TOPIC 8: CROPPING SYSTEMS

This refers to the patterns, techniques, procedures or practices followed in the cultivation and production of plants.

• SHIFTING CULTIVATION:

This is the cropping system whereby land is cultivated for several years until the crop yields become too low due to soil exhaustion.

ADVANTAGES

It is cheap since it does not require fertilisers.

• It is simple since operations are generally carried out using hand tools.

• It controls pests and weeds effectively through burning the bush.

DISADVANTAGES

• It requires a lot of land for the shifting process.

• It results in low yields due to the absence of fertilisers.

• The burning of vegetation destroys potential organic matter and some nutrients.

• It exposes land to erosion since vast areas have to be cleared.

• BUSH FALLOWING:

This means farming a plot then temporarily leaving it when exhausted so that it can regain fertility before returning to it later.

ADVANTAGES

• It is cheap as it does not need a lot of capital for fertilisers.

• It maintains soil fertility through the fallow periods.

DISADVANTAGES

• It encourages deforestation as one bush is cleared after the other.

• It increases the rate of soil erosion through careless cutting down of trees.

• It requires a lot of land which the farmers may not have.

• MONOCROPPING: This involves identifying one crop that is most suitable for the area.

• MONOCULTURE: This means cultivating only one crop during that particular growing season. The plot on which the crop is grown is known as pure stand.

ADVANTAGES

• It facilitates the use of machinery since they can be adjusted to suit the crop in the pure stand.

• It eliminates the possibility of competition from other crops.

• It is easy to use chemicals since the farmer has only the needs of one crop

DISADVANTAGE

• It increases the spread of pests and diseases.

• MIXED CROPPING:

This is the growing of two or more crops on the same plot at the same time. It is also called intercropping, interplanting, multiculture or polyculture

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TYPES OF MIXED CROPPING

• Intra-row mixed cropping: Two or more crops are grown within the same row either on the same planting station or different stations.

• Inter-row mixed cropping: One crop is grown between the rows of another crop i.e. on alternate ridges.

• Relay intercropping/ phased planting: A second crop is sown on the plot while the first one is still growing, established or even maturing.

ADVANTAGES

• It saves labour since some operations are done at once for all the crops.

• It saves land since the same land is used for more than one crop.

• It increases the total yield per hectare since the harvest is combined.

• It reduces the risk of crop failure since the farmer can rely on the other crop if one fails.

• It enables the crops to benefit from one another e.g. beans fixing nitrogen for maize.

• The mixture provides adequate soil cover which reduces erosion and weed growth.

DISADVANTAGES

• Mechanisation is difficult since each crop has specific needs.

• It requires large starting capital to get different machines and farm structures for different crops.

• It is difficult to use pesticides since a chemical used on one crop might be harmful to the other.

• It requires a wide range of knowledge and skills to manage different crops.

• Different crops might be shading one another reducing the rate of photosynthesis.

• CONTINUOUS CROPPING:

This is the practice of growing crops on a piece of land every year without resting the land.

ADVANTAGES

• It ensures 100% utilisation of the land resources available.

• It serves the soil since land is under cover all the time.

• Ensures food security and cash since the farmer gets harvests every year.

DISADVANTAGES

• It exhausts soil fertility since nutrients are removed every year.

• Soil structure is destroyed due to over- cropping.

• Multiplication of diseases, parasitic weeds and pests is high.

• CROP ROTATION: This is the practice of growing different crops (changing crops) on a piece of land in a particular order every year. The farm is divided into pots depending on the number of crops to be grown.

PRINCIPLES OF CROP ROTATION

• Alternating tap (deep) rooted crops with fibrous (shallow) rooted crops.

• Alternating leguminous crops (beans, g/nuts) with non-leguminous crops (cereals, cotton).

• Alternating heavy feeders (soil-exhausting crops) with light feeders.

• Alternating crops with good soil cover with those having little soil cover.

• NO-TILL CROPPING:

This is where the soil is cleared but neither tilled nor ridged hence also called zero tillage or minimum tillage.

ADVANTAGES

• Conserves the soil since it is not loosened by tillage.

• Saves labour since there is no ploughing and ridging.

Maintains soil structure since it is not damaged by repeated cultivations.

• Ensures that crop husbandry practices are completed on time.

• Saves money which would have been used for buying and maintaining cultivating machinery.

• Can be used effectively on hilly areas where machinery could not be used.

DISADVANTAGES

• May not improve the productivity of clay soils which require opening up.

• • Herbicides are expensive

  • BIOLOGICAL FARMING:

  This is where crops are grown using organic inputs rather than inorganic

  inputs like fertilisers, pesticides hence also called organic farming or eco-farming.

  ADVANTAGES

  • It prevents rivers and lakes from being polluted with fertilisers or pesticides.

  • It protects useful insects which would be destroyed if chemicals were applied.

  • Soil structure is improved through use of manure.

  • It is cheaper to make manure than to buy fertilisers.

  • It reduces the chances of poisoning

  • It keeps the ecosystem in state of balance since inorganic inputs tend to be environmental-friendly.

  DISADVANTAGE

  • Organic inputs are slow in producing results.