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1.
为揭示外源锌在绿洲盐化潮土中的转化特征,通过盆栽模拟试验,探究了盐渍条件下不同施锌量对玉米幼苗生长和锌形态转化的影响。结果表明,无论非盐渍条件还是盐渍条件下,随着施锌量的增加玉米的株高和干重均呈先增加后减小的趋势,施锌量为5~10 mg/kg时达到最大。玉米含锌量随施锌量的增加而增大,吸锌量随施锌量的增加先增大后减小,施锌量为10 mg/kg时达到最大。施锌0.5、1.0、2.0、5.0、10.0、20.0 mg/kg处理的株高与不施锌比较,在非盐渍条件下分别增加13.60%、13.89%、15.58%、20.84%、21.57%、19.58%,在盐渍条件下分别增加3.31%、8.00%、9.74%、11.51%、8.41%、6.87%。由此认为,绿洲盐化潮土的适宜施锌量为5~10 mg/kg,有害或过量施锌量为≥20 mg/kg。随施锌量的升高,盐渍条件下的土壤有效锌(DTPA-Zn)、碳酸盐结合态锌(CAB-Zn)、松结有机结合态锌(WBO-Zn)、氧化锰结合态锌(OxMn-Zn)、无定形氧化铁结合态锌(AOFe-Zn)、晶形氧化铁结合态锌(COFe-Zn)和残留矿物态锌(RES-Zn)均呈上升趋势,分别增加了15.63%~767.19%、7.69%~296.92%、5.68%~270.45%、0.72%~19.42%、1.82%~65.25%、1.01%~37.61%、0.18%~6.92%。与非盐渍条件下相比,盐渍条件下的玉米株高、干重、含锌量、吸锌量、土壤有效锌(DTPA-Zn)、植物可利用态锌(碳酸盐结合态锌、松结有机结合态锌、氧化锰结合态锌)均降低,其他态锌(无定形氧化铁结合态锌、晶形氧化铁结合态锌和残留矿物态锌)均升高。综合分析认为,施用适量锌肥能显著提高玉米的耐盐性,缓解长期盐分胁迫带来的毒害,在短期内能有效改善土壤-作物系统的锌营养水平。  相似文献   

2.
氮锌配施对石灰性土壤锌形态及肥效的影响   总被引:13,自引:1,他引:12  
通过分析石灰性土壤上施用锌肥后土壤中锌的形态变化,研究锌肥的有效性及后效,为指导合理施用锌肥提供理论依据。结果表明在潜在性缺锌的石灰性土壤施锌肥没有明显的增产效果,可增加小麦籽粒锌含量,但不同基因型反应差异很大;土壤中的锌主要以矿物态存在,占全锌91.5%~97.6%,其次为松结有机态锌(1.34%~5.53%)、碳酸盐结合态锌(0.47%~1.55%);施入土壤中的锌增加了交换态、松结有机态、碳酸盐结合态、氧化锰结合态锌含量,但大部分转化为矿物态;种植小麦可以使土壤中的锌向有效态转化;施氮增加了小麦对锌的吸收,也增加了锌矿化的比例;主成分分析结果表明,交换态、松结有机态和碳酸盐结合态均能不同程度反映土壤锌的有效性,石灰性土壤中碳酸盐结合态和有机结合态锌含量占有较为可观的比例,因此增加这两种形态储备容量是调节和控制土壤锌营养状况的重要措施。  相似文献   

3.
新疆石灰性土壤锌有效性及其影响因素   总被引:3,自引:1,他引:2  
为探讨新疆石灰性土壤锌的组分分布特征及锌有效性的影响因素,对南北疆3种最主要土壤类型农田土壤锌及其组分含量进行研究。结果表明:新疆石灰性土壤有效锌平均含量为潮土(0.69mg/kg)>棕漠土(0.57mg/kg)>灰漠土(0.51mg/kg),变异系数为灰漠土>潮土>棕漠土。在土壤锌组分中,松结有机态锌(WBO)、碳酸盐结合态锌(CARB)、氧化锰结合态锌(OxMn)、紧结有机态锌(SBO)、无定形铁结合态锌(AOFe)平均含量均为潮土>棕壤土>灰漠土。南北疆土壤锌背景值不同,南疆土壤全锌含量高于北疆土壤,而北疆土壤全锌变异较大。土壤碳酸钙含量和物理性粘粒含量与松结有机态、碳酸盐结合态、紧结有机态锌分配率高度相关。松结有机态锌、碳酸盐结合态锌及松结有机态锌分配率与土壤物理性粘粒含量呈(极)显著正相关。交换态锌与松结有机态锌呈显著正相关。松结有机态锌与碳酸盐结合态锌呈显著正相关。石灰性土壤有效锌含量与松结有机态锌、碳酸盐结合态锌含量呈显著正相关,可用方程Y=0.306+0.123WBO+0.116CARB(F=20.095,r2=0.801**)预测。  相似文献   

