Manuring and fertilization of citrus.ppt

it explain about manures and fertilizer required at different ages of citrus plant.

1. Manures & Frtilizers for Citrus
B.R. Kaini
National Horticulture Specialist

2. Dosage of manures and fertilizers
The following points are to be considered while
determining the dosages of fertilizers in citrus:
1.Nutrients uptake by the trees from soils
2.Location specific field trials
3.Soil and leaf analysis
4.Field observations on deficiency symptoms
5.Available literature

3. Age-wise dosages of manure and fertilizers for citrus
Tree age in
years
Rates of nutrients per trees in gm
Nitrogen Phosphorus Potash
1 75 50 75
2-3 100-110 50-70 75-100
4-5 110-130 70-100 100-150
6-7 130-200 100-150 150-200
8-9 200-300 150-200 200-250
10 & above 300-500 200-250 250-350
Conversion 1kg nitrogen= 2.17kg
urea
1 kg
phosphorus=2.17
Kg DAP
1kg Potash=1.6 kg
MOP

4. Suggestions
•50 % nitrogen should be applied in organic form,
i.e. FYM or compost
•Apply 10 kg of FYM or 15 kg of compost in the
first year and go on increasing by 10 kg each
year until 10th year.
•Do not apply chemical fertilizers and lime
together
•Take into account soil fertility and tree condition
of the specific orchard while determining doses.

5. Method of manures and fertilizers
application
Soil application (root feeding).
•Apply fertilizers in the basin by broadcasting
•While fertilizing the trees, care should be
taken to keep the trunks of the trees free from
the contact of fertilizers.
•Application of lime in alternate years is
essential to maintain optimum soil reaction
and to improve the soil structure.
• As 80-95 feeder roots are spread in the top 10
cm,avoid deep placement of fertilizers.

6. Basins prepared for fertilizer
application

7. Method of manures and fertilizers
application
Foliar application (foliar feeding
•Micronutrients and urea with low biuret content
(less than 0.25%) can be applied through foliar
spray.
•Any fertilizers, that are to be applied through
foliar spray, should be completely water soluble
and neutral in reaction.
•Foliar application of elements should be done on
young leaves or young flushes, when leaves
attain half expansion in growth.
•It is better and safe to have repeated
applications at low concentrations rather than a
single heavy dose.

8. Combined spray of nutrients
Nutrients Quantities (Kg)
Zinc sulphate 2.5
Copper sulphate 1.5
Magnesium sulphate 1.0
Manganese sulphate 1.0
Ferrous sulphate 1.0
Boric acid 1.0
Slaked lime 1.0
Urea 4.5
Water 450 liters

9. Optimum concentration for spraying
micronutrients
Zinc sulfate0.2%
Borax 0.1%
Ferrous sulfate 0.2%
Molybdic acid 0.05%
Manganese sulfate0.2%
Copper sulfate 0.2%

10. Fertigation
•Fertigation is the application of liquid
fertilizer through an irrigation system.
•A major benefit of fertigation is that it
provides greater flexibility and control of
applied nutrients than conventional
broadcast applications.
•Fertilizers are applied when needed and in
small doses, so water-soluble nutrients are
less subject to leaching by excess rainfall
or over-irrigation.

11. Fertigation: continued
•Nitrogen and potassium are most suited to
fertigation.
•Phosphorus application through fertigation
is not recommended.
•Nitrogen, in split applications should be
timed to provide nitrogen in demand
period

12. Time of manures and fertilizers
application
•Time of application of manures and
fertilizers in citrus depends on types of
manures and fertilizers, and phenological
stages of the tree.
•Organic manures, which are slow to
release mineral elements, should be
applied well before the initiation of new
growth and flowering.

13. Time of manures and fertilizers
application (continued)
•Inorganic fertilizers, which are generally
quick to release nutrients, should be
applied just before the initiation of new
growth or at the start of new growth.
•50% of the annual nitrogen requirements
and all of the phosphorus and potassium
requirements are generally applied in
February-March (15-20 days before
flowering).

14. Time of manures and fertilizers
application (continued)
•The remaining 50% of the nitrogen is applied
after fruit set and during the fruit enlargement
period (June-July).
•In case of non-bearing young trees, nitrogen
fertilizers are applied in 3 split doses depending
upon the soil conditions and plant growth. In this
case the 3rd dose is applied just after the rainy
season. Generally three split doses of nitrogen
are recommended only when trees are in poor
condition due to root rot.