5:15 PM - 7:15 PM
[AGE34-P05] Artificial Macropores to Promote Downward Infiltration and Increase Soil Organic Matter
1. Background and Purpose of the Study
Material circulation is the basis of ecosystems and is very important in supporting our lives. Soil pore space has a great influence on material cycles in the soil. However, in semi-arid regions where vegetation is scarce and water erosion is likely to occur due to heavy rainfall, infiltration is poor, and soil fertility is difficult to attain. In this study, artificial macropores were introduced as a method to artificially create pore spaces in the soil. This method can improve the soil environment without destroying soil clods. We conducted planting experiments and ignition loss tests to evaluate the effects of rainfall intensity and artificial macropores on soil moisture content and soil organic matter in semi-arid regions.
2. Research Methods
The soil was filled with 30-cm-deep columns of oligotrophic sandy soil and cowpea, which is mainly grown in Africa, was used in four experimental plots: 2M (2 mm/h with macropores), 2X (2 mm/h without macropores), 20M (20 mm/h with macropores), and 20X (20 mm/h without macropores). Water was applied by pump at a fixed time every day. Soil moisture sensors were placed at the top (7.5 cm depth) and bottom (22.5 cm depth) to measure volumetric moisture content. Other measurements such as plant height and number of leaves were taken over time, and at the end of the experimental period, plant residues were collected to measure the amount of organic matter, and above-ground dry matter weight and root weights were measured. In addition, ignition loss test was conducted to determine the organic matter content in the soil.
3. Results and Discussion
The presence of macropores through the column contributed to the high moisture content of the soil. The results for plant height suggested that the macropore structure had a positive effect on plant growth. There were no clear differences in above-ground dry matter weight and root weight, which are organic matter components other than soil, among the experimental plots. However, the number of leaves and the yield of seedlings indicated that these parameters were strongly influenced by the life history of the plants, such as defoliation and mortality. No significant differences were detected in the amount of organic matter in the soil by ignition loss, but the rainfall intensity was smaller and the macropore structure tended to detect a larger amount of organic matter.
4. Summary
Artificial macropores were found to be beneficial to soil moisture content and plant growth in the 30 cm surface layer. In addition, the effect of increasing the amount of organic matter in the soil was demonstrated, and it is expected to contribute to the improvement of the organic quality of the soil.
Material circulation is the basis of ecosystems and is very important in supporting our lives. Soil pore space has a great influence on material cycles in the soil. However, in semi-arid regions where vegetation is scarce and water erosion is likely to occur due to heavy rainfall, infiltration is poor, and soil fertility is difficult to attain. In this study, artificial macropores were introduced as a method to artificially create pore spaces in the soil. This method can improve the soil environment without destroying soil clods. We conducted planting experiments and ignition loss tests to evaluate the effects of rainfall intensity and artificial macropores on soil moisture content and soil organic matter in semi-arid regions.
2. Research Methods
The soil was filled with 30-cm-deep columns of oligotrophic sandy soil and cowpea, which is mainly grown in Africa, was used in four experimental plots: 2M (2 mm/h with macropores), 2X (2 mm/h without macropores), 20M (20 mm/h with macropores), and 20X (20 mm/h without macropores). Water was applied by pump at a fixed time every day. Soil moisture sensors were placed at the top (7.5 cm depth) and bottom (22.5 cm depth) to measure volumetric moisture content. Other measurements such as plant height and number of leaves were taken over time, and at the end of the experimental period, plant residues were collected to measure the amount of organic matter, and above-ground dry matter weight and root weights were measured. In addition, ignition loss test was conducted to determine the organic matter content in the soil.
3. Results and Discussion
The presence of macropores through the column contributed to the high moisture content of the soil. The results for plant height suggested that the macropore structure had a positive effect on plant growth. There were no clear differences in above-ground dry matter weight and root weight, which are organic matter components other than soil, among the experimental plots. However, the number of leaves and the yield of seedlings indicated that these parameters were strongly influenced by the life history of the plants, such as defoliation and mortality. No significant differences were detected in the amount of organic matter in the soil by ignition loss, but the rainfall intensity was smaller and the macropore structure tended to detect a larger amount of organic matter.
4. Summary
Artificial macropores were found to be beneficial to soil moisture content and plant growth in the 30 cm surface layer. In addition, the effect of increasing the amount of organic matter in the soil was demonstrated, and it is expected to contribute to the improvement of the organic quality of the soil.