4.
锌源和施锌方法对石灰性土壤锌组分及锌肥利用率的影响   总被引:2,自引:1,他引:1  
【目的】选用合适的锌肥以及合理的施肥方式不仅可以提高小麦籽粒锌营养品质,还可以提高石灰性土壤的锌肥利用率。因此,研究不同锌源和施肥方式对石灰性土壤中锌组分含量以及锌肥利用率的影响具有重要意义。【方法】采用盆栽试验,设置两种锌源(水溶态锌肥Zn SO4·7H2O和螯合态锌肥Zn-EDTA)全层混匀均施和表面条施两种方式,调查了土壤中交换态Zn(Ex-Zn)、松结有机态Zn(LOM-Zn)、碳酸盐结合态Zn(Carb-Zn)、氧化锰结合态Zn(Ox Mn-Zn)、紧结有机态Zn(TOM-Zn)5种形态锌的含量,分析了小麦对锌肥的利用率。【结果】全层混匀均施与表面条施,两种锌肥均增加了小麦籽粒和秸秆Zn含量,全层均施Zn SO4·7H2O处理的籽粒Zn含量比对照提高43%,均施和表面条施Zn-EDTA的籽粒Zn含量分别比对照提高57%和75%;Zn-EDTA均施和条施的锌肥利用率分别为6.5%和5.3%,Zn SO4·7H2O均施和条施的锌肥利用率分别为3.6%和1.3%。小麦收获后,条施Zn SO4·7H2O和Zn-EDTA的施锌区有效锌含量分别为9.25和1.97 mg/kg,分别为均施处理的2倍和1.8倍;与对照相比,Zn SO4·7H2O和Zn-EDTA条施及均施的4个处理均增加了土壤中各形态锌的含量,并且4个处理与对照土壤中各形态Zn含量的规律一致,即:松结有机态碳酸盐结合态紧结有机态氧化锰结合态交换态。均施Zn SO4·7H2O和Zn-EDTA 2个处理的交换态Zn含量分别为0.12和0.13 mg/kg,条施分别为0.38和0.54 mg/kg;均施处理松结有机态Zn含量分别为5.26和1.56 mg/kg;不同处理碳酸盐结合态Zn含量变化趋势与松结有机态Zn含量基本一致;条施Zn SO4·7H2O施肥区氧化锰结合态Zn含量为对照的4倍,不同处理的土壤中紧结有机态Zn含量变化规律与氧化锰结合态Zn含量变化规律相似。相关分析表明,土壤交换态Zn、松结有机态Zn和碳酸盐结合态Zn含量均与有效锌含量呈显著正相关关系,与不施锌肥相比,Zn-EDTA施入土壤后,小麦收获后松结有机态Zn和碳酸盐结合态Zn含量明显增加,而紧结有机态Zn则相对减少。【结论】潜在缺锌石灰性土壤上施用螯合态锌肥Zn-EDTA能显著增加土壤中潜在有效的锌组分以及锌肥利用率,而且施用螯合态锌肥后,较高的有效锌含量可以维持至小麦收获后,有效提高了锌肥利用率。与均施处理相比,条施这种集中施用的施肥方法可以增加近根系土壤中有效性较高的锌形态含量。  相似文献   

