international fertilizer correspondent
No 5
international fertilizer correspondent No 5 |
|
Quality - it's what counts in the market place
What
is it that influences consumers' choice when it comes to buying food? Even more
than price, it seems, it is the perception of the product's quality, that guides
the shopper's hand from shelf to shopping basket. And whatever 'quality' may
mean to the individual, balanced plant nutrition is the first essential for
farmers keen to capture the consumer's eye.
In a survey1 carried out in seven European countries, consumers said that quality, albeit closely followed by price, is their priority (Figure 1). Of course, the more affluent the society or individual, the greater the importance of quality relative to price. In the new industrialized countries, as in those long established, people demonstrate their wealth as much by their choice of food as by their choice of transport. In the developing countries, and those countries now free from centralized control, quality has become the new watchword. They may have paid less regard for quality in the past, preferring to lay emphasis on producing food to satisfy the energy and protein demands of a hungry population, but many of those same countries earn their foreign exchange principally from the export of raw, agricultural produce. On the world commodity market, just as much as in the supermarket, if you want to win customers, quality counts.
| Figure 1: Relative importance of product attributes in product choice |
|---|
| survey of consumers in 7 European countries |
 |
| after TRAILL, 1999 |
Quality is a nebulous concept that must be given hard edges if it is to be useful in the tough, inflexible world of food trading. An individual shopper may be able to indulge the senses and make a final selection on the basis of taste, smell and an attractive appearance but that shopper will have assumed that other quality factors are in place. These assumptions include the food's nutritional value, that it is safe (from impurities, contaminants, residues), that it is suitable for the purpose intended (that it can be stored or processed, for example), that it meets legislative standards and, increasingly, that its production is environmentally acceptable. These are the factors that should weigh most heavily with producers for these can be quantified and regulated. Once the standards are met, the race is on to produce food that looks, smells and tastes better than that produced by competitors. The key question is how to achieve this great diversity of quality factors.
Quality starts in the field. Exporters are unwilling to risk the purchase of inferior raw materials that may not comply with the quality standards of their trading partners. Processors take a similar view, knowing that poor quality from the field can create problems during processing when remedies are difficult and expensive to apply. Farmers do not want to lose potential markets but the problem in many developing countries is that they lack the technical information on how to feed plants to produce the top quality food that buyers demand. IPI is helping to overcome this by demonstrating the benefits of balanced nutrition and by disseminating the results as widely as possible.
IPI on-farm demonstration plots in Madhya Pradesh, India, for example, revealed that balanced fertilization with potash not only increased grain yields of wheat by 28% but that the nutritional quality also improved. The protein yield increased by almost 40%, sufficient to supply, per hectare, protein for an additional 12 people. In the same State, adequate K on soybean boosted the oil yield by 38%, an amount which could provide an additional 22 people with their annual requirement of 6.57 kg edible oil. Split application was shown to be more effective than a single basal dressing (Figure 2). Soybean is not the only oilseed to respond so positively to potash. Trials in West Bengal showed that oil yield in rape seed could be doubled and, in Orissa, oil output from groundnut was increased by 57%.
Different quality factors come into play depending on the purpose of the crop. With jute, for example, trials in West Bengal showed that potash improved the quality and yield of the fibres. With potatoes, it is the dry matter content which is important because this affects the colour of chips as well as storage life and processing quality (IFC 4). Balanced nutrition with potash produces potato tubers with a higher starch content (Figure 3) and therefore more acceptable chip colour, and it also reduces incidence of black spot disease, thereby pleasing the consumer who is seeking perfect table tubers2 . Freshness is an important quality factor in tea and this is influenced by the amino acid content which, in turn, is influenced by potash, especially when balanced with magnesium3 . Farmers selling sugar beet on a quality based procurement system, need to know that results of research in Hungary show that balanced fertilization promotes higher root yield and sugar content and, consequently, higher sugar yield4 (Figure 4). Farmers in Germany earned an additional net $140/ha from sugar beet at 360 kg/ha K2O in spite of higher fertilizer costs because, at adequate soil K levels, quality of beets improved and fetched a higher procurement price5. Vitamin C content, another important quality factor for consumers, was shown to be higher in cabbages fed with sufficient potash6 (Figure 5). To get the best possible quality, whatever that quality factor is, balanced nutrition can only help. In contrast, unbalanced nutrition can affect quality standards adversely, particularly when it relates to the build up of nitrate in plants.
The main public health concern about high dietary nitrate intake is that it may increase the risk of gastrointestinal cancer. Nitrate accumulates in the vacuoles of living plant tissue if N availability to the plant is in excess, relative to K. The main sources of dietary nitrate are therefore vegetables and fruits because it is the vegetative parts of the plant that are consumed. Nitrate levels may be particularly high in vegetables grown under the lower light conditions of temperate zones because nitrate reduction in leaves depends on light intensity. IPI trials in China have shown that with balanced fertilization, the nitrate content of celery is lower than if nutrition is unbalanced (IFC 4).
