Sun, 24 Sep 2017 09:45:20 +0000
By Mwiine Lubemba
(Not the Paramount Chief Chitimukulu)
SMALLHOLDER farmers countrywide want the Food Reserve Agency (FRA) to revert the maize price to last year’s K85 per 50-kilogramme bag instead of the current K60.
FRA recently announced the reduction in maize price from K85 to K60 per 50-kg bag. But the peasant farmers are reluctant to sell maize to FRA at the current price citing the high cost of fertiliser as the main reason.
In the interim, though, some have opted to sell half of their produce to FRA and keep the rest for future sale, so that they reduce on losses because private buyers do not reach remote areas hence mainly relying on FRA.
So how can the price of fertiliser become reduced to acceptable and affordable levels to smallholder farmers in Zambia?
Could the only fertiliser manufacturing entity of anhydrous ammonia, ammonia solution, liquid carbon dioxide, liquid oxygen, methanol, nitric acid, sulphuric acid, Nitrogen, Phosphorous and Potassium (NPK) compound fertilisers, ammonium fertilizer, ammonium sulphate and porous ammonium nitrate, Nitrogen Chemicals of Zambia (NCZ) manage to reduce the price of fertiliser so that it becomes affordable at the proposed K60 per 50-kg bag? I doubt it, if NCZ still remains the only major player in the fertiliser manufacturing sector.
Could this be, why smallholder farmers want FRA maize price revisited?
But, how important is the role of science in developing Zambia’s agricultural sector in general, and the fertiliser manufacturing sector in particular?
It is indeed important and a true picture of the agricultural reality and the Patriotic Front (PF) leaders have recognised that growth in agriculture is the most effective strategy for reducing poverty, increasing food security, creating jobs and promoting overall economic growth as the majority of Zambia’s unemployed population lives in rural areas, with at least 80 percent of the workforce engaged in agriculture.
Needless to say, science and innovation are crucial to the agricultural sector and especially for our country, which suffers from low yields.
Science and innovation can help farmers by developing new seed varieties, creating new cropping techniques, and also developing adapted fertilisers to satisfy Zambia’s specific soil characteristics and crop needs.
Zambia’s Industrial Development Corporation (IDC) in partnership with global industrial players like Dangote of Nigeria and the OCP group of Morocco which is one of the world’s biggest producers of phosphates, should consider developing and launching additional fertiliser manufacturing plants and affordable products specifically adapted to Zambia’s needs for the Farmers Input Support Programme (FISP).
Those new fertiliser manufacturing plants and products ought to be as the result of extensive research on agronomy, crop characteristics and smallholder farmer needs.
Going by what Dangote’s done to cement prices in Zambia, high fertiliser prices could be no exception.
In the last fourteen years of FISP implementation, Zambia’s agricultural sector has grown. Although moderately, but it is the highest average for the last five decades of independence and is beginning to show signs of improving the lives of poor people in the rural areas. This growth can be attributed partly to FISP’s emphasis on increasing productivity as well as private-public investment in the agriculture sector.
It is common knowledge that FISP is a Zambian government initiative, established in 2003 to accelerate agricultural growth, improve food security, nutrition, and increase incomes in the country’s largely small scale farm-based rural economies. It does this by raising agricultural productivity and encourages private and public investment in agriculture. Yet the positive gains made by FISP over the years had been coupled with increased uncertainty in chemical fertiliser import markets and prices.
The fertiliser crisis, which pushed international fertiliser prices to triple their 2003 levels, peaked in mid-2014. Again end-user prices of the imported topdressing commodity shot up dramatically in the latter half of that year, as the weakening of the local currency exchange rate against the major global currencies set in too. These back-to-back crises left most poor smallholder farmers in Zambia at the mercy of increased fertiliser price changes and gave them less access to resources, credit, and social protection. But is the government or private sector on the right path or is there more that can and should be done; if so where and what?
