Chapter 7
Factors effecting the plant uptake
影响养分吸收的因素主要包括介质中的养分浓度, 温
度, 光照强度, 土壤水分, 通气状况, 土壤 pH值, 养分离
子的理化性质, 根的代谢活性, 苗龄, 生育时期植物体内养
分状况等 。
The main factors that control plant nutrients uptake as
follow,the ion concentration in the nutrients medium,
temperature,light,soil water,soil atmosphere,the
properties and characteristics of nutrients,plant age and
root activity etc.
Factors effecting the plant uptake
在低浓度范围内, 离子的吸收率随介质养分
浓度的提高而上升,
在高浓度范围内, 离子吸收的选择性较低,
而陪伴离子及蒸腾速率对离子的吸收速率影响较大 。
When plant starved are exposed to nutrient
solutions with increasing concentration of lacking
nutrient,the plot of uptake may be reflected by a
Michaelis-Menten cure.
Ion concentration in the nutrient medium
植物对养分有反馈调节能力 。 中断某种养分的
供应, 往往会促进植物对这一养分的吸收 。
Plants which have been starved of particular
nutrient may take up the nutrient at a high rate
when re-supply the nutrient.
The effects of interruption of nutrients supply
含磷量 （ umol/g 干物重 ） *植物
8 天 -P 7 天 -P+1 天 +Pb 7 天 - Pb +3 天 +Pc
地上部 49(20) 151( 61 ) 412(176)
幼叶 26( 5 ) 684(141) 1647(483)
根系 43(24) 86( 48 ) 169( 94 )
不同供磷状况对大麦各部位含磷量的影响
*括号中的数字为相对值：对照为 1 0 0,即整个实验期持续供给
150μmol/LP。 a,不加磷生长 8天 。 b,不加磷生长 7天而后补加磷生长
1天 。 c,不加磷生长 7天天而后补加磷生长 3天 。
外界磷浓度对生长 4周的 8种植物以及生长 24
小时的大麦吸磷速率的影响
生长 24小时 生长 8周
0.001
0.01
0.1
1
10
0.01 0.1 1 10 100 1000
磷浓度（ μmol/L）
磷吸收率（
μm
ol/
g根鲜重
×
h）
Compartmentation ( 区隔化 ) of ions and
metabolites in the cell is important for normal
metabolic status.
Maitainning the extremely low Ca2+(<1μ M)
concentration and high K+(100-150mM) in cytosol
is necessary,The nutrients concentration in the
sytosol is regulated by the compartmentation in
vacuolar,The vacuolar is thus a storage site from
which the main plant nutrients may be mobilized if
required for metabolic purpose.
Compartmentation of ions in plant cell
[ion]
[ion]
vacuole
cytoplasm
cortex
stele
根部离子吸收的反馈调控模型
K+ concentration in sytosol and vacuole of barley root cells as
related to the K+ concentration in the outer solution
(Fernando et al,1992)
O u t e r s o l u t i o n V a c u o l e ( mol / m
3
) C y t o s o l ( mol / m
3
)
1, 2 85 144
0, 1 61 140
0, 0 1 21 131
Nutrient uptake needs the energy come from the
respiration,and the respiration is sensitive to the
temperature,so uptake of nutrient decline in the cold
condition,In hot condition (more than 40℃ ) the enzymes is
denatured,the uptake capacity is low too.
The soil nutrients availability is affected by the soil
temperature.
