冉洪珍,郭朝暉,肖細(xì)元,史 磊,封文利

?

改良劑連續(xù)施用對農(nóng)田水稻Cd吸收的影響

冉洪珍,郭朝暉*,肖細(xì)元,史 磊,封文利

(中南大學(xué)冶金與環(huán)境學(xué)院,湖南 長沙 410083)

通過連續(xù)2a田間試驗(yàn),研究了在Cd重度污染土壤上施用有機(jī)肥、石灰、石灰與有機(jī)肥配施1a后,第2a連續(xù)施用和不再施用改良劑對稻田土壤有效態(tài)Cd含量和水稻Cd吸收的影響.結(jié)果表明,有機(jī)肥、石灰單施及石灰與有機(jī)肥配施均能顯著提高稻田土壤pH值,降低土壤中有效態(tài)Cd含量和水稻各部位Cd含量,第1a有機(jī)肥、石灰、石灰與有機(jī)肥配施處理的糙米中Cd含量較對照分別顯著降低35.9%、69.2%和65.4%.與對照相比,第2a連續(xù)施用有機(jī)肥、石灰及石灰與有機(jī)肥配施處理下,稻田土壤pH值分別顯著升高0.27、0.57和1.05個(gè)單位,土壤有效態(tài)Cd分別顯著降低26.6%、29.7%和59.4%;糙米中Cd含量較對照分別顯著降低63.1%、79.5%和83.6%,其中,第2a連續(xù)石灰與有機(jī)肥配施處理下糙米中Cd含量為0.20mg/kg,達(dá)到《食品安全國家標(biāo)準(zhǔn)食品中污染物限量》(GB2762-2017)中糙米限量值.第2a不再施用有機(jī)肥、石灰及石灰與有機(jī)肥配施處理的糙米中Cd含量較對照分別顯著降低49.2%、69.7%和75.4%.雙因素方差分析結(jié)果表明其值與連續(xù)施用改良劑的處理無顯著性差異.上述結(jié)果表明,石灰與有機(jī)肥配施可有效降低污染稻田土壤中有效態(tài)Cd含量和水稻Cd含量,施加后一年內(nèi)可不施或減少改良劑施用量.

土壤改良劑；鎘；有效性；水稻；連續(xù)施用

我國南方部分地區(qū)農(nóng)田土壤存在Cd超標(biāo)問題,給作物生產(chǎn)帶來嚴(yán)重不利影響[1-3],因此解決農(nóng)田Cd污染問題,實(shí)現(xiàn)糧食安全生產(chǎn)意義重大.化學(xué)原位鈍化修復(fù)技術(shù)具有操作簡單、見效快、可以實(shí)現(xiàn)邊修復(fù)邊生產(chǎn)等優(yōu)勢而被廣泛應(yīng)用[4-6].近年來,選擇一些廉價(jià)有效的改良劑,如石灰、泥炭、羥基磷石灰、有機(jī)肥、沸石等[7-8],進(jìn)行原位穩(wěn)定土壤中Cd是實(shí)現(xiàn)Cd污染稻田安全生產(chǎn)的有效措施.施用石灰可顯著提高土壤pH值和陽離子交換量,增加了土壤微生物對碳源的利用能力,提高了其功能多樣性,進(jìn)而降低土壤中重金屬有效態(tài)含量[9-10];史磊等通過施用石灰顯著降低了稻田土壤中重金屬Cd的弱酸可提取態(tài)和可還原態(tài)比例,增加其殘?jiān)鼞B(tài)比例,從而降低了稻米中Cd含量[11].但連續(xù)施用石灰容易破壞土壤團(tuán)粒結(jié)構(gòu),造成土壤板結(jié)[9],同時(shí),土壤再次酸化會(huì)導(dǎo)致改良劑的效果退化[12].有機(jī)肥可以通過影響土壤pH值,土壤團(tuán)聚體數(shù)量和穩(wěn)定性,土壤吸附性能,土壤微生物豐度和活性等改變土壤中重金屬賦存形態(tài),從而降低重金屬對植物的毒性[13-14].然而,目前大部分以畜禽糞便為主要原料的市售有機(jī)肥重金屬含量超標(biāo)[15].石灰與低重金屬含量的菜籽餅有機(jī)肥施用能夠有效鈍化重金屬,同時(shí)減少土壤結(jié)構(gòu)破壞[16-18]; Zhou等研究石灰和海泡石、腐植酸與沸石復(fù)配能顯著抑制水稻植株P(guān)b、Cd、Cu和Zn的吸收積累,從而減少重金屬的毒性[19].