Many important efforts exist to develop Zambian agriculture, including the Mopani Copper Mines’ (MCM) completion of the US$500 million Mufulira smelter upgrade project, which was expected to stop the sulphur dioxide emissions (‘senta’) that have affected the area for over 70 years, it can be said that the frustration most affected local small scale farmers over FRA’s current price of K60 per 50-kg bag of maize could be a direct result of the government’s failure to facilitate development of phosphate mining in Zambia to provide adequate raw materials for production of cheaper fertilisers at the yet to be established fertiliser manufacturing entities in the country.
The Mufulira smelter’s capturing of 97 per cent of sulphur dioxide emissions and turning them into sulphuric acid, a major ingredient other than phosphates in fertiliser production should compel our government to speed up the process of issuing mining licences for phosphates in Eastern and Western provinces to willing foreign and local investors who had expressed interests to undertake the phosphate mining in the country.
As in many cases in Africa, the solution lies in ensuring end-to-end production. The yet to be established fertilizer manufacturing entities must do it by not only producing and selling alternative fertilisers to that currently done by NCZ, but also creating the necessary linkages to make this happen. Yet, still more needs to be done. Average fertiliser use in Zambia is around 10kg/ha whereas the minimum to give back to the soil its nutrients, and therefore increase yields sustainably, is 25kg/ha. And average fertiliser price is around K250 per 50 kg bag. What new developments or innovations should the IDC group come up with in targeting the fertiliser Zambian market with lower prices?
Notwithstanding, superphosphate is the fertiliser most commonly used in Zambia to ensure that soil has a sufficiently high phosphorous content. It is manufactured from the reaction between sulphuric acid and “phosphate rock” (rock rich in the mineral fluorapatite).
The basic reaction in the manufacture of superphosphate is the reaction of insoluble phosphate rock with sulphuric acid to form the soluble calcium di-hydrogen phosphate. The actual composition of the phosphate rock varies with the source. The reactions occurring during the production of superphosphate are complex. However, the production of superphosphate consists of three distinct steps.
Phosphate rock from different sources have different phosphate, fluoride and silica contents. These rocks are mixed in the blending plant to produce a product with a total phosphate concentration of 15 percemt. The phosphate rock mixture is passed through a hammer mill which reduces the particle size to 0.5cm or less. The coarsely ground rock is then passed through an air swept roller mill to attain a rock grist of approximately 75 percent less than 75 microns. The powdered rock is stored in a large hopper. The powder handling system is fitted with a dust collection system.
The ground rock and sulphuric acid are reacted in a horizontal mixer. A continuous flow of the sloppy mix drops out of the mixer into the Broadfield Den. The den consists of a slowly moving floor (approx. 300 mm/min) to enable setting of the ‘cake’ and reciprocating sides, which prevent the superphosphate adhering to the walls. The partially matured superphosphate cake is cut out of the den with a rotating cutter wheel after a retention time of approximately 30 minutes.
Additives such as limestone, potassium chloride (potash) and ammonium sulphate may be added to the superphosphate before it is worked further in the conditioner. The conditioner consists of a set of rotating paddles which break-up and knead the product. Water is usually added to improve the product consistency for granulation.
The granulation process is important in producing superphosphate of the required physical properties. The granulation circuit consists of a pulveriser, granulation drum and classifier. The pulveriser breaks up any lumps in the product before it is fed to the granulation drum. The granulation drum rolls and agglomerates the superphosphate to form granules.
The incline of the drum and the feed rate determine the retention time and bed depth. The granules are passed out of the end of the drum and through a classifier (wire screen). Oversize granules (>6 mm) are recycled through the drum via the pulveriser while the finished product is conveyed to the product stores.
The superphosphate continues to cure in the store for about two weeks and the product is “dressed” (oversize is passed through a hammer mill after screening) before dispatch. Trace elements and other nitrogen or potassium-containing compounds can be dry- blended with superphosphate to give complete fertilizers to meet different requirements.