一般 6~38oC的范围内, 根系对养分的吸收随温度升高
而增加 。
Temperature
The nutrient uptake requires energy,
mainly in the form of ATP for driving the
proton pumps or transporter,If oxygen
supply is limiting or photosynthesis and the
carbohydrate apply to the root is limited,the
nutrients uptake is low.
light
? Hoagland in the 1920's showed that Br- uptake by
Nitella was severely reduced in the dark and
increased correspondingly in sunlight,He
correctly concluded that the energy of
photosynthesis was being harnessed to do the
transport work,
? Soon after,Steward in Hoagland's lab showed
that Br- uptake by potato slices depended on the
availability of O2,and concluded that respiration
was necessary for ion uptake in non-green
tissues,
light
养分含量 （相对 %）照度
指数 NH4+ H2PO4- K+ Ca2+ Mg2+ Mn2+ SiO2
100 100 100 100 100 100 100 100
58 58 76 78 107 103 85 5
56 40 33 41 64 68 46 65
5 17 15 13 49 40 22 35
光照对水稻吸收养分的影响
Uptake of 15N labelled NH4+by rice plants
exposed to darkness before the uptake test was
measured (Mengel and Viro 1978) s h o o t R o o t s
Μ g
15
N / g f r e s h w e i g h t
C o n t r o l,n o d a r k n e s s 4 2, 4 1 0 8, 9
24 h d a r k n e s s 1 7, 0 4 5, 3
4 8 h d a r k n e s s 8, 4 3 4, 2
水分状况是决定土壤中养分离子以扩散还是以质
流方式迁移的重要因素, 也是化肥溶解和有机肥料矿
化的决定条件 。 水分状况对植物生长, 特别是对根系
的生长有很大影响, 从而间接影响到养分的吸收 。
Water is important to the plant nutrient uptake.
The roots growth and rooting profile are affected by
the soil moisture,The nutrient movement (such as
mass flow and diffusion) and mineralization of
organic nutrients is related with the soil water content.
water
The energy needed to accumulate the nutrient
elements to high concentrations comes from the
respiratory breakdown of products of photosynthesis.
So nutrient is sensitive to the lack of oxygen.
The nutrients forms and availability is affected by
the Eh.
Harm substances,such as H2S,low molecules
organic acids,are formed and accumulation when the Eh
is low in soil anaerobic conditions
Soil aeration and Eh
Soil pH
? The membrane charge and membrane
permeability is affected by the medium pH.
? The nutrients forms and availability are affected
by the soil pH
? The uptake of ions must be electrically balance,
So the soil pH is affected by nutrient forms.
? Plant growth,and particularly root growth is also
impaired by the low soil pH
离子吸收量 （ mg/kg 鲜重 /6h）培养液的
pH 变化 NH4+-N NO3--N 总吸收量
4.0 34 48 82
5.0 42 59 101
6.0 46 41 87
7.6 66 30 96
不同 pH条件对番茄吸收 NH4+-N及 NO3--N的影响
H+置换细胞膜中的 Ca2+离子，破坏（增加）膜的
选择透性，引起离子外渗。
? 细胞膜 — 蛋白质 — COO- — Ca2+ — PO4- — 磷脂 — 细胞膜
pH
2 3 4 5 6
0
+10
+20
K+
净吸收率
（
μmo
lg
/
鲜重×
3h
）
7 8 9 10
-10
+Ca2+
-Ca2+
The effect of the pH in the nutrient solution on the
concentration of organic anions in roots of maize and fata
beans (Yan et al 1992)
pH M a l a t e ( 苹果酸 ) P y r u v a t e（ 丙酮酸 ） L a c t a t e （ 乳酸 ）
N u t r i e n t s o l u t i o n
M mol / g d r y ma t t e r
M a i z e 7,0 128 8 15
M a i z e 3, 5 33 8 13
B e a n s 7, 0 415 5 42
B e a n s 4, 0 81 5 62
由于离子和其它溶质在很多情况下是逆浓度
梯度的累积, 所以需要直接或间接地消耗能量 。
在不进行光合作用的细胞和组织中 （ 包括根 ）,
能量的主要来源是呼吸作用 。 因此, 所有影响呼
吸作用的因子都可能影响离子的累积 。
Treatments with metabolic inhibitors e.g,low
temperature,anaerobic conditions or poisons such as
cyanide(氰化物 ) all reduce ion entry into roots
Metabolic activity of Plant
处 理 每株干物 质重 (g) 根呼吸作用(O
2 μL/g干物质 )
32P相对吸收速率
(cpm/g 干物质 )
对 照 2.46 0.174 100
去基部
叶 片 2.32 0.095 57
遮 荫 1.70 0.062 32
遮荫和去基部叶片对水稻根呼吸作用
和 32P吸收率的影响
离子间的拮抗作用是指在溶液中某一离子的
存在能抑制植物对另一离子的吸收,
Increasing the supply of one nutrient species in
the growth medium can thus depress the levels of
other ion species in the plant.
