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1.
M. I. Bajwa 《Journal of Agronomy and Crop Science》1987,158(1):65-68
Comparative fixation of NH4 and K by wetland rice soils in relation to clay mineral composition and treatment sequence is of agronomic interest, but information on the subject is scanty. An attempt has been made to clarify this relationship by employing the normally recommended doses of fertilizers, 3 application sequences, and 5 soil clays of divergent mineralogies. The results show that montmorillonitic clay is the greatest fixer of NH4 , but least of K. X-ray amorphous clay also prefers NH4 over K. Vermiculitic and beidellitic clays strongly fix both NH4 and K. Soil clay consisting of hydrous mica, chlorite, and halloysite fixes low proportions of applied NH4 and K. The sequence in which NH4 and K are applied does not appear to affect the relative amounts that are fixed. 相似文献
2.
富硒土壤中有效硒浸提剂和浸提条件研究 总被引：4，自引：0，他引：4
以青海东部富硒土壤为供试材料,对6种有效硒浸提剂NaHCO3、KH2PO4、K2SO4、EDTA、AB-DTPA和DTPA的最佳浸提时间和土液比进行了筛选,并结合土壤有效硒最佳浸提剂的小麦生物学校验,以找出适宜富硒土壤有效硒提取的浸提剂及其浸提条件。结果表明：6种有效硒浸提剂对富硒土壤中硒的浸提量均随着土液比的增大而减少,且均随浸提时间的逐渐增加而增加。EDTA和DTPA的最佳土液比则为1/20,振荡时间为30 min;K2SO4、AB-DTPA、NaHCO3和KH2PO4四种浸提剂最佳浸提土液比均为1/15,其中K2SO4和AB-DTPA的最佳提取时间为60 min,其余两种浸提剂NaHCO3和KH2PO4的最佳浸提时间均为90 min。6种不同浸提剂在最佳提取条件下提取的土壤有效硒含量与小麦籽粒中富集的硒含量呈极显著正相关关系,但土壤有效硒的提取量以DTPA最少,其次为K2SO4,分别只占KH2PO4、NaHCO3、AB-DTPA及EDTA提取量的16% ~ 47%和36% ~ 85%,故不适用于作为石灰性富硒土壤有效硒的浸提剂。KH2PO4、NaHCO3、AB-DTPA和EDTA 提取的硒含量不仅与小麦籽粒中硒含量呈极显著正相关,而且浸提量高,提取过程简单,重复性好,故均可作为石灰性富硒土壤的有效硒浸提剂。 相似文献
3.
镉污染条件下不同形态氮肥对苋菜品质的影响 总被引：1，自引：0，他引：1
通过盆栽试验,研究了在镉污染的情况下不同种类的氮肥（硝酸铵、乙酸铵、尿素、硫酸铵、碳酸氢铵、氯化铵）对苋菜品质的影响,结果表明：在镉污染的蔬菜土壤上,Vc含量：硝酸铵〉尿素〉乙酸铵〉碳铵〉硫酸铵〉氯化铵;叶绿素含量：除硫酸铵稍差外,其他几个处理没有差异;可溶性糖的含量：硫酸铵〉乙酸铵〉尿素〉氯化铵〉硝酸铵〉碳铵;可溶性蛋白质的含量：尿素〉氯化铵,其他的比不施氮肥要差;粗纤维的含量：与对照基本没有差异;灰分的含量：施硝酸铵效果最好,其次是乙酸铵、尿素、碳铵。以各蔬菜品质含量为标准,施用碳酸氢铵、乙酸铵、尿素的效果比其他几种肥料要好。 相似文献
4.
为探明离子交换树脂膜作为养分提取手段在土壤铵钾交互作用研究上的应用效果,设置了相同培养条件下的树脂膜埋置实验和油菜盆栽试验。结果表明,施钾能减少铵的膜提取量,而施铵对钾的膜提取量影响不显著,这与铵钾同时施用时铵优先固定有关。膜提取养分量与植株养分吸收量及干物重之间均达显著或极显著相关,加上树脂膜使用便捷且可以原位提取养分,因而树脂膜可以被当作“根系模拟器”进行养分原位提取和养分交互作用方面的研究。但由于膜与真正的植物根系毕竟不同,故研究中也发现了一些膜提取养分量与植株养分吸收量并不完全一致的情况,这一点在前人的研究中甚少提及,这些情况的发现说明今后的研究中对树脂膜的应用条件还应多加注意,以便对树脂膜更好地利用,达到仅通过树脂膜这种便捷手段不需要通过植物试验就能了解土壤中养分交互作用可能对养分植物有效性的影响的目的。 相似文献
5.
