Zinc fertilizer for more crops and less harm to soil

Agricultural land was very fertile at the beginning. There was no necessity to use fertilizer. But the fertility of soil gradually decreases due to constant and intense cultivation of crops. So the agriculturists, researchers, extension workers felt to use fertilizers. Out of sixteen essential elements for plant mostly Nitrogen (N), Phosphorus (P) and Potassium (K) are used as Urea, Triple Super Phosphate (TSP) and Murate of Potash. The fertility and productivity of soil decreases because of unbalanced use of chemical fertilizer and intensification of cultivation. It may be noted that now the total production of cereal crops has increased more than three times compared to the past decade. The government has taken initiative to set up soil testing laboratory in each upazila. It will bring little result if only major elements are applied to the soil, so it is very essential to apply micro elements like, Zinc, Boron, Manganese, Molydbenum and Copper. Among the micro-elements zinc and boron are becoming popular to the farmers. But the farmers are now at risk for want of Zn. However, there are some problems too, and that have to be overcome to yield full benefit. The problems and prospects of Zn is discussed below:-

Zinc deficiency symptoms: Front portion of young leaves become whitish in colour; older leaves become brownish; the size of the leaves become smaller and the edge of the leaves turn crinkled; uniform growth of plants is not obtained.

Functions of zinc: It is very essential that the cereal crop plants attain normal growth and development, specially rice, wheat, maize, sugarcane, lentil, fruits and vegetables. Zinc acts in formulation of proteins and enhances growth of hormones.

Present status of zinc utilisation: One third area of cultivatable land in Bangladesh has zinc deficiency specially in the northern and southeastern districts like Panchagar, Thakurgaon, Dinajpur, Rajshahi, Pabna, Comilla and some parts of Chandpur. The total area of zinc deficiency is about 39,35,855 hectare. Crops production is being hampered seriously because a vast area has zinc deficiency. To solve this problem two types of zinc sulphates are usually used. It is less soluble in water and for a few years remain as such. Zn sulphate breaks down into zinc ion and sulphate ion in the presence of water. Later on zinc mixes with TSP and becomes unavailable to the plant. On the other hand zinc sulphate mixes with soil and makes it acidic which to an extent degrades its quality.

Some disadvantages: When it mixes with the TSP and DAP the plant cannot take either zinc or TSP, because mixing with TSP, zinc forms a complex compound diminishing its availability to the plant. It increases acidity of the soil which affects the environment and cultivation of other crops is also hampered. Percentage of zinc in the compound also decreases in the process to the disadvantage of farmers.

Zinc fertilizer in developed countries: Many countries of the world have taken up appropriate measures and scientific use of zinc fertilizer after doing necessary research on it. Ciba of Switzerland has been working for the last 20 years on soil based industry and discovered such a zinc which is known as EDTA chelated zinc. It can be used by mixing with TSP. The good news is that in this fertilizer ion is kept in a ready-made form which the plant can take directly and there is no sulphate. As a result it does not create acidity.

What is EDTA chelated zinc? Chelated zinc is a special type of Zn developed through high technology which is readily taken by the plants. In other words it is covered by EDTA coat which is available to the plant in presence of water and it does not react with other materials. It reduces toxicity because there is no sulphate; it is friendly to the environment; it does not mix with other products because it has EDTA coating; its storage and transportation cost is less; it increases soil fertility and productivity.

Measures should be taken: It was not given importance before because the necessity of microelements was felt gradually and now in some areas without it corps cannot be cultivated. So agriculturists, soil scientists and others concerned have come forward to look into this matter seriously. It is a matter of sorrow that though there is a government circular to use this fertilizer no one including scientists, researchers, extension workers or related businessmen have taken initiative to import or market this product. In our own interest it is necessary to have knowledge about its quality, application and uses. Agriculturists, researchers, businessmen, NGO workers have to come forward to make it happen. We may seek cooperation from all strata of people. Now it is the age of information. So, we should go forward according to the new information, otherwise we may lay behind and sink into scarcity of food, malnutrition and poverty, not to speak of the detrimental effect to the environment.

Conclusion: To make up the scarcity of zinc fertilizer in Bangladesh we may use chelated zinc. To make it popular the following steps should be taken: Agriculturists and others concerned should take necessary steps to publicise its quality and effectiveness; training facilities should be provided to the extension workers of agricultural department; businessmen should be encouraged to import it; NGOs should be involved to disseminate information on its importance and utility.

Besides that mass communication and government publicity department should come forward to popularise this fertilizer. With all efforts from all levels the international standard chelated zinc could be introduced and the country would be self sufficient in food by checking deterioration of soil quality and environment.

Kbd Md Shahidul Islam is Ex. Officer, BRAC.