硝酸鹽反射儀和SPAD法對(duì)玉米氮素營(yíng)養(yǎng)診斷的比較*

夏文豪劉 濤關(guān) 鈺王 進(jìn)褚貴新**

(1.石河子大學(xué)農(nóng)學(xué)院/新疆生產(chǎn)建設(shè)兵團(tuán)綠洲生態(tài)農(nóng)業(yè)重點(diǎn)試驗(yàn)室 石河子 832003; 2.烏蘭烏蘇農(nóng)業(yè)氣象試驗(yàn)站 石河子 832003)

硝酸鹽反射儀和SPAD法對(duì)玉米氮素營(yíng)養(yǎng)診斷的比較*

夏文豪1劉 濤1關(guān) 鈺1王 進(jìn)2褚貴新1**

(1.石河子大學(xué)農(nóng)學(xué)院/新疆生產(chǎn)建設(shè)兵團(tuán)綠洲生態(tài)農(nóng)業(yè)重點(diǎn)試驗(yàn)室 石河子 832003; 2.烏蘭烏蘇農(nóng)業(yè)氣象試驗(yàn)站 石河子 832003)

精準(zhǔn)的營(yíng)養(yǎng)診斷是了解作物氮素營(yíng)養(yǎng)及推薦施肥的基礎(chǔ)。本文在田間滴灌條件下利用SPAD葉綠素儀(SPAD-502 Plus)和硝酸鹽反射儀(RQ flex10)兩種診斷方法對(duì)玉米關(guān)鍵生育時(shí)期的氮素營(yíng)養(yǎng)診斷進(jìn)行研究,旨在篩選出適宜的診斷方法,并依據(jù)診斷值建立滴灌玉米不同生育時(shí)期的施肥模型。試驗(yàn)設(shè)置0 kg(N)·hm-2(N0)、225 kg(N)·hm-2(N225)、330 kg(N)·hm-2(N330)、435 kg(N)·hm-2(N435)和540 kg(N)·hm-2(N540)5個(gè)施氮水平,在不同生育時(shí)期測(cè)定了玉米葉片SPAD值和葉鞘NO含量,并分別與施氮量、植株全氮含量、產(chǎn)量進(jìn)行方程擬合,比較兩種診斷方法對(duì)玉米氮素營(yíng)養(yǎng)的響應(yīng)。研究結(jié)果表明：1)玉米葉片SPAD值和葉鞘NO含量均隨施氮量的增加而顯著升高,且在拔節(jié)期對(duì)施氮量的響應(yīng)最敏感。葉鞘NO含量對(duì)施氮量變化的響應(yīng)較SPAD值大,其與施氮量及玉米產(chǎn)量的擬合度均高于SPAD值,說明硝酸鹽反射儀法對(duì)滴灌玉米氮素豐缺的反應(yīng)更靈敏。2)玉米全氮含量與葉片SPAD值呈顯著線性關(guān)系,而與葉鞘NO含量則以線性加平臺(tái)表示。當(dāng)葉鞘NO含量小于186 mg·L-1時(shí),植株全氮與NO間呈顯著線性相關(guān);當(dāng)葉鞘NO含量大于186 mg·L-1時(shí),植株全氮隨NO含量增加趨于不變。3)本農(nóng)作區(qū)滴灌玉米最佳經(jīng)濟(jì)施氮量為402.5 kg·hm-2,對(duì)應(yīng)的玉米產(chǎn)量為17 049 kg·hm-2。玉米拔節(jié)期、抽雄吐絲期和灌漿期的臨界葉鞘NO含量分別為729.3 mg·L-1、536 mg·L-1和81.2 mg·L-1。SPAD葉綠素儀和硝酸鹽反射儀均可對(duì)滴灌玉米進(jìn)行氮素營(yíng)養(yǎng)診斷,但硝酸鹽速測(cè)值能更敏感地反映氮素豐缺狀況,基于硝酸鹽反射法進(jìn)行作物氮素營(yíng)養(yǎng)診斷及推薦施肥具有較好的準(zhǔn)確性與適用性。

