topsoil is the most fertile layer of soil.
topsoil is the most fertile layer of soil.
which layer of soil is the most fertile?
topsoil
in soil science, agriculture and gardening, hardpan or soil pan is a dense layer of soil, usually found below the uppermost topsoil layer. there are different types of hardpan, all sharing the general characteristic of being a distinct soil layer that is largely impervious to water. some hardpans are formed by deposits in the soil that fuse and bind the soil particles. these deposits can range from dissolved silica to matrices formed from iron oxides and calcium carbonate. others are man-made, such as hardpan formed by compaction from repeated plowing, particularly with moldboard plows, or by heavy traffic or pollution.
hardpan
among the five geographical divisions of the tamil country in sangam literature, the marutam region was the most fit for cultivation, as it had the most fertile lands. the prosperity of a farmer depended on getting the necessary sunlight, seasonal rains and the fertility of the soil. among these elements of nature, sunlight was considered indispensable by the ancient tamils, because if rains fail other methods of irrigation could be put to use and if the soil wasn't naturally fertile, artificial manuring would enrich the soil. they differentiated the lands on the basis of fertility and accordingly cultivated the crops that were best suited for the kind of soil. they were "vanpulam" (hardland), "menpulam" (fertile land), "pinpulam" (dry land) and "kalarnilam" or "uvarnilam" (salty land). "vanpulam" in mullai and kurinji regions did not yield rich produce, whereas in "menpulam" the yield was very good. dry crops were cultivated on "pinpulam", because of the limited irrigation facilities. the "kalarnilam" was unfit for cultivation. some of the types of soil known to the people of this age were the alluvial soil, red soil, black soil, laterite soil and sandy soil and they knew what crops could be grown on each type of soil.
agriculture in ancient tamil country