The significance of soil texture are:
(a) Relative resistance to root penetration : Soil with high clay and silt content retard root growth and consequently the extent and degree of branching of roots are decreased.
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(b) Infiltration of water : Rain falling on a coarse textured soil penetrates almost immediately so that almost none is lost as runoff. In contrast the rate of infiltration of water into a heavy (fine texture) soil is very slow and because runoff is greater, the effectiveness of a given amount of rainfall is greatly reduced by runoff, because drops that runs off an area diminishes the amount of water available to the plants rooted there.
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(c) The rate of water movement : The rate of movement of water through a soil varies inversely with soil texture i.e., finer the state of division, the slower the rate of movement, because tiny interstitial spaces in fine textured soil offer considerable resistance to mass movement of water. Water moves downwards in a sandy soil so rapidly that most of it is soon beyond the reach of shallow rooted plants.
(d) Water holding capacity : Water is retained by soils as film which coat the surfaces of the particles, as wedges held in angles between particles and as moisture imbibed by colloids. In fine textured soils there are more aggregate surfaces to accommodate films, more angles to hold water and more colloidal matter and consequently more water can be held per unit volume of fine soil than in coarser soils. In regions where there are pronounced dry seasons plants are most favourably, situated when their roots are in contact with a body of fine textured soil, because fine soils absorb so much water during each rainy season that the supply is exhausted relatively late in the ensuing dry season as compared to sandy soils.