The absorption of cations to the root is more
or less a non specific process,depending mainly on
the concentration of the species in the nutrient
medium.
Ion interaction
离子间的拮抗作用 (antagonism)
K+ Na+ Ca2+ Mg2+ (sum)Treat
(cmol/kg DM)
Mg1 49 4 42 49 144
Mg2 57 3 31 61 152
Mg3 57 2 23 68 150
The effect of an increasing Mg application on the content of
various cation species in sunflower plants
(Scharrer and Jung,1955)
The effect of an interruption in the K supply on the cations
content of young barley plants; interruption period
8days(Forster and Mengel,1969)
Roots Shoots
control Interr,Control Interr.
Me/100gDM
K 157 28 170 152
Ca 9 12 24 66
Mg 36 74 54 21
Na 3 78 trace 12
total 205 192 248 251
Grain yield(g/pot),control 108; interr,86**
? In anion uptake,antagonistic effects are
less common although CI-,SO42- and
H2PO4- uptake can be stimulated when
NO3- uptake depressed.
? The most common anion antagonism is
between NO3- and CI-,
离子间的拮抗作用 (antagonism)
? The ionic interactions described above been
interpreted as non specific replacement
effects and not as carrier competition process,
They also compete each other for the driving
force (pH difference)=non special
antagonism
离子间的拮抗作用 (antagonism)
? It is generally accepted that closely related
ion species such as K+ and Rb+,or
Ca2+and Sr2+,or SO42- and SeO42-,or
phosphate （磷酸根） and arsenate（砷酸
根） compete for the same carrier site,
and in some case even the pattern of
distribution within the plant is same,=
special antagonism
离子间的拮抗作用 (antagonism)
离子间的协助作用是指在溶液中某一离子的存
在有利于根系对另一些离子的吸收 (one ion can
promotes uptake of other ions by the plant in
medium solution)。
这种作用主要表现在阳离子和阴离子之间, 以
及阴离子与阴离子之间 。
离子间的协助作用 synergism
Influence of the form of N nutrition on the cation-anion
balance in white mustard leaves(Kirkby,1968)
cations anions
Ca Mg K Na total NO3 H2PO4 SO4 CI Org.acid
s
total
Me/100g DM Me/100g DM
NO3 107 28 81 5 221 1 26 25 25 162 239
NH4 72 22 40 7 141 1 25 25 31 54 136
“维茨效应” (viets effect)
? Ca2+对多种离子的吸收有协助作用，一般认
为是由于它具有稳定质膜结构的特殊功能，有助
于质膜的选择性吸收的,这种协助作用也称“维茨
效应” (viets effect)。
? The blocking of outwardly directed
channels by the Ca2+ maybe responsible for
the Viets effect known for many years in
which Ca2+ promotes the net uptake of K+,
(umol/g FW 4h)
Maize Sugar beet外部溶液
NaCl+KCl Na+ K+ Na++K + Na+ K+ Na++ K+
-Ca 9.0 11.0 20.0 18.8 8.3 27.1
+CA 5.9 15.0 20.9 15.4 10.7 26.1
The effect of Ca2+ on the selective uptake of Na+ or K+ by plants
Medium solution
NaCI+KCI
Uptake rate
一般在植物生长初期, 养分吸收的数量少,
吸收强度低 。 随时间的推移, 植物对营养物质的
吸收逐渐增加, 往往在性器官分化期达到吸收高
峰 。 到了成熟阶段, 对营养元素的吸收又逐渐减
少 。
The rate of nutrients uptake is controlled by
the growth rate of plants and related to the
physiological requirement,High growth rates are
associated with high nutrient uptake rates and
vice versa,
Seedling age and growth phase
营养临界期 (Critical growing phases of plant
nutrition)是指植物生长发育的某一时期, 对某种养
分要求的绝对数量不多但很迫切, 并且当养分供应
不足或元素间数量不平衡时将对植物生长发育造成
难以弥补的损失, 这个时期就叫植物营养的临界期 。
不同作物对不同营养元素的临界期不同,
If the P supply to cereals is inadequate during
the early stages of development,a reduction in the
numbers of ears per unit area and hence a
depression in crop yield.