小麦对镉的吸收、富集及其镉污染预测研究进展 总被引：1，自引：0，他引：1
本研究回顾和总结了国内外学者对小麦镉吸收和富集的特点,对比分析了小麦各部位镉的富集系数,小麦不同部位镉富集顺序为：根>叶>茎>籽粒。土壤镉安全阈值是保障小麦质量的重要指标,小麦籽粒中镉含量可以由土壤中总镉含量及pH值来预测。对3类不同浸提剂浸提的土壤有效态镉进行探讨,发现这些浸提剂浸提的土壤有效态镉含量与小麦镉含量间的相关性顺序为：络合剂类>中性盐类(CaCl2)>稀（弱）酸类。最后提出了结论和展望,以期为今后小麦镉污染预测提供重要的理论指导和思路。 相似文献
6.
This study was conducted to elucidate the crop physiological basis for yield differences frequently observed in experiments comparing top‐dressing of N fertilizers with injection of ammonium or ammonium/urea solutions into the soil. The effects of diammonium phosphate (NH4‐N) injected at the two‐leaf stage, calcium nitrate (NO3‐N) broadcasted and incorporated before sowing, and a control without N fertilization (‐N) were assessed from measurements of growth, N‐uptake and N‐partitioning, light interception, gas exchange, leaf anatomy and the activity of key enzymes of N‐metabolism. The experiment was performed with spring barley (Hordeum vulgare L.) grown in 80‐l containers in a vegetation hall in Braunschweig, Germany. The plants in the NH4‐N treatment produced a 20 % higher grain yield than those in the NO3‐N treatment. The grain yield superiority of the NH4‐N plants was attributable to a higher number of ears per plant (+13 %) and more grains per ear (+6 %). The NH4‐N plants exhibited lower concentrations of inorganic cations than plants supplied with NO3‐N. In the NH4‐N treatment, the light penetrated more deeply into the crop canopy and the NH4‐N plants exhibited a higher leaf carbon exchange rate at the different leaf layers than the NO3‐N plants. It is concluded that as opposed to predominantly nitrate nutrition, provision of a persistent source of ammonium enables plants to take advantage of the positive yield effect of mixed N nutrition. 相似文献
7.
V. Borkovec S. Procházka M. El.-D. Ibrahim 《Journal of Agronomy and Crop Science》1990,165(4):217-223
A lysimeter trial is described in which the fate of 15 N was monitored in a sand, loam and clay soil by using it over a period of 6 years. The following results were obtained.
1. The uptake of fertilizer nitrogen by plants, determined by using15 N, is lower than by using the conventional method ("difference method"). Nitrate 15 N is better utilized by the plants than is ammonium 15 N. The total nitrogen uptake only gives hints of these differences.
2. The extent to which plants utilize fertilizer15 N is between 38 and 58%; in the case of the method of differences this figure is between 48 and 68%.
3. Plants remove more nitrogen from the soil when fertilizer N is applied than when without fertilization. The influence of these two nutrient forms is of subordinate significance.
4. After a trial period of six years between 26 and 54 % of the fertilizer15 N remains in the soil. The resulting sequences are clay > loam > sand > and ammonium > nitrate.
5. The immobilization of the fertilizer15 N is most pronounced in the first four years but then decreased considerably; in the case of the sandy soil it is then even slightly regressive.
6. The biggest part of the15 N is deposited in the uppermost layer of the soil. The amount of 15 N in the deeper layers is diminished appreciably. The type of soil has a greater influence than the form of nitrogen.
7. If the amount of fertilizer N left in the soil is compared with the N losses from the soil's reservoir (plants' uptake, leaching) there is a negative balance for the soil nitrogen which mainly is determined by the type of soil. 相似文献
1. The uptake of fertilizer nitrogen by plants, determined by using
2. The extent to which plants utilize fertilizer
3. Plants remove more nitrogen from the soil when fertilizer N is applied than when without fertilization. The influence of these two nutrient forms is of subordinate significance.
