Mulches beneficial effects

Mulches of plant materials also favor the growth of other forms of animal life, some of which are beneficial and some harmful, but the overall effect on crop production is not likely to be marked. Harmful insects and some diseases may, however, find the natural mulches to their liking, but this is usually a comparatively minor factor in crop production. 

The effects of mulches on yields of annual crops are nearly always beneficial since they usually make the soil a better medium for plant growth and also control weeds. 

The main benefits from leaving crop residues on the surface are in the reduction of wind and water erosion their effects on evaporation are usually minor. When rain falls at comparatively short intervals, mulches of plant residues retard loss by evaporation for a time, but after the surface moisture has disappeared the stubble-mulched soils lose moisture about as fast as a bare soil. This is true chiefly because there is little movement of water by capillarity from the deeper horizons. The extra retention of surface moisture, even if temporary, is often beneficial to seed germination and also to increased infiltration and downward movement of rainfall. 

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