Seedling age and growth phase
Nutrient requirement of maize per unit root length
to the age of plants (Mengel and Barber 1974)
Μ mo l / m r o o t l e n g t h A g e o f p l a n t s,
d a y s N P K Ca Mg
20 227 1 1, 3 53 1 4, 4 1 3, 8
30 32 0, 9 1 2, 4 5, 2 1, 6
40 19 0, 8 6 8, 0 0, 5 6 0, 9 0
50 11 0, 6 6 4, 8 0, 3 7 0, 7 8
60 5, 7 0, 3 7 1, 6 0, 0 8 0, 2 9
在植物生长阶段中所吸收的某种养分能发挥起最大效能
的时期, 叫植物营养的最大效率期 (Maximum efficiency stage
of plant nutrition)。 这一时期, 作物生长迅速, 吸收养分能力
特别强, 如能及时满足作物对养分的需要, 增产效果将非常显
著 。 玉米氮素最大效率期在喇叭口期至抽雄期；棉花的氮, 磷
最大效率期均在花铃期；对于甘薯来说, 块根膨大期是磷, 钾
肥料的最大效率期 。
Seedling age and growth phase
Factors effecting the plant uptake
影响养分吸收的因素主要包括介质中的养分浓度, 温
度, 光照强度, 土壤水分, 通气状况, 土壤 pH值, 养分离
子的理化性质, 根的代谢活性, 苗龄, 生育时期植物体内养
分状况等 。
The main factors that control plant nutrients uptake as
follow,the ion concentration in the nutrients medium,
temperature,light,soil water,soil atmosphere,the
properties and characteristics of nutrients,plant age and
root activity etc.
Factors effecting the plant uptake
在低浓度范围内, 离子的吸收率随介质养分
浓度的提高而上升,
在高浓度范围内, 离子吸收的选择性较低,
而陪伴离子及蒸腾速率对离子的吸收速率影响较大 。
When plant starved are exposed to nutrient
solutions with increasing concentration of lacking
nutrient,the plot of uptake may be reflected by a
Michaelis-Menten cure.
Ion concentration in the nutrient medium
植物对养分有反馈调节能力 。 中断某种养分的
供应, 往往会促进植物对这一养分的吸收 。
Plants which have been starved of particular
nutrient may take up the nutrient at a high rate
when re-supply the nutrient.
The effects of interruption of nutrients supply
含磷量 （ umol/g 干物重 ） *植物
8 天 -P 7 天 -P+1 天 +Pb 7 天 - Pb +3 天 +Pc
地上部 49(20) 151( 61 ) 412(176)
幼叶 26( 5 ) 684(141) 1647(483)
根系 43(24) 86( 48 ) 169( 94 )
不同供磷状况对大麦各部位含磷量的影响
*括号中的数字为相对值：对照为 1 0 0,即整个实验期持续供给
150μmol/LP。 a,不加磷生长 8天 。 b,不加磷生长 7天而后补加磷生长
1天 。 c,不加磷生长 7天天而后补加磷生长 3天 。
外界磷浓度对生长 4周的 8种植物以及生长 24
小时的大麦吸磷速率的影响
生长 24小时 生长 8周
0.001
0.01
0.1
1
10
0.01 0.1 1 10 100 1000
磷浓度（ μmol/L）
磷吸收率（
μm
ol/
g根鲜重
×
h）
Compartmentation ( 区隔化 ) of ions and
metabolites in the cell is important for normal
metabolic status.
Maitainning the extremely low Ca2+(<1μ M)
concentration and high K+(100-150mM) in cytosol
is necessary,The nutrients concentration in the
sytosol is regulated by the compartmentation in
vacuolar,The vacuolar is thus a storage site from
which the main plant nutrients may be mobilized if
required for metabolic purpose.
Compartmentation of ions in plant cell
[ion]
[ion]
vacuole
cytoplasm
cortex
stele
根部离子吸收的反馈调控模型
K+ concentration in sytosol and vacuole of barley root cells as
related to the K+ concentration in the outer solution
(Fernando et al,1992)
O u t e r s o l u t i o n V a c u o l e ( mol / m
3
) C y t o s o l ( mol / m
3
)
1, 2 85 144
0, 1 61 140
0, 0 1 21 131
Nutrient uptake needs the energy come from the
respiration,and the respiration is sensitive to the
temperature,so uptake of nutrient decline in the cold
condition,In hot condition (more than 40℃ ) the enzymes is
denatured,the uptake capacity is low too.
The soil nutrients availability is affected by the soil
temperature.
一般 6~38oC的范围内, 根系对养分的吸收随温度升高
而增加 。
Temperature
The nutrient uptake requires energy,
mainly in the form of ATP for driving the
proton pumps or transporter,If oxygen
supply is limiting or photosynthesis and the
carbohydrate apply to the root is limited,the
nutrients uptake is low.
light
? Hoagland in the 1920's showed that Br- uptake by
Nitella was severely reduced in the dark and
increased correspondingly in sunlight,He
correctly concluded that the energy of
photosynthesis was being harnessed to do the
transport work,
? Soon after,Steward in Hoagland's lab showed
that Br- uptake by potato slices depended on the
availability of O2,and concluded that respiration
was necessary for ion uptake in non-green
tissues,
light
养分含量 （相对 %）照度
指数 NH4+ H2PO4- K+ Ca2+ Mg2+ Mn2+ SiO2
100 100 100 100 100 100 100 100
58 58 76 78 107 103 85 5
56 40 33 41 64 68 46 65
5 17 15 13 49 40 22 35
光照对水稻吸收养分的影响
Uptake of 15N labelled NH4+by rice plants
exposed to darkness before the uptake test was
measured (Mengel and Viro 1978) s h o o t R o o t s
Μ g
15
N / g f r e s h w e i g h t
C o n t r o l,n o d a r k n e s s 4 2, 4 1 0 8, 9
24 h d a r k n e s s 1 7, 0 4 5, 3
4 8 h d a r k n e s s 8, 4 3 4, 2
水分状况是决定土壤中养分离子以扩散还是以质
流方式迁移的重要因素, 也是化肥溶解和有机肥料矿
化的决定条件 。 水分状况对植物生长, 特别是对根系
的生长有很大影响, 从而间接影响到养分的吸收 。
Water is important to the plant nutrient uptake.
The roots growth and rooting profile are affected by
the soil moisture,The nutrient movement (such as
mass flow and diffusion) and mineralization of
organic nutrients is related with the soil water content.
water
The energy needed to accumulate the nutrient
elements to high concentrations comes from the
respiratory breakdown of products of photosynthesis.
So nutrient is sensitive to the lack of oxygen.
The nutrients forms and availability is affected by
the Eh.
Harm substances,such as H2S,low molecules
organic acids,are formed and accumulation when the Eh
is low in soil anaerobic conditions
Soil aeration and Eh
Soil pH
? The membrane charge and membrane
permeability is affected by the medium pH.