土壤改良劑對土壤中重金屬的影響因改良劑的種類、施用量、土壤自身理化性質(zhì)的差異而不同[20-21].湖南省部分耕地土壤重金屬污染嚴(yán)重,存在石灰施用不合理且利用率低導(dǎo)致農(nóng)業(yè)資源浪費(fèi),土壤理化性質(zhì)被破壞等問題,制約了農(nóng)業(yè)的可持續(xù)發(fā)展,因此研究改良劑修復(fù)Cd污染土壤及后效,對改善改良劑的不合理施用及其利用率低的問題具有重要作用.研究表明在Cd輕度污染土壤上,石灰、石灰與海泡石配施、石灰與甘蔗渣配施處理對抑制水稻各部位Cd的吸收均有一定的后效[22-23],石灰、木炭等處理對銅鎘由活性態(tài)向非活性態(tài)和潛在活性態(tài)轉(zhuǎn)化也有一定的后效[24],但缺少與連續(xù)施用改良劑處理對比試驗(yàn),因此不能較好地說明施加改良劑的科學(xué)性.同時(shí),研究Cd重度污染土壤上施用改良劑后效的報(bào)道相對較少.因此,本試驗(yàn)針對湖南省典型Cd重度污染土壤開展田間試驗(yàn),通過對比連續(xù)施用和單季施用石灰、有機(jī)肥及石灰與有機(jī)肥配施,分析稻田土壤pH值、土壤有效態(tài)Cd含量以及水稻植株各部位對Cd的吸收特征,以期為進(jìn)一步優(yōu)化Cd污染稻田土壤治理效果和合理利用農(nóng)業(yè)資源提供科學(xué)依據(jù).

1 材料與方法

1.1 區(qū)域概況

田間試驗(yàn)選擇在湖南某退役老工業(yè)基地周邊污染稻田進(jìn)行.試驗(yàn)田區(qū)域?qū)傧娼掠魏庸燃扒鹆陰?成土母質(zhì)為第四紀(jì)紅土,屬亞熱帶季風(fēng)性濕潤氣候,年平均氣溫16℃至18℃,年降水量在1500mm左右.供試田塊土壤基本理化性質(zhì)見表1.

表1 供試土壤基本理化性質(zhì)(mg/kg) Table1 Basic properties of tested soil sample (mg/kg)

1.2 試驗(yàn)材料與設(shè)計(jì)

2016年6月,在該Cd污染田塊開展田間試驗(yàn),試驗(yàn)田翻耕后設(shè)置對照(CK)、施用有機(jī)肥(OM)、石灰(L)和石灰與有機(jī)肥配施(LOM)共4個(gè)處理,每個(gè)處理重復(fù)6次.每個(gè)處理小區(qū)面積為5m′6m=30m2,隨機(jī)排列.試驗(yàn)小區(qū)周邊設(shè)保護(hù)行,并用聚乙烯加厚塑料膜對小區(qū)田埂進(jìn)行保護(hù)用來消除各區(qū)之間的干擾.按照試驗(yàn)設(shè)計(jì)要求將改良劑施入相應(yīng)田塊小區(qū)中(石灰施加量為1500kg/hm2,有機(jī)肥施加量為2250kg/hm2,組配改良劑施用前先將兩種改良劑混合),隨后將改良劑和土壤充分混勻,老化7d.2016年7月15日移栽秧苗,11月8日收獲并采集土壤和相應(yīng)水稻樣品(2016T).2017年6月任選每個(gè)處理的三個(gè)小區(qū)繼續(xù)按照2016年的試驗(yàn)設(shè)計(jì)施加改良劑(2017T),其余三個(gè)小區(qū)不再施加改良劑(2017NT),并按照對照處理進(jìn)行移栽秧苗.整個(gè)水稻生長期間均按照當(dāng)?shù)匾话戕r(nóng)田的管理模式.

兩年水稻種植品種均為天優(yōu)華占,為秈型三系雜交水稻.田間試驗(yàn)用改良劑均為市售商品,其中石灰購自農(nóng)資市場,氧化鈣質(zhì)量分?jǐn)?shù)達(dá)80%,Cd含量為0.40mg/kg.有機(jī)肥購自湖南省湘暉農(nóng)業(yè)技術(shù)開發(fā)有限公司的菜籽餅有機(jī)肥,N+P2O5+K>5%,有機(jī)質(zhì)質(zhì)量分?jǐn)?shù)>45%,Cd含量為0.43mg/kg.

1.3 樣品采集及分析

水稻成熟期采集田間長勢均勻的代表性水稻植株樣品(每個(gè)處理3株),用自來水洗凈后,再用去離子水洗凈,然后按水稻根、莖葉以及籽粒分開,在105℃殺青30min,60℃烘干至恒重,記錄生物量.將樣品粉碎后分別放入聚乙烯封口袋中密封備用.采集水稻植株相應(yīng)的0~20cm表層土壤,經(jīng)自然風(fēng)干,除去動(dòng)植物殘?bào)w及碎石等雜物后研磨,分別過10目和100目尼龍篩后放入聚乙烯封口袋中備用.