施氮量 玉米 氮素營(yíng)養(yǎng) 硝酸鹽反射儀 葉綠素儀 SPAD值 葉鞘NO含量 營(yíng)養(yǎng)診斷

作物營(yíng)養(yǎng)診斷是通過簡(jiǎn)便、快捷的手段準(zhǔn)確獲取作物某一生育時(shí)期的營(yíng)養(yǎng)狀況,并以此為依據(jù)進(jìn)行診斷與施肥推薦的一項(xiàng)綜合技術(shù)。雖然植株全氮可很好地反映作物氮素營(yíng)養(yǎng),且與作物產(chǎn)量緊密相關(guān)[1],但測(cè)定中存在著化學(xué)分析環(huán)節(jié)多、時(shí)間長(zhǎng)、操作技術(shù)要求高等缺點(diǎn)?，F(xiàn)代農(nóng)業(yè)生產(chǎn)更需要精準(zhǔn)、迅速、便捷的作物氮素營(yíng)養(yǎng)輕簡(jiǎn)診斷技術(shù),近年來SPAD葉綠素儀、硝酸鹽反射儀及遙感光譜儀Greenseeker被逐漸應(yīng)用到作物氮素營(yíng)養(yǎng)診斷中來[2]。黨蕊娟等[3]證實(shí)夏玉米(Zea mays)不同葉層的SPAD值與含氮量顯著相關(guān),通過測(cè)定葉片中葉綠素含量可了解作物氮營(yíng)養(yǎng)狀況,并且可進(jìn)一步預(yù)測(cè)作物產(chǎn)量[4];陳曉群等[5]利用葉綠素儀法進(jìn)行水稻(Oryza sativa)田間氮肥管理;胡昊等[6]嘗試通過SPAD值和NDVI值對(duì)冬小麥(Triticum aestivum)產(chǎn)量進(jìn)行估算;Piekkielek等[7]與Francis等[8]均報(bào)道了利用葉綠素儀讀取作物SPAD值預(yù)測(cè)作物氮肥追施量,并進(jìn)行施肥指導(dǎo)。硝態(tài)氮是反映旱作物氮素狀況的敏感指標(biāo),Papastylianou等[9]研究了以硝酸鹽反射儀測(cè)定NO代替全氮作為氮營(yíng)養(yǎng)診斷指標(biāo),認(rèn)為可用該方法估計(jì)植株氮素營(yíng)養(yǎng)狀況及推薦追肥。我國(guó)在20世紀(jì)末初步建立了小麥、玉米的硝酸鹽診斷追肥技術(shù)體系[10]。王曉靜等[11]采用反射儀測(cè)量棉花(Gossypium sp.)葉柄硝酸鹽濃度進(jìn)行植株氮素營(yíng)養(yǎng)診斷并且指導(dǎo)施肥。雖然葉綠素儀具有操作簡(jiǎn)單、數(shù)據(jù)獲取迅速等優(yōu)點(diǎn),但SPAD讀數(shù)受光照輻射度的影響較大[12],且該方法需要測(cè)定多株作物以其平均值作為測(cè)定結(jié)果,工作量較大[13]。郭建華等[14]研究認(rèn)為雖然作物組織中NO含量能靈敏反映作物氮素營(yíng)養(yǎng)狀況,但當(dāng)植株體內(nèi)NO含量高時(shí),測(cè)定結(jié)果不穩(wěn)定。說明不同的氮素診斷方式具有一定的適用性和局限性,而篩選出作物較適宜的診斷方式在農(nóng)業(yè)生產(chǎn)中顯得尤為重要。前人基于氮素診斷技術(shù)研究較多,大部分闡述單一診斷技術(shù)在作物營(yíng)養(yǎng)診斷及施肥的應(yīng)用,鮮有針對(duì)作物利用不同技術(shù)進(jìn)行氮素診斷,進(jìn)而系統(tǒng)比較不同診斷技術(shù)的準(zhǔn)確性與適用性。本方法旨在篩選確立玉米較優(yōu)的氮素診斷方法,并依此推薦施肥。

天山北坡綠洲是新疆重要的節(jié)水滴灌農(nóng)業(yè)區(qū)。在滴灌水肥一體化農(nóng)作模式下,化肥氮追施量通常占施氮總量80%以上,在不同生育階段通過5～7次隨水滴施,以滿足作物氮素營(yíng)養(yǎng)需求[15-16]。在這種施肥模式下,及時(shí)對(duì)作物不同生育時(shí)期氮素營(yíng)養(yǎng)進(jìn)行準(zhǔn)確診斷是確定每次隨水滴施追肥推薦用量的前提。為此比較研究了葉綠素儀和硝酸鹽反射儀法在滴灌玉米氮素營(yíng)養(yǎng)診斷上的應(yīng)用效果,以期得出適合滴灌玉米的氮素營(yíng)養(yǎng)診斷方法,并為玉米不同生育階段的氮肥精準(zhǔn)追施提供依據(jù)。

1 材料與方法

1.1 試驗(yàn)地概況

試驗(yàn)于2013年在新疆沙灣縣烏蘭烏蘇氣象站進(jìn)行(44°17′N,85°51′E)。該站平均海拔450 m,年均降雨量約187.7 mm。試驗(yàn)區(qū)土壤類型為灌溉灰漠土(Calcaric Fluvisal),質(zhì)地為壤土,耕層(0～20 cm)土壤pH 8.52,有機(jī)質(zhì)18.73 g·kg-1,全氮0.96 g·kg-1,速效磷23.87 mg·kg-1,速效鉀340.95 mg·kg-1。供試作物為玉米,品種為春玉米‘良玉66號(hào)’(Zea mays cv Liangyu 66)。

1.2 田間試驗(yàn)設(shè)計(jì)

