Research Division > Research > Agronomy > Extension Services
FERTILIZE CORRECTLY FOR HIGH YIELDS AND PROFIT
Chemical Fertilizers are very essential to cane production in order to obtain satisfactory cane yields. Yet, some farmers are reluctant to apply adequate quantities of fertilizer because it is claimed to be too expensive and is not affordable. Worst of all, after a price increase these farmers often swear that they will not be buying fertilizer or reduce considerably the amount to be used. This practice is unwise because, the price that the farmer receives for his cane can pay for the fertilizer used. Very often the farmer spends all the monies he can afford to pay extra for harvesting the cane, whether or not it is cut clean or delivered fresh to the factory. Yet he is reluctant to do the single most important practice of fertilizing correctly to obtain a good cane yield. This no doubt is being “penny wise and pound foolish”.
The price that the farmer gets per tonne of cane suggests that he can well afford the cost of the fertilizer that is to be applied. SIRI recommends a fertilizer application rate of 10 - 12 bags per hectare ie. 4-5 bags/acre where field conditions are satisfactory. This generally has been found to be the economic rate required per unit area. Fields producing higher yields and with specific conditions will require higher rates of fertilizer.
Why use Fertilizer
Fertilizer perhaps, more than any other input can have dramatic impact on yield and profitability. In as much as yield will be low in the absence of fertilizer usage, improper use such as too little, too much, wrong blend or late application will affect yields, cane quality and profitability.
For good growth and high sucrose, sugar cane requires adequate water and a balanced supply of nutrient elements from the soil. These nutrient elements are often supplemented by the use of recommended fertilizer. Fertilizer recommendations are usually centered around three major elements Nitrogen, Phosphorus and Potassium (NPK). Each crop that is harvested removes large amounts of these nutrient elements from the soil. Unless these elements are replaced with fertilizers after each harvest, cane yields will be less and less each year. Low cane yields result in low profitability or no profit at all.
Fertilizing is Profitable
The application of 10 bags per hectare (4 bags/ ac) of the recommended 16-9-18 for example at $560/bag cost $5,500/ha or $2,240/ac. At today’s cane price of approximately $1060/ tonne average, it takes about 6 tonnes of cane to pay for the fertilizer used, including all the other associated costs. A yield of at least 75 tc/ha often promises a satisfactory return from the business. Good cultivation practices with adequate fertilizer can produce better yields and higher profits. Poor practices and reduced fertilizer usage lower cane yields and profitability.
It is well recognised that fertilizer is an expensive commodity, but it is paid for by the cane produced. Why therefore should a farmer reduce his fertilizer usage by 1 or 2 bags “per acre” to save $560 or $1,200, but loses 5-10 tonnes cane in return? Five to ten tonnes of cane at today’s cane price amounts to $5,300 - $10,600.
If you do that this year and adopt the same practice next year, yield losses will likely increase to 10 - 15 tonnes or 25-37 tonnes/ha. Don’t be “penny wise and pound foolish”.
Know Your Fertilizer Blends
There are several blends of fertilizers available on the market. For sugar cane cultivation this has been kept to about 10 varying blends. The most widely used, based on soil needs are the 14-28-14, 16-9-18, 17-0-17, 23-10-20, 18-9-18, 17-0-20, 17-0-23 and grades such as Sulphate of Ammonia, Urea and Muriate of Potash. The prices of these vary based on the nutrient content of each blend.
What is in the Bag?
A bag of fertilizer weighs 50 kg or 112 lbs (1cwt). It contains predominantly Nitrogen
(N) Phosphorus (P2O5) and Potassium as (K2O) as indicated by the numbers on the bag. For example 16-9-18 means 16% Nitrogen, 9% Phosphorus as P2O5 and 18% Potassium as K2O (NPK). In addition, there are usually small amounts of other nutrients being present such as Sulphur, Magnesium, Zinc etc.
A bag of 17-0-17 contains 17% Nitrogen, zero Phosphorus and 17% Potassium. A bag of Sulphate of Ammonia contains only Nitrogen and will not supply any other nutrient to the plant. Always choose the right blend of fertilizer to supply the nutrient needs of the plant.
When to Fertilize
Fertilizers should be applied as early as possible so that it will be taken up during the active growing period of the plant.
Fertilizer containing Phosphorus which is applied at planting stimulates early root formation and gives rapid and vigorous start to the plants. Therefore a recommendation of 5-7 bags of 14-28-14/ha applied in the furrow below the seed cane at planting is best for plant canes. This is followed by specific recommendation of any of the following :- 17-0-17, 17-0-20, 17-0-23 etc. to be applied 8-10 weeks after planting.
After harvesting, ratoon canes should be fertilized as soon as possible and preferably within 2 weeks after harvesting. Specific recommendations based on soil and leaf test gives the requirement for ratoons. Late application of of fertilizer starves the plant of the nutrients needed for growth, delays maturity and affects cane quality.
Fertilizer like all other inputs should therefore be used wisely to obtain satisfactory results.
Always remember the following: use the correct blend of fertilizer, use adequate quantities and apply fertilizer during the early growing period of the plant.
For more on Fertilizer usage contact your SIRI Extension Officer at the factory nearest you or the Extension Department, SIRI, Mandeville.