44. NCERT Exemplar XXVI

 

Soil is fertile when it can sustain plant growth, i.e., provide habitat to plants and result in constant high-quality yields. Fertile soil is rich in nutrients necessary for basic plant nutrients, including nitrogen, phosphorus and sodiumnitrogen, phosphorus and potassiumammonia, phosphorus and lithium. Fertile soil has abundant humus. Humus is nutrient-rich, partially decomposed organic matter that is dark in colour. It dedreases the soil's air and water retention capacity It maintain the soil's air and water retention capacity It increases the soil's air and water retention capacity by making it porous. Plant growth is enhanced by humus, which is high in nutrients. Because it is dark, it absorbs heat and helps to warm the soil.

 

    

Step farming or terrace farming is practised in hilly areas in which small fields are formed in steps or terraces to cultivate crops. This technique reduces the flow of rainwater down the slopes of hills.This technique increase the flow of rainwater down the slopes of hills.The use of nutrients is reduced in step farming. Moreover, eroded soil from the upper regions of hills gets deposited in lower terraces. In this way, soil erosiondepositioncorrosion can be checked in hilly regions.