Skip to main content

Pesticides

Pesticides include herbicides, fungicides and insecticides. They are used especially in a monoculture to control agricultural pests. Most pesticides kill the harmful organisms, as well as, the harmless and beneficial ones. Insecticides kill pollinating agents like bees and butterflies along with pests like leafhoppers, stem borers and yam beetles. In addition, animals like toads and birds that used to feed on the killed organisms find that their food source is gone and move to other areas, thus affecting the ecosystems. These are the immediate results of spraying pesticides.
    When crops are sprayed with pesticides, some fall on the crops and some fall on the ground. When such crops are eaten, the pesticides tend to accumulate in the body of the consumers. Over a period of time, the pesticides accumulate in their bodies, building up to toxic levels and causing them harm. The pesticides that fall on the ground get into the ground water and eventually reach surrounding water bodies. Here, they get into the bodies of living organisms and cause harm.
    Today, farmers are advised to use pesticides with great care and only when essential. Scientists have produced a number of pesticides which do not build up in the bodies of living organisms. Many farmers also control population of insect pests by introducing animals which prey on them. However, caret must be used to make sure that the introduced predator does not upset the ecosystem.

Comments

Post a Comment

Popular posts from this blog

Natural soil

 Natural soils are influenced by rainfall and temperature,heavy rain causes the soil to become leached. High temperatures increase the rate of decomposition of organic matter in the soil, thereby lowering its humus content. Thus, climatic conditions tend to produce poor soils in the tropics and rich soils in the temperate regions. Besides climate and vegetation, the parent rock material also contributes to the quality of the soil. For example volcanic rocks tend to produce fertile soils.    Laterite, a red soil which is a product of leaching, is commonly found in the tropics. It is composed mainly of iron and aluminium compounds,and poor in humus and essential plant nutrients, such as phosphorus, nitrogen and potassium. The black and brown soil of the temperate grasslands are the world's richest soils, with a high mineral and humus content. The light coloured desert soils tend to be very rich in minerals but have a low humus content.    Mainly the soils ar...
Post a Comment
Read more

What do women really want?

What men want is thought to be understood quite well. In general, their sexual desire is orderly, consistent, and narrowly directed. A heterosexual man is heterosexual. If you show him heterosexual sex, his sexual physiology and subjective, reported desire rise in tandem. Homosexual sex will leave him cold both physically and emotionally. For men, there is an excellent match between physiological arousal (as measured by penile tumescence) and level of reported desire. Viagra’s success demonstrates the simplicity of the male mechanism. Viagra does not target desire, but works by increasing genital blood flow, allowing erection. This, apparently, is all that is needed in many cases. As the penis rises, desire is already waiting.       For women, the story is different. The female body, studies show , likes everything, or at least responds to everything (or does not know what it likes, some cynics will say). Female physiological arousal (as measured by vaginal lu...
Post a Comment
Read more

What the Bible says about marriage and divorce

Matthew 5:31-32  “It has been said, ‘Anyone who divorces his wife must give her a certificate of divorce, but  I tell you that anyone who divorces his wife, except for sexual immorality, makes her the victim of adultery, and anyone who marries a divorced woman commits adultery. Mark 10:2-12 Some Pharisees came and tested him by asking, “Is it lawful for a man to divorce his wife?” 3 “What did Moses command you?” he replied. 4 They said, “Moses permitted a man to write a certificate of divorce and send her away"  “It was because your hearts were hard that Moses wrote you this law,” Jesus replied. 6 “But at the beginning of creation God ‘made them male and female. 7 ‘For this reason a man will leave his father and mother and be united to his wife, 8 and the two will become one flesh. So they are no longer two, but one flesh. 9 Therefore what God has joined together, let no one separate"  When they were in the house again, the disciples asked Jesus about this. ...
Post a Comment
Read more