? The nutrients forms and availability are affected
by the soil pH
? The uptake of ions must be electrically balance,
So the soil pH is affected by nutrient forms.
? Plant growth,and particularly root growth is also
impaired by the low soil pH
离子吸收量 （ mg/kg 鲜重 /6h）培养液的
pH 变化 NH4+-N NO3--N 总吸收量
4.0 34 48 82
5.0 42 59 101
6.0 46 41 87
7.6 66 30 96
不同 pH条件对番茄吸收 NH4+-N及 NO3--N的影响
H+置换细胞膜中的 Ca2+离子，破坏（增加）膜的
选择透性，引起离子外渗。
? 细胞膜 — 蛋白质 — COO- — Ca2+ — PO4- — 磷脂 — 细胞膜
pH
2 3 4 5 6
0
+10
+20
K+
净吸收率
（
μmo
lg
/
鲜重×
3h
）
7 8 9 10
-10
+Ca2+
-Ca2+
The effect of the pH in the nutrient solution on the
concentration of organic anions in roots of maize and fata
beans (Yan et al 1992)
pH M a l a t e ( 苹果酸 ) P y r u v a t e（ 丙酮酸 ） L a c t a t e （ 乳酸 ）
N u t r i e n t s o l u t i o n
M mol / g d r y ma t t e r
M a i z e 7,0 128 8 15
M a i z e 3, 5 33 8 13
B e a n s 7, 0 415 5 42
B e a n s 4, 0 81 5 62
由于离子和其它溶质在很多情况下是逆浓度
梯度的累积, 所以需要直接或间接地消耗能量 。
在不进行光合作用的细胞和组织中 （ 包括根 ）,
能量的主要来源是呼吸作用 。 因此, 所有影响呼
吸作用的因子都可能影响离子的累积 。
Treatments with metabolic inhibitors e.g,low
temperature,anaerobic conditions or poisons such as
cyanide(氰化物 ) all reduce ion entry into roots
Metabolic activity of Plant
处 理 每株干物 质重 (g) 根呼吸作用(O
2 μL/g干物质 )
32P相对吸收速率
(cpm/g 干物质 )
对 照 2.46 0.174 100
去基部
叶 片 2.32 0.095 57
遮 荫 1.70 0.062 32
遮荫和去基部叶片对水稻根呼吸作用
和 32P吸收率的影响
离子间的拮抗作用是指在溶液中某一离子的
存在能抑制植物对另一离子的吸收,
Increasing the supply of one nutrient species in
the growth medium can thus depress the levels of
other ion species in the plant.
The absorption of cations to the root is more
or less a non specific process,depending mainly on
the concentration of the species in the nutrient
medium.
Ion interaction
离子间的拮抗作用 (antagonism)
K+ Na+ Ca2+ Mg2+ (sum)Treat
(cmol/kg DM)
Mg1 49 4 42 49 144
Mg2 57 3 31 61 152
Mg3 57 2 23 68 150
The effect of an increasing Mg application on the content of
various cation species in sunflower plants
(Scharrer and Jung,1955)
The effect of an interruption in the K supply on the cations
content of young barley plants; interruption period
8days(Forster and Mengel,1969)
Roots Shoots
control Interr,Control Interr.
Me/100gDM
K 157 28 170 152
Ca 9 12 24 66
Mg 36 74 54 21
Na 3 78 trace 12
total 205 192 248 251
Grain yield(g/pot),control 108; interr,86**
? In anion uptake,antagonistic effects are
less common although CI-,SO42- and
H2PO4- uptake can be stimulated when
NO3- uptake depressed.
