Fertilization of cotton: how to get better yield, water use efficiency and fibre fineness

Fertilization of cotton: how to get better yield, water use efficiency and fibre fineness

By supplying the exact amount of needed nutrients with Haifa's fertilizers, the cotton reaches its maximum quality

 

Plant population: 60,000-90,000 plants/ha.
Expected yield: 4.0 MT/ha .
Recommended average rates of nutrients (Kg/Ha):

 

 

N

P2O5

K2O

200-235

80-110

200-250

 

 

 

Nitrogen -  Increases plant height, their boll-bearing capacity and seed weight, and improves seed yield. To obtain the highest efficiency from N it is recommended to base-dress with one-third of the total amount of N and to divide the rest amount amongst the irrigations till the beggining of August.

Phosphate - Improves root development, water use efficiency, the enrgy balance and the weight, oil and protein contents of the seed as well as fiber quality.

Potassium - Improves fibre fineness and strength, and results in early maturity of the crop.

 

Nutrients required (kg/ha)

Recommended fertilizers (kg/ha)

N

P2O5

K2O

AN

TSP

SOP

120

92

135-155

360

200

280

 

Fertigation (to be applied during 90 irrigation days)

Growth stage

Nutrient demand
---------kg/ha/day-------

Recommended fertilizers
---------kg/ha/day-------

N

P2O5

K2O

Multi-K

MAP

AN

Vegetative development

0.03-0.1

0.02-0.07

0.03-0.05

0.06-0.12

0.03-0.12

0.05-0.25

First flower up to two weeks after flowering

0.25-0.35

0.09-0.18

0.23-0.28

0.5-0.6

0.15-0.30

0.5-0.7

Boll development

0.6

0.18-0.09*

0.7-0.28*

1.5-0.6*

0.3-0.15*

1.2-1.4

 

TSP = Triple superphosphate (0-46-0)
SOP = Potassium sulfate (0-0-50)
AN = Ammonium nitrate  (34% Nitrogen)
Multi-K = Potassium nitrate (13-0-46)
MAP = Mono ammonium phosphate (12-61-0)
* Rates are decreasing during these stages

 

Experimentation

The following is a layout of a characteristic experiment for the elucidation of the Multi-K spraying benefits.

Objective: to increase yield and lint quality.

Treatments:

  1. Control, unsprayed.
  2. One application of 20 Kg/Ha Multi-K.
  3. Two applications of 20 Kg/Ha Multi-K.
  4. Three applications of 20 Kg/Ha Multi-K.
  5. Four applications of 20 Kg/Ha Multi-K.

Applications should start when first flowers appear, with intervals of 7-10 days.
Applications can be combined with insecticides.
When applying by ground sprayers please provide 400-500 liter spray solution per Ha.
Applications should take place when plants are in full turgor, preferably early in the morning.

Effect of Method and Time of Potassium application on Cotton Lint Yield (Better Crops/ vol. 82 (1998, No. 2  p. 25-27):
Foliar KNO3  applied at 5 to 7 day intervals resulted in significant yield increase over the untreated plots in 1995. This increase in yield was 175 Lb/A  (0.196 MT/ha).  The higher lint yield for the split soil-applied and foliar KNO3 treatments indicates the importance of plant available K at the time of boll filling.

 

Nutrients uptake data

Variety: Acala.
Soil type: Loamy.
Plant Density: 60,000 plants / Ha.
Expected yield: 4.0 T/Ha.
Growth period (days from seeding/planting to harvest): 160 days.

 

Time interval
(days after emergence or planting)

Nutrients requirement (Kg/Ha/Day)

N

P2O5

K2O

1-10

0.10 

0.00

0.12

11-20

0.20

0.11

0.12

21-30

0.20

0.11

0.36

31-40

0.50

0.23

0.60

41-50

1.00

0.23

0.60

51-60

2.00

0.69

2.41

61-70

2.50

0.92

3.01

71-80

4.50

2.06

7.23

81-90

3.20

1.15

2.41

91-100

3.30

1.26

2.41

101-110

5.00

2.40

3.01

111-120

0.50

0.46

-

121-130

0.30

0.23

-

131-150

0.07

0.16

-

150-160

-

-

-

Total (Kg/Ha)

240

103.06

222.85

 

Source: B. Bar-Yosef . Fertilization under drip irrigation.

 

 

Macro elements removed by 1 ton cotton seed

 

N

P

K

Ca

Mg

S

----------------------- Kg/ha -------------------------

22

4

7

1

0.5

0.6

Macro elements removed by 1 ton cotton whole plants

N

P

K

Ca

Mg

S

----------------------- Kg/ha -------------------------

40-60

6-12

25-40

15-40

4-10

1-2

Source: Kinoch: VOLHOUBARE LANDBOU, RSA. Processed by Frans Lourens, Haifa, RSA May, 1999.

 

Potassium deficiency symptoms in modern varieties are often observed in the upper canopy, (immature leaves) rather than in older, mature leaves, possibly due to a heightened demand by developing bolls. The expression of the symptoms progresses from flowering through boll formation, see photo attached.

 

Plant analysis guide

Nutrient sufficiency ranges (source: A & L, Agronomy Handbook, Ankerman & Large Eds.)

Field crops*

 

Cotton

N

S

P

K

Mg

Ca

Na

B

Zn

Mn

Fe

Cu

Al

Mo

------------------------ % -------------------------

--------------- p.p.m ---------------
From

3.50

0.18

0.25

1.30

0.25

1.25

0.05

20

20

25

50

8

50

 
To

4.75

0.60

0.50

2.90

2.90

0.75

0.15

80

50

200

250

20

125

 

*  Plant part to sample:
     1 week prior to first bloom: petiole of first fully expanded leaf from top of plant
     Repeat weekly for 8 to 9 weeks: petiole of first fully expanded leaf from top of  
     plant.

Plant tissue sampling procedures:

Stage of growth Plant Part
At full bloom Youngest fully matured leaf

 

Cotton – Mineral analysis values

 

Leaves and petioles

Nutrient

Average value

Critical level

 

(%)

N

3.30

1.80

S

0.46

0.18

P

0.50

0.18

K

2.90

1.00

Mg

0.60

0.28

Ca

2.80

1.20

Na

0.12

0.12

 

(ppm)

Fe

120

70

Al

95 

 

Mn

85

25

B

50

20

Cu

12

6

Zn

35

15

Mo

3

 

 

Need more information about growing cotton? You can always return to the cotton fertilizer