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

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.

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Biosolids Effects in Chihuahuan Desert Rangelands: A Ten-Year Study

Applied and Environmental Soil Science ◽

10.1155/2011/717863 ◽

2011 ◽

Vol 2011 ◽

pp. 1-13 ◽

Cited By ~ 6

Author(s):

David B. Wester ◽

Ronald E. Sosebee ◽

Richard E. Zartman ◽

Ernest B. Fish ◽

J. Carlos Villalobos ◽

...

Keyword(s):

Water Quality ◽

Soil Water ◽

Water Infiltration ◽

Forage Production ◽

Positive Effects ◽

Application Rates ◽

Soil Water Infiltration ◽

Desert Rangelands ◽

Leachate Water ◽

Biosolids Application

Arid and semiarid rangelands are suitable for responsible biosolids application. Topical application is critical to avoid soil and vegetation disturbance. Surface-applied biosolids have long-lasting effects in these ecosystems. We conducted a 10-year research program investigating effects of biosolids applied at rates from 0 to 90 dry Mg ha−1on soil water infiltration; runoff and leachate water quality; soil erosion; forage production and quality; seedling establishment; plant physiological responses; nitrogen dynamics; biosolids decomposition; and grazing animal behavior and management. Biosolids increased soil water infiltration and reduced erosion. Effects on soil water quality were observed only at the highest application rates. Biosolids increased soil nitrate-nitrogen. Biosolids increased forage production and improved forage quality. Biosolids increased leaf area of grasses; photosynthetic rates were not necessarily increased by biosolids. Biosolids effects on plant establishment are expected only under moderately favorable conditions. Over an 82-mo exposure period, total organic carbon, nitrogen, and total and available phosphorus decreased and inorganic matter increased. Grazing animals spent more time grazing, ruminating, and resting in biosolids-treated areas; positive effects on average daily gain were observed during periods of higher rainfall. Our results suggest that annual biosolids application rates of up to 18 Mg ha−1are appropriate for desert rangelands.

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Comparative study of the impact of two mechanical perforation densities on the behavior of a sandy soil

Progress in Agricultural Engineering Sciences ◽

10.1556/progress.8.2012.2 ◽

2012 ◽

Vol 8 (1) ◽

pp. 37-48

Author(s):

S. Chehaibi ◽

K. Abrougui ◽

F. Haouala

Keyword(s):

Soil Water ◽

Sandy Soil ◽

Water Infiltration ◽

Cone Penetration ◽

Initial State ◽

Soil Water Infiltration ◽

Good Improvement ◽

The Impact ◽

Positive Effect ◽

Resistance To Penetration

The effects of mechanical perforation densities by extracting soil cores through an aerator Vertidrain with a working width of 1.6 m and equipped with hollow tines spaced of 65 mm, were studied on a sandy soil of a grassy sward in the Golf Course El Kantaoui in Sousse (Tunisia). The mechanical aeration was performed at two densities: 250 and 350 holes/m2. The cone penetration resistance and soil water infiltration were measured. These parameters were performed at initial state before aeration (E0) and then on the 10th, 20th and 30th day after aeration. These results showed that perforation density of 350 holes/m2 had a positive effect on the soil by reducing its cone resistance to penetration compared to the initial state (Rp = 14.8 daN/cm2). At 5 cm depth the decrease in resistance to penetration was 34% and 43% on the 10th and 20th day after aeration, respectively. However, on the 30th day after aeration the soil resistance to penetration tended to grow and its value compared to the initial state decreased only by 21 and 26%, respectively, at 5 and 15 cm of depth only by 10% and 9% with 250 holes/m2 density. The soil water infiltration made a good improvement after aeration compared to the initial state. This parameter increased from 4.8 cm/h to 8.3, 10.9 and 13.1 cm/h with 250 holes/m2 density and to 10, 12.9 and 14.8 cm/h with 350 holes/m2 density on the 10th, 20th and 30th day following the aeration.

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