TABLE OF CONTENTS
Title Page – – – – – – – – – i
Declaration – – – – – – – – – ii
Certification – – – – – – – – – iii
Dedication – – – – – – – – – iv
Acknowledgements – – – – – – – v
Table of Contents – – – – – – – – vi
CHAPTER ONE
1.0 INTRODUCTION – – – – – – – 1
CHAPTER TWO
2.0 The trend of using chemical fertilizers in agriculture – – 4
2.1 Agrochemical Expose and Poisoning – – – – – 7
2.2 Classifications of Agrochemicals – – – – – 8
2.3 Insecticides – – – – – – – – 10
2.3.1 Inorganic Insecticides – – – – – – 11
2.3.2 Organic Insecticides – – – – – – 12
CHAPTER THREE
3.0 Impact of Agrochemicals on Environments – – – 13
3.1 Adverse effects on non-target Animal – – – – 13
3.2 Adverse effects of non-target plants – – – – 14
3.3 Adverse effect on microbial community – – – 15
3.4 Water contamination – – – – – – 16
3.5 Negative health consequences of chemical pesticide
and fertilizer use – – – – – – – 16
3.6 Role of agrochemicals for increasing environmental
pollution and eco-system damage – – – – 17
3.7 Use of bio-organic fertilizers: The pros and cons – – 20
3.8 Strategies to reduce chemical fertilizers and pesticides
use in agriculture – – – – – – – 22
CHAPTER FOUR
SUMMARY AND CONCLUSION
4.1 Summary – – – – – – – – 24
4.2 Conclusion – – – – – – – – 25
REFERENCES
CHAPTER ONE
I.0 INTRODUCATION
Since, the advent of human civilization, agriculture has played a most vital role in food production for the growing population and put an immense contribution to the economy (Godfray and Garnett, 2014). In developing countries, the highly increasing population is often facing hardship to maintain food supply for consumption the expedited the process of imbalance between human needs and sustainable use of agricultural land. Interestingly, agricultural practice mainly depends on soil fertility which was created by the ecosystems (Kibblewhite et al., 2008).
On the other hand, soil fertility is being destroyed when lands are used for agricultural purposes. In reality, ecosystems are threatened by agricultural expansion and nutrient release from chemical fertilizers. Though the use of chemical fertilizers and pesticides sufficiently increased the production of crops but consequently invited significant environmental and health problems (Aktar et al., 2009). Prolonged use of chemical fertilizers and pesticides has potential adverse effects on the soil quality, ecosystem networks, and the ultimate consumers.
Agrochemical (or agrichemical) is a generic term for the various chemical products, such as fertilizer, hormone, fungicide, insecticide, or soil treatment that improves the production of crops (Islam, 2000).
Excessive use of agrochemicals is a major source of water contamination, especially in agricultural regions in developing countries where environmental laws are lax. When any one of the three main plant macronutrients (nitrogen, phosphorus, and potassium) is lacking in the soil, crop productivity is limited. As a result, these three ingredients in the requisite proportions are frequently added into commercial fertilizers. However, plants can absorb only limited amounts of these macronutrients from the added chemical or composed fertilizer. With rain, the excess fertilizer in the soil leaches into streams and ends up in distant locations, including reservoirs. Therefore, the recommendations for fertilizer applications and their use should be based on actual crop-soil requirements. However, such soil testing or information is not readily available in farming areas in most developing countries. Consequently, farmers are using quantities of fertilizer blindly and excessively, wasting resources and polluting the environment, with the expectation that more is better, which is not the case (Wimalawansa and Wimalawansa, 2014a).
This leads to under- and over-fertilization of agricultural fields. For example, phosphate is one of the most commonly used components in chemical fertilizer mixtures and the one most abused by farmer in some regions. Excessive use of phosphates has led to hyper-eutrophication of phosphate (and in certain instances nitrates as well) in canals and reservoirs (Lewis et al., 2011).
