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1.
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   

2.
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   

3.
为了揭示施锌对绿洲盐化潮土区玉米生长和锌形态变化的影响,通过盆栽模拟的方法,探讨了不同盐分浓度条件下(轻度、中度、重度)外源锌施入对玉米株高、干重、含锌量、吸锌量和各形态锌含量的影响。结果表明:相同盐分浓度条件下,施锌10 mg/kg使得玉米株高、干重、含锌量、吸锌量和土壤有效锌含量分别增加了8.5%~21.6%、21.7%~333.3%、107.3%~154.7%、166.7%~965.9%和451.3%~547.2%,碳酸盐结合态、松结有机态、氧化锰结合态、无定形氧化铁结合态、晶型氧化铁结合态、残留矿物态锌含量分别增加了147.4%~173.3%、122.4%~152.1%、11.6%~12.6%、32.6%~33.4%、17.6%~18.0%、3.1%~3.2%;相同施锌条件下,随着土壤盐分浓度的增加,玉米株高、干重、含锌量、吸锌量和土壤有效锌含量分别降低了6.5%~36.4%、12.8%~89.9%、5.5%~22.0%、17.4%~92.2%和4.8%~18.1%,碳酸盐结合态、松结有机态、氧化锰结合态锌含量分别降低了4.7%~15.0%、3.6%~13.7%、10.4%~25.6%,无定形氧化铁结合态、晶型氧化铁结合态、残留矿物态锌含量分别升高了1.9%~5.8%、0.4%~3.5%、0.6%~2.2%。综合分析认为,在盐渍化环境中,施锌能够改善玉米生长状况的主要原因是大幅度提高了碳酸盐结合态、松结有机态2种有效态锌含量,在短期内改善了土壤-作物系统锌营养水平,提高了玉米的耐盐性。  相似文献   

4.
不同有机肥中Cu、 Zn在农田土壤中的有效性与形态归趋   总被引:6,自引:0,他引:6  
【目的】畜禽粪便有机肥的施用是造成我国农田土壤重金属污染的重要原因之一。本文选用两种典型规模化养殖场畜禽粪便有机肥,研究其在石灰性土壤和酸性土壤上施用1年后Cu、 Zn的有效性和形态归趋,为客观评价畜禽粪便有机肥中重金属进入土壤后的环境行为和生态风险提供理论依据。【方法】采用温室土壤培养试验,在石灰性土壤和酸性土壤上分别设对照(CK)、 施2%鸡粪(CM2%)、 施5%鸡粪(CM5%)、 施与CM2%、 CM5%含等量Cu、 Zn的重金属无机盐溶液(CS2%、 CS5%)、 施2%猪粪(PM2%)、 施5%猪粪(PM5%)、 施与PM2%、 PM5%含等量Cu、 Zn的重金属无机盐溶液(PS2%、 PS5%)9个处理,每个处理设3次重复,在温室条件下培养1年。测定土壤pH值, EDTA提取有效态Cu、 Zn以及采用改进Tessier连续提取法提取的各形态Cu、 Zn的含量,分析鸡粪、 猪粪及等量无机盐溶液中Cu、 Zn进入土壤后的有效性和形态归趋。【结果】施用鸡粪和猪粪1年后,石灰性土壤的pH值降低,酸性土壤的pH值升高,施用5%猪粪时石灰性土壤pH值降低了0.23个单位,酸性土壤pH值升高了0.87个单位。施入鸡粪、 猪粪1年后,石灰性土壤中有效态Zn和酸性土壤中有效态Cu、 Zn含量显著增加,施用5%猪粪时酸性土壤中有效态Cu含量增加了1.95倍,施用5%鸡粪时2种土壤中有效态Cu的含量均显著低于等量无机盐。施用鸡粪和等量无机盐后,2种土壤中交换态和有机结合态Cu的含量显著增加,交换态、 碳酸盐结合态、 有机结合态和铁锰氧化物结合态Zn的含量显著增加; 施用猪粪和等量无机盐后,2种土壤中交换态、 铁锰氧化物结合态和有机结合态Cu的含量显著增加,碳酸盐结合态和铁锰氧化物结合态Zn的含量显著增加。【结论】施用鸡粪、 猪粪提高了石灰性土壤中Zn和酸性土壤中Cu、 Zn的有效性,高用量条件下鸡粪中Cu的有效性低于等量无机盐。1年后, 通过畜禽粪便有机肥带入2种土壤中的Cu 主要以交换态和有机结合态的形式存在,Zn则主要以碳酸盐结合态、 铁锰氧化物结合态和有机结合态的形式存在。2种土壤上有机肥带入的Cu、 Zn转化为铁锰氧化物结合态的比例低于等量无机盐,2种有机肥带入2种土壤中的Cu转化为交换态和有机结合态的比例高于等量无机盐。鸡粪带入的Zn转化为交换态的比例在酸性土壤中低于等量无机盐,但在石灰性土壤中则高于等量无机盐。  相似文献   

