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Description:
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Soils from arid and semiairid regions are often structurally unstable and seal . This surface sealing phenomenon negatively effects many components of the soil -plant system , thereby limiting crop production . Delayed or erratic plant emergence are direct effects of the surface sealing and subsequent crusting phase of the soU . Increased water runoff loss , decreased water infiltration , and enhanced wind erosion are all negative indirect effects of surface seals . Since the 1980's , there has been renewed interest in the use of water soluble polymers for enhancing soil physical properties . Several factors contributing to this use are more efficient application strategies , availability of inexpensive and , more effective polymers . Better understanding of the beneficial effects of using polymers on surface sealing (increased infiltration and reduced surface strength and hardening ) and on the emergence and development of various crops will make crop growing more economical and profitable in soils susceptible to seal formation . Subsequently , farmers (especially from the Southern High Plains of Texas ) will benefit from a wider range of crops that they could grow and thus improve productivity and profits .
This project investigated polymer addition to the soil surface to (i ) decrease soil sealing and (ii ) enhance seedling emergence . Polymers of differing charges and molecular weight were sprayed on the soil surface at several rates . |