土壤pH值采用1:2.5土水比浸提,用pH計(jì)(上海雷磁,PHS-3C)測定;土壤有機(jī)質(zhì)含量采用重鉻酸鉀容量法測定;堿解氮采用堿解擴(kuò)散-硫酸滴定法測定;有效磷采用碳酸氫鈉提取-釩鉬黃比色法測定;速效鉀采用醋酸銨提取-火焰光度計(jì)法測定[25].土壤中有效態(tài)Cd采用DTPA提取法提取[25].土壤樣品用HNO3-HF-HClO4法消解,水稻植株和糙米樣品采用HNO3-HClO4法消解,浸提液和消解液中Cd含量采用ICP-MS(美國,Thermo Fisher X2)測定.

1.4 數(shù)據(jù)處理

數(shù)據(jù)統(tǒng)計(jì)采用Microsoft Excel2013進(jìn)行分析,采用origin 9.0軟件作圖.單因素方差分析(One-way ANOVA)和相關(guān)性分析均采用SPSS 19.0完成,<0.05表示處理間有顯著性差異,<0.01表示處理間有極顯著差異.

2 結(jié)果與分析

2.1 土壤改良劑對土壤pH值,有機(jī)質(zhì)和有效態(tài)Cd含量的影響

由圖1可知,不同改良劑處理對土壤pH值影響程度不同.但與對照相比,施加有機(jī)肥、石灰及石灰和有機(jī)肥配施均能處理能顯著(<0.05)提高土壤pH值.2016年施用OM、L和LOM的處理比對照土壤pH值顯著(<0.05)提高0.46~1.20,施用石灰和有機(jī)肥均能在短期內(nèi)不同程度提高土壤pH值[26-27]. 2017年連續(xù)施用OM、L和LOM處理的土壤pH值較對照顯著提高0.27~1.05,僅2016年水稻季施用土壤改良劑的土壤pH值分別較對照提高0.19、0.37和0.75.說明連續(xù)施加土壤改良劑能夠更有效維持土壤pH值.改良劑提高土壤pH值的效果表現(xiàn)為LOM>L>OM,說明對于Cd污染土壤,石灰和有機(jī)肥配施能進(jìn)一步提高土壤pH值[28].有機(jī)肥的施用將大量的有機(jī)物帶入土壤中.一方面,有機(jī)肥中有機(jī)物腐解過程產(chǎn)生的有機(jī)酸對土壤中重金屬產(chǎn)生活化效應(yīng),增加重金屬的生物有效性[29];但另一方面,有機(jī)質(zhì)中大量的官能團(tuán)吸附重金屬[30],腐殖質(zhì)分解產(chǎn)生的腐植酸與重金屬離子形成絡(luò)合物均能降低土壤重金屬的有效性[31].從圖1可知,與對照相比,2016年施用OM、L和LOM,2017年連續(xù)施用和不施用OM、L和LOM的土壤有機(jī)質(zhì)質(zhì)量分?jǐn)?shù)均無顯著性差異.僅2017年連續(xù)施用改良劑的土壤有機(jī)質(zhì)質(zhì)量分?jǐn)?shù)略高于單季施用改良劑的處理.這可能與土壤有機(jī)質(zhì)本底值較高,該種菜籽餅有機(jī)肥最佳肥效期為45d,其后有機(jī)質(zhì)含量下降[32]及有機(jī)肥的施用量較少有很大的關(guān)系.

與對照相比,連續(xù)或單季施用OM、L和LOM處理均能顯著(<0.05)降低土壤有效態(tài)Cd含量,2016年水稻收獲后施用土壤改良劑的處理比對照土壤有效態(tài)Cd含量分別顯著(<0.05)降低25.1%、20.8%和55.8%.與對照相比,2017年水稻季連續(xù)施用土壤改良劑土壤有效態(tài)Cd分別顯著降低26.6%、29.7%和59.4%;不繼續(xù)施加土壤改良劑的土壤有效態(tài)Cd含量也顯著(<0.05)降低.土壤有效態(tài)Cd含量與土壤pH值的變化趨勢一致,相比于石灰和有機(jī)肥單施,石灰和有機(jī)肥配施處理能進(jìn)一步顯著(<0.05)降低土壤有效態(tài)Cd含量.施用石灰能顯著提高土壤pH值,增加土壤膠體表面的負(fù)電荷,同時(shí)促進(jìn)土壤中鐵錳氧化物的形成,進(jìn)而增加土壤重金屬的吸附位點(diǎn)和增強(qiáng)重金屬的吸附能力,減少土壤重金屬有效態(tài)[10,33].由于有機(jī)肥自身較高的pH值以及分解過程中釋放的少量NH3,添加有機(jī)肥能一定程度提高土壤pH值,同時(shí)有機(jī)肥所含的有機(jī)質(zhì)含有較大的比表面積和大量的官能團(tuán),使得土壤有效態(tài)Cd向其他形態(tài)轉(zhuǎn)化[34-36].從圖1中可以看出,連續(xù)施用土壤改良劑并不會(huì)進(jìn)一步降低土壤有效態(tài)Cd含量,說明土壤改良劑的施用能有效降低土壤有效態(tài)Cd含量,單季施加的土壤改良劑有較強(qiáng)的后效[37].可見有機(jī)、無機(jī)改良劑配施能有效降低土壤有效態(tài)Cd含量,施加改良劑后的一定年限內(nèi)可不施或適當(dāng)減少改良劑的施用量以便降低農(nóng)業(yè)生產(chǎn)投入成本和避免改良劑施用不合理導(dǎo)致的利用效率低的問題.

