at seeding and postseeding (plants 15 cm tall) were analyzed for NH + 4-N and NO? 3 -N using a quick-test (N-Trak) and a standard laboratory method. Wheat yield response to N fertilizer was limited, but strong to soil NO? 3-N.  相似文献   

8.
The effects of nitrogen (N) forms (ammonium- or nitrate-N) on plant growth under salinity stress [150 mmol sodium chloride (NaCl)] were studied in hydroponically cultured cotton. Net fluxes of sodium (Na+), ammonium (NH4+), and nitrate (NO3?) were also determined using the Non-Invasive Micro-Test Technology. Plant growth was impaired under salinity stress, but nitrate-fed plants were less sensitive to salinity than ammonium-fed plants due mainly to superior root growth by the nitrate-fed plants. The root length, root surface area, root volume, and root viability of seedlings treated with NO3-N were greater than those treated with NH4-N with or without salinity stress. Under salinity stress, the Na+ content of seedlings treated with NO3-N was lower than that in seedlings treated with NH4-N owing to higher root Na+ efflux. A lower net NO3? efflux was observed in roots of nitrate-fed plants relative to the net NH4+ efflux from roots of ammonium-fed plants. This resulted in much more nitrogen accumulation in different tissues, especially in leaves, thereby enhancing photosynthesis in nitrate-fed plants under salinity stress. Nitrate-N is superior to ammonium-N based on nitrogen uptake and cotton growth under salinity stress.  相似文献   

9.
The objective of this study was to test if the effects of different nitrogen forms on potato growth depend on the plant growth stage. Plants from different potato cultivars were treated with different forms of nitrogen before tuber initiation and after tuber formation. A nitrification inhibitor was used to prevent the transformation of ammonium (NH4+) to nitrate (NO3?). Plant growth, tuber formation, leaf area, leaf chlorophyll content, and tuber yield were assessed. The results obtained over 2 years indicate that plants treated with NO3-nitrogen (N) before or at tuber initiation produced more tubers per plant than those treated with NH4-N. However, plants treated with NH4-N develop tubers earlier. Additionally, after tuber formation, plants treated with NH4-N had better shoot growth than plants treated with NO3-N. A larger leaf area with higher leaf chlorophyll content resulted in greater dry matter accumulation and higher tuber yield at harvest for plants treated with NH4-N.  相似文献   

10.
The aim of this study was to evaluate the sustainability of an agro-industry sludge as a nitrogen (N) fertilizer in perennial crops by assessing its dynamics of release of: 1) N as ammonium (NH4+)- and nitrate (NO3?)-N, and 2) carbon as soil respiration. In incubation assay, application of agro-industry sludge promoted the maximum NH4+-N concentration (50 mg kg?1) 2 h after application, then it decreased with time until day 26. NO3?-N increased, reaching the maximum between day 60 and day 100, according to a second degree function. Agro-industry sludge showed a slower release of NO3?-N compared with urea. Soil basal respiration and cumulative amount of carbon dioxide were higher in sludge from day 71 on. In field, soil NO3?-N increased after fertilization treatments and was higher in Calcari Stagnic Cambisols soil. Sludge showed a potential lower environment impact in terms of mineral N release, than urea.  相似文献   

11.
增硝营养对不同基因型水稻苗期氮素吸收同化的影响   总被引:21,自引:7,他引:21  
利用控制条件下的溶液培养方法,研究了增硝营养(NH4+∶NO3-比例为100∶0和50∶50)对4种不同的基因型水稻(常规籼稻、常规粳稻、杂交籼稻、杂交粳稻)苗期生长和氮素吸收同化的影响。结果表明,增NO3-营养可以增加水稻叶片的光合速率,促进水稻对氮素的吸收,提高氮素利用率,进而促进水稻生长;不同基因型水稻在增NO3-营养下氮积累量增幅不同主要是由于其生物量增幅不同,而整株氮素含量增幅差异不大;NO3-的存在可增强谷氨酰胺合成酶和硝酸还原酶的活力,促进水稻对NH4+和NO3-的同化利用,从而增加了氮素在植株地上部的积累同化;籼稻与粳稻相比,杂交粳稻与杂交籼稻相比,前者在氮素吸收利用上均表现出更为明显的优势。  相似文献   