研究采用滴灌小區(qū)試驗(yàn),試驗(yàn)設(shè)計(jì)5個(gè)施氮水平,分別為0 kg(N)·hm-2(N0)、225 kg(N)·hm-2(N225)、330 kg(N)·hm-2(N330)、435 kg(N)·hm-2(N435)和540 kg(N)·hm-2(N540),3次重復(fù),共計(jì)15個(gè)小區(qū),采用隨機(jī)區(qū)組排列。供試氮肥為尿素(N≥46.6%),磷肥為磷酸一銨(N≥12%,P2O5≥61%),鉀肥為硫酸鉀(K2O≥51%)。

4月27—28日播種,5月5—6日出苗。40 cm+80 cm寬窄行覆膜種植,膜寬70 cm,膜間距60 cm,株距14.5 cm,一膜2行,鋪設(shè)1條滴灌帶,種植密度為114 945株·hm-2。每小區(qū)4膜,小區(qū)面積38.4 m2(4.8 m× 8.0 m)。生育期內(nèi)總灌水量為6 750 m3·hm-2,磷肥用量為90 kg(P2O5)·hm-2,鉀肥用量為90 kg(K2O)·hm-2,氮肥、磷肥和鉀肥全部作追肥隨水滴施,生育期內(nèi)共滴水10次,隨水施肥8次,各生育時(shí)期田間管理措施等同當(dāng)?shù)卮筇?。各生育時(shí)期滴水施肥分配比例見表1。

表1 滴灌玉米不同生育時(shí)期水肥分配比例Table 1 Proportion of water and fertilizer distribution during drip irrigation at different maize growth stages

1.3 測(cè)試指標(biāo)及方法

葉片SPAD測(cè)定：分別在玉米拔節(jié)期(大喇叭口期)、抽雄吐絲期、灌漿期選擇晴朗無(wú)云天氣進(jìn)行測(cè)定,測(cè)定時(shí)段為上午10：00—12：00。拔節(jié)期測(cè)定最上部完全展開葉,抽雄吐絲期和灌漿期測(cè)定穗位葉。用葉綠素儀(SPAD-502Plus,日本產(chǎn))在葉緣和葉脈的1/4、2/4、3/4處測(cè)定并取平均值。每小區(qū)隨機(jī)抽取無(wú)損傷且長(zhǎng)勢(shì)均勻的10株進(jìn)行測(cè)定。

植株全氮的測(cè)定：樣品粉碎后,采用凱氏定氮法測(cè)定其全氮含量。

產(chǎn)量測(cè)定：在成熟期取樣進(jìn)行考種,并實(shí)收測(cè)定小區(qū)產(chǎn)量。

1.4 數(shù)據(jù)分析

數(shù)據(jù)處理采用Microsoft Excel 2013、SPSS 20.0和多元統(tǒng)計(jì)分析軟件GraphPad Prism 5.0(GraphPad Software,San Diego,USA)進(jìn)行作圖,采用單因素方差分析法(One-way ANOVA)及 LSD多重比較法(α=0.05)分析處理間差異顯著性,變量相關(guān)性分析均用全部觀測(cè)值進(jìn)行。

2 結(jié)果與分析

2.1 玉米葉片SPAD值與葉鞘NO3-含量的動(dòng)態(tài)變化

由圖1A可知,玉米葉片SPAD值(以下簡(jiǎn)稱SPAD值)變化范圍為45.3～56.5,SPAD值隨玉米生育進(jìn)程而升高,且在各時(shí)期均隨施氮量增加而增加,其中以N540處理表現(xiàn)最高。各施氮處理的SPAD值顯著高于CK(N0)處理(P＜0.05),但N225、N330和N435施氮處理間無(wú)顯著差異。由圖1B可知,玉米葉鞘NO含量(以下簡(jiǎn)稱 NO含量)的變化范圍為17.0～886.7 mg·L-1,NO含量隨著生育進(jìn)程而降低,灌漿期各處理的NO含量急劇下降(低于100 mg·L-1)。各生育時(shí)期均表現(xiàn)為玉米葉鞘NO含量隨著施氮量的增加而升高,且各施氮處理NO含量顯著高于CK處理(P＜0.05),但N435和N540處理間差異不顯著。在玉米拔節(jié)—灌漿期葉鞘NO含量對(duì)施氮量的響應(yīng)明顯大于SPAD值。

圖1 玉米不同生育時(shí)期施氮對(duì)葉片SPAD值(A)與葉鞘NO含量(B)的影響Fig.1 Influence of N fertilizer application rate on leaf SPAD reading(A)and sheath NO3-concentration(B)at different maize growth stages

2.2 玉米葉片SPAD值與葉鞘NO3-含量對(duì)施氮量的響應(yīng)