2.2 土壤改良劑對水稻各部位Cd吸收的影響

水稻植株中Cd含量的變化如圖2所示.與對照相比,連續(xù)或單季施用OM、L和LOM處理均能顯著(<0.05)降低水稻植株各部位Cd含量.水稻植株各部位Cd含量差異明顯,大小順序?yàn)楦厩o葉＞糙米,這與植物各部位代謝程度有關(guān)[38].石灰和有機(jī)肥通過控制土壤中有效態(tài)Cd含量減少Cd向水稻植株各部位遷移[13,19,39-40].2016年施用OM、L和LOM處理比對照處理下水稻根中Cd含量顯著(<0.05)降低44.9%~85.8%.2017年連續(xù)施用OM、L和LOM處理的水稻根中Cd含量較對照分別顯著(<0.05)下降60.4%、77.3%和86.2%,略低于單季施加OM、L和LOM處理下水稻根中Cd含量,其下降幅度分別為56.0%、73.5%和87.1%(<0.05).與對照相比,2016年施用OM、L和LOM處理莖葉中Cd含量均顯著(<0.05)下降,尤其是LOM處理下水稻莖葉中Cd含量降低至0.58mg/kg.2017年連續(xù)施用OM、L和LOM處理水稻莖葉中Cd含量略低于單季施加土壤改良劑處理,與對照相比,水稻莖葉中Cd含量分別顯著(<0.05)下降68.8%~88.7%和54.7%~ 86.1%.與水稻根和莖葉中Cd含量變化趨勢相一致,與對照相比,單季或連續(xù)施用OM、L和LOM處理均能顯著(<0.05)降低糙米中Cd含量.2016年施用OM、L和LOM處理糙米中Cd含量比對照處理顯著(<0.05)降低35.9%、69.2%和65.4%.2017年連續(xù)施用OM、L和LOM處理的水稻糙米中Cd含量分別比對照顯著(<0.05)降低63.1%、79.5%和83.6%,其中石灰與有機(jī)肥配施處理下糙米中Cd含量降低至0.20mg/kg,達(dá)到《食品安全國家標(biāo)準(zhǔn)食品中污染物限量》(GB2762-2017)中Cd限量值.與對照相比,單季施加土壤改良劑處理的糙米中Cd含量分別顯著(<0.05)降低49.2%、69.7%和75.4%,雙因素方差分析結(jié)果表明(表2)不連續(xù)與連續(xù)施用土壤改良劑對糙米中Cd含量無顯著性影響.僅鈍化劑種類對水稻地上部Cd含量產(chǎn)生極顯著(<0.01)影響;就衡量因素作用大小的平方和(SS)來看,鈍化劑種類因素的影響最明顯,即水稻對Cd的吸收特征主要受鈍化劑種類的控制.上述結(jié)果表明,施用土壤改良劑對減少水稻Cd吸收有較強(qiáng)的后效.

綜上所述,石灰比有機(jī)肥能更有效地抑制水稻各部位對Cd的吸收.與石灰和有機(jī)肥單施相比較,石灰與有機(jī)肥配施效果最佳.石灰、有機(jī)肥和石灰與有機(jī)肥配施對抑制水稻各部位Cd的吸收均有較強(qiáng)的后效.因此從農(nóng)業(yè)經(jīng)濟(jì)成本和改良劑對土壤環(huán)境質(zhì)量影響的角度考慮,在輕Cd污染土壤上施加改良劑后一年內(nèi)不施改良劑或在重Cd污染土壤上一定年限內(nèi)適當(dāng)減少改良劑使用量也可達(dá)到顯著減少水稻植物體內(nèi)重金屬含量的效果.

表2 鈍化劑種類與不同處理方式交互作用對水稻各部位的雙因素方差分析 Table 2 Two-way ANOVA of interactions of the soil amendments andthe application strategies of the soil amendments on the Cd contents in different organs of rice

注:表中數(shù)據(jù)自由度值=3;<0.05表示該變異來源因素對水稻部位中Cd含量影響顯著;CdG,CdS,CdR分別表示水稻糙米、莖葉和根中Cd含量(下同).

