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Crop Production and Management - Agricultural Practices and Soil Preparation

Grade 8CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

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Crops: When plants of the same kind are cultivated at one place on a large scale, it is called a crop. For example, a crop of wheat means all plants grown in a field are wheat.

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Kharif Crops: These are sown in the rainy season (generally from June to September). Examples include paddy, maize, soyabean, groundnut, and cotton.

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Rabi Crops: These are grown in the winter season (October to March). Examples are wheat, gram, pea, mustard, and linseed.

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Basic Agricultural Practices: A sequence of steps followed by farmers: Soil Preparation →\rightarrow Sowing →\rightarrow Adding Manure/Fertilizers →\rightarrow Irrigation →\rightarrow Protecting from Weeds →\rightarrow Harvesting →\rightarrow Storage.

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Soil Preparation: This is the first step. It involves loosening and turning the soil, which allows roots to penetrate deep and breathe easily. Loosened soil helps in the growth of earthworms and microbes.

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Tilling or Ploughing: The process of loosening and turning the soil using a plough. Big clumps of soil called 'crumbs' are broken during this process.

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Levelling: The tilled field is levelled using a leveller for even sowing and irrigation, preventing soil erosion.

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Agricultural Implements: Main tools used are the Plough (for tilling and adding fertilizers), Hoe (for removing weeds), and Cultivator (tractor-driven tool to save labor and time).

📐Formulae

6CO2+6H2O→Sunlight/ChlorophyllC6H12O6+6O26CO_2 + 6H_2O \xrightarrow{\text{Sunlight/Chlorophyll}} C_6H_{12}O_6 + 6O_2

Fertilizer Content=N+P+K (Nitrogen, Phosphorus, Potassium)\text{Fertilizer Content} = N + P + K \text{ (Nitrogen, Phosphorus, Potassium)}

Soil Porosity∝Degree of Tilling\text{Soil Porosity} \propto \text{Degree of Tilling}

Vtotal=Vsolids+VvoidsV_{total} = V_{solids} + V_{voids}

💡Examples

Problem 1:

Why is it essential to turn and loosen the soil before sowing seeds?

Solution:

Turning and loosening soil brings nutrient-rich soil from the bottom to the top so that plants can use these nutrients. It also allows the roots to breathe by increasing air spaces (O2O_2 availability) and helps roots penetrate deeper.

Explanation:

Plants require minerals, water, and air from the soil. Loosening facilitates the movement of H2OH_2O and gases and aids the growth of friendly microbes that add humushumus to the soil.

Problem 2:

Identify the crop type for a plant sown in October and harvested in March, like WheatWheat.

Solution:

Rabi Crop.

Explanation:

Crops grown in the winter season (October to March) are classified as Rabi crops. They generally require less water compared to Kharif crops like paddy (OryzaOryza sativasativa).

Problem 3:

What is the function of a 'Leveller' in agricultural practices?

Solution:

A leveller is used to break soil crumbs and ensure the field is flat for uniform irrigation.

Explanation:

If the field is not level, water may accumulate in certain areas while others remain dry, and topsoil may be easily washed away by wind or water (Soil Erosion).

Agricultural Practices and Soil Preparation Revision - Class 8 Science CBSE