Question

In the early days of farming, people did not understand how plants obtained

essential nutrients. It so happened that wood ash, fish remains and slaughterhouse

waste were thrown on vacant land just to get rid of them. Then, people started

to notice that the grass, bushes and shrubs on this vacant land began to grow

very well. They reasoned that if their farmland were similarly treated, the growth

of their crops would also improve. People gradually began to realize that the

nutrients required by plants came from the soil and that the amount of nutrients

could be increased by the application of such organic remains to the soil. Thus

started the manuring process in farming.

The practice of manuring has been practised as early since the seventeenth

century. However, the importance of manuring was not properly understood

until scientists began to study the nutritional needs of plants and gave birth to

fertilizers. Thus, gradually, the use of fertilizers became accepted by farmers.

There are many types of manure and fertilizer currently being used. Manure

is a substance derived from animals and plants. The most important advantage

of using manure is the fact that they not only supply a wide range of plant

nutrients, but also improve the structure of the soil. It cements together the soil

particles to form soil crumbs. The crumb structure is a desirable condition of

cultivated soil. The addition of manure to soil will increase the inorganic and

humus content which helps to prevent soil erosion and loss of plant nutrients

when it rains. The common manure used in farming consists of farmyard manure,

compost, blood meal, bone meal and fish meal.

Unlike manure, fertilizers are inorganic substances which do not improve the

structure of the soil. They only supply extra amounts of nutrients to the growing

plants when applied to the soil. The commercial fertilizers commonly used today

can be classified into three major categories; namely, nitrogen (N), phosphate

and potash fertilizers.

Besides knowing the type of fertilizer to use, a farmer also needs to know

when to apply the fertilizer and how to apply it. The fertilizer should be applied

at the time when the plants need a particular nutrient most. The time and method

of application will determine how profitably the fertilizers have been used in

farming. Fertilizers which have not been properly applied cannot be absorbed in

large quantities by plant roots. These fertilizers may be washed away by rain

or they may kill the plants. This would mean a definite financial loss for the

farmer
find out similar words from the passage
1 necessary 2 comprise 3 step by step 4 ascertain
​

Answer 1

Answer:

1.necessary-essential

is all which I know.

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