Evaluation of Infiltration Improvement and Surface Reduction Using Various Soil Conservation Techniques in Coffee Agroforestry Systems in Sumbermanjing Wetan

The uneven distribution and intensity of rain cause a shortage and excess of water in dry land farming. It appears that the problem of soil conservation in principle is the regulation of the relationship between rainfall intensity, infiltration capacity, and runoff adjustment. To improve the physical properties of the soil, and the hydrological function of the land use it cannot only be stressed on the coffee plant. Other factors such as soil surface management, such as providing organic matter, covering the soil surface with understory plants, making absorption holes, terraces, waterways and so on, can improve the hydrological function of the land. Rainwater management can be carried out through controlling surface runoff, harvesting rainwater, increasing soil infiltration capacity, managing soil, controlling evaporation and seepage, lining waterways. The use of silt pit parallel is considered quite effective because it is able to produce the lowest surface runoff and sufficient water storage. Silt pit parallel can produce 0.6% of rainfall into surface runoff and also can store water as much as 62.35% of the rainfall that enters the plot. The functions of a silt pit are to increase water infiltration into the soil. On dry land, silt pit functions as a place for harvesting rainwater and surface runoff. Based on the correlation regression test, the amount of surface runoff is closely influenced by the intensity of rain or rainfall.

Effect of Land Cover Differences on Soil Infiltration at UB Forest, Karangploso Malang

Changes in land cover of forest provide different soil organic matter which affects soil infiltration through soil porosity. The purpose of this study was to determine the effect of differences in land cover on soil infiltration at UB Forest of Karangploso Malang. The study area was divided into six plots, namely protected area plots, mahogany production forests, pine production forests intercropped with coffee plants that have three different canopy densities (tenuous, sufficient and tight) and pine production forests intercropped with seasonal crops. Field observations were carried out to analyze the characteristics of vegetation with a sample plot measuring 20x20 m. The parameters observed were canopy density, basal area, plant density, litter and understorey. The taking of soil samples was done by making minipit which was repeated four times; the parameters observed were organic matter, texture, bulk density, particle density and soil porosity. Infiltration measurements were carried out with two methods i.e. single ring infiltrometer and rainfall simulator, each of which was repeated three times. Observation data were subjected to Analysis of Variance (ANOVA) and followed by with LSD test with a significant level of 5%. The results showed that differences in land cover can affect soil infiltration (F-count > F-table 3.33). The effect of land cover on infiltration occurs through litter which is a source of organic material which will then affect the physical properties of the soil, namely soil porosity. Soil porosity is a very influential factor in soil infiltration. The highest soil infiltration reta of 131.33 cm hour-1 was found in protected areas. Meanwhile, the lowest infiltration rate of 12 cm hour-1 was found in pine production forest plots intercropped with annual crops.

Contrasts in Top Soil Infiltration Processes for Degraded vs. Restored Lands. A Case Study at the Perijá Range in Colombia

Governments are increasingly committing to significant ecological restoration. However, the impacts of forest restoration on local hydrological services are surprisingly poorly understood. Particularly, limited information is available about the impacts of tree planting on soil infiltration processes and runoff pathways. Thus, we investigated the saturated hydraulic conductivity (Ks) and preferential flow pathways in three land-cover types: (i) Active Restoration, (ii) Degraded Land, and (iii) Reference Forest, with contrasting differences in soil profile and land use history in the municipality of La Jagua de Ibirico, César department, Colombia. We conducted soil sampling, using the Beerkan method to determine Ks values. We also measured vegetation attributes (i.e., canopy cover, vegetation height, diameter at breast height, and total number of trees) and carried out three dye tracer experiments for each study site. The blue dye experiments revealed that near surface matrix infiltration was dominant for Degraded Land, while at the Active Restoration and Reference Forest, this only occurred at local surface depressions. The general infiltration pattern at the three land uses is indicated as being macropore flow with mixed interaction with the matrix and highly affected by the presence of rock fragments. The deeper infiltration patterns occur by preferential flow due to the presence of roots and rock fragments. The mean Ks for the Active Restoration (240 mm h−1) was much higher than the Ks at Degraded Land (40 mm h−1) but still considerably lower than the Reference Forest (324 mm h−1). These results indicate that top soil infiltration capacity and soil physical parameters not only directly regulate the amount of infiltration but also infiltration patterns and runoff processes, leading to lower infiltration and increased excess overland flow for Degraded Land than for other land uses.

EFFECTS OF ROOT PLANTS AND LITTER ON SOIL MACROPOROSITY, INFILTATION RATE AND EROSION

Plant roots and litter produced by tree that grow have an important role in the entry of rainwater into the soil (infiltration) as water storage in the future. The effects of plant roots and litter on increasing infiltration rate is due to increased soil macroporosity. The presence of roots that spread in various layers in the soil profile will further increase the organic matter content of the soil and loosen the soil thereby increasing soil macroporosity. In addition, dead roots will form empty spaces that can be filled by infiltration water, as well as active roots that have gaps between roots and soil that can be filled infiltration water. The high infiltration rate will reduce the amount of excessive runoff water so as to reduce the occurrence of erosion.

Assessing the effect of soil parameterization in land use change impact modeling

This study addresses the importance of integrating the effect of land use on soil infiltration rate into land use change impact modeling. Based on a validated version 9.05.04 of the Water balance Simulation Model-WaSiM (statistical quality measures > 0.7), and field measurement of the infiltration rate under cropland and fallow, sixteen model simulations were performed. The impact of land use change is computed comparing LULC status of years 1990 and 2013. The effect of soil parameterization is computed using a refined soil map integrating land use change impact of soil infiltration rate and a classic soil map not considering this interaction. The results show differences in model results as an effect of soil parameterization approaches, indicating that the model is sensitive to the integration of LULC related effects on soil hydraulic conductivity. These differences are more pronounced with increasing modeling time steps (24 and 28 h). The signal-to-noise-ratio indicates that, results achieved in LULC impact assessment with a classic and a refined soil parameterization are very comparable except for interflow.