2.3 玉米葉片SPAD值、葉鞘NO3-含量及植株全氮含量間關(guān)系

如圖3所示,在玉米拔節(jié)—灌漿期植株全氮含量、SPAD值及NO含量呈不同的函數(shù)關(guān)系。玉米全氮含量隨葉片SPAD值的增加而升高,兩者呈極顯著線性關(guān)系(圖3A)。植株全氮與葉鞘NO含量的關(guān)系則呈線性加平臺(tái)關(guān)系(圖3B)。當(dāng)葉鞘NO含量小于186 mg·L-1時(shí),植株全氮含量隨NO含量增加呈線性升高;當(dāng)葉鞘NO含量大于186 mg·L-1時(shí),植株全氮隨著NO含量增加則趨于不變。由于NO含量變化的值域較大(17.0～886.7 mg·L-1),玉米全氮含量在葉鞘NO含量大于186 mg·L-1時(shí)無(wú)明顯變化, 而NO含量卻發(fā)生顯著變化,說明此時(shí)全氮已經(jīng)不能敏感響應(yīng)玉米的氮素營(yíng)養(yǎng)狀況。此外,玉米SPAD值與葉鞘NO含量關(guān)系可分別擬合出線性加平臺(tái)和指數(shù)函數(shù)模型。當(dāng)葉鞘NO含量小于213.2 mg·L-1時(shí),SPAD值隨著NO含量增加而線性升高;當(dāng)葉鞘 NO含量大于 213.2 mg·L-1時(shí),SPAD值隨著NO含量增加有不變趨勢(shì)(圖3C)。玉米NO含量隨SPAD值增加呈指數(shù)升高,單位SPAD值變化可引起NO含量的明顯變化(圖3D)。以上進(jìn)一步說明,葉鞘NO含量較SPAD值可更靈敏地反映玉米氮素營(yíng)養(yǎng)狀況。

圖2 玉米不同生育時(shí)期施氮量與葉片SPAD值(A)、葉鞘NO含量(B)的關(guān)系Fig.2 Relationship between N fertilizer application rate at different maize growth stages and leaf SPAD reading(A),sheath NO3-concentration(B)

圖3 玉米SPAD值、葉鞘NO含量及植株全氮之間的相關(guān)關(guān)系Fig.3 Relationship between SPAD reading,sheath NO3-concentration and maize total N content

2.4 SPAD值、NO3-含量與玉米產(chǎn)量間關(guān)系及基于葉鞘NO3-的診斷施肥模型建立

通過玉米產(chǎn)量和總施氮量進(jìn)行擬合可得：y= -0.046 2x2+39.422x+8 665.9(R2=0.883 5**,n=15)。其中方程中y為玉米產(chǎn)量,x為施氮量。對(duì)方程求一階導(dǎo)可得玉米最高產(chǎn)量為17 076 kg·hm-2,對(duì)應(yīng)的施氮量為426.7 kg·hm-2。此施氮量可作為玉米獲取最高產(chǎn)量的全生育期參考施氮量。計(jì)算最佳施氮量經(jīng)濟(jì)效應(yīng)是指單位面積上獲得最大經(jīng)濟(jì)效應(yīng)的氮肥施用量,即邊際產(chǎn)值等于邊際成本時(shí),此時(shí)單位面積的經(jīng)濟(jì)效應(yīng)最大。參考2014年玉米價(jià)格為1.75元·kg-1,尿素價(jià)格為1.8元·kg-1,即純氮的價(jià)格為3.9元·kg-1(尿素純N含量46.6%)。當(dāng)方程一階導(dǎo)等于商品玉米與純氮的價(jià)格比值時(shí),可求得最佳經(jīng)濟(jì)施氮量為402.5 kg·hm-2,其對(duì)應(yīng)的玉米產(chǎn)量為17 049 kg·hm-2。

表2 玉米不同生育時(shí)期葉片SPAD值、葉鞘NO含量與產(chǎn)量的函數(shù)關(guān)系Table 2 Correlations between leaf SPAD reading,sheath NOconcentration at different maize growth stages and maize yield

表2 玉米不同生育時(shí)期葉片SPAD值、葉鞘NO含量與產(chǎn)量的函數(shù)關(guān)系Table 2 Correlations between leaf SPAD reading,sheath NOconcentration at different maize growth stages and maize yield

生育期Growing stage SPAD值(x)與產(chǎn)量(y)的關(guān)系Relationship between SPAD(x)and maize yield(y)葉鞘NO含量(x)與產(chǎn)量(y)的關(guān)系Relationship between sheath NO3-concentration(x)and maize yield(y)擬合方程Fitting equation R2擬合方程Fitting equation R2拔節(jié)期Jointing stage y=-605.08x2+59 086x-1E+06 0.574 5**y=-0.045 9x2+66.946x-7361.5 0.726 5**抽雄吐絲期Tassel emerge stage y=-38.001x2+5 172.4x-152 620 0.559 5**y=-0.039 2x2+45.708x+3811.5 0.839 9**灌漿期Filling stage y=-107.55x2+12 470x-344 022 0.653 8**y=-1.524 2x2+282.61x+4 105 0.891 3**

表3 玉米各生育時(shí)期氮肥推薦模型Table 3 Recommendation models of N fertilizer application at different maize growth stages

