Simulated experiment for preventing slope soil erosion using corn stalk juice as soil amendment.

Although polyacrylamide and other manufactured soil amendments have been effective in runoff and sediment reduction, there is a need to seek natural products that may provide the same soil conservation benefits. In the process of developing green biomass utilization, such as fiber extraction, the plant juice becomes a natural byproduct because only water is used in the extraction. In this research, corn stalk juice was tested for its effects on runoff generation intensity and sediment yield intensity. The experimental design involved four simulated rainfall intensities (25, 50, 75, and 100 mm/h), four diluted corn stalk juice concentrations (10%, 25%, 50%, and 75%), and two diluted corn stalk juice amounts (400 and 800 g) on four 0.5-m-long, 0.2-m-wide, and 0.1-m-deep soil boxes set at 5% slope. Experiments were conducted at the USDA-ARS National Soil Erosion Research Lab. Surface soil (0-10 cm) of a Crosby-Miami complex alfisol with 20% clay, 66% silt and 14% sand was from the Purdue Animal Science Research and Education Center in West Lafayette, Indiana. The test soil was air-dried, crushed and then passed through an 8-mm sieve. The corn stalk juice used in this study was extracted from field corn plants grown at Purdue Agronomy Farm at West Lafayette, Indiana. A 100-min continuous rainstorm was applied. The storm consisted of four intensity sequences: 50 mm/h for 60 min, 25 mm/hfor 20 min, 75 mm/h for 10 min and 100 mm/h for 10 min. Runoff samples were collected in 1-liter HDPE bottles every 5 min during the two lower intensity rains and every 3 min during the two higher intensity rains. Time to fill the runoff bottle was recorded. After each run, the sample bottles were weighed immediately to obtain the runoff rate. Approximately 5 mL of saturated alum solution was added to the sample bottles to flocculate the suspended sediment. After settling overnight, the excess water was poured off the bottles. The bottles were placed in the oven set at 105°C for at least 24 h or until the sediments were dried. Dry weights were then taken to calculate the sediment delivery rate and concentration. The results showed that all kinds of diluted corn stalk juice applications and concentrations reduced runoff generation intensity and sediment yield intensity. Sediment reduction benefit was greater than the corresponding runoff reduction benefit under the same diluted corn stalk juice application and concentration. When diluted corn stalk juice application was 400 g, runoff reduction ratio was 31.243%, 31.685%, 34.595%, 39.475% and sediment reduction ratio was 23.167%, 41.993%, 37.918%, 64.606% with diluted corn stalk juice concentration increasing from 10% to 25%, 50% and 75%, respectively. When diluted corn stalk juice application was 800 g, runoff reduction ratio was 37.583%, 56.433%, 63.170%, 76.360% and sediment reduction ratio was 48.214%, 77.219%, 88.572%, 95.539% with diluted corn stalk juice concentration increasing from 10% to 25%, 50% and 75%, respectively. The relationships of runoff generation intensity and diluted corn stalk juice concentration, sediment yield intensity and diluted corn stalk juice concentration were both established as decreasing exponential function when diluted corn stalk juice application and rainfall intensity were both same. The relationship between sediment yield intensity and rainfall intensity was established as increasing power function when diluted corn stalk juice application and concentration were both same. However, the relationship between runoff generation intensity and rainfall intensity was relatively complex. When diluted corn stalk juice application amount was 400 g, the relationship between runoff generation intensity and rainfall intensity was established as a significant increasing linear function. When diluted corn stalk juice application amount was 800 g, the relationship between runoff generation intensity and rainfall intensity was established as a significant increasing exponential function. This research can provide a new idea for prevention and control of soil erosion by water, and provide a new method for the prevention and control of water erosion desertification. [ABSTRACT FROM AUTHOR]