5.
黄土高原旱地连续施用锰肥的土壤效应研究   总被引:1,自引:0,他引:1  
采用连续浸提形态分级方法,研究了连续施用锰肥17a后锰的土壤化学特性变化。结果表明:经过长期连续施用锰肥,土壤全锰和DTPA—Mn含量增加不多。土壤DTPA—Mn含量随试验时间的延长呈增加趋势,施锰土壤有效锰提高不多,土壤DTPA—Mn含量只增加了0.4~1.7mgkg^-1。土壤中的锰主要以矿物态存在,占土壤全锰含量的比例为87.3%~91.8%。碳酸盐态、氧化锰态和紧结有机态锰占全锰的比例相当,土壤中各形态锰按含量大致呈矿物态〉碳酸盐态〉氧化锰态〉紧结有机态〉松结有机态〉交换态的顺序。施入土壤的锰肥有91.1%~98.6%进入碳酸盐结合态、氧化锰结合态、紧结有机态和矿物态,只有很少一部分仍留在有效态锰库中。交换态和松结有机态锰对土壤锰的有效性起着主要作用,可以反映土壤锰的供给状况,碳酸盐态和紧结有机态锰不能反映土壤锰的有效性。  相似文献   

6.
盆栽试验研究3种阴离子形态Zn肥对水稻生长发育、养分吸收及土壤Zn形态的影响。结果表明,NO3-或NO3-与SO42-配合较SO42-、Cl-有利于提高水稻产量。供试土壤各形态Zn含量以交换态(Ex-Zn)和有机结合态(OM-Zn)最低,其次为碳酸盐结合态(CAB-Zn),再次为晶体氧化铁结合态(COFe-Zn)、无定型氧化铁结合态(AOFe-Zn)及氧化锰结合态(OMn-Zn),其中Ex-Zn、OM-Zn及OMn-Zn 3形态Zn之和(即土壤有效锌)为9.2mg/kg,占全Zn量的9.6%;土壤矿物态锌是土壤Zn素的主要组分,含量为69.3mg/kg,占全Zn量的72.0%。植稻提高了土壤CAB-Zn、AOFe-Zn、OMn-Zn含量,土壤各形态Zn仍以Ex-Zn、OM-Zn最低,其次为COFe-Zn,再次为CAB-Zn、AOFe-Zn及OMn-Zn含量,Ex-Zn、OM-Zn及OMn-Zn 3形态Zn之和为10.5mg/kg,占全Zn量的11.2%。土壤矿物态锌仍是土壤Zn素的主要组分,但含量及占全Zn量的比例较种植前分别减少4.2mg/kg和2.7%。水稻施Zn提高了植株吸Zn量和土壤全Zn量及OMn-Zn、COFe-Zn含量,土壤有效锌(Ex-Zn、OM-Zn及OMn-Zn 3形态之和)含量较对照增加12.7%~103.8%。  相似文献   

7.
湖南省主要茶园土壤锌的形态及其有效性   总被引:2,自引:1,他引:1  
采用野外调查采样分析和田间试验方法研究了湖南省主要茶园生态系统中土壤Zn的形态及其有效性.结果显示:①成土母质明显影响土壤中各种形态Zn的含量,与母质本身的特性有关;②生物 秸秆和秸秆覆盖处理能明显提高茶园土中有效态Zn与有机态Zn的含量,而对其他形态Zn的含量影响不太明显;③土壤中对有效态Zn(AZn)含量影响最大的是交换态Zn(ExZn)与无定形氧化铁结合态Zn(AFeZn),其次为氧化锰结合态Zn(MnOZn)、有机态Zn(OMZn)及晶形氧化铁结合态Zn(CFeZn).  相似文献   

8.
氮锌配施对冬小麦根土界面锌有效性及形态分级的影响   总被引:3,自引:1,他引:2  
【目的】 氮能够促进冬小麦根系对锌的吸收及在籽粒中的积累。研究氮锌配施对冬小麦根土界面锌有效性及形态分级的影响,有助于探究氮锌配施促进冬小麦吸收锌的可能机制,为合理施用氮肥来提高冬小麦籽粒锌含量提供一定的理论依据。 【方法】 以冬小麦为试材进行了根箱培养试验。分别设置三个氮水平 (0、0.2和0.4 g/kg) 和两个锌水平 (0和10 mg/kg),分析了冬小麦地上部锌含量、根际土和非根际土有效锌含量、pH以及六种锌形态含量。 【结果】 氮锌配施 (N0.2Zn10和N0.4Zn10) 处理显著提高了冬小麦地上部干物质重和锌含量。在不施锌 (Zn0) 条件下,N0.4处理显著提高根际土壤的有效锌含量;在Zn10条件下,N0.4和N0.2处理均显著降低根际土有效锌含量,却提高了非根际土有效锌含量。无论施锌与否,N0.4和N0.2处理均显著降低根际土壤的pH,但对非根际土壤的pH影响不大。在Zn0条件下,N0.4和N0.2处理显著降低了根际土壤交换态锌、碳酸盐结合态锌及非根际土氧化物结合态锌含量,提高了非根际土交换态锌、根际与非根际土壤残渣态锌含量。在Zn10条件下,N0.4和N0.2处理显著提高了根际和非根际土交换态锌、非根际土松结有机态和紧结有机态锌及根际土残渣态锌含量,降低了根际土松结有机态、碳酸盐结合态锌及根际与非根际土壤残渣态锌含量。 【结论】 氮锌配施提高冬小麦锌含量,促进冬小麦锌的吸收,可能是由于氮锌配施与冬小麦根系共同作用降低了根际土壤pH,促进土壤中锌从松结有机态和碳酸盐结合态向交换态转化,从而提高了土壤锌的有效性。   相似文献   