3 討論

研究表明作物氮含量與SPAD值間具有極顯著相關(guān)性,能較好地反映作物氮素營(yíng)養(yǎng)狀況[17]。本研究中玉米葉鞘NO濃度與土壤供氮量以及玉米氮素營(yíng)養(yǎng)密切相關(guān),這與米艷華等[18]研究結(jié)果一致。玉米葉鞘NO含量在拔節(jié)期最高,且對(duì)土壤供氮量的反應(yīng)最靈敏,隨著生育時(shí)期的推進(jìn)而呈下降趨勢(shì),至灌漿期最低。原因可能是氮素在植物體內(nèi)移動(dòng)性強(qiáng),此時(shí)期玉米植株?duì)I養(yǎng)物質(zhì)開始大量由葉片、葉鞘等營(yíng)養(yǎng)器官向生殖器官(穗部)轉(zhuǎn)運(yùn),氮素同化速率快,故體內(nèi)游離的硝酸鹽含量低。危常州等[19]在利用反射儀法診斷棉花的氮素營(yíng)養(yǎng)時(shí)也發(fā)現(xiàn)了相似的硝酸鹽濃度隨棉花生育進(jìn)程而遞減變化的規(guī)律。Geyer等[20]認(rèn)為玉米NO含量值域范圍較大,由于有明顯的營(yíng)養(yǎng)級(jí)劃分,可以比較數(shù)值的變化范圍直觀地判斷出玉米在不同時(shí)期的氮素豐缺狀況。SPAD值能直接反映作物的葉綠素相對(duì)含量,葉綠素為鎂卟啉化合物,相比于離子態(tài)NO對(duì)氮素微量變化的反饋效果較差,這在本研究中也得到證實(shí)。如葉片SPAD值在玉米生育期變化范圍較小(45.3～56.5),而NO含量變化范圍較大(17.0～886.7 mg·L-1),由NO含量與植株全氮的線性加平臺(tái)關(guān)系可看出,超過平臺(tái)拐點(diǎn)186 mg·L-1后,繼續(xù)增加施氮量能引起NO含量的變化,但植株全氮含量并未發(fā)生明顯依變。本文通過比較可發(fā)現(xiàn),葉鞘硝酸鹽測(cè)定較葉綠素儀和全氮測(cè)定更能反映過量施氮問題。李銀水等[21]比較了SPAD葉綠素儀法、硝酸鹽反射儀法和光譜儀法在油菜(Brassica napus)氮素營(yíng)養(yǎng)快速診斷上的適宜性,通過篩選認(rèn)為SPAD值法是最適宜氮素診斷指標(biāo)。而在本研究中,結(jié)果與上述試驗(yàn)結(jié)果并不一致,SPAD值取決于葉片葉綠素對(duì)特定波段光線的吸收,但玉米不同生育時(shí)期葉片的厚度不同,單位面積上的葉綠素分子數(shù)量不同,從而影響葉片的SPAD值[22]。同時(shí)在葉片基部單位面積上葉脈數(shù)量較多,葉綠素儀檢測(cè)窗口壓在葉脈上的機(jī)率也大大增加,導(dǎo)致在葉基部測(cè)定結(jié)果偏低、變異較大[13],這可作為解釋本試驗(yàn)玉米葉片SPAD值不穩(wěn)定的可能原因。

本文重在闡述比較SPAD葉綠素儀法、硝酸鹽反射儀法對(duì)滴灌玉米氮素診斷的優(yōu)劣性,對(duì)基于NO含量構(gòu)建的氮肥推薦模型需進(jìn)一步驗(yàn)證。試驗(yàn)結(jié)果是由1年數(shù)據(jù)產(chǎn)生,應(yīng)利用后續(xù)的大量試驗(yàn)探究此診斷模型在本區(qū)域不同品種玉米的普適性,并對(duì)其進(jìn)行完善與優(yōu)化。

4 結(jié)論

通過SPAD葉綠素儀與硝酸鹽反射儀對(duì)滴灌玉米進(jìn)行快速氮素診斷,得出植株在各生育階段NO含量與施氮量、產(chǎn)量的方程擬合度均高于SPAD值。硝酸鹽速測(cè)較SPAD值測(cè)定對(duì)氮素豐缺反應(yīng)更靈敏,數(shù)據(jù)更穩(wěn)定。

由肥料效應(yīng)方程可得玉米最佳經(jīng)濟(jì)施氮量為402.5 kg·hm-2,其對(duì)應(yīng)的玉米產(chǎn)量為17 049 kg·hm-2。基于硝酸鹽反射儀可診斷出玉米拔節(jié)期、抽雄吐絲期和灌漿期的NO臨界診斷值,分別為729.3 mg·L-1、536 mg·L-1和81.2 mg·L-1,其對(duì)應(yīng)的單位NO含量變動(dòng)施肥量為0.178 kg·hm-2、0.452 kg·hm-2和3.82 kg·hm-2。當(dāng)NO實(shí)測(cè)含量低于該生育階段的臨界值時(shí),可依據(jù)單位NO含量變動(dòng)施肥量精準(zhǔn)計(jì)算出需要追加的施氮量。

