Comparison of the Effects of Polyacrylamide and Sodium Carboxymethylcellulose Application on Soil Water Infiltration in Sandy Loam Soils

Songrui Ning,Quanjiu Wang,Lijun Su,Halidaimu Jumai,Yuyang Shan,Jihong Zhang,Beibei Zhou

doi:10.1155/2019/6869454

Songrui Ning, Quanjiu Wang + Show 5 more

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https://doi.org/10.1155/2019/6869454

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Abstract

Superabsorbent polymers have been used widely in agricultural production in arid and semi-arid regions to manage the soil water holding capacity. As the common water-retention polymers, the molecular weights, and structures of polyacrylamide (PAM) and sodium carboxymethylcellulose (CMC) are obviously different. Modified soil water management with polymers (i.e., PAM and CMC) has shown great promise for water conservation. Few researchers have reported the comparison of the effects of PAM and CMC on soil infiltration characteristics, especially in coarse-textured soils (i.e., sandy loam). In this research, two high-molecular polymers (PAM and CMC) were used to investigate the effects of polymers on soil water infiltration characteristics by laboratory experiment. The infiltration reduction effects of CMC treatments were more obvious than those of PAM treatments. With the applied rates of PAM (0.2–0.8 g/kg) and CMC (1–4 g/kg) increased, the processes of soil water infiltration were inhibited. The average infiltration time of CMC with different application rates is 1.85 times than that of PAM with different treatments. The mean wetting front distances of different application rates treatments of PAM and CMC were 22.20 and 19.23 cm. At the same application rate, applied CMC is more effective in reducing soil sorptivity than applied PAM in sandy loam soils. Moreover, the cost of application of CMC is lower than the cost of application of PAM. The mean economic inputs of PAM and CMC were 153.90 and 35.24 RMB/hm2. Therefore, CMC was selected and recommended as the suitable water retention agent in sandy loam soils.

Highlights

Soil water in ltration is an essential path in the hydrologic cycle; and it mainly controls water intake by the soil pro le and leakage [1]
Arid and semiarid regions are characterized by low erratic rainfall, long dry seasons, and high evaporation rate [2]. e rapid in ltration of soil and scarcity of water in these regions required soil water management schemes to improve the water holding capacity of the soil
E ectiveness of polymers depends on many factors including soil texture and mineralogy, soil management, application rate, and method, water quality, etc. [6,7,8]

Summary

Introduction

Soil water in ltration is an essential path in the hydrologic cycle; and it mainly controls water intake by the soil pro le and leakage [1]. Superabsorbent polymers have long been used in agriculture and recognized as viable soil conditioners for water-retention agents [3]. Ese polymers used in agriculture is commonly considered environmentally safe Such as polyacrylamide (PAM) [(H2-CH-CO-NH2)n] is a long-chain synthetic macromolecule polymer, and sodium carboxymethylcellulose (CMC) is an anionic water-soluble polymer [4, 5]. Ese polymers’ application rates are low and can be considered as successful water retention agents for soils, with low cost, increased stability of the soil structure, etc. E ectiveness of polymers depends on many factors including soil texture and mineralogy, soil management, application rate, and method, water quality, etc. As for the application methods of PAM, spreading on soil

Methods

Discussion

Conclusion