9.
铜锌镍锰赋存形态的土体变化特征研究   总被引:1,自引:0,他引:1  
本文用逐步连续分级法研究了砂姜黑土中铜锌镍锰的化学形态在土壤剖面中的变化特征以及耕作措施等对其的影响力,结果表明,砂姜黑土中换态,有机态和无定形铁结合态铜锌镍锰的相对含量随剖面深度增加而降低,氧化锰态和残留态则随剖面加深而提高;碳酸盐结合态因元素种类的耕种方式而异,抑或增加抑或降低;晶形氧化铁态可以分类两类,铜镍变化不很明显,锌锰随剖面深度增加而增加,旱耕熟化尤其是水旱轮作后,土壤中铜锌镍锰由植物  相似文献   

10.
本文用逐步连续分级法研究了砂姜黑土中铜锌镍锰的化学形态在土壤剖面中的变化特征以及耕作措施等对其的影响力。结果表明,砂姜黑土中代换态、有机态和无定形铁结合态铜锌镍锰的相对含量随剖面深度增加而降低;氧化锰态和残留态则随剖面加深而提高;碳酸盐结合态因元素种类和耕种方式而异,抑或增加抑或降低;晶形氧化铁态可以分成两类,铜镍变化不很明显,锌锰随剖面深度增加而增加。早耕熟化尤其是水旱轮作后,土壤中铜锌镍锰由植物无效的残留态或者有效性较低的晶形铁态(锌和锰)向有效性较高的代换态、有机态和无定形铁态转化,从而提高了土壤中铜锌镍锰的可移动性和有效性.  相似文献   

11.
Abstract

Zinc toxicity of peanuts (Arachis hypogaea L.), resulting from excessive amounts of Zn applied to previous crops, has been observed for many years in a limited number of peanut fields in Georgia. A tentative critical value of 12 mg/kg of Mehlich No.1 extractable soil Zn has been reported, but soil pH should be considered in establishing a more precise critical value since availability of soil Zn is affected greatly by soil acidity. A 3‐year study was conducted on a Tifton loamy sand (thermic, Plinthic Paleudults) to evaluate the relationship between soil pH and soil Zn on concentration of Zn in peanut leaves. Factorial treatments were 0, residual, medium, and high rates of Zn and soil pH levels near 5.5, 5.9, 6.2, and 6.8. Pod yields were not affected by treatments and Zn toxicity was not observed. Leaf Zn was affected more by soil pH than by soil Zn, but correlation coefficients were highest where both soil pH and soil Zn were included in the determination. A regression equation, based on soil pH and soil Zn, showed that an increase in soil Zn from 1.0 to 10.0 mg/kg increased leaf Zn 202 mg/kg at soil pH 4.6 and only 9 mg/kg at pH 6.6. Data from growers’ fields, in which samples were collected from eight healthy and toxic areas, indicated that a leaf Ca:Zn ratio of 50 or less was required for Zn toxicity of peanuts rather than high concentrations of leaf Zn per se.  相似文献   

