RUBBER

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

1. Incorporate 150 kg of powdered rock phosphate per ha, i.e. 1.5 kg per 100 sq. m of the nursery bed as a basal dressing at the time of preparing the nursery bed
2. For the first crop of bud-wood, apply 250 g of 10-10-4-1.5 N-P-K-Mg mixture per plant in two equal split doses. Apply the first split of 125 g per plant two to three months after planting the budded stump or cutting back if budding is carried out in situ. The second dose of 125 g per plant should be applied 8-9 months after planting
3. For the second and subsequent crops of bud-wood from the nursery, apply 125 g of 10-10-4-1.5 N-P-K-Mg mixture per plant in one single dose two to three months after cutting back

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

1. 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.


2. 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

   
   
3. 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:

1. Mixing the straight fertilizers, 65 kg of urea, 150 kg rock phosphate and 50 kg of muriate of potash
2. 300 kg/ha of 10-10-10 or 250 kg/ha of 12-12-12 NPK mixture
3. 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
4. 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

The general recommendation is 30-30-30 NPK kg/ha.

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

Last updated: 24-05-2008