2.3 相關(guān)性分析

相關(guān)性分析結(jié)果(表3)表明,土壤DTPA提取態(tài)Cd含量、水稻根、莖葉和糙米中Cd含量與土壤pH值均呈極顯著負(fù)相關(guān)(0.01).土壤pH值與土壤DTPA-Cd含量的相關(guān)系數(shù)為0.834,與水稻根、莖葉和糙米中Cd含量的相關(guān)系數(shù)分別為0.790,0.773, 0.711,說明稻田土壤pH值升高首先會(huì)引起土壤有效態(tài)Cd含量降低,從而進(jìn)一步抑制水稻根對Cd的吸收及其向水稻地上部遷移.土壤DTPA-Cd含量、水稻根、莖葉和糙米中Cd含量均與土壤有機(jī)質(zhì)含量呈負(fù)相關(guān).在中性偏堿性的土壤中,土壤有機(jī)物隨著pH值增加溶解度增大,絡(luò)合能力增強(qiáng),故大量重金屬被絡(luò)合[41],土壤DTPA-Cd含量減少.表3結(jié)果表明,土壤DTPA-Cd含量與土壤有機(jī)質(zhì)含量相關(guān)性不顯著,說明石灰和有機(jī)肥等堿性改良劑主要通過提高土壤pH值來降低土壤有效態(tài)重金屬含量.李忠義等[42]和Zeng等[43]的研究中,土壤有效態(tài)Cd、Cu、Pb和Zn等與土壤pH值呈極顯著負(fù)相關(guān)(<0.01),而與土壤有機(jī)質(zhì)含量呈顯著正相關(guān),這可能是由于土壤中有效態(tài)重金屬含量在短期內(nèi)受外源添加物的影響較大.糙米中Cd含量與土壤DTPA-Cd含量、水稻根、莖葉中Cd含量均呈極顯著正相關(guān)(<0.01),相關(guān)系數(shù)分別為0.666,0.932和0.914,該結(jié)果說明Cd首先通過從土壤中向根部轉(zhuǎn)移,再經(jīng)過木質(zhì)部的蒸騰作用和功能葉中韌皮部隨著同化物一起從輸送到籽粒[44].因此,通過降低土壤中有效態(tài)Cd的含量,減少土壤Cd向水稻根和莖葉中轉(zhuǎn)移能有效控制水稻糙米中重金屬的含量.

表3 土壤pH值,有機(jī)質(zhì)、DTPA-Cd含量與水稻各器官Cd的相關(guān)系數(shù) Table 3 The correlation analysis between Cd contents in rice and soil pH, organic matter and DTPA-extractable Cd content in soil

注:表中數(shù)據(jù)為相關(guān)性系數(shù)(=3);* 表示顯著相關(guān)性水平0.05;**表示極顯著相關(guān)性水平0.01.SOM表示土壤有機(jī)質(zhì).

3 結(jié)論

3.1 有機(jī)肥、石灰單施及石灰與有機(jī)肥配施對提高稻田土壤pH值、降低土壤中有效態(tài)Cd含量和水稻各部位Cd含量均有顯著效果,其中石灰與有機(jī)肥配施效果更顯著.在4.70mg/kg Cd污染稻田土壤中,石灰與有機(jī)肥連續(xù)配施的糙米Cd含量降低至0.2mg/kg,較未施用處理顯著降低83.6%,達(dá)到《食品安全國家標(biāo)準(zhǔn)食品中污染物限量》(GB2762-2017)中糙米限量值.

3.2 石灰、有機(jī)肥和石灰與有機(jī)肥配施處理對抑制水稻各部位Cd的吸收有較強(qiáng)的后效,尤其是石灰與有機(jī)肥配施處理,因此在Cd污染稻田土壤上施加改良劑后一年內(nèi)可不施或少施改良劑.

[1] Yang P G, Mao R Z, Shao H B, et al. An investigation on the distribution of eight hazardous heavy metals in the suburban farmland of China [J]. Journal of Hazardous Materials, 2009,167(1-3):1246- 1251.

[2] Huang B, Guo Z X, Tu W J, et al. Geochemistry and ecological risk of metal(loid)s in overbank sediments near an abandoned lead/zinc mine in Central South China [J]. Environmental Earth Sciences, 2018, 77(3):68.

[3] 曾 鵬,郭朝暉,肖細(xì)元,等.構(gòu)樹修復(fù)對重金屬污染土壤環(huán)境質(zhì)量的影響[J]. 中國環(huán)境科學(xué), 2018,38(7):2639-2645.Zeng P, Guo Z H, Xiao X Y, et al. Effect of phytoremediation withon the biological quality in soil contaminated with heavy metals [J]. China Environmental Science, 2018,38(7): 2639-2645.

[4] Garau G, Castaldi P, Santona L, et al. Influence of red mud, zeolite and lime on heavy metal immobilization, culturable heterotrophic microbial populations and enzyme activities in a contaminated soil [J]. Geoderma, 2007,142(1):47-57.

[5] Seshadri B, Bolan N S, Choppala G, et al. Potential value of phosphate compounds in enhancing immobilization and reducing bioavailability of mixed heavy metal contaminants in shooting range soil [J]. Chemosphere, 2017,184:197-206.

[6] Sanderson P, Naidu R, Bolan N. The effect of environmental conditions and soil physicochemistry on phosphate stabilisation of Pb in shooting range soils [J]. Journal of Environmental Management, 2016,170:123-130.

[7] 辜嬌峰,周 航,吳玉俊,等.復(fù)合改良劑對稻田Cd、As活性與累積的協(xié)同調(diào)控[J]. 中國環(huán)境科學(xué), 2016,36(1):206-214.Gu J F, Zhou H, Wu Yu J, et al. Synergistic control of combined amendment on bioavailability and accumulation of Cd and As in rice paddy soil [J]. China Environmental Science, 2016,36(1):206-214.

