Question

hello please answer question =2,4 and 8 please

Answer 1

Heya

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(2) Macronutrients: They are the nutrients required by plants in large amounts. They are present in plant tissues in amounts more than 10 mmole kg –1 of dry matter. Examples include hydrogen, oxygen, and nitrogen.

Micronutrients: They are also called trace elements and are present in plant bodies in very small amounts, i.e., amounts less than 10 mmole kg – 1 of dry matter. Examples include cobalt, manganese, zinc, etc.

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(4) During cultivation when the manures are only applied the soil will obviously get enriched with the nutrients as well as the organic matter and there by the fertility of the soil get increased. Each crops requires specific nutrients which can be obtained only when applying fertilizers. If adequate nutrients are not obtained by the crop it will result in the decrease in the crop production. Similarly when only the fertilizers is added during crop cultivation, it will destroy the fertility of the soil there by causing harm to the micro organism which aids in the recycling of the nutrients.So it is advisable to use both the fertilizers for short term and manure for long term benefits so that it will result in the maximum yield from the crop.

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(8) A farmer grows maize crop in a field year after year. After few years, he finds that the yield of crop has become low. This is because the respective crop uses the same nutrient from the soil ,nitrogen or potassium, which makes the soil deficient of the minerals. This can be overcome by adding the fertilisers or manures that contains the required amount of the nutrient. This act of adding fertilisers to replenish the soil is known as manuring. Other method of overcoming this problem is crop rotation. Crop rotation is the practice of growing two or more varieties of crops in the same region in sequential seasons. A common example of crop rotation is to cultivate maize followed by soyabean. The crops selected, vary in nutrient requirements. This ensures complete and uniform utilization of nutrients thereby preventing crops from pests and diseases, without causing loss to soil fertility.

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Hope it helps u

# Nikky

try to make as brainlist :))