Fertiliser decisions on the coconut industry
A coconut products facility.
It is important to understand that we have to provide the plants what the plants need and not what we can give, what we have or what the legislation of a country allows. This is the bottom line which we have to understand and work towards a sustainable plant stability and optimum production both in quality and quantity.
It is estimated that presently coconut occupies about 1.1 million acres across Sri Lanka providing employment to about 1 million people with a smallholder dominance of about 75 percent.
Coconut is the second-most consumed food item of our country and a lot of its products are exported to lucrative international markets. This indicates the stability of the coconut plants on our soil and its contribution towards the food security, small and large holders’ economy while contributing towards the economy and the foreign exchange coffers of our country. This justifies why we should give the coconut palm what it needs and not what we want, what we have or what the legislation of the country intends.
It is scientifically proven that each adult coconut palm needs the following nutrients annually: Carbon, Hydrogen and Oxygen, all three of which are provided free of charge by nature via air and water and energy is given free of charge by the sun.
Other essential ingredients are as follows:
1. Nitrogen in the form of either Urea (800 grammes-gm) or Ammonium Sulphate (1600 gm)
2. Phosphorus in the form of Eppawala Rock Phosphate (600 gm) or Supphosphate
3. Potassium in the form of Muriate of Potash (1600 gm) or Sulphate of Potash (1850 gm).
4. Magnesium in the form of Dolomite (2000 gm) or keiserite.
5. Sodium Chloride in the form of common salt (2000 gm).
6. Micro Nutrients (Copper, Zinc, Boron, Manganese) (about 100 gm).
7. Sulphur in the form of Sulphonite (about 100 gm).
While these are the annual requirements what each coconut tree needs, some of these will be provided by the existing soil and the balance we’ll have to provide. These estimates are for the normal tall varieties of coconut but the new hybrids require more.
There are three different ways of providing them: By inorganic manure; by organic manure and by both organic and inorganic manures.
Inorganic manure
The following inorganic manures are available in the country:
- Eppawala Rock Phosphate, Dolomite and common salt.
- Micro Nutrients could be supplied by the organic materials available on the estates.
- Therefore we have to import only Urea or Ammonium Sulphate for Nitrogen and Muriate of Potash or Sulphate of Pottash for Potassium. Out of these Sulphate of Potash is allowed for organic cultivation by the international bodies governing organic cultivations.
Combination of organic and
inorganic manures
According to the Coconut Research Institution, which is an apex body and an authority on scientific data, the following recommendations have been made:
Cattle, Goat, Pig or Poultry (layer) manure ——- 25 to 30 kgm per plant per year
With Muriate of Potash or Sulphate of Potash—– 1000gm/ 1250 gm per plant per year.
These figures are subject to mild variations depending on the soil conditions and the plant variety, Or:
Glidiciria——– 30 kgm with Supphosphate —– 300 gm.
Muriate of Potash /Sulphate of Potash–1000 gm./1250 gm and Dolomite —- 500 gm per plant per year.
Organic
Now let us consider the availability of raw materials for organic conversion in the country.
As mentioned earlier Sri Lanka has about 1.1 million acres under coconut cultivation. Now with the new plantations in the North and the East it will be more. Leaving aside 0.1 million acres for uncultivated areas within the plantations and taking into account plant density of about 60 palms per acre, Sri Lanka should have about 60 million coconut trees to feed.
Nitrogen supplement
At a plant requirement of about 30 kgm of cow dung, the country will need 180 million kgm of dry cow dung of which the wet weight will be about 720 million kgm of cow dung per year. Now we have to find out whether we have an adequate number of cattle well spread in the coconut plantations to supply this requirement and whether we have adequate grazable land for their fodder and at the same time we should not forget that we have to take into account other crops and young coconut plants as well.
Potassium
This is not available locally in adequate quantities and is a very important component. This helps in nut settings and nut formation and affects the number and the quality of the nuts. It is also important in the absorption and utilisation of Nitrogen and Phosphorus and creating condusive Nitrogen Potassium and Potassium Phosphorus ratios. It is scientifically proven that each adult coconut palm needs about 1 kgm of Muriate of Potash or a bit more of Sulphate of Potassium to supplement the cattle manure with minor variations depending on the soil types.