The laboratory within the manufacturing plant, is responsible both for quality control and for research. Firstly, the laboratory monitors the exact composition of the phosphate rock blend (which varies significantly depending on the source of the rock).
This is important as the physical properties of the finished product (particle size, dryness, friability, etc.) which are critical if the fertiliser is to be easily spread and interact with the soil in a satisfactory way depend on these parameters.
Secondly, research could be conducted both on site and through scientists at the yet to be established fertilizer manufacturing entities and their development laboratories. Research and development work could obviously be focused on improving environmental performance particularly with regard to minimising gaseous emissions.
The most significant potential environmental hazards are dust (from the grinding of phosphate rock) and gaseous hydrofluosilicic acid (from the reaction between hydrofluoric acid and silica or quartz) emissions. These are both carefully monitored, and a dust catcher and gas scrubber may be used.
It is worth mentioning though, that phosphate fertilisers are used worldwide to sustain and improve crop yields, which are required to meet the needs of both a growing world population and annual depletion of soil nutrients.
Most of the phosphate production is processed to fertiliser and shipped directly to consumer markets. The significant players in the industry are fully integrated i.e. they mine and beneficiate the ore, process the product to fertiliser and market it on a regional and global scale. For this reason, the most important factor to controlling supply in the fertiliser market is ownership of phosphate reserves.
However, the starting point for the manufacture of most phosphate products is phosphoric acid as shown in the schematic diagram below. It is made by the acidulation of phosphate concentrate (phosrock) using sulphuric acid and filtering out the resulting calcium sulphate (gypsum), leaving phosphoric acid containing 25 percent to 40 percent phosphorous pentoxide (P2O5), depending on the process being employed. Thus access to low-cost sulphuric acid is also very important in the process. Acidulating one tonne of phosphate rock concentrate requires .85 to .90 tonnes of sulphuric acid.
Diammonium phosphate (DAP), the most widely used fertilizer, is made from phosphoric acid by interaction with anhydrous ammonia. The same reaction of the phosphoric acid and ammonia can also produce monoammonium phosphate (MAP), which is more suitable to Zambian soil conditions. The end results are the same for DAP and MAP i.e. supplying phosphorous to the soil for use by the crops. Merchant grade phosphoric acid (MGA), super phosphoric acid (SPA) are concentrated forms of phosphoric acid which also find common use as fertilizers, animal feed and maybe further upgraded by solvent extraction to purified acid for the industrial markets.
Due to a variety of end products, each with a different phosphate content, the industry globally has adopted the phosphorous pentoxide (P2O5) content as the unit of measure or yardstick for all phosphate material from ore to final product. This may be viewed as a measure of the relative nutrient value of the product. In the following table, the P2O5 content of four common fertilizer products is indicated:
Nevertheless, I strongly believe that unless the high cost of basal fertilizer production is addressed at NCZ, unless the importation of topdressing fertilizer is curtailed, unless IDC facilitates the setting up of standalone primary phosphate raw material processing plants in Eastern and Western provinces to process phosphate ores into the various starting chemical raw materials, unless the raw materials include those for use together in the compound fertilizer section at the NCZ plant are aggressively pursued, unless the capturing of sulphur dioxide emissions and turning them into sulphuric acid at the first acid plant, by MCM in Mufulira is enhanced and utilized, unless sulphuric acid which is a key ingredient in the production of superphosphate fertilizers can be transported to Eastern and Western provinces by rail or road, unless late distribution of farming inputs is minimized, unless, unless, unless… FISP budget constraints in connection with basal and topdressing fertilizers’ procurement by government cannot really be reduced and smallholder farmers will continue to cry foul.
I only hope that the PF leadership including the Petauke Central and Kankoyo members of parliament would not close their ears to this clarion call to action to have fertilizer manufacturing entities established in their respective constituencies for the country to achieve the objective of reducing the fertilizer price to K60 per 50 kg bag. Below, is the overview of the standard phosphate industry that could be replicated in Zambia:
