OPTAIN : Pesnica river catchment

Converting cropland to grazing land: The technology is applied in flatlands of Ljubljana with an average altitude of 350 m.a.s.l. The average annual precipitation is 1400 mm. The area is characterized with often stormy precipitation events and occasional droughts. Silty loam soils in the area are moderately deep to deep with medium soil organic matter. Area has good availability of surface water and groundwater of good drinking quality. Area has medium biodiversity without salinity and flooding problems. Sedentary agriculture with mixed or commercial agriculture is practiced with less than 10% of income from off-farm. Individual farm households are average in wealth and they are basically mechanized/motorized. The examined farm household, as all housholds in the region has good access to all services and infrastructures. Farm is medium in scale with land owned partly by the farmer and partly leased from other private owners.
Cropland area was converted to permanent grassland or pasture land by sowing of grass and by a fence as protection. Grazing is organized in a rotation system between suckler cow's pasture and paddocks.
The purpose of the technology is to use the natural potential of the soils. As soils are shallow with low water holding capacity permanent grassland is much more resilient and adapted to the drought; permanent grassland needs not only less water, but as well less nutrients. Grass has the capacity to grow well after any rainfall event at any time of the growing period. During drought when, maize fields get dry, grasslands subsist and just wait until the rain falls. While maize yield is lost in drought years, grassland can sustain and nurrish animals until mid-autumn. Another advantage of grassland is its building up of organic matter in the soils.

Mulch-till: (also called “conservation agriculture” or “minimum tillage”) is a method of land management with modified, less intensive tillage, where land is covered with plant residues year-round (at least 30% cover) or grass, energy consumption is reduced, and there is less trampling/ compaction of the soil because of fewer machine passes and the protected surface. Under mulch-till, special agricultural machinery and attachments are required. Disc harrows and chisel ploughs are used to loosen the soil, and direct drills are employed for seeding.

Retention ponds: “Retention ponds” comprise both simple, small ponds (up to 2000 m3, up to 4 m deep) and larger, more complex reservoirs (greater than 2000 m3). Retention ponds are designed to provide storage capacity to attenuate surface runoff during rainfall events. Each consists of a permanent ponded area with landscaped banks. Retention ponds achieve both storm water attenuation and water quality treatment through supplementary storage capacity of runoff. Water is then released at a controlled rate once the risk of flooding has passed. The technology can be applied in a natural or human environment. Before construction of a pond it is essential to follow legislation, which covers conditions and restrictions for the given location. Once a site is selected, technical documentation is prepared: first the conceptual design, then documentation for obtaining opinion, consent and a building permit. Later there is also project documentation for implementation. If the water is to be used for other purposes as well (e.g. for irrigation), it is necessary to plan for usage and environmental impact. Retention and still water promotes pollutant removal through sedimentation, while aquatic vegetation and biological uptake mechanisms offer additional treatment. Retention ponds are effective in removing urban pollutants and improving water quality.