12.
The effects of soil residual nitrate (NO3-N) and ammonium (NH4-4) on wheat (Triticum aestivum L.) grain yield and N uptake were evaluated in a three-year experiment from 1991 to 1993, in the province of Quebec, Canada. Soil samples were collected at harvest from the depth of 0-30 and 30–60 cm from 20 wheat sites and analyzed in the laboratory for NO3-N and NH4-N. Wheat yield and N-uptake was also determined. Using statistical analysis system (SAS) and Matlab, data were analyzed and the best-fitted regression equations were plotted. Significant amounts of soil NO3-N was found in the soil ranging from 31.6 to 61.6 kg/ha. The amount of soil NH4-N varied from 9.2 to 23.3 kg/ha. The statistical effects of model parameters indicated that soil NO3-N and soil NH4-N significantly influenced wheat yield and N uptake. It may be possible to investigate wheat behavior at harvest using soil residual NO3-N and NH4-N.  相似文献   

13.
采用田间试验研究了硝态氮、铵态氮、酰胺态及不同硝态氮与铵态氮配比对川芎生长发育和产量与品质的影响。结果表明,硝态氮、铵态氮、酰胺态及硝态氮与铵态氮配施均可在一定程度上促进川芎的生长,延长其根长,茎蘖数增加,干物质积累增加,从而显著提高川芎的产量以及阿魏酸和生物碱含量。在硝态氮、铵态氮和酰胺态氮单独施用时,以尿素的增产增收和改善品质的效果最好,硝态氮最差;硝态氮与铵态氮配施可增强其肥效,延长其肥效持续期。高产高效的最佳施肥方式是50%的硝酸钙与50%的碳酸铵配施;优质高产的最佳施肥方式是75%的硝酸钙与25%的碳酸铵配施。  相似文献   

14.
To-date, assessments of nitrogen use efficiency (NUE) of sugarcane have not included the contribution of its components, nitrogen uptake efficiency (NUpE) and nitrogen utilization efficiency (NUtE). This study determined these values, based on biomass and plant nitrogen (N) content, in two four-month-old pot-grown genotypes. The treatments included six N regimes, with nitrate (NO3N) or ammonium (NH4+-N) supplied alone, or as NO3?-N for the first 6 weeks and then NH4+-N until harvest, each as 4 or 20 mM. Regardless of the N form, NUE was higher at four than at 20 mM due to significantly higher NUpE at low N supply. The results indicated that there was luxury N uptake and preference for NH4+-N nutrition, which resulted in the highest determined NUE. There were significant differences between genotypes in biomass, morphological growth parameters, N uptake, total plant N and NUE, the latter matching previously established sucrose yield-based NUE field rankings.  相似文献   

15.
This study evaluated the petiole uptake of nitrogen, phosphorus, potassium, and sulfur (N, P, K, and S) by the potato from two seed meals, mint compost, and five commercially available organic fertilizers under an irrigated certified organic production system. Available soil nitrate (NO3-N) and ammonium (NH4-N) from each amendment averaged 115 kg N ha?1 at application and 25 kg N ha?1 30 d after planting through harvest, with minor differences between fertilizers. Petiole N declined from an average of 25,000 mg N kg?1, 4 wk after emergence to 3,000 mg N kg?1 prior to harvest. Petiole P and K concentrations were maintained above 4,000 mg P kg?1, 10,000 mg K kg?1, and 2,000 mg S kg?1 tissue, respectively, throughout the growing season in all treatments. Tuber yields were not different between fertilized treatments averaging 53 Mg ha?1. This study provides organic potato growers baseline information on the performance of a diverse array of organic fertilizers and amendments.  相似文献   