[8] 李 平,王興祥,郎 漫,等.改良劑對Cu、Cd污染土壤重金屬形態(tài)轉(zhuǎn)化的影響[J]. 中國環(huán)境科學(xué), 2012,36(7):1241-1249.Li P, Wang X X, Lang M, et al. Effects of amendments on the fraction transform of heavy metals in soil contaminated by copper and cadmium [J]. China Environmental Science, 2012,32(7):1241-1249.

[9] Zhu H H, Chen C, Xu C, et al. Effects of soil acidification and liming on the phytoavailability of cadmium in paddy soils of central subtropical China [J]. Environmental Pollution. 2016,219:99-106.

[10] Lahori H L, Zhang Z Q, Guo Z Y, et al.Potential use of lime combined with additives on (im)mobilization and phytoavailability of heavy metals from Pb/Zn smelt [J]. Ecotoxicology and Environmental Safety, 2017,145(1):313.

[11] 史 磊,郭朝暉,彭 馳,等.石灰組配土壤改良劑抑制污染農(nóng)田水稻鎘吸收[J]. 農(nóng)業(yè)工程學(xué)報(bào), 2018,(11):207-216.Shi L, Guo Z H, Peng C, et al. Lime based amendments inhibiting uptake of cadmium in rice planted in contaminated soils [J]. Transactions of the Chinese Society of Agricultural Engineering, 2018,(11):207-216.

[12] 陳遠(yuǎn)其,張 煜,陳國梁.石灰對土壤重金屬污染修復(fù)研究進(jìn)展[J]. 生態(tài)環(huán)境學(xué)報(bào), 2016,25(8):1419-1424.Chen Y Q, Zhang Y, Chen G L. Remediation of Heavy Metal Contaminated Soils by Lime: A Review [J]. Ecology and Environmental Sciences. 2016,25(8):1419-1424.

[13] Yin B K, Zhou L Q, Yin B, et al. Effects of organic amendments on rice (L.) growth and uptake of heavy metals in contaminated soil [J]. Journal of Soils and Sediments, 2016,16(2):537- 546.

[14] Ning C C, Gao P D, Wang B Q, et al. Impacts of chemical fertilizer reduction and organic amendments supplementation on soil nutrient, enzyme activity and heavy metal content [J]. Journal of Integrative Agriculture, 2017,16(8):1819-1831.

[15] Meier S, Curaqueo G, Khan N, et al. Chicken-manure-derived biochar reduced bioavailability of copper in a contaminated soil [J]. Journal of Soils and Sediments, 2017,17(3):741-750.

[16] 曾黎明,王少靜,寧 琳,等.生物有機(jī)肥與石灰對土壤肥力和木薯產(chǎn)量質(zhì)量的影響[J]. 中國農(nóng)學(xué)通報(bào), 2011,27(15):212-216.Zeng L M, Wang S J, Ning L, et al. Effects of Bioorganic Fertilizer and Lime on Soil Fertility, Yield and Quality of Cassava [J]. Chinese Agricultural Science Bulletin, 2011,27(15):212-216.

[17] 郭 婷,張 迪,謝曉偉,等.石灰配施生物有機(jī)肥對連作大蒜品質(zhì)及產(chǎn)量的影響[J]. 北方園藝, 2018,(6):42-46.Guo T, Zhang D, Xie X W, et al. Effect of lime combined with bio-organic fertilizer on quality and yield of continuous cropping garlic [J]. Northern Horticulture, 2018,(6):42-46.

[18] Pandit T K, Naik S K, Patra P K. Influence of lime and organic matter on the mobility of cadmium in cadmium-contaminated soil in relation to nutrition of spinach [j]. Journal of soil contamination, 2012,4(21): 419-433.

[19] Zhou H, Zhou X, Zeng M, et al. Effects of combined amendments on heavy metal accumulation in rice(L.) planted on contaminated paddy soil [J]. Ecotoxicology and Environmental Safety, 2014,101(1):226-232.

[20] 黎秋君,黎大榮,王英輝,等.3種有機(jī)物料對土壤理化性質(zhì)和重金屬有效態(tài)的影響[J]. 水土保持學(xué)報(bào), 2013,27(6):182-185.Li Q J, Li D R, Wang Y H, et al. Effects of three kinds of organic materials on physicochemical properties and available heavy metals in soil [J]. Journal of Soil and Water Conservation, 2013,27(6):182-185.

[21] 周 航,周 歆,曾 敏,等.2種組配改良劑對稻田土壤重金屬有效性的效果[J]. 中國環(huán)境科學(xué), 2014,34(2):437-444.Zhou H, Zhou X, Zeng M, et al. Effects of two combined amendments on heavy metal bioaccumulation in paddy soil. [J]. China Environmental Science. 2014,34(2):437-444.

