Whole catchment
Meteorology
Meteo measurements are made by a rainfall gauge, installed on top of the hill. Rainfall amount and intensity are recorded
One time measurements
Soil parameters at measurement points, which correspond to the various plots determined by the superposition of the land use map on the topography and the soil distribution: texture and stoniness, organic matter, saturated hydraulic conductivity, porosity, depth. Ksat, porosity and bulk density are measured with 100CC sample rings
Repeated monitoring and observation (2 weekly)
a. Regular soil surface assessment (crusting/surface structure, roughness.
- The random roughness is measured using a pinmètre consists of several pins of equal length. Sampling is done randomly within measurement plots. The measurement of cohesion is made using a TORVANE, 10 measurements per plot in different places The penetration resistance is a means to determine the carrying capacity load of soil and the ease with which the roots will penetrate to reach deep. The measurement principle is to enter a graduated rod into the ground, whose resistance is measured using a spring that provides directly the value on a scale calibrated in kg/cm2. The methodology for each sample is taken with a penetrometer 10 measurements per plot in different locations to determine the average penetration.
b. Crop characteristics: height (cm), cover fraction‐coverage and vegetation height.
- Determining the rate of plant is covered by the point quadrat method which involves taking readings at 100 points along a meter tape of 1 meter in length. Reading is the reduction of a plot to the size of a point for every inch. Leaf area index (LAI): sampling procedure is to collect 20 leaves representing the whole plot with the distinction between different species and taking into account their frequency and size of leaves.
c. mulch cover fraction, digital analysis using 1m2 frames at sample locations
d. Erosion features (rill and gully density and dimensions)
- All incisions that were identified and measured the width and length of trenches are measured every five meters along the incision.
Repeated measurements (monthly for most, 2 weekly for humidity)
a. Soil moisture with portable TDR probe (0‐6 cm depth).
- Average of 5 measurements per sample location. Frequency 2 weekly and after rainfall. The humidity measurements are made with TDR to take each sample at different locations, 5 measurements per plot to determine an average moisture content for each plot,
b. Surface roughness (max difference microrelief in cm)
- Infiltration rate, using double ring infiltrometer (mm/h): Infiltration is measured using a double cylinder infiltrometer implanted in the soil. The outer cylinder is filled with water to saturate the soil around the central cylinder and also to limit the lateral flow of water infiltrated into the soil from the latter to promote vertical flow of water.
Continuous measurements
Discharge measurement with a V‐notch installed in September 2008 The flow measurement requires the installation of the weir at the outlet of the watershed with a pressure gauge. The gauge measures the pressure variations caused by changes in water level, with a permanent record of 2min repetition.
Radio‐isotopes measurements
7Be is a natural radioisotope with short half life of 53 days. Its production is relatively constant. Be is also highly adsorbed by fine soil particles but only in upper soil surface, about 4cm, because of its short half life. Its analysis is based on comparison between site inventories and local reference inventory. 7Be technique informs on soil redistribution related to rainfall event. Rates of soil loss and gain are given by using converting models.
7Be technique can also be used to study the efficiency of sustainable strategies of soil conservation. Indeed, after use of the selected soil conservation technique, because of its short life, 7Be can inform if this technique contributes to preserve soil from degradation.
The samples will be taken in the field two times, one year and 2 years after implementation of the conservation measures.
Surface runoff
Surface runoff in the catchment will be modelled using the event‐based LISEM which simulates surface runoff and erosion for individual rain events. LISEM works with maps of soil physical, soil surface and crop parameters. These maps will be constructed by attributing parameter values to the various fields based on their land use and soil type.
Agronomical activities by stakeholder
- Dates and type of tillage: ploughing, sowing, weeding, harvest
- Application of chemicals/fertilizer etc
- Animal practices (stocking density)
- Other input (fuel, labour, time)
Yield assessment
- Total yield in kg/ha
- General yield quality or herd/grazing quality assessment
- General impression by stakeholder (advantages/disadvantages)
- Comparative assessment with regular practice