4. After a trial period of six years between 26 and 54 % of the fertilizer
5. The immobilization of the fertilizer
6. The biggest part of the
7. If the amount of fertilizer N left in the soil is compared with the N losses from the soil's reservoir (plants' uptake, leaching) there is a negative balance for the soil nitrogen which mainly is determined by the type of soil. 相似文献
8.
针对旱地玉米春季干旱难捉全苗和碳铵播前利用率低等问题，进行了碳铵秋施试验，结果表明，碳铵秋可明显地改善上述情况，增加玉米产量和提高经济效益，并就其产机理进行了分析。 相似文献
9.
试验以青稞新育品种‘黄青2号’不同生长期的土壤为材料,对比测定不同施肥处理、不同土层土壤铵态氮、硝态氮含量,研究了土壤中铵态氮、硝态氮动态变化规律。结果显示：土壤中铵态氮、硝态氮含量在整个生育期都呈现“降低—升高—降低”的变化趋势,铵态氮含量在抽穗期最高,硝态氮含量在苗期最高,分别为2.75 mg/kg和22.64 mg/kg。0~20 cm土壤中铵态氮、硝态氮含量为1.76 mg/kg和11.82 mg/kg,分别是20~40 cm的1.76倍和2.00倍,说明物质的转化、吸收和运输主要在上层土壤中进行。土壤中铵态氮达到一定浓度时,硝态氮含量与铵态氮浓度没有相关性,而与硝酸酶活性有关。不同施肥处理下铵态氮、硝态氮含量有所差异,3种缓释肥料处理下土壤中铵态氮、硝态氮有效利用率更高。 相似文献
10.
通过对在采自浙江省金华市的12种不同性质的水稻土添加江西省吴村磷矿粉（WPR）进行淹水培养试验,研究淹水条件下影响磷矿粉溶解和有效性的土壤因素。结果表明,磷矿粉在土壤中的溶解量与土壤pH（KCl）、交换性钙离子含量以及土壤粉粒含量呈极显著或显著的负相关,而与土壤粘粒含量呈显著的正相关。经逐步回归发现,土壤pH（KCl）是影响磷矿粉溶解的第一因素,土壤pH（KCl）和土壤磷吸附常数K共同解释了78%的磷矿粉溶解。加入磷矿粉后土壤有效磷的增加量（Resin-P）与土壤的Olsen-P含量呈极显著的正相关。施用磷矿粉后土壤有效磷增加量占溶解量的百分比与土壤Olsen-P含量呈极显著性正相关,而与土壤粘粒含量、最大吸磷量呈显著负相关。 相似文献
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12.
室内培养条件下多元素长效颗粒碳铵与尿素氮素释放规律比较研究 总被引：2，自引：0，他引：2
通过对多元素长效碳铵颗粒肥和尿素在水溶液和土壤中铵态氮、硝态氮及酰胺态氮积累量比较研究发现,在相同温度下,随着培养时间的增加,两种肥料在水溶液中铵态氮、硝态氮及酰胺态氮3种形态氮素均呈线性增加趋势,且本试验研制的多元素长效碳铵颗粒肥的铵态氮积累量较尿素的积累量低,在一定程度上可起到缓释效果。此外,通过对两种肥料施入土壤进行恒温培养淋洗试验结果表明,随着培养时间的延长,多元素长效碳铵颗粒肥和尿素在土壤中的铵态氮、硝态氮及酰胺态氮3种形态氮素淋出积累速率均不断降低,而淋出积累量则不断增加,且在培养期间,多元素长效碳铵颗粒肥的无机氮淋出积累速率和淋出积累量始终低于普通尿素,这说明多元素长效碳铵颗粒肥在施入土壤后,无机氮素释放速率相对较低,这样可以延长肥效时间,达到肥料氮素缓释的效果。 相似文献
13.
为探讨有机硅土壤调理剂和有机硅功能底肥对河套灌区盐碱土壤碱化度、养分有效性及作物增产效果,在内蒙古巴彦淖尔市五原县通过采取田间小区试验设置3个处理：（1）有机硅土壤调理剂45 kg/hm2,有机硅功能肥7.5 kg/hm2;（2）有机硅土壤调理剂75 kg/hm2,有机硅功能底肥5 kg/hm2;（3）磷酸二铵 16.3 kg/hm2,氯化钾16.5 kg/hm2,尿素11.5 kg/hm2。结果表明：施用有机硅土壤调理剂后,可增加向日葵百粒重,进而增加向日葵产量,且随着有机硅土壤调理剂施用量的增加,向日葵产量呈上升趋势,施用量为75 kg/hm2时,增产幅度为9.0%,增产效果显著。在基施有机硅土壤调理剂45 kg/hm2和追施有机硅功能肥7.5 kg/hm2的前提下经济效益最佳,施用有机硅土壤调理剂后,可增加土壤有效养分,降低土壤pH、含盐量、碱化度和容重,可有效提高耕地质量和修复障碍层次。 相似文献
14.