[22] Wu Y J, Zhou H, Zou Z J, et al. A three-year in-situ study on the persistence of a combined amendment (limestone+sepiolite) for remedying paddy soil polluted with heavy metals [J]. Ecotoxicology and Environmental Safety, 2016,130:163-170.

[23] He Y B, Huang D Y, Zhu Q H, et al. A three-season field study on the in-situ remediation of Cd-contaminated paddy soil using lime, two industrial by-products, and a low-Cd-accumulation rice cultivar [J]. Ecotoxicology and Environmental Safety, 2017,136:135-141.

[24] 崔紅標(biāo),范玉超,周 靜,等.改良劑對土壤銅鎘有效性和微生物群落結(jié)構(gòu)的影響[J]. 中國環(huán)境科學(xué), 2016,36(1):197-205.Cui H B, Fan Y C, Zhou J, et al. Availability of soil Cu and Cd and microbial community structure as affected by applications of amendments [J]. China Environmental Science, 2016,36(1):197-205.

[25] 魯如坤.土壤農(nóng)業(yè)化學(xué)分析方法[M]. 北京:中國農(nóng)業(yè)科技出版社, 2000:1-638.Lu R K. Analytical methods of soil agricultural chemistry [M]. Beijing: Agriculture Science and Technology Press, 2000:1-638.

[26] Chan K Y, Heenan D P. Effect of lime (CaCO3) application on soil structural stability of a red earth [J]. Soil Research, 1998,36(1):73-86.

[27] 吳文成,陳顯斌,劉曉文,等.有機(jī)及無機(jī)肥料修復(fù)重金屬污染水稻土效果差異研究[J]. 農(nóng)業(yè)環(huán)境科學(xué)學(xué)報(bào), 2015,34(10):1928-1935.Wu W C, Chen X B, Liu X W, et al Effects of Organic and Inorganic Fertilizers on Heavy Metal Immobilization in Paddy Soil [J]. Journal of Agro-Environment Science, 2015,34(10):1928-1935.

[28] 倪中應(yīng),沈 倩,章明奎.秸稈還田配施石灰對水田土壤銅、鋅、鉛、鎘活性的影響[J]. 農(nóng)業(yè)資源與環(huán)境學(xué)報(bào), 2017,34(3):215-225.Ni Z Y, Shen Q, Zhang M K. Effects of crop straw returning with lime on activity of Cu, Zn, Pb and Cd in paddy soil [J]. Journal of Agricultural Resources and Environment, 2017,34(3):215-225.

[29] 高 明,車福才,魏朝富,等.長期施用有機(jī)肥對紫色水稻土鐵錳銅鋅形態(tài)的影響[J]. 植物營養(yǎng)與肥料學(xué)報(bào), 2000,6(1):11-17.Gao M, Che F C, Wei C F, et al. Effect of long-term application of manures on forms of Fe, Mn, Cu and Zn in purple paddy soil [J]. Plant Nutrition and Fertilizer Science, 2000,6(1):11-17.

[30] Tian X L, Li T T, Yang K, et al. Effect of humic acids on physicochemical property and Cd(II) sorption of multiwalled carbon nanotubes [J]. Chemosphere. 2012,89(11):1316-1322.

[31] Udovic M, Mcbride M B. Influence of compost addition on lead and arsenic bioavailability in reclaimed orchard soil assessed using Porcellioscaber bioaccumulation test [J]. Journal of Hazardous Materials, 2012,(205/206):144-149.

[32] 祝紅蕾,儲(chǔ)大勇,趙紅艷,等.菜籽餅粕有機(jī)肥腐熟過程中有效成分變化的研究[J]. 安徽化工, 2015,41(1):59-61.Zhu honglei, Chu Dayong, Zhao hongyan, et al. Study on changes of effective components during fermentation of rapeseed cake organic fertilizer [J]. Anhui Chemical Industry, 2015,41(1):59-61.

[33] Tiller R, Bolan N S, Kookana R S. Ionic-strength and pH effects on the sorption of cadmium and the surface charge of soils [J]. European Journal of Soil Science, 2010,45(4):419-429.

[34] Zeng F, Ali S, Zhang H, et al. The influence of pH and organic matter content in paddy soil on heavy metal availability and their uptake by rice plants [J]. Environmental Pollution, 2011,159(1):84-91.

[35] Meier S, Curaqueo G, Khan N, et al. Chicken-manure-derived biochar reduced bioavailability of copper in a contaminated soil [J]. Journal of Soils and Sediments, 2017,17(3):741-750.

[36] 謝運(yùn)河,紀(jì)雄輝,吳家梅,等.不同有機(jī)肥對土壤鎘鋅生物有效性的影響[J]. 應(yīng)用生態(tài)學(xué)報(bào), 2015,39(3):399-405.Xie Y H, Ji X H, Wu J M, et al. Effect of different organic fertilizers on bioavailability of soil Cd and Zn [J]. Chinese Journal of Applied Ecology, 2015,39(3):399-405.

