The objective of this study was to evaluate the impact of different land use systems on soil erosion rates, surface evolution processes and physico-chemical properties on a moraine hilly topography in Lithuania. The soil of the experimental site is Bathihypogleyi – Eutric Albeluvisols (abe–gld–w) whose texture is a sandy loam. After a 27-year use of different land conservation systems, three critical slope segments (slightly eroded, active erosion and accumulation) were formed. Soil physical properties of the soil texture and particle sizes distribution were examined. Chemical properties analysed for were soil ph, available phosphorus (P) and potassium (K), soil organic carbon (SOC) and total nitrogen (N). We estimated the variation in thickness of the soil Ap horizon and soil physico-chemical properties prone to a sustained erosion process. During the study period (2010–2012) water erosion occurred under the grain– grass and grass–grain crop rotations, at rates of 1.38 and 0.11 m3 ha–1 yr–1, respectively. Soil exhumed due to erosion from elevated positions accumulated in the slope bottom. As a result, topographic transfiguration of hills and changes in soil properties occurred. However, the accumulation segments of slopes had significantly higher silt/clay ratios and SOC content. In the active erosion segments a lighter soil texture and lower soil ph were recorded. Only long-term grassland completely stopped soil erosion effects; therefore geomorphologic change and degradation of hills was estimated there as minimal.

No abstract

The objective of this study was to estimate long-term effect of different land-use/cover systems on soil erosion processes on the hilly topography of Žemaičiai Upland in Lithuania. The study analyses long-term (18 years) monitoring data from three individual erosion experiments set up on slopes of 7-8°, 7-9° and 9-11° steepness with installed water and outwash collectors. Six land-use systems were investigated: field crop rotation (F), field crop rotation with the black fallow (FF), erosion-resisting grain-grass (GR), erosion-resisting grass-grain (GS), not fertilized and not used grassland (NG) and fertilized and mown grassland (FG). It was found that soil erosion losses and water runoff volume on the slopes of the arable agricultural land generally depended on the erosionpreventative capabilities of different crops, tillage technology and vegetation cover of slope, soil texture and precipitation characteristics. Torrential rainfall in summer and autumn was the cause of most cases of rainwash and soil loss -167.8-229 Mg ha -1 yr -1 , which is described as very strong erosion. Climate warming processes (about 0.7°C over more than 30 years) and a positive air temperature encouraged snow melting and runoff water flow down of the slope surface, even during the cold period. Summarized long-term research results suggest that the highest average annual precipitation runoff volume -529 hl ha -1 yr -1 and average annual soil loss -11.6 Mg ha -1 yr -1 were from bare soil plot in the black fallow land-use system on 9-11° slope with a larger amount of sand particles, compared with the other experimental soil. Erosionresisting grain-grass and grass-grain land-use systems decreased soil loss compared with black fallow system by on average 5 and 15.5 times, respectively. Effectiveness of soil loss reduction of the not fertilized and not used grassland and fertilized and mown grassland land-use/cover systems with a cover formed of permanent multicomponent plant mixture was 99-100%. High erosion resistance of plants by using suitable land-use systems on the hillslopes markedly reduced soil loss (r = −0.99, P < 0.01, n = 18) and runoff volume (r = −0.607, P < 0.01, n = 18). Not fertilized and not used and fertilized and mown grassland systems prevented erosion regardless of the location, steepness of the slope and soil texture and increased the stability against erosion by water on the hilly topography of Lithuania.

Eksperimentai daryti 2011-2012 m. Lietuvos agrarinių ir miškų mokslų centro (LAMMC) Vėžaičių filialo trijuose Kaltinėnų dirvožemio erozijos stacionarų laukuose, esančiuose 7-9°, 9-11° ir 7-8° statumo šlaituose. Dirvožemis-menkai ir vidutiniškai eroduotas, giliau glėjiškas, pasotintasis balkšvažemis-Jlg4-b-el ir Jlg4-b-e2 (Endohypogleyic-Eutri Albeluvisol-Abe-gld-el ir Abe-gld-e2). Kiekviename stacionaro šlaite yra po 10 laukelių. Tyrimo metais stacionaruose augintos daugiametės žolės, vasariniai miežiai, bulvės, laikytas juodasis pūdymas ir ilgaamžiai šienaujami bei nešienaujami žolynai. Nustatyta, kad vandeninės dirvožemio erozijos nuostoliai, vandens nuotėkis ir prarastų maisto medžiagų kiekis labiausiai priklausė nuo šlaito dirvožemio apželdinimo augalais ir granuliometrinės dirvožemio sudėties. Šlaitai, apauginti ilgalaikiais žolynais, kuriuose susiformavusi stipri velėna, atsparūs ardymui. Kai dirvožemis be augalų, pūdymuoja, dirvožemio nuostoliai didžiausi lengvo priemolio 9-11° šlaite (229,34 t ha-1), o vandens nuotėkis-vidutinio ir sunkaus priemolio šlaituose. Mažiausias vandens nuotėkis (308,3-843,6 hl ha-1) ir minimalūs sauso dirvožemio nuostoliai (0-1,56 t ha-1) nustatyti 9-11° lengvo priemolio šlaite, apželdintame ilgalaikiais daugiakomponenčiais žolynais. Esant juodajam pūdymui arba dirvožemiui be augalinės dangos, jautriausias nuardymui ir N, P, K maisto medžiagų netekimui buvo lengvo priemolio statesnio (9-11°) šlaito dirvožemis: per dvejus metus su dirvožemiu ir vandens nuotėkiu judriojo fosforo prarasta 34,39 kg ha-1 , azoto-12,16 kg ha-1 , judriojo kalio-32,86 kg ha-1. Tyrimais nustatyta, jog tarp paviršinio vandens nuotėkio ir mėnesio kritulių kiekio buvo vidutinė priklausomybė (r = 0,61*-0,69* (2011 m.), r = 0,54-0,64* (2012 m.)). Dirvožemio nuostoliai kalvų šlaituose mažai priklausė nuo mėnesio kritulių kiekio.

Agricultural experts' perception and knowledge towards farming conditions and natural agro-environmental problems are important to develop a sustainable rural strategy and may serve when planning land use in sloping agricultural areas to avoid land abandonment. The objective of investigations was to analyze the attitudes of agricultural experts in the Eastern Lithuania region towards the state of the generic agrarian sector, soil erosion processes and natural handicaps. Replies of respondents indicated that the means (the Likert Scale) of the evaluation towards the items "Soil quality", "Agricultural sector development" and "Land suitability for generic agricultural activity" were 2.68, 3.11 and 2.73, respectively. The evaluations indicating that the mean score perceived by respondents towards impact of soil erosion on common farming activity in the region was 2.63. A questionnaire study showed that respondents recognized that the impact of terrain and soil texture factors on the potential of soil erosion processes is the highest in the region, thus the factor of soil type has been evaluated as the least important. The most frequently noticed topographical parameter of the terrain influencing the intensity of soil erosion was slope steepness (63.1% of respondents), followed by slope aspect (21.1%) and length (15.8%). Hilly terrain and soil acidity constraints by frequency 24.5 and 18.9%, respectively, have showed the most important attitude of respondents, in the content of the natural handicaps limiting successful farming activity in the region. However, the study disclosed that unfavourable climate conditions and soil cover diversity were the two least crucial natural constraints for farming. These empirical findings intended to bring benefits and can help in decision-making framework in order to decide the best soil conservation measures and improving farming conditions in agricultural areas under natural handicaps.