16.
用营养液培养方法研究了铁和两种形态氮素对玉米植株吸收铁、锰、铜、锌等微量元素及其在体内分布的影响。结果表明:与硝态氮(NO3--N)相比,铵态氮(NH4+-N)显著提高了玉米对铁的吸收,降低了对锰、铜及锌的吸收。供铁也明显提高了植株地上部铁的吸收总量,降低了锰及锌的吸收量,尤其是在供应No3--N时这种作用更为明显。在缺铁条件下,NH4+-N处理的玉米新叶中铁的含量明显高于NO3--N处理;而新叶、老叶、茎中锰、锌、铜含量以及根中锰、锌含量都明显低于NO3--N处理。但使用NH4+-N时,根中铜的含量较高。在供铁条件下,NH4+-N处理的玉米植株四个不同器官中锰和锌的含量显著低于NO3--N处理的植株,而铜的含量正好相反。在缺铁条件下,玉米新叶中活性锰、活性锌的含量显著高于供铁处理;与NO3--N相比,NH4+-N的供应也显著降低了玉米新叶中活性锰以及活性锌的含量。  相似文献   

17.
Impacts of crop residue biochar on soil C and N dynamics have been found to be subtly inconsistent in diverse soils. In the present study, three soils differing in texture (loamy sand, sandy clay loam and clay) were amended with different rates (0%, 0.5%, 1%, 2% and 4%) of rice-residue biochar and incubated at 25°C for 60 days. Soil respiration was measured throughout the incubation period whereas, microbial biomass C (MBC), dissolved organic C (DOC), NH4+-N and NO3N were analysed after 2, 7, 14, 28 and 60 days of incubation. Carbon mineralization differed significantly between the soils with loamy sand evolving the greatest CO2 followed by sandy clay loam and clay. Likewise, irrespective of the sampling period, MBC, DOC, NH4+-N and NO3N increased significantly with increasing rate of biochar addition, with consistently higher values in loamy sand than the other two soils. Furthermore, regardless of the biochar rates, NO3-N concentration increased significantly with increasing period of incubation, but in contrast, NH4+-N temporarily increased and thereafter, decreased until day 60 in all soils. It is concluded that C and N mineralization in the biochar amended soils varied with the texture and native organic C status of the soils.  相似文献   

18.
稻田土壤中氮素淋失的研究   总被引:88,自引:3,他引:88  
本文应用稻田大型原状土柱渗漏计,研究了双季稻田土壤中氮素随渗漏水流淋失的形态、数量、季节性变化以及若干农化因子的影响。明确了稻田中氮素淋失的基本形态是硝态氮(NO3^--N),估算出双季稻田中氮素淋失总量可接近30kgN/ha,同时肯定了农田施用氮肥对地下水体环境可能的NO3^--N污染,建议双季稻田中每季水稻的氮肥用量宜控制在150kgN/ha;本文还证实氮肥用量对氮素淋失有明显影响,不同氮肥品  相似文献   

19.
Abstract

To determine the relationships between microbial biomass nitrogen (N), nitrate–nitrogen leaching (NO3-N leaching) and N uptake by plants, a field experiment and a soil column experiment were conducted. In the field experiment, microbial biomass N, 0.5 mol L?1 K2SO4 extractable N (extractable N), NO3-N leaching and N uptake by corn were monitored in sawdust compost (SDC: 20 Mg ha?1 containing 158 kg N ha?1 of total N [approximately 50% is easily decomposable organic N]), chemical fertilizer (CF) and no fertilizer (NF) treatments from May 2000 to September 2002. In the soil column experiment, microbial biomass N, extractable N and NO3-N leaching were monitored in soil treated with SDC (20 Mg ha?1) + rice straw (RS) at five different application rates (0, 2.5, 5, 7.5 and 10 Mg ha?1 containing 0, 15, 29, 44 and 59 kg N ha?1) and in soil treated with CF in 2001. Nitrogen was applied as (NH4)2SO4 at rates of 220 kg N ha?1 for SDC and SDC + RS treatments and at a rate of 300 kg N ha?1 for the CF treatment in both experiments. In the field experiment, microbial biomass N in the SDC treatment increased to 147 kg N ha?1 at 7 days after treatment (DAT) and was maintained at 60–70 kg N ha?1 after 30 days. Conversely, microbial biomass N in the CF treatment did not increase significantly. Extractable N in the surface soil increased immediately after treatment, but was found at lower levels in the SDC treatment compared to the CF treatment until 7 DAT. A small amount of NO3-N leaching was observed until 21 DAT and increased markedly from 27 to 42 DAT in the SDC and CF treatments. Cumulative NO3-N leaching in the CF treatment was 146 kg N ha?1, which was equal to half of the applied N, but only 53 kg N ha?1 in the SDC treatment. In contrast, there was no significant difference between N uptake by corn in the SDC and CF treatments. In the soil column experiment, microbial biomass N in the SDC + RS treatment at 7 DAT increased with increased RS application. Conversely, extractable N at 7 DAT and cumulative NO3-N leaching until 42 DAT decreased with increased RS application. In both experiments, microbial biomass N was negatively correlated with extractable N at 7 DAT and cumulative NO3-N leaching until 42 DAT, and extractable N was positively correlated with cumulative NO3-N leaching. We concluded that microbial biomass N formation in the surface soil decreased extractable N and, consequently, contributed to decreasing NO3-N leaching without impacting negatively on N uptake by plants.  相似文献   