5.
【目的】在潜在缺锌石灰性土壤上,特别是种植小麦并以此为主粮的地区,缺锌问题日益受到人们的关注。提高小麦籽粒锌含量以满足人体锌需求,对于改善人体锌营养不良的现状具有重要意义。【方法】以ZnSO4和Zn-EDTA为锌源,布置了2个为期两年的田间定位试验。试验均采用裂区设计,即主因子为喷施锌肥,设喷施与不喷2个主处理;副因子为土施方法,设不施锌、均施、条施3个副处理。在第1季试验基础上,第2季不再土施锌肥,调查了小麦籽粒锌含量、土壤有效锌含量及锌组分含量,分析了第1季锌肥的后效。【结果】第2季单独喷施ZnSO4小麦籽粒Zn含量提高了11.13 mg/kg,提高幅度为33%,而喷Zn-EDTA无明显效果。不喷Zn时,第1季均施和条施的ZnSO4在第2季均表现出一定后效,小麦籽粒锌含量比对照分别提高了6.05、3.51 mg/kg,提高幅度为20%和11%;喷Zn时,第2季均施和条施ZnSO4处理的小麦籽粒锌含量增加了28.59和21.59 mg/kg,增幅100%和76%,表现出显著富锌作用,但增加幅度比单独喷施要小很多。第1季土施的两种锌肥在第2季小麦收获后DTPA-Zn仍维持在1 mg/kg以上,即不喷Zn时,均施和条施ZnSO4处理的土壤有效锌含量分别为1.99和1.65 mg/kg,均施和条施Zn-EDTA的有效锌含量分别为1.23和1.01 mg/kg;喷Zn时,均施和条施ZnSO4处理的土壤有效锌含量分别为1.44和2.22 mg/kg,均施和条施Zn-EDTA处理的有效锌含量分别为1.16和1.10 mg/kg。土壤各锌组分含量均表现为:松结有机态Zn > 碳酸盐结合态Zn > 氧化锰结合态Zn > 紧结有机态Zn > 交换态Zn。具体而言,第1季均施和条施ZnSO4,第2季结束后交换态Zn(Ex-Zn)、松结有机态Zn(Wbo-Zn)、碳酸盐结合态Zn(Car-Zn)含量均显著提高,其提高幅度分别为184%和116%;75%和85%;53%和43%。而均施和条施Zn-EDTA仅Ex-Zn、Wbo-Zn含量显著提高,其提高幅度分别为232%和132%;18%和10%。均施Zn-EDTA处理的锌肥利用率为0.27%,条施为0.70%,后者约为前者的3倍;而条施与均施ZnSO4无差异。【结论】在潜在缺锌石灰性土壤上,单独喷施ZnSO4显著提高了小麦籽粒锌含量,而喷施Zn-EDTA效果不显著;土施ZnSO4和Zn-EDTA,不论条施或均施,虽然会使有效锌(DTPA-Zn)及较高活性锌形态(Ex-Zn、Wbo-Zn)长时间维持较高含量,但对第2季小麦籽粒富锌的后效有限;土施基础上配合喷施ZnSO4对小麦籽粒锌的含量效果最令人满意。  相似文献   

6.
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   

7.
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   

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.
氮锌配施对不同冬小麦品种产量及锌营养的影响   总被引:13,自引:2,他引:11  
为比较石灰性土壤氮锌配施对不同小麦品种生长及锌营养的影响,选10种本地主要种植小麦品种,进行连续两年的田间试验,测定小麦产量及锌含量。结果表明,在石灰性土壤上单施锌肥和氮锌配施对小麦产量、籽粒锌含量的影响因品种而异。单施锌肥及氮锌配施处理可显著增加土壤有效锌含量,但单施锌肥处理仅增加"西杂1号"、"武农148"、"郑麦9023"籽粒锌含量;氮锌配施增加除"小偃22"外其余9种供试小麦品种籽粒锌含量,增幅为7.3%~54.7%。单施锌肥对小麦锌累积量增加的效果不明显;氮锌配施可显著增加小麦地上部锌累积量,两季分别增加6.5%、29.8%。单施氮肥可显著增加小麦锌吸收,但其主要累积在小麦茎叶部。在石灰性土壤上,单施锌肥虽显著增加了土壤有效锌含量,但对小麦产量及籽粒Zn含量增加有限,氮锌肥配施可取得较好效果。  相似文献   

