Soil Erosion Evaluation

a. Amount of Eroded Soil

This was measured using erosion bars that were installed in the monitoring plots. Changes in heights were determined and the amount of eroded soil was computed using soil bulk density in the plots to arrive at soil erosion values expressed in tons/ha.

b. Gully and Rill Occurrence

The degree of gully and rill occurrence especially in cultivated portions of the farm was documented.

These were part of my methodology when we conducted soil degradation research here in our country for my thesis manuscript. Hoping this will be useful to you.

Dear Dernie Olguera, thank you very much for your methods !!

HI Dernie, may I ask several more questions regarding to erosion bar-(1) Is there a high variability in changes of height- eg. in an area of 1 hectare, how many bars to put is recommended? (2) How long does it take to measure the changes of heights? Thank you very much.

A missing part of the methodology

Establishment of Soil Monitoring Plots

Four (4) soil monitoring plots each measuring 5m x 10m were established at each study site for soil degradation evaluation and monitoring relative to the adjacent areas or space-for-time substitution approach (Asio et al., 1998). The plots were adjacent and within 50 meters from each other and have comparable soil morphology and origin. Soil erosion was evaluated and monitored by establishing soil erosion bars. The corresponding changes in the height of the ground surface were determined from the erosion bars every three (3) months for six (6) month duration of the study. A composite eroded soil was collected below each plot for physical and chemical analyses.

Your establishment will depend on the area and perhaps your objectives. You can take it by month, or by weeks. You don't need to have a hectare of land, just a certain area and placed four to six erosion bars.

No 2.

It depend on you Tao, may be every one month

Thank you very much for the detailed description, I have a better idea of measuring soil erosion now. It helps a lot.

Best,

Hsiao

Meanwhile, this information will surely help you a lot. Sorry for the late reply because need to create this so that you may have a real grasp of the method. If any constraints comes in your way, just keep in touch.

The attached file will explain further.

Thanks.

Best Regards,

Dernie

Thanks very much Dernie. Your file of method description, calculation and figure is fantastic !!

Best,

Hsiao

Your always welcome Hsiao!

Hi Hsiao,

I would recommend you to refer the following book to get a proper understanding on the methods of soil loss measurements.

Toy, T.J., Foster, G.R., and Renard, K.G., 2002, Soil erosion: processes, predictions, measurements, and control: New York, John Wiley & Sons, 338 p.

The following document is also very useful for your research, in which you could use the given methods to assess the soil losses in your experimental sites. Perhaps, you may be able to download this document from the web.

Stocking, M.A., and Murnaghan, N., 2000, Land degradation - guidelines for field assessment: Norwich, UK, Overseas development group, University of East Anglia, p. 120.