依据某蓄电池厂土壤铅污染的基本情况,在修复工程实施前,开展了稳定化固化药剂的筛选试验。在试验过程中采用了石灰、水泥、磷酸二氢钠、磷酸二氢铵、磷酸二氢钙、磷酸氢钙、磷酸三钙、磷酸、磷肥等9 种药剂,分别进行了铅污染土壤稳定化试验。针对低浓度污染土壤,采用10%石灰、20%石灰、10%水泥、20%的水泥、10%的磷酸二氢钙、10%磷酸三钙、20%磷酸三钙、10%磷酸二氢铵、20%磷酸二氢铵和20%的磷酸可以达到修复目标。针对高浓度污染土壤,当添加20%的水泥、20%的磷酸氢钙、10%磷酸三钙、20%磷酸三钙、10%磷酸二氢铵、20%磷酸二氢铵、10%磷酸和20%磷酸可以达到修复目标。从修复成本考虑,建议采用水泥作为稳定化药剂,低浓度污染土壤的添加量为10%,高浓度污染土壤的添加量为20%。 相似文献
15.
为了阐明石灰土中植物缺铁失绿的生理生化机理,综述了石灰土或重碳酸盐胁迫下植物对铁吸收和转运的研究进展。在石灰土壤中,由于存在CaCO3或MgCO3,它们与CO2和H2O反应形成过量的碳酸氢根离子（也叫重碳酸盐）,从而导致了石灰土中富含重碳酸盐。总结了重碳酸盐改变土壤pH,降低了土壤中铁的可利用性,从而限制了植物对土壤中铁的吸收;另一方面,植物在重碳酸盐胁迫下,诱导植物根系产生一系列的生理生化反应响应低铁生境,包括植物根系分泌相关的物质或质子到根际土壤酸化土壤,诱导根系铁还原酶基因表达从而增强铁还原酶活性,以及诱导铁转运体基因的表达等。石灰土壤中的存在大量的重碳酸盐,针对该土壤环境的特殊性,未来应加强以下几个方面的研究,（1）重点研究重碳酸盐对铁在植物组织之间的长距离运输的影响,挖掘重碳盐影响铁转运的分子机制;（2）植物细胞内的铁蛋白是否受到重碳酸盐的影响,仍然需要开展相关的研究;（3）进一步研究土壤中的微生物与重碳酸盐在植物胁迫中的作用。 相似文献
16.
17.
田菁改良重度盐渍化土壤的效果分析 总被引：5，自引：0，他引：5
为评价田菁改良重度盐渍化土壤的效果,试验设置4个处理：（1）只种植田菁(T);（2）种植田菁,施用二铵450 kg/hm2(TA);（3）种植田菁,施用磷石膏2250 kg/hm2(TG);（4）不种植田菁的空白处理作对照(CK)。结果表明：施用磷石膏能够显著促进田菁生长(P<0.05),TG处理地上部、地下部生物量较T、TA处理分别增加了14.24%、24.77%和8.32%、12.39%,施用二铵对田菁生长的促进作用不显著。种植田菁能够显著降低重度盐渍化土壤含盐量、容重,提高土壤速效氮、速效钾、水溶性有机质(DOC)含量,及土壤大团聚体含量、平均重量直径(MWD)、总孔隙度(P<0.05),TG处理改良效果最大。相关分析表明,盐渍化土壤含盐量、Na+含量、DOC、有机质是维系盐渍化土壤结构的关键性状,降低土壤含盐量、Na+含量,提高DOC、有机质含量是盐渍化土壤改良方向。种植田菁,同时施用磷石膏是一种快速提升重度盐渍化土壤肥力的有效方法。 相似文献
18.
