Turmeric Cultivation: Land Preparation, Climate & Soil Requirement, Harvesting & More

Turmeric is a plant in the same botanical family as ginger. It is native to Southern Asia, but turmeric is grown in a few other warm, humid climates around the globe. Turmeric is used mostly in the kitchen and as the medicine of injuries.

Turmeric (Curcuma longa L), sometimes known as "Indian saffron," is a major commercial spice crop cultivated in India. It has a variety of uses as a seasoning, flavoring, and coloring agent as well as serving as the main curry powder ingredient in Indian cuisine.

It is used in the pharmaceutical and cosmetic industries because of its anti-cancer and anti-viral properties. As a by-product of turmeric, "kum-kum," which is beloved by all housewives, is also produced. It is included in the offerings made during religious and ceremonial events. Additionally, a certain kind of turmeric is used to extract a specific sort of starch. Turmeric is a perfect crop to use as a food colorant because of the rising demand for natural goods as food additives.

Let us discuss the production guide for turmeric in detail.

Climate & Soil

A warm, humid environment is necessary for the growth of turmeric. It may be cultivated in various tropical environments, from mean sea level of 1500 mm and above, temperatures between 20- 30 °C and a rainfall of at least 1500 mm annually, or under irrigated circumstances.

Although turmeric may grow in a variety of soils, including clayey loams, light black loams, and red soils, rich loamy soils with access to irrigation and natural drainage are ideal. The crop cannot stand waterlogging or alkalinity.

Land Preparation

The early arrival of monsoon rains helps in preparing the soil. With the help of four or five deep ploughings, the soil is brought to a fine tilth. For laterite soils, depending on the soil pH, hydrated lime must be administered at a rate of 500–1000 kg/ha and should be tilled properly.

As soon as premonsoon rains start, beds are made with a 50 cm separation between them and dimensions of 1.0 m in width, 30 cm in height, and a convenient length. Creating ridges and furrows is another method of planting. The field should be free from stubble and weeds.

Seed Rate

Turmeric is propagated through rhizomes. A seed rate of 1000 kg rhizomes is required for planting one acre of land. 

Sowing Time

The crop can be sown directly in the field by the end of April.  The sowing can be delayed for a week in subcutaneous and northern districts. It can also be raised by transplanting up to the first fortnight of June without losing much yield. 

On the beds, little trenches are dug with a manual hoe at intervals of 25 x 30 cm. Well-decomposed compost or bovine dung is used to fill pits. Seed rhizomes are then planted on top of the compost or manure, and the soil is added. The ideal distance in ridges and furrows is 25 cm between plants and 45-60 cm between rows.

Green leaves at a rate of 12–15 t/ha are to be used as mulch immediately after sowing the crop. Following weeding, fertilizer application, and earthing up, mulching may be repeated at a rate of 7.5 t/ha at 40 and 90 days following planting.

Manure and Fertilizers

Farmyard manure (FYM) or compost at a rate of 30–40 t/ha is applied by broadcasting and ploughing during the process of preparing the ground for planting or as a base dressing by spreading over the beds or into the planting pits. You can also apply organic manures such as oil cakes at a rate of 2 t/ha. The dosage of FYM may be decreased in such a situation. The general recommendation for turmeric in Kerala is 60 kg N, 50 kg P2 O5, and 120 kg K2 O per hectare. Additionally, it is advised to integrate the application of coir compost (@ 2.5 t/ha), FYM, biofertilizer (Azospirillum), and half the necessary dose of NPK.

Weed Management and Irrigation

As per the weed infestation, it is generally advised to do weeding after 60, 90, and 120 DAP (days after planting).

The number of times irrigation for the turmeric will depend upon the soil and climate conditions. Depending upon the soil and rainfall 15 to 25 times irrigation in medium heavy soil and in case of lights textures red soil 35-40 irrigation is needed.

Harvesting

Depending on the cultivar, the crop is available for harvesting 7 to 9 months after seeding and must be harvested at the proper maturity. The late forms need around nine months to mature, the intermediate types about eight months, and the aromatic types about seven months. Typically, the ground is tilled before the rhizomes are either hand-picked or carefully dug up with a shovel. Rhizomes that have been harvested are cleansed to remove any dirt or other foreign objects stuck to them. There are 8 to 10 tonnes of green turmeric produced on average per acre. Mother rhizomes are separated from the fingers. Mother rhizomes are often stored as seed stock. To obtain dry turmeric, the green turmeric is treated.

Preservation of Rhizome

Rhizomes for seed are typically piled and covered with turmeric leaves under trees or in well-ventilated shelters. The mound is occasionally covered in soil mixed with cow feces. The seed rhizomes can also be kept in sawdust-filled pits. Wooden boards with one or two holes for air circulation can be used to cover the trenches.

Yield

Pure crop yields range from 8000 to 10,000 kg per acre. Under extraordinarily favorable circumstances, such as ample irrigation and extensive manuring, it may go as high as 12000 kg per acre.

Post Harvest Processing

Before being sold, the collected turmeric rhizomes go through a variety of post-harvest processing steps like boiling, drying, and polishing to become a stable product. Turmeric is used for boiling 3 to 4 days after harvest. Since the bulbs (or mother rhizomes) take a bit longer to cook than the fingers, they are divided and cured individually. The different turmeric types' dry recovery rates range substantially, from 19 to 23%.

Boiled rhizomes are dried in the sun. On a small scale, dried rhizomes are polished by rubbing them against a hard surface whereas, on a commercial scale, special polishing drums are available.

Compounds called curcuminoids are the most important of which is Curcumin. Curcumin is the main active ingredient in turmeric. It has powerful, anti-inflammatory effects and is a very strong antioxidant.