12.
Abstract

Many soil extractants have been developed for determination of zinc (Zn) availability to plants. The optimum soil Zn extractant should be useful not only for prediction of plant Zn concentration but also for detection of applied Zn levels. The objectives of this study were: i) to compare soil Zn extradants for detecting applied Zn and for predicting peanut leaf Zn over a range of soil pH levels, and ii) to correlate other soil‐extractable Zn levels with Mehlich‐1. Soil and peanut leaf samples were taken from a field study testing pH levels as the main plots and Zn application rates in the sub‐plots. Extractable Zn was determined on soil samples using Mehlich‐1, Mehlich‐3, DTPA, MgNO3, and many dilute salt extradants of varied strength and pH. Correlation of extractable soil Zn to cumulative applied Zn levels revealed Mehlich‐1, Mehlich‐3, DTPA, and AlCl3 extradants to be among the best indicators of applied Zn. Leaf Zn concentration was best correlated with soil Zn extracted by dilute salts, such as KCl, CaCl2, NH4Cl, CaSO4, and MgCl2. Including soil pH as an independent variable in the regression to predict leaf Zn considerably improved R‐square values. The DTPA‐extractable soil Zn levels were very well correlated with Mehlich‐1‐extractable Zn. Mehlich‐3 extracted about 20% more soil Zn than Mehlich‐1, but Mehlich‐3 soil Zn was not as well correlated to Mehlich‐1 soil Zn as DTPA soil Zn. Lower pH solutions extracted more of the applied Zn, but more neutral solutions extracted Zn amounts which were better correlated with Zn uptake. On the other hand, Mehlich‐1, which had a lower pH, had better correlations with both applied Zn and leaf Zn than did Mehlich‐3. Shortening the DTPA extraction time to 30 minutes resulted in better correlations than the standard two hour extraction time. Chloride (Cl) was the best anion tested in relation to soil applied Zn recovery in combination with potassium (K), calcium (Ca), and aluminum (Al), and Cl optimized leaf Zn correlations for ammonium (NH4), K, Ca, and magnesium (Mg). The larger the valence of the cation, the better the correlation with applied Zn and the poorer the correlation with leaf Zn.  相似文献   

13.
The movement and availability of Zn from six organic Zn sources in a Typic Xerorthent (calcareous) soil were compared by incubation, column assay, and in a greenhouse study with maize (Zea mays L.). Zinc soil behavior was studied by sequential, diethylenetriaminepentaacetate, and Mehlich-3 extractions. In the incubation experiment, the differences in Zn concentration observed in the water soluble plus exchangeable fraction strongly correlated with Zn uptake by plants in the greenhouse experiment. Zinc applied to the surface of soil columns scarcely moved into deeper layers except for Zn-ethylenediaminetetraacetate (EDTA) that showed the greatest distribution of labile Zn throughout the soil and the highest proportion of leaching of the applied Zn. In the upper part of the column, changes in the chemical forms of all treatments occurred and an increase in organically complexed and amorphous Fe oxide-bound fractions was detected. However, the water soluble plus exchangeable fraction was not detected. The same results were obtained at the end of the greenhouse experiment. Significant increases were found in plant dry matter yield and Zn concentration as compared with the control treatment without Zn addition. Increasing Zn rate in the soil increased dry matter yield in all cases but Zn concentration in the plant increased only with Zn-EDTA and Zn-ethylenediaminedi-o-hydroxyphenyl-acetate (EDDHA) fertilizers. Higher Zn concentration in plants (50.9 mg kg(-)(1)) occurred when 20 mg Zn kg(-)(1) was added to the soil as Zn-EDTA. The relative effectiveness of the different Zn carriers in increasing Zn uptake was in the order: Zn-EDTA > Zn-EDDHA > Zn-heptagluconate >/= Zn-phenolate approximately Zn-polyflavonoid approximately Zn-lignosulfonate.  相似文献   

14.
用溶液培养的方法研究了玉米幼苗对短暂供锌的反应及缺锌后再供锌的恢复效果.结果表明:10~12小时的正常供锌后再缺锌培养,对玉米幼苗的危害比一直缺锌的还大;缺锌培养使玉米幼苗出现缺锌症状后再正常供锌,可使之恢复,低锌使玉米出现的缺锌症状比缺锌培养的更难以恢复,证明低锌比缺锌对玉米造成的危害更大,缺锌使玉米的有机酸分泌增加,低锌增加的更多.  相似文献   

15.
不同白菜品种对锌的响应及锌利用效率研究   总被引:2,自引:0,他引:2  
采用盆栽试验研究了白菜[Brassica campestris L.ssp.Chinensis(L.)Makino]4个品种对不同浓度锌(Zn 0、1、10 mg/kg)的响应.结果表明,白菜的生物量及体内锌含量随锌水平的增加而增加;但白菜品种对锌营养反应的敏感性不同.地上部锌含量、锌积累量和锌吸收效率均以日本华冠(J...  相似文献   

