The coconut palm is known as the 'Kalpavriksha' or the 'tree of heaven' because every part of it is useful to humans in some way. It provides food, drink, fuel, and timber. In India, millions of families rely on coconuts for their livelihood, either directly or indirectly. India is the third-largest producer of coconuts in the world, with the four southern states - Kerala, Tamil Nadu, Karnataka, and Andhra Pradesh - being the major producers, contributing to over 90% of the total area and production. There is significant potential to increase coconut productivity by adopting scientific nutrient protection techniques, which we will discuss further.
What coconut trees need to grow:
1. Primary Nutrients:
Potash (K) and nitrogen (N) are super important for coconut trees. They really need these to grow well, and they usually respond well when we give them these nutrients. However, phosphorus (P) only needs it sometimes and in certain places.
2. Secondary Nutrients:
Magnesium (Mg) and chlorine (Cl) are also helpful for coconut trees. Then comes calcium (Ca), sulfur (S), and sodium (Na), which are like extra helpers for the trees.
3. Micro-nutrients:
Coconut trees sometimes need tiny amounts of zinc (Zn), boron (B), and manganese (Mn), but only in specific situations. These are like special vitamins for the trees.
Taking care of the nutrients in coconut palms is super important for their health. To help them grow really well, it's suggested to use either 50kg of Organic Manure or 30kg of green manure for each palm every year. Also, 500g of N, 320g of P2O5, and 1200g of K2O should be added to each palm annually, splitting it into two doses in September and May. It's also a good idea to put 500g of MgO on each palm, especially if the leaves are turning yellow because of Coconut root (wilt) infection. However, it's best to test the soil to know exactly what nutrients your palms need for efficient use of resources.
Here's a breakdown of how to take care of coconut palms:
1. Manuring:
● Starting in the 5th year, use 50 kg of FYM (Farm Yard Manure), compost, or green manure.
● In June-July and December-January, divide 1.3 kg urea, 2.0 kg superphosphate, and 2.0 kg muriate of potash into two equal splits.
● Apply these manures and fertilizers in circular basins 1.8 meters away from the palm base. Then, water the area.
● In the 2nd, 3rd, and 4th years, adjust the doses of fertilizers accordingly.
● Ensure there is enough moisture when applying manures.
● Fertigation (a method of applying fertilizer through irrigation) can be done monthly with 75% of the recommended dose.
● If good-quality water is available, phosphate can be applied either as super phosphate in the basins or as DAP through drip irrigation.
● Root feeding of TNAU coconut tonic at 200ml/palm every six months is recommended for mature coconut palms bearing nuts.
2. Bio-fertilizer recommendation:
● Mix 50 g of Azospirillum, 50 g of Phosphobacteria (or 100 g Azophos), and 50 g of VAM (Vesicular Arbuscular Mycorrhizae) with sufficient compost or FYM.
● Apply near the palm's feeding roots every six months starting from planting. Avoid mixing with chemical fertilizers and pesticides.
3. Organic recycling:
● Instead of compost, you can sow green manure crops like Sunnhemp, wild indigo, Calapagonium, or Daincha. Plough them into the soil at the time of flowering.
● Sow Sunnhemp at 50 g per palm in the basin and incorporate it before flowering.
● Coir pith compost or vermicompost made from coir pith, coconut leaves, or other coconut grove wastes can also be applied.
Furthermore, it's essential to address boron deficiency in coconut palms, which can be corrected by applying 160 g borax per palm in four split doses, burying husks in the basin, and applying vermicompost at a rate of 20 kg per palm.
Two nutrient mixtures, 'Kalpa Poshak' and 'Kalpa Vardhini,' have been created and tested to see how well they help coconut palms grow and produce fruit. You can use 'Kalpa Poshak' for young palms by applying 100g per palm each year, split into two doses. For mature palms that are already bearing fruit, 'Kalpa Vardhini' is recommended. Apply 500g per palm each year, also split into two doses.
Drip fertigation is a great way to save on fertilizers. You only need to apply 50% of the recommended dose through drip fertigation to get the same results as applying 100% of the dose. For one palm, you'd need to apply 70g of Urea, 60g of DAP, and 170g of Muriate of Potash for each application, and you'll need to do this seven times to meet the recommended fertilizer dose for each palm through fertigation. If you need to add phosphorus, you can use commercial phosphoric acid.
Additionally, a web-based tool for computing soil test-based nutrient recommendations has been developed and uploaded to the CPCRI website, providing valuable guidance for farmers.
Soil Moisture and Fertility Maintenance Methods
When it comes to managing water for coconut palms, here are some suggestions:
For basin irrigation, aim for 200 litres of water every four days. With drip irrigation, use 66% of the open pan evaporation from December to May. This method saves about 34% more water compared to traditional ways.
Consider sprinkler irrigation if you're growing mixed crops or using intercropping systems. Use about 20 mm of water to wet the entire surface evenly.
To keep the soil moist and fertile, there are different methods you can try:
1. Mulching: Use materials like coconut husk, coir dust, and coconut leaves to cover the soil.
2. Organic or green manure: Apply these to add nutrients to the soil.
3. Intercropping: Planting other crops alongside coconut palms helps retain moisture and enrich the soil.
4. Bunding and terracing: Creating barriers and steps in the land helps prevent soil erosion and retain water.
In sloping areas, specific techniques work well:
1. Trenches filled with coconut husk
2. Half-moon bunds
3. Staggered catch pits with pineapple reinforcement
4. Growing CO3 grass across the slope
For conserving water resources:
1. Collecting surface runoff water
2. Harvesting rainwater from rooftops
Use this harvested water for watering plants. These methods help maintain soil moisture and preserve water for irrigation.