? The most common anion antagonism is
between NO3- and CI-,
离子间的拮抗作用 (antagonism)
? The ionic interactions described above been
interpreted as non specific replacement
effects and not as carrier competition process,
They also compete each other for the driving
force (pH difference)=non special
antagonism
离子间的拮抗作用 (antagonism)
? It is generally accepted that closely related
ion species such as K+ and Rb+,or
Ca2+and Sr2+,or SO42- and SeO42-,or
phosphate （磷酸根） and arsenate（砷酸
根） compete for the same carrier site,
and in some case even the pattern of
distribution within the plant is same,=
special antagonism
离子间的拮抗作用 (antagonism)
离子间的协助作用是指在溶液中某一离子的存
在有利于根系对另一些离子的吸收 (one ion can
promotes uptake of other ions by the plant in
medium solution)。
这种作用主要表现在阳离子和阴离子之间, 以
及阴离子与阴离子之间 。
离子间的协助作用 synergism
Influence of the form of N nutrition on the cation-anion
balance in white mustard leaves(Kirkby,1968)
cations anions
Ca Mg K Na total NO3 H2PO4 SO4 CI Org.acid
s
total
Me/100g DM Me/100g DM
NO3 107 28 81 5 221 1 26 25 25 162 239
NH4 72 22 40 7 141 1 25 25 31 54 136
“维茨效应” (viets effect)
? Ca2+对多种离子的吸收有协助作用，一般认
为是由于它具有稳定质膜结构的特殊功能，有助
于质膜的选择性吸收的,这种协助作用也称“维茨
效应” (viets effect)。
? The blocking of outwardly directed
channels by the Ca2+ maybe responsible for
the Viets effect known for many years in
which Ca2+ promotes the net uptake of K+,
(umol/g FW 4h)
Maize Sugar beet外部溶液
NaCl+KCl Na+ K+ Na++K + Na+ K+ Na++ K+
-Ca 9.0 11.0 20.0 18.8 8.3 27.1
+CA 5.9 15.0 20.9 15.4 10.7 26.1
The effect of Ca2+ on the selective uptake of Na+ or K+ by plants
Medium solution
NaCI+KCI
Uptake rate
一般在植物生长初期, 养分吸收的数量少,
吸收强度低 。 随时间的推移, 植物对营养物质的
吸收逐渐增加, 往往在性器官分化期达到吸收高
峰 。 到了成熟阶段, 对营养元素的吸收又逐渐减
少 。
The rate of nutrients uptake is controlled by
the growth rate of plants and related to the
physiological requirement,High growth rates are
associated with high nutrient uptake rates and
vice versa,
Seedling age and growth phase
营养临界期 (Critical growing phases of plant
nutrition)是指植物生长发育的某一时期, 对某种养
分要求的绝对数量不多但很迫切, 并且当养分供应
不足或元素间数量不平衡时将对植物生长发育造成
难以弥补的损失, 这个时期就叫植物营养的临界期 。
不同作物对不同营养元素的临界期不同,
If the P supply to cereals is inadequate during
the early stages of development,a reduction in the
numbers of ears per unit area and hence a
depression in crop yield.
Seedling age and growth phase
Nutrient requirement of maize per unit root length
to the age of plants (Mengel and Barber 1974)
Μ mo l / m r o o t l e n g t h A g e o f p l a n t s,
d a y s N P K Ca Mg
20 227 1 1, 3 53 1 4, 4 1 3, 8
30 32 0, 9 1 2, 4 5, 2 1, 6
40 19 0, 8 6 8, 0 0, 5 6 0, 9 0
50 11 0, 6 6 4, 8 0, 3 7 0, 7 8
60 5, 7 0, 3 7 1, 6 0, 0 8 0, 2 9
在植物生长阶段中所吸收的某种养分能发挥起最大效能
的时期, 叫植物营养的最大效率期 (Maximum efficiency stage
of plant nutrition)。 这一时期, 作物生长迅速, 吸收养分能力
特别强, 如能及时满足作物对养分的需要, 增产效果将非常显
著 。 玉米氮素最大效率期在喇叭口期至抽雄期；棉花的氮, 磷
最大效率期均在花铃期；对于甘薯来说, 块根膨大期是磷, 钾
肥料的最大效率期 。
Seedling age and growth phase
