Fertiliser shortage and its long term impact on tea
Newspaper reports recently said that Sri Lankan plantations have been hit by an acute shortage of fertiliser and that this would have a detrimental effect on the industry such as loss of crop, reduction of green leaf quality and inability to offer a suficient number of day’s work to the workers due to lack of crop.
Traditionally manuring is an important entity in tree crop cultivation.
According to the Government, the country is experiencing adverse effects of the use of chemical fertiliser and agrochemicals introduced to increase crop production.
We know productivity gains are necessary and possible. We know that more fertiliser is needed. Further, the fertiliser use can be far more productive and efficient if we do it the right way and in the right context. Using organic manure alone is not the answer.
Next to plucking, fertiliser is the most expensive item of cost in the cultivation of tea. It is not surprising, therefore, that fertiliser costs come under scrutiny when there is need to save on expenditure. A complete cessation of applications of fertilizers would not only reduce yield, but may affect the tea bush. The drop in crop would, of course, be gradual and may not be even apparent immediately. It may take from six months to three years, depending on the type of soil, health of the tea, fertiliser previously accumulated, etc for the drop in yield to reach its maximum.
It is, therefore, evident that the complete omission of fertiliser should not be contemplated in tea land other than those which are to be abandoned.
Plants need adequate supply of elements such as N.P., K, Ca, Mg and S etc from soil which are known as essential plant nutrients.Fertiliser is the chemical that supply these essential plants nutrient, mostly N.P and K which are removed by crop plants in large quantities and such heavy removal of plant nutrients from soil leads to depletion of soil fertility which shows up in crop yield decline and lowered productivity.
The present 50 kilo bag of manure is given to smallholders at the rate of Rs. 1,300 when the actual cost is in the range of Rs. 6,000. This type of subsidy cannot go for ever. We need to go back to our basics and increase the fertility level, using compost to rehabilitate our soil. We certainty have to look at slow releasing fertilisers.
We have to live with our poor soils eroded for many decades. There are no new lands available for tea plantation. The smallholders are very productive as much as in any tea growing country in spite of eroded lands available for tea plantations.
Our tea bushes are now acclimatised for a high dosage of fertilizer and our inputs are very high. I do not know whether the Tea Research Institute’s new mixture of fertilizer has been beneficial in increasing the crop.
An agriculturist is well aware of the many advantages of applying organic manure to the soil. The scientific methods of composting is known but it is not being followed in practice, maybe because it is believed to be labour intensive and materials for composting are not available in large quantities.
This is not true. The main organic resources are available in agricultural areas such as cattle dung, poultry titter, manure, urine, crop waste/residues like rice straw, coir dust, rice husk, prunings, shade loppings, refuse tea, etc.
Green manuring can very effectively contribute to economise on nitrogen fertilisers. In the past, and even currently emphasis has been and is being placed on increased use of chemical fertilisers and other agro chemicals thus increasing cost of production.
Among the many challenges faced by the tea industry today, the most urgent need is to adopt suitable soil management practices such as mulching and growing of leguminous ground covers. Another aspect that needs priority is drainage and proper water managment systems. Though water may not be a factor in some areas, a certain percentage of rain water is also wasted as run – off cause erosion. Management of rain water is important to increase production and to prevent soil erosion.
Whatever strategy is adopted to increase the production, a constant watch on nutrient supply in the soil is needed.
The tea industry in the country is currently enjoying a bonanza in the form of record tea prices. A policy of phased out national replanting programme should be formulated and strictly enforced. The estate sector is expected to follow an annual three per cent replanting programme but this doesn’t happen. This sector has a huge backlog for replanting. As the prices are attractive there is a tendency to prolong the replanting cycle. A 30-year span is considered as the economic life of a tree.
Let us not deviate from this for short term benefits. This is the time for the government to enforce and encourage the growers to go for the much needed replanting.
This should be considered as a national programme and adequate replanting funds allotted to cover the entire replanting cost and phased out replanting should be made mandatory. (The writer is a retired planter).