10.
施用生物炭和石灰对土壤镉形态转化的影响   总被引:1,自引:0,他引:1  
通过室内培养试验,比较石灰、生物炭及生物炭和石灰配施3种改良剂作用下镉污染草甸土中土壤镉各形态转化以及pH的影响。结果表明,土壤添加生物炭培养60d,土壤pH呈随时间增加逐渐增加的趋势,而添加石灰和生物炭与石灰配施处理,土壤pH呈现先增加至最大值而后缓缓降低趋于稳定的趋势,但均显著高于对照。各改良剂的施用均显著降低土壤可交换态Cd含量,与CK处理相比,添加生物炭、石灰和生物炭石灰混合改良剂后,土壤可交换态Cd含量分别降低8.6%~13.7%,17.8%~21.7%和18.4%~23.3%。相关分析结果表明,土壤可交换态Cd含量与土壤pH之间均存在极显著的负相关关系(R2=0.74)。土壤添加改良剂后,显著降低土壤可交换态Cd比例,增加碳酸盐结合态、铁锰氧化物结合态、有机结合态和残渣态Cd比例,从而降低土壤重金属的生物有效性。  相似文献   

11.
低锌旱地土壤水分对小麦产量和锌利用的影响   总被引:2,自引:1,他引:1  
【目的】西北旱地土壤有机质含量低,pH和碳酸钙含量高,导致土壤有效锌含量低,加之水分缺乏,不仅制约冬小麦生长和产量,还严重影响小麦锌的吸收利用。本研究选取西北旱地典型缺锌区,在土施锌肥的基础上,设置了2年的补充灌水田间试验,进一步研究水分对土壤锌有效性、 小麦生长、 产量以及锌和相关元素吸收利用的影响。【方法】田间试验于2010~2012年在陕西永寿县进行,采用裂区设计,锌肥为主处理,在不施锌与施锌(ZnSO4·7H2O)50 kg/hm2的基础上,设置在冬小麦关键生长期补充和不补充灌水2个副处理。在成熟期采集植株样品,测定了小麦产量、 生物量,各器官部位的锌及氮、 磷、 钾、 铁的含量; 采集0—40 cm土层土壤,测定了土壤有效性锌含量。【结果】在返青期、 孕穗期补灌20~30 mm水分对小麦产量、 土壤有效锌含量无显著影响,却有提高小麦各部位锌含量、 锌肥利用率的趋势,不施锌和施锌条件下,灌水比不灌水处理小麦籽粒锌含量分别提高3.8%~16.3%、 3.8%~13.1%,灌水使锌肥利用率提高21.2%~177.8%。灌水量和灌水时期的不同也影响锌在小麦各器官部位的分配与累积,第一季施锌和不施锌条件下,灌水比不灌水处理锌收获指数分别降低5.1%和2.0%,而第二季锌收获指数分别提高2.1%和2.7%。两季灌水对小麦籽粒中铁及大量元素氮磷钾含量的影响亦各不相同。【结论】在旱地缺锌土壤上,小麦生长关键期灌水对小麦产量、 土壤有效锌含量无显著影响,却有提高小麦各部分锌含量、 锌肥利用率的趋势,说明水肥结合对旱地石灰性土壤锌和锌肥有效性的影响应引起进一步重视,这对提高旱地缺锌地区作物和人体锌营养水平具有潜在意义。  相似文献   

12.
Fertilization of grain legumes with zinc (Zn) can affect both marketable yield and Zn content of the grain, which is important in addressing human nutritional deficiencies in certain regions of the world. A pot experiment was conducted to determine the response of three different market classes of lentil to Zn fertilization using ten surface soils from Saskatchewan (Canada). The distribution of Zn among labile and stable fractions chemically separated from the soil was also determined in the ten prairie soils and related to the lentil responses observed. The three market classes of lentils (large and small green, small red) were grown without Zn (control), and with 2.5 and 5 kg Zn ha?1 added as zinc sulfate to each soil prior to planting. Zinc fertilizer application significantly influenced grain yield and was soil dependent. A significant increase in grain yield over the control was observed from application of Zn on some low organic matter, high pH Brown Chernozem soils whereas a decrease in grain yield over control was observed in other soils such as a Black Chernozem of high organic matter content and low (<7) pH. Lack of positive yield response to addition of Zn were related to measured high diethylene triamine pentaacetic acid (DTPA) extractable and plant root simulator (PRS) resin membrane probe Zn, and large amounts of native Zn in exchangeable and iron/manganese (Fe/Mn) oxide bound fractions. Application of Zn fertilizer generally increased the grain concentration of Zn. For example, an increase of ~20% in Zn concentration over control was observed when 5 kg Zn ha?1 was added to a loamy textured low organic matter Brown Chernozem soil. Overall, small green lentil was more consistent in producing a positive response to Zn fertilizer application on soils with low plant available Zn compared to large green lentil and small red lentil.  相似文献   