[37] He Y B, Huang D Y, Zhu Q H, et al. A three-season field study on the in-situ remediation of Cd-contaminated paddy soil using lime, two industrial by-products, and a low-Cd-accumulation rice cultivar [J]. Ecotoxicology and Environmental Safety, 2017,136:135-141.

[38] 封文利,郭朝暉,史 磊,等.控源及改良措施對稻田土壤和水稻鎘累積的影響[J]. 環(huán)境科學(xué), 2018,39(1):399-405.Feng W L, Guo Z H, Shi L, et al. Distribution and accumulation of cadmium in paddy soil and rice affected by pollutant sources control and improvement measures [J]. Environmental Science, 2018,39(1): 399-405.

[39] Lee S H, Lee J S, Choi Y J, et al. In situ stabilization of cadmium-, lead-, and zinc-contaminated soil using various amendments [J]. Chemosphere, 2009,77(8):1069-1075.

[40] 周 歆,周 航,曾 敏,等.石灰石和海泡石組配對水稻糙米重金屬積累的影響[J]. 土壤學(xué)報(bào), 2014,(3):555-563.Zhou X, Zhou H, Zeng M, et al. Effects of combined amendment (Limestone + Sepiolite) on heavy metal accumulation in brown rice [J]. Acta Pedologica Sinica, 2014,(3):555-563.

[41] 鐘曉蘭,周生路,黃明麗,等.土壤重金屬的形態(tài)分布特征及其影響因素[J]. 生態(tài)環(huán)境學(xué)報(bào), 2009,18(4):1266-1273.Zhong X L, Zhou S L, Huang M L, et al. Chemical form distribution characteristic of soil heavy metals and its influencing factors [J]. Ecology and Environmental Sciences, 2009,18(4):1266-1273.

[42] 李忠義,張超蘭,鄧超冰,等.鉛鋅礦區(qū)農(nóng)田土壤重金屬有效態(tài)空間分布及其影響因子分析[J]. 生態(tài)環(huán)境學(xué)報(bào), 2009,18(5):1772-1776.Li Z Y, Zhang C L, Deng C B, et al. Analysis on spatial distribution of soil available heavy metals and its influential factors in a lead-zinc mining area of Guangxi, China [J]. Ecology and Environmental Sciences, 2009,18(5):1772-1776.

[43] Zeng F R, Ali S, Zhang H T, et al. The influence of pH and organic matter content in paddy soil on heavy metal availability and their uptake by rice plants [J]. Environmental Pollution, 2011,159(1):84-91.

[44] Li H, Luo N, Li Y W, et al. Cadmium in rice: Transport mechanisms, influencing factors, and minimizing measures [J]. Environmental Pollution, 2017,224(1):622-630.

Effects of continuous application of soil amendments on cadmium availability in paddy soil and uptake by rice.

RAN Hong-zhen, GUO Zhao-hui*, XIAO Xi-yuan, SHI Lei, FENG Wen-li

(School of Metallurgy and Environment, Central South University, Changsha 410083, China)., 2019,39(3)：1117~1123

A two-year field experiment was conducted to study the effects of organic fertilizer and lime on remediation of Cd-contaminated paddy soil. The application strategies of the soil amendments including continuous application and application only in the first year were compared. The results showed that the individual or combined application of organic fertilizer and lime both increased significantly pH and available Cd contents in the soil as well as Cd contents in different parts of the planted rice. The Cd contents of brown rice in the first year were reduced significantly by 35.9%, 69.2%, and 65.4% compared with the control, respectively. Under the continuous application strategy, the soil pH significantly increased by 0.27, 0.57 and 1.05 units respectively, the contents of available Cd in the soils decreased by 26.6%, 29.7% and 59.4% respectively and the rice Cd concentrations decreased significantly by 63.1%, 79.5% and 83.6%, respectively. Especially under continuous application of both organic fertilizer and lime, the rice Cd contents was 0.20mg/kg which had reached the National Standard of Pollutant in Food of China (GB 2762~2017). Under the strategy of application only in the first year, the Cd contents in the brown rice reduced significantly by 49.2%, 69.7% and 75.4%, respectively. The two-way ANOVA suggested no significant difference between the two strategies of continuous application and application only in the first year. The results indicated that the application of organic fertilizer and lime can effectively reduce the contents of available Cd in soil and Cd in rice, and the remediation effects can lasts two years without significant reduction after the first application.

soil amendment；cadmium；effectiveness；rice；continuous application

X53

A

1000-6923(2019)03-1117-07

冉洪珍(1994-),女,重慶巫溪人,中南大學(xué)冶金與環(huán)境學(xué)院碩士研究生,主要從事重金屬污染土壤修復(fù)研究.發(fā)表論文5篇.

2018-07-26

國家科技支撐計(jì)劃課題(2015BAD05B02);重金屬污染耕地修復(fù)機(jī)理及技術(shù)模式優(yōu)化集成項(xiàng)目(農(nóng)業(yè)部財(cái)政部農(nóng)辦財(cái)函〔2016〕6號)

* 責(zé)任作者, 教授, zhguo@csu.edu.cn