Consumers are also concerned that nitrate may be ingested through drinking water. IPI trials in China studied the content of nitrate in the subsoil after harvesting cabbage grown according to farmers' usual cultivation methods. This was compared to nitrate levels following a crop grown with more balanced application of fertilizer. Farmers in the region supply their crops with nitrogen and farmyard manure but they neglect potassium. Under farmers' practice, some 140 kg/ha N, in the form of nitrate, was measured in subsoils whereas the NO3-N content decreased to around 100 kg/ha after adding K to high N application rates. It declined further, to less than 40 kg/ha NO3-N, when N was well balanced with K (Figure 6).
Studies which attempt to establish whether dietary nitrate is directly linked to gastrointestinal cancer produce conflicting and often contradictory results. This was highlighted in a paper by Carlo Leifert7 and others from Aberdeen University's Centre for Organic Agriculture, UK, presented at the recent IFA Agricultural Conference held in Barcelona, Spain, on Managing Plant Nutrition. There is growing evidence to suggest a beneficial physiological role of dietary nitrate in controlling food borne pathogens, including Helicobacter pylori which is increasingly recognized to be associated with gastric malignancy. However, as Leifert and coworkers say, "Although the apparent beneficial effects of nitrite (from nitrate) in the prevention of infectious diseases are likely to change the current negative perception of vegetable based dietary nitrate intake, the authors feel that a sensible limit for levels of nitrate in drinking water should be enforced. Rising nitrate levels are a symptom of improper use of nitrogen fertilizers and poor agricultural management practice".
In order to be a successful food exporter, a country must produce foods that are both sought after and acceptable in quality. Compliance with international food trading standards is an unavoidable prerequisite for food exporters. It is particularly tough for developing countries, most of whom depend to a large extent on their exports of primary produce and yet whose producers are battling against the ravages of tropical pests and diseases. The USA, which imports more than half its food and food products from less developed countries, detains about 24% of food shipments into the country on the basis of suspected microbial and mould contamination and pesticide residues above the permitted levels8. "Countries will continue to tarnish their commercial images by exporting poor quality food," says W.C.K.Hammer, FAO, "unless appropriate steps are taken by industry, governments and relevant international organizations to assist them to address the reasons for their poor performances." One way to improve the quality and the performance is to provide the growing crop with sufficient potash, thereby helping the plant to resist pests and diseases. Research shows that the incidence can be reduced by 50% (see IPI Research Topics No. 3). The nutrition of plants is known to have a substantial impact on the predisposition of plants to succumb to, or resist, pest and disease attack. K deficiency can result in cracks and lesions on fruits and leaves which not only provide an easy entrance for invading pathogens but also repel potential customers. Of course K is not the only nutrient that affects quality. It is balanced nutrition that increases resistance, lowers production costs, improves the product's appearance and reduces the risk of rejection. Again, quality starts in the field.
Potassium is a health factor for animals and humans, as well as plants. In a recent article on "The potassium diet miracle", ("Das Kalium Diät Wunder") an attractive cover girl informs the reader of the German women's magazine "Freundin" (Vol. 13, 1999, Burda Medien) on the function of 'versatile potassium' in the context of slimming with the 'power mineral'. The article claims that with food high in potassium one can easily and naturally lose surplus weight. This is because potassium stimulates water exchange in the tissue and its release through the kidneys; it stimulates the metabolism by activating the enzyme systems which regulate the digestion of food and fat, and it stimulates protein synthesis for building muscle rather than fat. Foods considered rich in potassium are potatoes, dried fruits, strawberries, avocado, beef, chicken breast, bananas and whole grain bread. Bon appetit!
1
Traill, W.B. (1999): Prospects for the future: Nutritional, environmental and
sustainable food production considerations - changes in cultural and consumer
habits. FAO/WHO/WTO Conf. on Int. Food Trade beyond 2000, Melbourne, Australia,
11-15 Oct. 1999.
2 Orlovius, K. (1996): Kalium-Menge und -form bestimmen
Ertrag und Qualität. Kartoffelbau 3/96.
3 Ruan, J., Wu, X. and Härdter, R. (1999): Effects
of potassium and magnesium nutrition on the quality components of different
types of tea. J. Sci. Food Agric. 79: 47-52.
4 Kulcsar, L. and Debreczeni, K. (1997): IPI Report.
5
Orlovius, K. (1996): Einfluss verminderter Kaliversorgung auf Qualität und Ertrag
von Zuckerrüben. Zuckerrübe 45, 1, 28-29.
6
Prokoshev, V. (1998): IPI internal report.
7 Leifert, C., Fite, A., Hong Li, Golden, M., Mowet,
A. and Frazer, A. (1999): Human health effects of nitrate. IFA Agric. Conf.
on Managing plant nutrition. June 29-July 2, 1999, Barcelona, Spain.
8 Hammer, W.C.K. (1999): Food trade and implementation
of the SPS and TBT agreements: current status of food trade, including food
quality and safety problems. FAO/WHO/WTO Conf. on Int. Food Trade beyond 2000,
Melbourne, Australia, 11-15 Oct. 1999.
gross income
minus K-costs DM/ha
quality bonus DM/ha
