Anionic polyacrylamide (PAM) can improve soil structure, but the required concentration for soil amendment remains unclear. In a laboratory soil column experiment, PAM was used to control nitrate-nitrogen (N) and soluble phosphorus (P) losses from a Lou soil collected from Guanzhong irrigation area, China. The tested PAM concentrations were: 0 (control), 100, 200, 400, and 500 ppm. Deionized water (200 mL) was added to each column and allowed to leach over 4 d, with the resultant leachates collected and analysed for nitrate-N and soluble P. This process was totally repeated six times (i.e., 24 d of total leaching). The results revealed that PAM had an inhibitory effect on the nutrients in the soil columns. In general, with increasing PAM concentration, the inhibitory effect on the nutrients was significantly increased. In the collected leachate, mean nitrate-N and soluble P concentrations were at least 8.64% and 17.89% lower, respectively, in the PAM treatments than those in the control. The soluble P concentrations in the leachate in the initial three sampling times were lower than those in the final three sampling times, whereas the opposite trend was observed for the nitrate-N concentration. There was a significant logarithmic and linear relationship between leaching time, nitrate-N and cumulative soluble P leakage, respectively. Nitrate-N and cumulative soluble P leakagein the leachate were 29.07%-56.12% and 18.37%-42.71% less, respectively, for the PAM treatments than those for the control. This study provides a reference to the concentration of PAM for use in future field experiments.
|Number of pages||8|
|Journal||International Agricultural Engineering Journal|
|Publication status||Published - 10 May 2017|
- Lou soil
- Nutrient leaching
- Soil column experiment
- Soluble phosphorus