全 文 ：文章编号: 1007-0435( 2006) 03-0295-03 ·博士论文摘要·
甘肃秦王川灌区苜蓿草地土壤水盐动态
及其生态灌溉调控模式
博士生: 成自勇1　导师: 张自和1, 2
( 1. 甘肃农业大学, 兰州　730070; 2. 兰州大学农业部草地农业生态系统学重点开放实验室, 兰州　730020)
　　以 “生态灌溉”的思路研究秦王川干旱灌区苜
蓿草地土壤水盐运移规律及其生态灌溉调控模式;
苜蓿在水盐等逆境胁迫下的生理生态特征、生育阶
段水分生产函数及生态灌溉制度;应用系统工程方
法对灌区苜蓿(Medicago sativa)种植结构及经济效
益进行优化配置;构建灌溉水-光合作用-生物产量
转化效益及土壤水盐-牧草作物-灌区生态系统协调
优化的生态灌溉体系。
1.当土壤含盐量达到0. 279%时,对苜蓿种子萌
发则有明显的抑制作用,当达到0. 428%时萌发几乎
停止;随着土壤盐分浓度的增加苜蓿地上部受抑制
的程度逐渐大于根部,水分利用效率 ( Water U se
Ef ficiency, WUE)显著降低;灌水后电导率在不同深
度土层与土壤含水量互为逆向变化;适当浓度的钠
盐、镁盐可使苜蓿体内的氨基酸含量增加,但氯离子
则抑制氨基酸的合成;水分胁迫对苜蓿脯氨酸含量
有明显影响; NaCl、NaHCO 3和MgSO 4在8和15 g/ L
浓度下均表现出高浓度对应高植物蛋白现象,该结
论成为苜蓿营养生长阶段通过水盐有限调控达到理
想品质的生态灌溉基本内涵之一;在不同地温下,电
导率呈较明显的分段函数特征, 且各段内电导率与
地温之间都呈线性正相关关系。
2.苜蓿叶面积指数和株高之间呈线性正相关关
系;水分胁迫对根系吸水的补偿效应有明显的影响,
因而降低根系的吸水速率和相对湿度对苜蓿干草产
量的影响最大。
3.蒸腾速率与光合速率呈正相关,但一定程度的
水分亏缺可以提高光合和蒸腾之比(即水分利用率) ,
是苜蓿在刈割前生态灌溉生理调控的机理所在;在重
度水分胁迫( 45%～50% FC)下,高浓度NaCl对苜蓿
的蒸腾产生了明显的抑制作用; 苜蓿土壤-植物-大气
连续体 ( Soil-Plant-Atmosphere Continuum, SPAC)
系统水势由土壤到根系再到茎叶降幅比约为 1∶
2. 5∶6,灌水后降幅扩大至1∶5. 5∶9。
4.应用彭曼-蒙特斯公式 ( 1948) ( Penman-Mon-
teith) 实测土壤水分、灌水量和降水量等试验数据,
分析计算得出苜蓿在不同生育期水分梯度胁迫下的
生态需水、耗水规律、水分生理特征和生物产量等内
在关系及结果。
5.水分生产函数加法模型和乘法模型都能较好
地体现苜蓿生育阶段水分对生物产量的反应,其中
加法模型更加适合于初花期刈割的苜蓿;用线性规
划法和动态规划法得出初花期刈获苜蓿的生态型经
济灌溉制度;轻度水分胁迫为苜蓿生态适宜性控制
指标,其土壤含水量下限为60%～65% FC。
6. 第 1、2、3 茬苜蓿在轻度水分胁迫下WUE较
高,从3. 2下降到2. 2 kg/ cm 3;苜蓿单方水生产效益高
出小麦(w heat) 0. 595 元/ m 2、蚕豆( V icia f aba) 0. 585
元/ m 2;秦王川灌区由水量控制的粮、经、草优化种植
比例为1∶0. 43∶0. 45,其中苜蓿最优种植面积为1.