References

[1]Leight R A,Johnston A B.Nitrogen concentrations in fieldgrown spring barley：An examination of the usefulness of expressing concentrations on the basis of tissue water[J].The Journal of Agricultural Science,1985,105(2)：397-406

[2]賈良良,陳新平,張福鎖.作物氮營(yíng)養(yǎng)診斷的無(wú)損測(cè)試技術(shù)[J].世界農(nóng)業(yè),2001(6)：36-37 Jia L L,Chen X P,Zhang F S.Nondestructive testing techniques for the diagnosis of crop nitrogen nutrition[J]. World Agriculture,2001(6)：36-37

[3]黨蕊娟,李世清,穆曉慧,等.施氮對(duì)半濕潤(rùn)農(nóng)田夏玉米冠層氮素及葉綠素相對(duì)值(SPAD值)垂直分布的影響[J].中國(guó)生態(tài)農(nóng)業(yè)學(xué)報(bào),2009,17(1)：54-59 Dang R J,Li S Q,Mu X H,et al.Effect of nitrogen on vertical distribution of canopy nitrogen and chlorophyll relative value (SPAD value)of summer maize in sub-humid areas[J]. Chinese Journal of Eco-Agriculture,2009,17(1)：54-59

[4]吳良?xì)g,陶勤南.水稻葉綠素計(jì)診斷追氮法研究[J].浙江農(nóng)業(yè)大學(xué)學(xué)報(bào),1999,25(2)：135-138 Wu L H,Tao Q N.Nitrogen fertilizer application based on the diagnosis of nitrogen nutrition of rice plants(Oryza sativa L.) using chlorophyll meter[J].Journal of Zhejiang Agricultural University,1999,25(2)：135-138

[5]陳曉群,張學(xué)軍,白建忠,等.基于水稻不同生育期葉綠素值推薦追施氮量的研究初報(bào)[J].中國(guó)農(nóng)學(xué)通報(bào),2010,26(7)：147-151 Chen X Q,Zhang X J,Bai J Z,et al.Preliminary study on amount of recommended topdressing nitrogen using chlorophyll SPAD of rice during different growth stage[J]. Chinese Agricultural Science Bulletin,2010,26(7)：147-151

[6]胡昊,白由路,楊俐蘋,等.基于SPAD-502與GreenSeeker的冬小麥氮營(yíng)養(yǎng)診斷研究[J].中國(guó)生態(tài)農(nóng)業(yè)學(xué)報(bào),2010, 18(4)：748-752 Hu H,Bai Y L,Yang L P,et al.Diagnosis of nitrogen nutritionin winter wheat(Triticum aestivum)via SPAD-502 and GreenSeeker[J].Chinese Journal of Eco-Agriculture,2010, 18(4)：748-752

[7]Piekkielek W P,Fox R H.Use of a chlorophyll meter to predict sidedress nitrogen[J].Agronomy Journal,1991,84(1)：59-65

[8]Francis D D,Piekielek W P.Assessing crop nitrogen needs with chlorophyll meters[R].SSMG-12.Site-Secific Management Guidelines,1998

[9]Papastylianou I,Puckridge D W.Stem nitrate nitrogen and yield ofwheatin a permanentrotation experiment[J]. Australian Journal of Agricultural Research,1983,34(6)：599-606

[10]李志宏,張福鎖,王興仁.我國(guó)北方地區(qū)幾種主要作物氮營(yíng)養(yǎng)診斷及追肥推薦研究Ⅲ.春小麥氮營(yíng)養(yǎng)診斷及追肥推薦體系的研究[J].植物營(yíng)養(yǎng)與肥料學(xué)報(bào),1997,3(4)：349-356 Li Z H,Zhang F S,Wang X R.Nitrogen nutritional diagnosis and recommendation as topdressing fertilizer N for several crops in north ChinaⅢ.Nitrogen nutritional diagnosis and recommendation as topdressing fertilizer N forspring wheat[J].Plant Nutrition and Fertilizer Science,1997,3(4)：349-356

[11]王曉靜,張炎,李磐,等.棉花氮素營(yíng)養(yǎng)狀況的診斷研究[J].植物營(yíng)養(yǎng)與肥料學(xué)報(bào),2006,12(5)：656-661 Wang X J,Zhang Y,Li P,et al.Study on cotton nitrogen diagnosis with reflectance meter[J].Plant Nutrition and Fertilizer Science,2006,12(5)：656-661

[12]Hoel B O,Solhaug K A.Effect of irradiance on chlorophyll estimation with theMinoltaSPAD-502 leaf chlorophyll meter[J].Annals of Botany,1998,82(3)：389-392

