BAAP II - 2002

Latvia, Description of demonstration / monitoring catchment Mellupite

The demonstration / monitoring watershed (Figure 1) is situated in the Saldus region in the western part of Latvia and is the part of the Venta river basin. It is located about 110 km from Jelgava and 160 km from Riga. The watershed area is 9.64 km2. Of the total watershed area 68% or 658 hectares are agricultural land. Major part of the agricultural land belongs to private farmers. The forest area is 306 hectares and only 55 hectares are private forests. Average size of farms is 27.2 hectares varying from 4.8 to 180 ha. Total population in farms in the Mellupite watershed is 76 people. Mellupite catchment represents average arming situation and might be typical for the present level of agriculture in Latvia.

Fig 1. Mellupite demonstration watershed.

Table 1. Description of the agricultural run-off monitoring system in the Mellupite catchment. 

The soils at the monitoring sites are imperfectly to poorly drained. Most of the agricultural land in the small catchment Mellupite is drained with tile drains (depth 1.1 - 1.3 m, spacing between drains 10 - 32 m). Some properties of the soils are shown in the Table 2.

Table 2. Soil properties in the monitoring site Mellupite (demonstration farm data). 

The landscape is gently rolling and 74 - 88 m above sea level. The moraine landscape, created by the last glaciation, has produced naturally fertile soils in Mellupite site. The quarternary sediment layer thickness is 10 - 20 m. According to the granulometric composition of the moraine dominated soil is clay loam. The moraine is rich in carbonate, and free calcium carbonate is normally present within the uppermost 1.5 meter of the loamy tills. Luvisols is the dominating soil type within the Mellupite watershed.

Demonstration farm 

The farm "Kaudzites" was established in 1926 by Andris` grandfather, who owned 16.75 hectares of land. Today the acreage of the demonstration farm is 81.7 hectares, of which 62.2 hectares within watershed. According to the land use 6.6 hectares is forest and 72.6 hectares is agricultural land. Totally the farmer A.Andersons is using about 180 hectares of agricultural land, parts of which are rented from 7 neighborhood farms. Farmer has 3 tractors, grain harvester, manure spreader, pesticide sprayer, sowing machine, plough, mineral fertilizers spreader and machinery for making hay.

Figure 2. Demonstration farm Kaudzites, plot level and drainage field level monitoring.

Winter wheat, barley, oats and grass are the most important crops grown on the farm. The most usual crop rotation is winter wheat, barley, oats and grass mixed with clover. Sometimes winter wheat is grown for two years and only one spring cereal crop is following. Usually grasslands are grown for two or more years. Generally cereals are grown for sale and partly for livestock fodder. A small area of potatoes and fodder beets are grown for food and for animal feeding. The typical structure of the sown area is as follows: 35% winter cereals, 40% summer cereals and 25% grasses.

The number of cattle has changed very much during the last years. There was in Kaudzites farm 5 cows and 15 fattening pigs in 2001. The concrete slurry storage with roof and necessary slurry mixing and pump equipment is constructed in the farm.

Catchment monitoring station 

Monitoring station (Figure 3) was designed taking into account experience available in Nordic countries (Melby site in Sweden). Mellupite station consist of two floor building (6 x 4 m). Underground floor level is 1.5 m below land surface making possible free inlet both from plot drainage and outlet to the stream from building. Station building has pipeline connection with water level in the weir allowing direct water level / discharge measurements inside the station building. Upper floor of building has been used as the education room for seminars and farmers meetings.

Figure 3. Main monitoring station and hydraulic measurement structure - Crump weir

For discharge measurements Crump weir type structure was constructed using Nordic experience (run-off stations in Norway). Some of the advantages are its high accuracy, ability to transport sediments and easy construction work. Water head in control section of Crump weir is measured in the stilling well inside the station building.

Field drainage

Field drainage system (Figure 2) is located about 500 m from main station and borders with plot drainage site. Acreage of the drainage field is 12 ha run-off area includes 1 ha forestland. Maximal drainage design discharge is 8.4 l/sec, surface run-off from forest 0.5 l/s. Short time maximal discharges might be up to 25-35 l/s.

Plot drainage

16 drainage plots (Figure 2) has been constructed 140 m from main station building. Size of plot is 0.12 ha. Single plot is drained with 3 clay tile drains (diameter 5 cm, spacing 11-12 m, depth 1.1-1.3m). For connection of the drainage system of each plot with tipping bucket in the main station plastic pipes (diameter 63 mm) were used. Additionally one surface run-off plot with acreage of 0,6 ha and measurement registration in the data logger of main station was constructed in 1999.