Prevention of Soil Pollution: • Use manures instead of chemical fertilizers. • Industrial waste should be treated before release. • Avoid use of polythene and plastic or they should not get mixed in soil. Prevention of Soil Erosion: • Afforestation: large scale planting in place of cut down forests.Read more
Prevention of Soil Pollution:
• Use manures instead of chemical fertilizers.
• Industrial waste should be treated before release.
• Avoid use of polythene and plastic or they should not get mixed in soil.
Prevention of Soil Erosion:
• Afforestation: large scale planting in place of cut down forests.
• Avoiding over-grazing of grass lands.
• Use of step-farming in hill regions.
Rate of percolation= Amount of water (ml) / Percolation time (minutes) = 200 ml / 40 min = 5 ml / min https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-9/
Rate of percolation= Amount of water (ml) / Percolation time (minutes) = 200 ml / 40 min = 5 ml / min
Clayey soil: 1. Ratio of fine particles is higher. 2. Soil retains water and becomes sticky and wet. 3. Suitable for crops like paddy, wheat and gram. 4. Difficult to plough when wet. Sandy soil. 1. Ratio of large particles is higher. 2. Loose particles, air permeate through the soil. 3. Suitable foRead more
Clayey soil:
1. Ratio of fine particles is higher.
2. Soil retains water and becomes sticky and wet.
3. Suitable for crops like paddy, wheat and gram.
4. Difficult to plough when wet.
Sandy soil.
1. Ratio of large particles is higher.
2. Loose particles, air permeate through the soil.
3. Suitable for vegetables, peanuts and cotton cultivation.
4. Dries up easily. Cannot retain water.
Clayey soil is rich in humus and are very fertile, so it is suitable for growing cereals like wheat and gram. Such soil is good at retaining water. For paddy, soils rich in clay and organic matter and having a good capacity to retain water are ideal. For lentils (masoor) and other pulses, loamy soilRead more
Clayey soil is rich in humus and are very fertile, so it is suitable for growing cereals like wheat and gram. Such soil is good at retaining water.
For paddy, soils rich in clay and organic matter and having a good capacity to retain water are ideal. For lentils (masoor) and other pulses, loamy soils, which drain water easily, are required.
Soil is formed by weathering of rocks. Weathering is the breakdown of rocks by the action of air, wind and water. Soil formation is a slow process. It occurs all the time. Soil formation is a two-step process: • Weathering of rocks takes place. Rock is broken down into small particles. • These smallRead more
Soil is formed by weathering of rocks. Weathering is the breakdown of rocks by the action of air, wind and water. Soil formation is a slow process. It occurs all the time. Soil formation is a two-step process:
• Weathering of rocks takes place. Rock is broken down into small particles.
• These small particles mix with humus (organic matter) and form soil.
Explain how soil pollution and soil erosion could be prevented.
Prevention of Soil Pollution: • Use manures instead of chemical fertilizers. • Industrial waste should be treated before release. • Avoid use of polythene and plastic or they should not get mixed in soil. Prevention of Soil Erosion: • Afforestation: large scale planting in place of cut down forests.Read more
Prevention of Soil Pollution:
See less• Use manures instead of chemical fertilizers.
• Industrial waste should be treated before release.
• Avoid use of polythene and plastic or they should not get mixed in soil.
Prevention of Soil Erosion:
• Afforestation: large scale planting in place of cut down forests.
• Avoiding over-grazing of grass lands.
• Use of step-farming in hill regions.
Razia conducted an experiment in the field related to the rate of percolation. She observed that it took 40 min for 200 mL of water to percolate through the soil sample. Calculate the rate of percolation.
Rate of percolation= Amount of water (ml) / Percolation time (minutes) = 200 ml / 40 min = 5 ml / min https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-9/
Rate of percolation= Amount of water (ml) / Percolation time (minutes) = 200 ml / 40 min = 5 ml / min
https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-9/
See lessList the differences between clayey soil and sandy soil.
Clayey soil: 1. Ratio of fine particles is higher. 2. Soil retains water and becomes sticky and wet. 3. Suitable for crops like paddy, wheat and gram. 4. Difficult to plough when wet. Sandy soil. 1. Ratio of large particles is higher. 2. Loose particles, air permeate through the soil. 3. Suitable foRead more
Clayey soil:
See less1. Ratio of fine particles is higher.
2. Soil retains water and becomes sticky and wet.
3. Suitable for crops like paddy, wheat and gram.
4. Difficult to plough when wet.
Sandy soil.
1. Ratio of large particles is higher.
2. Loose particles, air permeate through the soil.
3. Suitable for vegetables, peanuts and cotton cultivation.
4. Dries up easily. Cannot retain water.
How is clayey soil useful for crops?
Clayey soil is rich in humus and are very fertile, so it is suitable for growing cereals like wheat and gram. Such soil is good at retaining water. For paddy, soils rich in clay and organic matter and having a good capacity to retain water are ideal. For lentils (masoor) and other pulses, loamy soilRead more
Clayey soil is rich in humus and are very fertile, so it is suitable for growing cereals like wheat and gram. Such soil is good at retaining water.
For paddy, soils rich in clay and organic matter and having a good capacity to retain water are ideal. For lentils (masoor) and other pulses, loamy soils, which drain water easily, are required.
https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-9/
See lessExplain how soil is formed.
Soil is formed by weathering of rocks. Weathering is the breakdown of rocks by the action of air, wind and water. Soil formation is a slow process. It occurs all the time. Soil formation is a two-step process: • Weathering of rocks takes place. Rock is broken down into small particles. • These smallRead more
Soil is formed by weathering of rocks. Weathering is the breakdown of rocks by the action of air, wind and water. Soil formation is a slow process. It occurs all the time. Soil formation is a two-step process:
• Weathering of rocks takes place. Rock is broken down into small particles.
• These small particles mix with humus (organic matter) and form soil.
https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-9/
See less