Effects of cropping history on soil erodibility of kaingin farms in Mt. Makiling Laguna, Philippines / by Delfin Jaboli Ganapin, Jr.

By: Contributor(s): Material type: TextTextLanguage: English Publication details: Los Baños, Laguna : 1983. Cavite State University- Main Campus,Description: 176 pages : illustrations ; 28 cmContent type:
  • text
Media type:
  • unmediated
Carrier type:
  • volume
Subject(s): DDC classification:
  • 631.45  G15 1983
Online resources: Abstract: GANAPIN, DELFIN JR. y JABOLI, University of the Philippines at Los Banos, April, 1983. Effects of Cropping History on Soil Erodibility of Kaingin Farms in Mt. Makiling, Laguna, Philippines. Major: Professor: Dx. Romeo S. Raros Erosion is a major problem of kaingin farming. This study was aimed to better understand the soil and other characteristics of kaingin areas of different cropping ages that affect erodibility. In the process, two other objectives were achieved: establishment of the relationship between kaingin land use and soil erodibility and assessment of the effectiveness of the raindrop impact technique in determining soil erodibility. Erosion plots were established at sloves of 36%, 50%, and 70% gradients of the secondary forest (zero age cropping), new kaingin (three-year old cropping) and old kaingin (five-year old cropping) areas. Runoff and sediment load were monitored in relation to various soil properties, vegetation cover and climatic factors. Soil samples were collected for testing with the raindrop impact technique. Results of the investigation show that the significance of cropping age on erosion depended primarily on vegetation cover and organic matter. There was a sharp decline in organic matter from the secondary forest to the new and old kaingins. A levelling trend, however, was observed for the new and the old kaingins. This was attributed to the kaingineros’ ability to shift their cropping and cultural practices to those that could maintain the soil organic matter level. Consequently, the resulting erosion from the new and old kaingins did not differ much. Analysis of the data showed the primary importance of vegetation cover and organic matter in protecting the soil against erosion. In the raindrop impact technique determination of soil erodidility, organic — was found to be the most important strengthening factor against breakage even under wet conditions where the soil peds were much weaker than those under either air-dried or oven-dried conditions. The other soil characteristics such as bulk density, particle density, percent porosity, seaweed sand, percent silt and percent clay did not show definite trends in relation to different cropping ages. Though showing interactive relationships with each other and with organic matter, these factors when taken individually did not significantly influence erosion with the exception of soil texture in some cases. The dynamics of runoff was shown to be different from that of sediment load with runoff influenced more by climatic factors while sediment load, more by soil factors. Total rainfall, rainfall intensity and wind velocity significantly influenced runoff, For sediment load, wind velocity was the only significant climatic factor. Sediment load, however, was strongly influenced by runoff. The general trend of soil erodibility at various cropping ages as determined by the raindrop impact technique showed similarity to that determined by actual field monitoring using erosion plots, The difference was attributed to some inherent weaknesses of the raindrop impact technique such as its inability to account for effects of factors such as vegetation cover and slope and variability due to effects of ped size and shape.
Star ratings
    Average rating: 0.0 (0 votes)
Holdings
Item type Current library Collection Call number Materials specified URL Status Notes Date due Barcode
Theses / Manuscripts Theses / Manuscripts Ladislao N. Diwa Memorial Library Theses Section Non-fiction 631.45 G15 1983 (Browse shelf(Opens below)) Link to resource Room use only T-1309 00002256

Thesis (M.S. - - Forestry : Forest Biological Sciences) University of the Philippines, College Laguna.

Includes bibliographical references.

GANAPIN, DELFIN JR. y JABOLI, University of the Philippines at Los Banos, April, 1983. Effects of Cropping History on Soil Erodibility of Kaingin Farms in Mt. Makiling, Laguna, Philippines. Major: Professor: Dx. Romeo S. Raros

Erosion is a major problem of kaingin farming. This study was aimed to better understand the soil and other characteristics of kaingin areas of different cropping ages that affect erodibility. In the process, two other objectives were achieved: establishment of the relationship between kaingin land use and soil erodibility and assessment of the effectiveness of the raindrop impact technique in determining soil erodibility.

Erosion plots were established at sloves of 36%, 50%, and 70% gradients of the secondary forest (zero age cropping), new kaingin (three-year old cropping) and old kaingin (five-year old cropping) areas. Runoff and sediment load were monitored in relation to various soil properties, vegetation cover and climatic factors. Soil samples were collected for testing with the raindrop impact technique.

Results of the investigation show that the significance of cropping age on erosion depended primarily on vegetation cover and organic matter. There was a sharp decline in organic matter from the secondary forest to the new and old kaingins. A levelling trend, however, was observed for the new and the old kaingins. This was attributed to the kaingineros’ ability to shift their cropping and cultural practices to those that could maintain the soil organic matter level. Consequently, the resulting erosion from the new and old kaingins did not differ much.

Analysis of the data showed the primary importance of vegetation cover and organic matter in protecting the soil against erosion. In the raindrop impact technique determination of soil erodidility, organic — was found to be the most important strengthening factor against breakage even under wet conditions where the soil peds were much weaker than those under either air-dried or oven-dried conditions.

The other soil characteristics such as bulk density, particle density, percent porosity, seaweed sand, percent silt and percent clay did not show definite trends in relation to different cropping ages. Though showing interactive relationships with each other and with organic matter, these factors when taken individually did not significantly influence erosion with the exception of soil texture in some cases.

The dynamics of runoff was shown to be different from that of sediment load with runoff influenced more by climatic factors while sediment load, more by soil factors. Total rainfall, rainfall intensity and wind velocity significantly influenced runoff, For sediment load, wind velocity was the only significant climatic factor. Sediment load, however, was strongly influenced by runoff.

The general trend of soil erodibility at various cropping ages as determined by the raindrop impact technique showed similarity to that determined by actual field monitoring using erosion plots, The difference was attributed to some inherent weaknesses of the raindrop impact technique such as its inability to account for effects of factors such as vegetation cover and slope and variability due to effects of ped size and shape.

Submitted to the University Library 01/07/1994 T-1309

Copyright © 2023. Cavite State University | Koha 23.05