[13]李志宏,張?jiān)瀑F,劉宏斌,等.葉綠素儀在夏玉米氮營(yíng)養(yǎng)診斷中的應(yīng)用[J].植物營(yíng)養(yǎng)與肥料學(xué)報(bào),2005,11(6)：764-768 Li Z H,Zhang Y G,Liu H B,et al.Application of chlorophyll meter on N nutritional diagnosis for summer corn[J].Plant Nutrition and Fertilizer Science,2005,11(6)：764-768

[14]郭建華,趙春江,王秀,等.作物氮素營(yíng)養(yǎng)診斷方法的研究現(xiàn)狀及進(jìn)展[J].中國(guó)土壤與肥料,2008(4)：10-14 Guo J H,Zhao C J,Wang X,et al.Research advancement and status on crop nitrogen nutrition diagnosis[J].Soiland Fertilizer Sciences in China,2008(4)：10-14

[15]寧松瑞,左強(qiáng),石建初,等.新疆典型膜下滴灌棉花種植模式的用水效率與效益[J].農(nóng)業(yè)工程學(xué)報(bào),2013,29(22)：90-99 Ning S R,Zuo Q,Shi J C,et al.Water use efficiency and benefit for typical planting modes of drip-irrigated cotton under film in Xinjiang[J].Transactions of the Chinese Society of Agricultural Engineering,2013,29(22)：90-99

[16]譚華,鄭德波,鄒成林,等.水肥一體膜下滴灌對(duì)玉米產(chǎn)量與氮素利用的影響[J].干旱地區(qū)農(nóng)業(yè)研究,2015,33(3)：18-23 Tan H,Zheng D B,Zou C L,et al.Effect of drip irrigation and fertilization on grain yield and nitrogen utilization of maize[J]. Agricultural Research in the Arid Areas,2015,33(3)：18-23

[17]Samborski S M,Tremblay N,Fallon E.Strategies to make use of plant sensors-based diagnostic information for nitrogen recommendations[J].Agronomy Journal,2009,101(4)：800-816

[18]米艷華,李茂萱,潘艷華,等.玉米N素營(yíng)養(yǎng)快速診斷精準(zhǔn)施肥技術(shù)研究[J].西南農(nóng)業(yè)學(xué)報(bào),2008,21(2)：402-407 Mi Y H,Li M X,Pan Y H,et al.Studies on precision fertilization technology for maize nitrogen nutrition rapid diagnose[J].Southwest China Journal of Agricultural Sciences, 2008,21(2)：402-407

[19]危常州,張福鎖,朱和明,等.新疆棉花氮營(yíng)養(yǎng)診斷及追肥推薦研究[J].中國(guó)農(nóng)業(yè)科學(xué),2002,35(12)：1500-1505 Wei C Z,Zhang F S,Zhu H M,et al.Study on cotton nitrogen diagnosis and topdressing recommendation in north Xinjiang[J]. Scientia Agricultura Sinica,2002,35(12)：1500-1505

[20]Geyer B, Marschner H. Charakterisierung des Stick stoffversorgungsgrades bei Mais mit Hilfe des Nitrat-Schnelltests[J].Zeitschrift für Pflanzenern?hrung und Bodenkunde, 1990,153(5)：341-348

[21]李銀水,余常兵,廖星,等.三種氮素營(yíng)養(yǎng)快速診斷方法在油菜上的適宜性分析[J].中國(guó)油料作物學(xué)報(bào),2012,34(5)：508-513 Li Y S,Yu C B,Liao X,et al.Applicability of three rapid methodsofnitrogen nutrition diagnosison rapeseed[J]. Chinese Journal of Oil Crop Sciences,2012,34(5)：508-513

[22]童淑媛,宋鳳斌.SPAD值在玉米氮素營(yíng)養(yǎng)診斷及推薦施肥中的應(yīng)用[J].農(nóng)業(yè)系統(tǒng)科學(xué)與綜合研究,2009,25(2)：233-238 Tong S Y,Song F B.Application of SPAD value on N nutritionaldiagnosisand fertilization recommendation[J]. System Sciences and Comprehensive Studies in Agriculture, 2009,25(2)：233-238

[23]賈良良,陳新平,張福鎖.葉綠素儀與植株硝酸鹽濃度測(cè)試對(duì)冬小麥氮營(yíng)養(yǎng)診斷準(zhǔn)確性的比較研究[J].華北農(nóng)學(xué)報(bào), 2007,22(6)：157-160 Jia L L,Chen X P,Zhang F S.The comparision of SPAD chlorophyll meter and sap nitrate test as N diagnosis methods for winter wheat[J].Acta Agriculturae Boreali-Sinica,2007, 22(6)：157-160

[24]李世清,王瑞軍,李紫燕,等.半干旱半濕潤(rùn)農(nóng)田生態(tài)系統(tǒng)不可忽視的土壤氮庫(kù)——土壤剖面中累積的硝態(tài)氮[J].干旱地區(qū)農(nóng)業(yè)研究,2004,22(4)：1-13 Li S Q,Wang R J,Li Z Y,et al.Soil nitrogen pool not to be ignored residual NO-N accumulated in soil profile in semiarid and semihumid agro-ecological system[J].Agricultural Research in the Arid Areas,2004,22(4)：1-13

