|
Manuring / fertilizer application
The nutrient requirements of rubber plant vary considerably during the three important
stages of growth - the nursery, immature and mature stages.
Seedling nursery
Basal dressing: Incorporate
two and a half tonnes of compost or well rotted cattle manure and 350 kg of powdered
rock phosphate (18-20% P2O5) for every effective ha, i.e.,
25 kg of compost and 3.5 kg of rock phosphate per 100 m2 of the nursery bed.
Top Dressing: Apply 2500 kg
of 10-10-4-1.5 N-P-K-Mg mixture per effective ha, i.e., 25 kg per 100 m2
of the nursery bed 6-8 weeks after planting. Again apply 550 kg of urea per effective
ha, i.e., 5.5 kg per 100 m2, six to eight weeks after the first top dressing.
The first application of the recommended quantity of N-P-K-Mg mixture should be
made during September-October period, i.e., 6-8 weeks after planting the germinated
seeds in the nursery beds.
Budwood nursery
Bud wood nursery is raised by planting polybag plants
or buded stems of authentic planting materials of desired clones at a
spacing of 90cm x 60 cm. before planting bud wood nurseriws are given
- Basal dose of 165 kg of powdered rock phosphate per hectare (1.65kg/100m 2)
- 2 to 3 MAP, 125g of 10-10-4-1.5 NPKMg mixture per plant is applied.
- a second application of same rate is given 8 to 9 MAP. This dose should also be
applied 2 to 3 MAP after each harvest of budwood.
The fertiliser application should be made during September–October and March-April
either in a band 8 cm away from the base of the plant or in between two rows and
lightly forked with a hand rake.
Immature rubber
(a) Up to the fourth year
- Pit manuring:
Incorporate 12 kg of compost or well rotted cattle manure and 175 g of rock phosphate
in every pit at the time of filling to provide good soil conditions for development
of a good root system. In newly cleared forest areas, it is enough to apply only
175 g rock phosphate, well mixed with the top 20 cm soil in the pit as the surface
soil in general will be rich in organic matter.
- In Kanyakumari district of Tamilnadu, Thrissur, Palakkad,
Malappuram, Kozhikode, Waynad, Kannur and Kasargod districts of Kerala, in the states
of Karnataka, Goa, Maharashtra and N. E. India, the available Mg status of the soil
is high and application of 12-12-6 N-P-K mixture is recommended. In all other regions,
10-10-4-1.5 N-P-K-Mg mixture may be applied.
|
Quantity and the schedule of fertilizer application during the first four years
|
|
Year of planting
|
Month after planting
|
Time of application
|
Qty of mixture per plant (g)
|
Qty of mixture per ha with 440-450 plant points (kg)
|
|
10-10-4-1.5 (NPKMg)
|
12-12-6(NPK)
|
10-10-4-1.5 (NPKMg)
|
12-12-6 (NPK)
|
|
1st year
|
3 months
|
Sep-Oct
|
225
|
190
|
100
|
85
|
|
2nd year
|
9 months
|
Apr-May
|
450
|
380
|
200
|
170
|
|
do
|
15 months
|
Sep-Oct
|
450
|
380
|
200
|
170
|
|
3rd year
|
21 months
|
Apr-May
|
550
|
480
|
250
|
215
|
|
do
|
27 months
|
Sep-Oct
|
550
|
480
|
250
|
215
|
|
4th year
|
33 months
|
Apr-May
|
450
|
380
|
200
|
170
|
|
do
|
39 months
|
Sep-Oct
|
450
|
380
|
200
|
170
|
- In the first two years, it is advantageous to apply
50 per cent of the phosphorus in the water-soluble form for better growth of the
rubber plants
- Fertilizers should be evenly distributed over a circular
band of about 30 cm around the base of the young plant, leaving about 7 cm from
the base all around and slightly forked into the top 5-8 cm of the soil. The plant
bases should then be immediately mulched.
(b) From the fifth year of planting to maturity
The fertilizer recommendation from the 5th year of planting for a well maintained
field where mulching is practiced and leguminous ground cover is established and
maintained:
NPK: 30, 30, 30 kg/ha.
This can be supplied by:
- Mixing the straight fertilizers, 65 kg of urea, 150 kg rock phosphate and 50 kg
of muriate of potash
- 300 kg/ha of 10-10-10 or 250 kg/ha of 12-12-12 NPK mixture
- Any of the complex fertilizers of the grades 15-15-15
or 17-17-17 or 19-19-19 NPK and the quantities of these should be 200,175 or 160
kg/ha respectively
- 10-26-26 NPK complex (115 kg)
mixed with urea (40 kg) or ammonium phosphate sulphate (ammophos 20-20) (150 kg)
with muriate of potash (50 kg) or 65 kg diammonium phosphate (DAP) mixed with 40
kg urea and 50 kg muriate of potash
Diammonium phosphate is recommended for soils having pH 6.0 or above which is very
rare.
The recommendation for areas where no legume ground
covers were established and no mulching practiced during the initial years:
NPK: 60, 40, 24 kg/ha.
This can be supplied through 400 kg of 15-10-6 mixture applied in two split doses
of 200 kg each during the 5th and subsequent years till the plants become ready
for tapping.
Mature rubber under tapping
N:P2O5:K2O (10:10:10) mixture @ 300 kg/ha or 900
g per tree may be applied every year as a single dose during April-May or in two
splits during April-May and September- October. To make 100 kg of this mixture,
use 22 kg urea, 50 kg rock phosphate, 17 kg muriate of potash and 11 kg filler.
Instead of the above fertilizer mixture, any of the complex fertilizers of the grades
15:15:15 or 17:17:17 or 19:19:19 N:P2O5:K2O may
also be used. The quantities of these being 200 kg, 175 kg and 160 kg/ha, respectively.
Ammophos (20:20) @ 150 kg mixed with 50 kg of muriate of potash can also be used
for one hectare. For mature rubber, it will be desirable to follow discriminatory
fertilizer recommendation based on soil and leaf analysis. This facility is available
at the Rubber Research Institute of India, Kottayam and also at the Regional Laboratories
at Adoor, Kanjirapally, Pala, Muvattupuzha, Thrissur, Kozhikode and Nedumangadu
.
Fertilisers should be applied in square or rectangular patches in between rows,
each patch serving four trees. Once the canopy of the plants closes, say, 5 to 6
years after planting, light forking to incorporate the fertilisers into the topsoil
is necessary.
In areas where the legume ground cover is present or where the legume cover has
died out leaving thick mulch, it is enough to broadcast the fertilizers between
two rows of rubber trees. Deep pocket placement of fertilizers and application too
close to the base of the trees should be avoided.
Discriminatory fertilizer recommendation
Fertility status of the individual fields can be assessed by soil and leaf analyses
and the fertilizers are recommended based on the individual case history of the
field.
- Soil may be analyzed before starting rubber cultivation
to ascertain soil fertility and to obtain the fertilizer schedule to be adopted
during the initial four years
- During the fourth
year of planting, soil and leaf samples may be analyzed to obtain fertilizer recommendation
for the fifth year
- Leaf sample may be analyzed every year while soil samples
need be analyzed only once in three years
|