13.
小麦分泌的有机酸影响钙质土中锌的释放   总被引:1,自引:0,他引:1  
Rhizosphere drives plant uptake of sparingly soluble soil zinc(Zn).An investigation with three experiments was conducted to study organic acid exudation by two contrasting wheat genotypes(Sehar-06 and Vatan),Zn fractions in 10 different calcareous soils from Punjab,Pakistan,and release of different soil Zn fractions by organic acids.The two genotypes differed significantly in biomass production and Zn accumulation under deficient and optimum Zn levels in nutrient solution.At a deficient Zn level,Sehar-06 released more maleic acid in the rhizosphere than Vatan.Ten soils used in the present study had very different physicochemical properties;their total Zn and Zn distribution among different fractions varied significantly.Zinc release behaviour was determined by extracting the soils with 0.005 mol L-1 citric acid or maleic acid.The parabolic diffusion model best described Zn release as a function of time.Parabolic diffusion model fitting indicated more maleic acid-driven than citric acid-driven soil Zn mobility from different fractions.Cumulative Zn release in six consecutive extractions during 24 h ranged from 1.85 to 13.58 mg kg-1 using maleic acid and from 0.37 to 11.84 mg kg-1 using citric acid.In the selected calcareous soils,the results of stepwise linear regression indicated significant release of Fe-Mn oxide-bounded soil Zn by maleic acid and its availability to the Zn-effcient genotype.Hence,release of maleic acid by plants roots played an important role in phytoavailability of Zn from calcareous soils.  相似文献   

14.
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   

15.
Information on soil zinc (Zn) distribution is essential for understanding its chemical reactions and bioavailability. An experiment was conducted to evaluate the effect of wheat straw, cow manure, and vermicompost applied with Zn rates on Zn distribution in a calcareous soil. A sequential extraction scheme was used to fractionate Zn into soluble and exchangeable, bound to carbonate, organically bound, bound to manganese (Mn) oxide, bound to amorphous iron (Fe) oxide, bound to crystalline Fe oxide, and residual forms. In untreated soil, Zn was mainly in the residual fraction. Increasing rates of applied Zn increased all forms of Zn. Carbonate and residual forms showed the greatest increase. Organic materials application increased all fractions, except Mn-oxide form, and this increase was more pronounced for the organically bound form. Concentration of soluble, exchangeable, and organically bound forms was greatest in cow manure–amended samples as compared to other organic materials, suggesting that cow manure contained more bioavailable Zn than other organic materials.  相似文献   

16.
Apparent utilization of zinc (Zn) and potassium (K) fertilizers was examined in rice (Oryza sativa L.)-wheat (Triticum aestivum L.) using combinations of no K; soil applied K levels and no Zn; soil and foliar applied Zn. Application of 33.2 kg K ha?1 in rice and 24.9 kg K ha?1 in wheat along with foliar spray of 2 kg Zn ha?1 at 30 and 60 days gave the highest mean grain yields. Foliar application of zinc increased Zn concentration in flag leaves, grain, and straw of rice and wheat and K concentration in flag leaves of rice and straw of wheat significantly. Potassium application increased Zn concentration in rice grain and straw and K concentration in wheat straw significantly. Zinc and K increased the uptake of each other in grain; straw and total uptake by both crops significantly. Zinc fertilizer enhanced the utilization of soil K. Potassium fertilizer enhanced the utilization of applied Zn.  相似文献   

17.
长期施肥对潮土耕层土壤和作物籽粒微量元素动态的影响   总被引:4,自引:0,他引:4  
Micronutrient status in soils can be affected by long-term fertilization and intensive cropping.A 19-year experiment (1990-2008) was carried out to investigate the influence of different fertilization regimes on micronutrients in an Aquic Inceptisol and maize and wheat grains in Zhengzhou,China.The results showed that soil total Cu and Zn markedly declined after 19 years with application of N fertilizer alone.Soil total Fe and Mn were significantly increased mainly due to atmospheric deposition.Applications...  相似文献   

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