[25]Ferguson R B,Hergert G W,Schepers J S,et al.Site-specific nitrogen management of irrigated maize[J].Soil Science Society of America Journal,2002,66(2)：544-553

[26]Blackmer T M,Schepers J S,Vigil M F.Chlorophyll meter readings in corn as affected by plant spacing[J]. Communications in Soil Science and Plant Analysis,1993, 24(17/18)：2507-2516

Comparison of RQ flex and SPAD methods of diagnosing maize (Zea mays)nitrogen nutrient*

XIA Wenhao1,LIU Tao1,GUAN Yu1,WANG Jin2,CHU Guixin1**
(1.College of Agronomy,Shihezi University/Key Laboratory of Oasis Eco-agriculture,Xinjiang Production and Construction Group,Shihezi 832003,China;2.Wulanwusu Agro-meteorological Experiment Station,Shihezi 832003,China)

Precise and prompt approach of crop nutrient diagnosis is the prerequisite in determining crop N content and the recommendation of reasonable amount of N fertilizer.In this study,a field experiment was carried out under drip irrigation condition,the chlorophyll equipment(SPAD-502 Plus)and nitrate reflectrometer(RQ flex10)was employed in terms of diagnosis of maize N nutrition during key growth stages.The aim of the study was to build maize fertilization mode by using the most suitable diagnosis approach.Five N fertilizer application rates were arrayed,including N0[0 kg(N)·hm-2],N225[225 kg(N)·hm-2],N330[330 kg(N)·hm-2],N435[435 kg(N)·hm-2]and N540[540 kg(N)·hm-2].The difference of diagnostic effect between SPAD-502 Plus and RQ flex10 methods on maize plant N nutrient were compared based on correlation analysis.The analysis compared the relationships between corn leaf SPAD and leaf sheath NOconcentration for various N fertilizerapplication rates,plant total N content and yield during different maize growth stages.Also the sensitivities of the RQ flex 10 and SPAD methods of diagnosis of maize plant N nutrient were compared.The results were as follows：1)Maize leaf SPAD and leaf sheath NOconcentration significantly increased with increasing N fertilizer application rate and the most sensitive period was from jointing stage to either tassel-emergence stage or grain-filling stage.The response of sheath NOconcentration to N application rate was more sensitive than that of SPAD.This resulted into a higher degree of fit between NOconcentration determined by RQ flex 10 method and N application rate or maize yield.RQ flex 10 method was more sensitive in diagnosis of maize N nutrition.2)The total N content in maize had a significant linear correlation with leaf SPAD,while there was linear and then a constant correlation between the total N and sheath NOconcentration.That was,total N content was linearly correlated with NOconcentration as corn sheath NOconcentration less than 186 mg·L-1,however,total N content varied slight when sheath NOconcentration exceeding 186 mg·L-1.3)The recommended economic fertilizer application rate in maize under drip irrigation was 402.5 kg·hm-2,which produced a yield of 17 049 kg·hm-2.The critical NOconcentration was 729.3 mg·L-1at jointing stage,536 mg·L-1at tassel emergence stage and 81.2 mg·L-1at grouting stage, respectively.In conclusion,our study showed that both the chlorophyll meter and RQ flex 10 were suitable for maize N nutrient diagnosis.Moreover,the RQ flex 10 approach was a more sensitive method than the chlorophyll meter in diagnosing maize N nutrient status.The study suggested that the RQ flex method was highly suitable for the recommendation of N fertilizer as well as better N resource management in maize fields.

N application rate;Maize;Nitrogen nutrient;Nitrate reflectrometer;Chlorophyll meter;SPAD reading;Sheath NOconcentration;Nutrient diagnosis

S513;S<143.1 文獻(xiàn)標(biāo)識(shí)碼:A class="emphasis_bold">143.1 文獻(xiàn)標(biāo)識(shí)碼:A 文章編號(hào):1671-3990(2016)10-1339-08143.1 文獻(xiàn)標(biāo)識(shí)碼:A

1671-3990(2016)10-1339-08

A 文章編號(hào):1671-3990(2016)10-1339-08

10.13930/j.cnki.cjea.160182

* 國(guó)家“十二五”科技支撐項(xiàng)目(2012BAD42B02)資助

**通訊作者：褚貴新,主要從事植物營(yíng)養(yǎng)生理生態(tài)、土壤微生物分子生態(tài)研究。E-mail：chuguixinshzu@163.com

夏文豪,主要從事作物養(yǎng)分資源高效利用研究。E-mail：xiawenhaohh@163.com

2016-02-27 接受日期：2016-06-12

* The study was funded by the National Key Technologies R&D Program of China(2012BAD42B02).

**Corresponding author,E-mail：chuguixinshzu@163.com

Received Feb.27,2016;accepted Jun.12,2016