20.
Extraction of soil nitrate nitrogen (NO3 ?-N) and ammonium nitrogen (NH4 +-N) by chemical reagents and their determinations by continuous flow analysis were used to ascertain factors affecting analysis of soil mineral N. In this study, six factors affecting extraction of soil NO3 ?-N and NH4 +-N were investigated in 10 soils sampled from five arable fields in autumn and spring in northwestern China, with three replications for each soil sample. The six factors were air drying, sieve size (1, 3, and 5 mm), extracting solution [0.01 mol L?1 calcium chloride (CaCl2), 1 mol L?1 potassium chloride (KCl), and 0.5 mol L?1 potassium sulfate (K2SO4)] and concentration (0.5, 1, and 2 mol L?1 KCl), solution-to-soil ratio (5:1, 10:1, and 20:1), shaking time (30, 60, and 120 min), storage time (2, 4, and 6 weeks), and storage temperature (?18 oC, 4 oC, and 25 oC) of extracted solution. The recovery of soil NO3 ?-N and NH4 +-N was also measured to compare the differences of three extracting reagents (CaCl2, KCl, and K2SO4) for NO3 ?-N and NH4 +-N extraction. Air drying decreased NO3 ?-N but increased NH4 +-N concentration in soil. Soil passed through a 3-mm sieve and shaken for 60 min yielded greater NO3 ?-N and NH4 +-N concentrations compared to other treatments. The concentrations of extracted NO3 ?-N and NH4 +-N in soil were significantly (P < 0.05) affected by extracting reagents. KCl was found to be most suitable for NO3 ?-N and NH4 +-N extraction, as it had better recovery for soil mineral N extraction, which averaged 113.3% for NO3 ?-N and 94.9% for NH4 +-N. K2SO4 was not found suitable for NO3 ?-N extraction in soil, with an average recovery as high as 137.0%, and the average recovery of CaCl2 was only 57.3% for NH4 +-N. For KCl, the concentration of extracting solution played an important role, and 0.5 mol L?1 KCl could fully extract NO3 ?-N. A ratio of 10:1 of solution to soil was adequate for NO3 ?-N extraction, whereas the NH4 +-N concentration was almost doubled when the solution-to-soil ratio was increased from 5:1 to 20:1. Storage of extracted solution at ?18 °C, 4 °C, and 25 °C had no significant effect (P < 0.05) on NO3 ?-N concentration, whereas the NH4 +-N concentration varied greatly with storage temperature. Storing the extracted solution at ?18 oC obtained significantly (P < 0.05) similar results with that determined immediately for both NO3 ?-N and NH4 +-N concentrations. Compared with the immediate extraction, the averaged NO3 ?-N concentration significantly (P < 0.05) increased after storing 2, 4, and 6 weeks, respectively, whereas NH4 +-N varied in the two seasons. In conclusion, using fresh soil passed through a 3-mm sieve and extracted by 0.5 mol L?1 KCl at a solution-to-soil ratio of 10:1 was suitable for extracting NO3 ?-N, whereas the concentration of extracted NH4 +-N varied with KCl concentration and increased with increasing solution-to-soil ratio. The findings also suggest that shaking for 60 min and immediate determination or storage of soil extract at ?18 oC could improve the reliability of NO3 ?-N and NH4 +-N results.  相似文献   

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