WHAT IS CROP ROTATION AND PRINCIPLES CROP ROTATION AND ITS IMPORTANCE

CROP ROTATION IN AGRICULTURE

Definition: Crop rotation is defined as the planting of different types of crops on the same piece of land in a definite sequence.
In other words, it is a system that involves the growing of different crops on the same piece of land year after year, with each crop following the other in a definite sequence. This system is practiced in areas where farmland is in short supply. For example, a farmland may be acquired and grown with different crops year after year. This means that the farmer may plant maize on the whole farm this year, while he plants cowpea next year and so on. He may come back to plant maize in four years’ time depending on his course of rotation.
Another way of practicing this system is that the farmland may be divided into plots and each is used to grow a different crop every year. The different crops can then be rotated every year from one plot to another.

Design of a 4-year crop rotation system using yam, cassava, maize and groundnut.
1st plot 2nd plot 3rd plot 4th plot
1st year
2nd year
3rd year
4th year Yam
Groundnut
Cassava
Maize Groundnut
Cassava
Maize
Yam Cassava
Maize
Yam
Groundnut Maize
Yam
Groundnut
Cassava

Different types of crop rotation

N.B: For the purpose of the 4 crops given:
(i) Yam and cassava must not follow each other
(ii) Groundnut and maize must not follow each other
A rotational mixed cropping may also be adopted in a situation where different mixture of crops is grown on the same piece of land every year, in the rotational cycle or course. There may be two, three, four or five year rotation course.

PRINCIPLES OF CROP ROTATION

In order to adopt the principles of crop rotation, the farmer must first consider the following factors:
(i) Climatic conditions such as rainfall, temperature, humidity and sunlight. read how these factors affects agricultural production here
(ii) Vegetation of the area.
(iii) Soil type.
(iv) Soil fertility.
(v) Crops to be planted.
(vi) The root system of the crops to be planted.
With these factors in the mind of the farmer, he will ensure that the principles which include the following are adhered to:
(i) Closely related crops do not follow each other in the same sequence, since such crops will be drawing the same type of nutrients from the soil e.g. maize should not be followed by rice or sorghum in the rotation.
(ii) Deep rooted crops should not follow each other in the same sequence. Therefore, deep rooted crops should be followed by shallow rooted crops. For example, yam should be followed by maize.
(iii) Crops of the same family should not follow each other, since they will be susceptible to the same diseases and pests e.g. maize, wheat, rice, sorghum and millet.
(iv) Crops planted should be ones that are suitable to the climate of the area. For example, tree crops should be grown in rain-forest zone, while crops such as maize, millet beans, groundnut, etc. should be grown in savannah area. Swamp rice should be restricted to swampy area.
(v) Period of fallow should be included in the rotational course, as this will help to replenish the soil fertility.
(vi) During fallowing, leguminous crops may be planted for building up more nitrogen.

Factors that Determine the Adoption of a Cropping System

There are many factors that determine the use of cropping system. These include the following:
(i)

Climatic factors

: These include rainfall, relative humidity, and temperature and photo-period (i.e. length of daylight in every 24 hours). For example, in Southern Nigeria, there are two peak periods of rainfall compared to the North where there is one period of rainfall, and this determines the types of crop to be grown and the type of cropping system to adopt Relay cropping can be successfully practised in the South due to long period of rainfall. Other climatic factors also contribute in one way or the other to the type of cropping system that may be used in an area.
(ii)

Soil factors:

The soil factors include topography, physical and chemical soil conditions, availability of nutrients in the soil. For example, steepy/sloppy land will encourage strip inter- cropping, rather than using such land for other cropping systems. If a particular soil is high in nutrients capacity, the farmer can use such soil for continuous cropping, but the farmer may adopt crop rotation in a situation of low level of soil fertility, where many crops are grown and each crop will be rotated yearly on a particular soil.
(iii)

Economic factors: These include transportation facilities, marketing structures and price. These factors go a long way to determine the type of crops to be grown and the cropping system to be adopted. For example, if the price of rice is high, the farmer can go ahead to produce riceyear after year, thereby adopting a Mono-cropping system.
(iv)

Social factors:

These include people’s tastes and local beliefs, which determine the type of crops to be grown, and the cropping system to adopt. For example, Muslims forbid the eating of pork, a product of pig. As a result, the Northern Nigerian farmers which are predominantly Muslims do not rear pigs.
Northern farmers mostly plant cereal crops e.g. maize, millet and sorghum. Each of these crops may be the single-crop to occupy a particular farmland, which is Mono-cropping. In the South, the farmers mostly plant root and tuber crops, legumes and vegetables, which are concentrated on a particular farmland known as mixed cropping. Ideally, taste determines the planting of cereals in the North, which serves as staple food in the area, while tubers and roots are mainly consumed in the South.

(v)

Technological factors:

The technological advancement of any country can in a big way contribute to the type of cropping system one may adopt in a particular area. For example, where farmers have access to modern machines, a large expanse of land can be cultivated with a single •crop e.g. rice, (Monocropping). But if the farmers are used to crude implements such as cutlass and hoe, such farmers will end up practicing traditional agriculture, thereby adopting mixed cropping system.

demand and supply

RINDER PESTS
148. NEWCASTLE DISEASE
149. BACTERIA DISEASES
150. ANTHRAX
151. BRUCELLOSIS
152. TUBERCULOSIS
153. FUNGAL DISEASES

PROTOZOAN DISEASES
155. TRYPONOSOMIASIS