16.
用溶液培养法研究不同Zn浓度对玉米缺Zn后恢复效果及胚乳在缺Zn中作用结果表明,不同基因型玉米缺Zn后恢复所需的适宜Zn浓度不同,敏感品种比非敏感品种要求更高的Zn浓度。缺Zn后恢复所需适宜Zn浓度高于正常培养所需适宜Zn浓度,低浓度Zn(0.1μmol/L)无恢复作用(生物量)。带上胚乳使敏感品种在缺Zn、低Zn下受抑程度(缺Zn与供Zn生物量差值)提高,而非敏感品种受抑程度反而减小。缺Zn与低Zn培养时体内P含量提高,胚乳可缓解这种影响。缺Zn后再供Zn可使体内Zn含量提高,而P含量降低,玉米对Zn产生奢侈吸收,使体内Zn含量超过正常供Zn水平,表明缺Zn后植物对Zn的要求提高。0.1μmol/L Zn恢复对“吉单120”玉米Zn含量无明显影响,但“辽单22”玉米Zn含量显著提高,这表明非敏感品种比敏感品种利用低Zn的能力更强。  相似文献   

17.
Abstract

Z1nc (Zn) deficiency of corn (Zea mays L.) has been detected in 20 or more states 1n the United States including Georgia. Since soil pH is a major factor in assessing the availability of soil Zn, this measurement has been included with acid extractable soil Zn in developing calibration Zn soil tests in North Carolina and Virginia. The objectives of this study were to develop a reliable soil test for Zn based on soil pH and Mehlich 1 soil Zn for corn gown on coarse‐textured soils and to compare our soil test values with those recently published from North Carolina where Mehlich 3 was the extractant. The study was conducted 1n 1979 to 1981 on a Tifton loamy sand (Plinthic Paleudult) site which had been used to study the influence of lime rates on micronutrient availability since 1970. Treatments consisted of four soil pH levels ranging from 5.3 to 6.6 and soil Zn levels ranging from 0.5 to 4.9 mg/kg. The Zn levels were established from the previous study where 5.6 kg Zn/ha had been applied annually for eight years (residual treatment) and by applying 3.36 or 6.72 kg Zn/ha during 1979, 1980 and 1981.

Soil Zn, corn shoot, and ear leaf Zn values were reflective of the amount of Zn applied except that the residual Zn treatment resulted in Zn concentrations > than the annual application of 3.36 kg Zn/ha. Zinc tended to accumulate in the soil and in corn leaf tissue more from the residual Zn than the recently applied Zn treatments, especially at the highest pH levels. Increasingly more soil Zn was required to increase corn shoot and ear leaf Zn one mg/kg as soil pH increased. In the initial year, each unit (kg/ha) of applied Zn increased corn shoot Zn approximately 4 units (mg/kg) at pH 5.3 and only 0.3 unit at pH 6.6. Zinc deficiency symptoms developed in corn shoots for the two highest soil pH levels in two of three years. Corn yields were increased by Zn only in 1980 and were increased by residual or applied Zn at pH levels of 6.2 and 6.6. Regression equations from these studies were utilized to develop predictive corn shoot and ear leaf Zn values over wide ranges in soil Zn and pH. Our field research data using Mehlich 1 extractant could possibly be used satisfactorily in North Carolina regression equations where Mehlich 3 was the extractant; however, certain limitations would need to be imposed in the North Carolina equations.  相似文献   

18.
Abstract

Maize (Zea mays L.) was greenhouse cultivated with doses of 5, 10, and 15 ppm of zinc (Zn) in order to test the effectiveness of laboratory‐prepared coated and uncoated Zn fertilizers with commercial Zn‐EDTA and Zn‐ligno‐sulphonate (LS). Large increases were achieved both in crop yield and in Zn uptake in all cases while a large part of the Zn applied remained in the soil in easily plant‐available forms. Positive significant correlations were obtained between available Zn and the first three sequentially extracted fractions (water soluble plus exchangeable, organically complexed and that associated to amorphous sesquioxides) and also between the variables, yield, Zn concentration, and plant Zn uptake. Zinc uptake by the maize plants can be fairly accurately predicted from its sequential fractioning in the soil using an equation obtained by multiple regression analysis. Consideration of the amounts of Zn remaining as available (DTPA extractable) in the soil and results of a plant analysis let us conclude that under the conditions of our tests, Zn‐EDTA is a better Zn source than Zn‐LS. In addition, coating of Zn‐EDTA products with rosin improves their performance.  相似文献   