223 hm
2。
7.根据苜蓿生育期非充分灌溉与营养生长阶段
水盐敏感程度,对苜蓿水盐有限调亏使其达到理想
品质,提高水分利用效率及最佳生物产量,构成生态
灌溉基本内涵;在灌区生态系统与水资源双重约束
下,依照灌区生态型多元种植结构与苜蓿种植效益
优化相结合,通过水资源配置及苜蓿灌溉制度的优
化,形成“生态灌溉”的实际内涵。
关键词: 秦王川灌区; 苜蓿; 土壤水盐动态; 光合生理生态; 水分生产函数; 生态灌溉调控
中图分类号: S812　　　文献标识码: A
完成时间: 2005 年11月
收稿日期: 2006-02-14; 修回日期: 2005-05-14
基金项目: 教育部世行贷款高等理工科教改项目( 1282B12071)
作者简介: 成自勇( 1956-) ,男,博士,教授,研究方向为水工程与生态环境, E-mail : chengziyong@ tom. com
导师简介: 张自和( 1944-) ,男,教授,研究方向为草业科学, E -mail : zhzih e@ lzu. edu . cn
第 14 卷　第3 期
　Vol. 14　 No . 3
草　地　学　报
ACTA AGREST IA SINICA
　　　2006 年　 9 月
　Sep.　　 2006
Research on the Soil Water and Salt Dynamics of the Purple Medic Grassland
and the Mode of an Optimal Ecological Irrigation Control in the
Qinwangchuan Irrigated Regions, Gansu Province
Candidate: CHENG Zi-yong
1　Advisor s: ZHANG Zi-he1, 2
( 1. Gan su Agricu lture Un iversi ty, Lanzhou, Gansu Pr ovin ce 730070, China;
2. Key Laboratory of Gras sland Agro-Ecosystem s, Lan zhou University and Min ist ry of Agricul ture, Lanzhou , Gan su Provin ce 730020, Chin a)
Based on the concept o f ecolo gical irrigat ion, we studied the physio logical influence of soil w ater and salt
dynam ics on the purple medic g rassland of the Qinw angchuan Irrig at ion Region and pat terned a mode of ecolo g-
ical irrigat ion control in the region, in consideration of the g rassland so il w ater and sal t st ress, and the ecologi-
cal and econom ical irrig ation quo ta for the harvest of purple medic during its early anthesis. The present paper
pr esents an optimal eco logical irrig at ion system in the arid region that saves w ater and achieves economic ef fi-
ciency, a harmonic ecolog ical irrig at ion sy stem insur es irrigat ion w ater-photosynthesis-yield in pasturage irriga-
tion, and an innovat ive harmonious w ater and salt-g rass-ecosy stem.
The results show that seed germ inat ion rate w as reduced sharply w hen soil salinity r eached 0. 279%. And
it almost stopped when the salinity w ent up to 0. 428%. Along w ith the rising o f the soil salinity during the
plant bear ing period, grow th o f the aboveground biomass o f the purple medic w as stunted more obviously than
that of the undergr ound par t , w hile the w ater use ef ficiency w eakened. U nder the joint w ater-and-salt st ress,
the conductiv ity in different soil depths and the soil moisture content changed reversely af ter irrig at ion. Suit-
able concentrat ion of sodium salt and o f magnesium sal t could increase the prol ine content of purple medic,
w hile chlorine ion could balk at the synthesis of amino acid. The condition of 8 g/ L and 15 g / L of NaCl, NaH-
CO3 and M gSO 4show ed that high salt st reng th corresponds to high pro tein, w hich became one o f the basic theo-
ries of ecolog ical ir rigat ion to achieve an ideal quality through limited regulated irr ig ation in the purple medic
vegetative stage. The conduct ivity show ed a quite obvious partit ion funct ion characterist ic under differ ent soil
temperature gradients. There w as a posit ive linear corr elat ion betw een the soil conduct ivity and temperatur e in
various so il temperatur es.
