Nagpur orange fertiliser (santra khat vyavasthapan): what to ask your KVK before you apply

Why does this guide give no fertiliser doses?

Because the published recommendations do not agree. ICAR-CCRI Nagpur's monthly calendar gives doses as fertiliser products in grams per tree by tree age; Dr. PDKV, Akola, gives pure nutrients (nitrogen, phosphorus, potash) per tree per year, and its own citrus research page lists more than one recommendation. Which one fits your orchard depends on your soil test, your trees' age and your bahar.

Our text has been checked only with AI assistance, not by an agronomist. A wrong dose costs money and can harm the trees, so the dose should come from your KVK, an agronomist or the university, against your soil test. The links at the end of this page take you to the institutes' own pages.

Why test the soil and leaves first?

Only a soil and leaf test shows which nutrient is short or already high in your own land. Get the soil tested at a KVK or a soil testing laboratory before the season's first application, and take the report with you when you ask for a dose.

The Geographical Indication application for Nagpur Orange describes how to sample leaves: for ambia bahar, 5 to 6 month old leaves in August to October; for mrig bahar, 6 to 8 month old leaves in December and February. Take the second to fourth leaf from the tip of a shoot that carries no fruit, at 1.5 to 2 m above the ground.

What should I ask my KVK or agronomist?

Take your soil test report, the age of your trees and your bahar (ambia or mrig). Then ask:

• How much nitrogen, phosphorus and potash does a tree of my age need this year, given my soil test?
• In how many parts should I split it, and in which months for my bahar?
• Which fertiliser products give those nutrients, and how many grams of each per tree?
• Does my soil or leaf test show a shortage of zinc, iron, manganese or boron, and should it go to the soil or as a spray?
• How much farmyard manure or compost should go on, and when?

What do the published recommendations agree on?

Both institutes set the dose by the tree's age, with young trees (1 to 4 years) getting less than bearing trees. Both split the year's fertiliser into two or three applications instead of one. Dr. PDKV ties the first application to the release of the water stress, before flowering; ICAR-CCRI asks for fertiliser on moist soil, spread along the periphery of the tree rather than against the trunk.

The Geographical Indication application gives one more pattern: nitrogen in three equal splits in January, July and November, phosphorus in January and July, potash once in January, with about a third of the nitrogen from farmyard manure, compost or oil cakes. Ask your KVK which pattern suits your orchard.

How do I recognise zinc and iron deficiency?

Zinc: yellow blotches between the veins of terminal leaves while the midrib and lateral veins stay green. Leaves are small, narrow and pointed; twigs are erect and bushy; leaves drop early and twigs die back; fruit is small and insipid (National Horticulture Board and TNAU).

Iron: a network of green veins on a light green or yellow background on young leaves; leaves stay small. It is a bigger problem in limy, high-pH soils (NHB). Zinc and iron symptoms can look alike, so have a leaf test done before you treat either.

What does the satellite say about fertiliser?

A satellite does not measure which nutrient is short. It can only show that a strip of your orchard is less green than the rest, and there are many causes: water, disease, soil, a nutrient shortage. So it points to the strip, and you check the leaves and soil there. Our weekly message likewise says only what changed, never a fertiliser amount.