The commonly available Potassium supplements are coconut husks and wood ash. If we are using coconut husks we need about 300 husks per tree per year. With the present national average production of 60 nuts per plant per year and if we completely forget the fibre and other husk related industries and use all the husks for Potassium supplements still we will be short by about 240 husks per tree per year.
All the other nutrients are available locally and only Urea/ Ammonium Sulphate and Muriate of Potash / Sulphate of Potash must be imported to support the wellbeing of the plantations.
Now let us consider why the authorities are prohibiting the importation of Urea. To my knowledge it is due to the presence of Cadmium and Biuret as contaminants in the imported Urea. While Cadmium is a heavy metal and Biuret gets converted into Cyanuric acid which is a toxic material to the plants we do understand the reason for the prohibition imposed on the importation of Urea.
In the international markets refined Urea is available with permissible amounts of Cadmium and Biuret. When we buy Urea we can request for Urea with these permissible quantities.
In the case of Muriate of Potash (Potassium Chloride) or Sulphate of Potash applied in the recommended doses poses no health hazard to plants and animals including human beings. The latter can increase the acidity of the soil after continuous use and this could be easily rectified by applying Dolomite which is anyway used to supply the required amounts of Magnesium which is essential for the building up of Chlorophyll.
Another factor to consider is when these fertilisers are used in recommended doses within the coconut lands there is no risk of soil or soil water contamination unlike the paddy lands where the excess water joins the natural waterways.
Therefore I cannot visualise the rationale behind the prohibition of the importation of good quality Urea, Ammonium Sulphate, Muriate of Pottash and Sulphate of Pottash.
Now let us consider the alternatives the authorities have given us to fill the void of Urea and MOP. They have recommended the use of compost. I consider compost to be more of a soil conditioner than a proper well balanced fertiliser; well-balanced for the simple reason that nobody knows what and how much of raw materials to be used to make compost of good quality.
In the final product the mineral ratios should be in correct proportions and the pH value should be correct, otherwise the absorption and utilisation of the elements will be hampered. There should be facilities to get the samples of compost analysed as many try to make compost with whatever muck they could lay their hands on and market them as good compost with attractive labels. Another factor to consider is that when organic materials are kept exposed on the lands for long periods of time they make excellent breeding grounds for beetles and without proper insecticides to control them it will be disastrous to plantations.
Some people including politicians cite Sinharaja forest as an example of a plantation without any additional inorganic manure. They little know that as Sinharaja is a protected rain forest, there is auto recycling of all the products of fauna and flora within the forest without any material been taken out of the forest unlike in agricultural plantations where a fair amount of products are taken out of the perimeters regularly and those should be replenished to assist the plants for future sustainable production.
As a remedial measure to supplement the void of Nitrogen and Potassium the government is planning to import compost/ organic fertilisers from other countries. We should have proper, adequate facilities to check such material at the borders prior to unloading, lest the country could be plagued with infections and infestations.
We welcome the government move to convert food cultivations to organic for two reasons – one is to feed the people with healthy, uncontaminated foods and two to fetch lucrative, organic loving, niche foreign markets to better our foreign exchange coffers. However if we don’t give the plants what they want they will not provide us with adequate amounts to reach self-sufficiency. For example without inorganic manure and chemicals a drop of paddy production by about 40 percent is expected. Inevitably we’ll have to import rice from other countries. What is the guarantee that we’ll get rice milled from organically grown paddy?
Way forward
The government’s decision to go organic should be done correctly and systematically. For the present requirements of inorganic fertilisers namely MOP or SOP (the latter of which is permitted by the international bodies governing organic cultivations), Urea with permissible or lower amounts of Cadmium and Biuret should be imported for the plantations to reach their targets. In the meantime the farmer community should be educated and supplied with materials to go organic.
Decentralised laboratory facilities or material collection centres should be established to do soil and foliar analysis whereby the plants could be supplied with exactly what they want without over feeding them causing unnecessary expenditure and toxicity.