The r esults also indicate that ther e w as a posit ive linear correlat ion betw een the leaf area index and plant
height . The compensat ion ef fect of roo t moisture-absorpt ion under w ater st ress w as obviously bigg er than the
control , though the ro ot moisture absorption rate w as slow ed down by w ater str ess. T he results o f the f iled ex-
periment show ed that there w as a relation betw een purple medic dry matter and local meteor olog ical facto r; rel-
ative humidity exercised the most important inf luence on the dry mat ter y ield.
In the aspect of response of purple medic to photosynthesis and eco-physiolog y, there w as a posit iv e corre-
lation betw een pho to synthet ic r ate and transpir at ion rate. The research also show ed that the incr ease o f soil
w ater st ress could improve the r at io of photosynthetic rate divided by transpirat ion rate ( WUE) . High concen-
tr ation of NaCl impeded the t ranspiration under serious w ater stress ( 45%～50% FC) . The measurements of
the w ater potent ial gradient of SPAC( soil plant atmosphere cont inuum) show ed that each part of w ater potent ial
decr eased from roo t to stem and leaf , w ith the ratio being 1: 2. 5: 6 and the elev ated r at io being 1∶5. 5∶9 after
irrigat ion.
Penman-M onteith formula w as appl ied to calculate the actual so il moisture and the amount of irr ig ation and
rainfall. T he intr insic relations among the result of the ecolo gical w ater , the rule o f w ater consumpt ion, the
w ater bio logical characterist ics, and the biolog ical y ield during dif ferent grow ing periods o f purple medic under
the gradient of moistur e st ress w ere analyzed and obtained.
The optimum regulat ion and control ling system w ere studied and the idea o f eco log ical irrigat ion w as
296 草　地　学　报 第 14卷
po sed. The study showed that the Blanks and Jensens crop water pr oduct ion models w er e eff icient . T he Blank
model w as much more suitable to the harvest of purple medic dur ing early anthesis. Furthermor e, the economi-
cal ir rigat ion sy stem w as consistent w ith the w ay of dynam ic pr ogramming in the ear ly anthesis stage. And soil
moisture should be maintained at least at 60%～65% of field capacity .
Water use eff iciency of perennial purple medic w as increased under low-g rade w ater st ress fo r the f irst
thr ee cutt ings in a year. The output value o f per-stere w ater irrig at ing the purple medic w as RMB 0. 595 Y/ m
2
higher than the same amount of w ater for w heat , and RMB 0. 585 Y/ m
2
higher than that irrigat ing the bro ad
bean. In the Qinw angchuan Irrig ation Reg ion, the opt imal plant ing area ratio under w ater cont rol among
gr ain, economic crop, and forag e is 1∶0. 43∶0. 45, w ith the opt imal plant ing area of 1. 223 hm 2 for pur ple
medic.
Due to the sensit ivity of the g row ing-stage pur ple medic to insuf ficient w ater and of it s vegetative stage to
nutrit ion, w e adjusted the appr opr iate rat io of w ater and sal t for ir rigat ion so as to achiev e the maximum water
use ef ficiency and to obtain an opt imal yield. Rest ricted by the given eco-system and limited w ater resources,
w e combined the ecolog ical diversif ied farming w ith the reassuring pur ple medic yield through scient if ic dist ri-
but ion of w ater resour ces and opt imal irrigat ion sy stem of purple medic to achieve the theory o f “ecolog ical irri-
gat ion”.
Key words : Qinw angchuan Irrig ation Reg ion; Purple medic; Dynamics of soil w ater and salt ; Eco-phy sio-
logical characteristics; Water pr oduct ion functions; Ecolog ical irr ig ation control
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297第 2期 成自勇:甘肃秦王川灌区苜蓿草地土壤水盐动态及其生态灌溉调控模式