Genetic variation in wheat cadmium accumulation on soils with different cadmium concentrations 总被引：5，自引：0，他引：5
Cadmium (Cd) accumulation in wheat genotypes of spring bread wheat (Triticum aestivum L.) and spring durum wheat (Triticum turgidum var. durum) was studied in field trials every third week throughout the growing season. The study was carried out in Sweden on three different soils and during two growing seasons. The results showed that the genetic variation in shoot and grain Cd accumulation remained consistent, regardless of soil type or growing season. In addition, it was possible to select the genotype that accumulated most Cd already at the beginning of the growing season, since this genotype also accumulated most Cd in the vegetative tissues of the shoot. These results indicate that it is possible to identify genotypes that accumulate most Cd in the grain at an early plant development stage. High Cd concentrations in the shoot were also observed to give high Cd concentrations in the grain. This indicates that the regulatory mechanism for grain Cd accumulation is not located in the shoot, but in the root or as a feature of root Cd uptake. The soil material and the soil solution at all three sites were analysed for strongly bound Cd (as extracted with 2 m HNO3), more easily plant‐available Cd (as extracted with ammonium lactate), pH, organic matter, clay content and conductivity. None of these parameters was clearly correlated to the Cd concentration in the grain. 相似文献
19.
A field experiment was conducted at the Indian Agricultural Research Institute, New Delhi to study the growth and yield of wheat as influenced by the concentrations of ammonium-N and nitrate-N in soil. A series of ammonium and nitrate nitrogen concentrations in soil on a time frame was developed by treating prilled urea with nitrification inhibitors DCD or neem cake as well as by changing the dose and time of N application. The study revealed that number of tillers m-1 as well as ears m-1 row length were significantly positively correlated with ammonium-N concentration at 15 and 30 DAS and nitrate-N concentration at 30 and 45 DAS. Number of grains ear-1 was significantly positively correlated with ammonium-N at 30, 45 and 60 DAS and nitrate-N at 45 and 60 DAS. Ultimately grain yield in wheat was significantly positively correlated with ammonium-N concentration at 15 and 30 DAS and nitrate-N concentration at 30, 45 and 60 DAS. The response between grain yield and concentrations of both ammonium and nitrate forms of N was quadratic. The optimum concentration of ammonium-N in soil for maximum grain yield gradually decreased with the age of the crop from 54.6 to 63.6 μg g-1 at 15 DAS to 22.7 to 26 μg g-1 at 30 DAS. In the case of nitrate-N its optimum concentration for maximum grain yield increased with age of the crop from 25.1 to 30 μg g-1 at 15 DAS to 31.6 to 34 at 45 DAS and it decreased thereafter. 相似文献
20.
长期定位施肥土壤硝态氮和铵态氮积累特征及其与玉米产量的关系 总被引：8，自引：0，他引：8
为潮土中硝态氮和铵态氮的运移、积累特征及其与夏玉米产量之间的关系,以始于1978年的莱阳长期定位施肥试验为基础,在2014,2015年夏玉米收获后,分别测定0~20,20~40,40~60,60~80,80~100 cm土层硝态氮、铵态氮含量,并计算0~100 cm不同土层硝态氮、铵态氮积累量及夏玉米产量。结果表明:施用有机肥或化学氮肥均能提高土壤硝态氮或铵态氮含量及其积累量;在0~100 cm土层中各处理硝态氮的垂直迁移趋势不同,而铵态氮的垂直迁移趋势基本一致;与化肥相比,施用有机肥可滞缓硝态氮向土壤深层淋溶,但两者对铵态氮向土壤深层迁移趋势的影响不明显;长期施用有机肥、氮肥对硝态氮、铵态氮积累量的影响均达极显著水平,且对土壤硝态氮积累量存在极显著的交互效应;与长期不施肥M_0N_0(CK)相比,施肥处理(M_0N_1、M_0N_2、M_1N_0、M_1N_1、M_1N_2、M_2N_0、M_2N_1、M_2N_2)硝态氮积累量、铵态氮积累量分别显著增加112%~396%和69%~259%(P0.05);在0~20,0~40,0~60,0~80,0~100 cm各土层中,硝态氮、铵态氮积累量与夏玉米产量具有不同线性关系。研究表明,合理的有机无机肥配施可以降低土壤硝态氮、铵态氮淋溶及其积累,从而有利于提高作物产量,维持农田土壤生态系统的稳定性,促进农业可持续发展并保护地下水源。 相似文献