19.
Abstract

A significant portion of chemical zinc (Zn) fertilizers applied to calcareous soils is not absorbed by the first crop and may, therefore, affect the growth and chemical composition of the subsequent crops. This is called the residual effect of Zn. Soil tests may be used to predict such effects. The present experiment was conducted to study the residual effects of zinc sulfate (ZnSO4) on the second crop of corn (Zea mays L.) grown on selected highly calcareous soils of Iran and to compare the suitability of three soil tests for prediction of the effects. Twenty highly calcareous soils of southern Iran (16–58% calcium carbonate equivalent; pH 7.9–8.5), previously treated with three levels of Zn (0, 10, and 20 mg Zn/kg as ZnSO4) and under one crop of corn, was used in greenhouse to grow a second crop of corn without additional Zn fertilizer but with uniform application of nitrogen (N), phosphorus (P), and iron (Fe). Soils were sampled before the second crop and extracted with three Zn extradants, DTPA, EDTA‐(NH4)2CO3, and EDTA. Dry weight of plant tops and Zn concentration and uptake after eight weeks under the greenhouse conditions were used as the plant responses to residual Zn. Statistical analyses including F‐test and multiple regression equations showed that the overall effect of previously‐applied Zn on dry matter was nonsignificant, but Zn concentration and uptake were significantly increased. The three soil tests predicted the Zn concentration and uptake equally well. Moreover, DTPA and EDTA soil tests could predict the dry matter of plants at the highest level of previuosly‐applied Zn (20 mg Zn/kg), especially when selected chemical properties of soil, namely, calcium carbonate equivalent or organic matter content, were considered in the regression equations.  相似文献   

20.
在缺锌土壤中施用锌肥不仅可提高马铃薯产量,而且能显著提高马铃薯块茎锌含量,研究旨在揭示不同 熟性马铃薯叶面施用锌肥的不同施肥量、施肥时期及施肥种类在提高马铃薯产量和块茎锌含量方面的差异。以马 铃薯品种费乌瑞它、大西洋、定薯 4 号为供试材料,于 2020 年 4 月至 2021 年 10 月在大田条件下设置 3 组试验: 试验 1 为不同类型锌肥喷施试验,设不施锌肥为对照(G0)、喷施硫酸锌水溶液(G1)、喷施硫酸锌 + 尿素水溶 液(G2)和喷施安米达·糖醇锌水溶液(G3)4 个处理;试验 2 为不同锌肥喷施量试验,设喷施浓度为 0.00% (F0)、0.02%(F1)、0.03%(F2)、0.04%(F3)、0.05%(F4)和 0.06%(F5)6 个处理;试验 3 为不同时期喷 施锌肥试验,设全生育期不喷施锌肥为对照(L0)、苗期喷施(L1)、现蕾期喷施(L2)、块茎形成期喷施(L3) 和块茎膨大期喷施(L4)5 个处理。结果表明,叶面喷施适量硫酸锌,马铃薯产量、块茎锌含量和叶片 SPAD 值 均有所提高。早熟品种费乌瑞它与中熟品种大西洋,喷施锌肥浓度为 0.30% 时,块茎锌含量较未喷施分别显著增 加 37.25% 和 32.26%;晚熟品种定薯 4 号锌肥浓度为 0.50% 时块茎锌含显著增加 31.75%。不同品种马铃薯喷施关 键时期均在块茎形成期和膨大期,块茎锌含量较未喷施平均显著增加 46.26%。叶面喷施硫酸锌和尿素水溶液增产 增效显著,块茎锌含量显著增加 42.11%,产量显著增加 12.86%。综上所述,结合叶面施锌增加马铃薯产量和块 茎锌含量的田间应用效果分析,在早、中熟品种马铃薯上采用 0.30% 硫酸锌水溶液,晚熟品种上采用 0.50% 硫酸 锌水溶液,因地制宜采用叶面喷施硫酸锌水溶液配施 0.05% 尿素,在马铃薯块茎形成期和块茎膨大期两个关键时 期进行喷施,可协同实现最佳肥料利用效率、最大程度的稳产增产和提高马铃薯的锌营养含量。  相似文献   

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