The associated effect of ameliorative works and soil tillage on the field capacity of soils from complex slope land of Ursului Valley, Iasi county

Abstract

The purpose of this study is to establish the associated effect of ameliorative works and soil tillage on the field capacity and on water distribution of the main soil units represented by cambic (i), cambic-coluvic (ii) and cambic-clinogleic (iii) Chernozems. The study of the capacity of soils to retain water was carried out on a slope with North-Eastern exposure of the Ezareni farm from geomorphological unit of Rolling Jijia Field where the mean annual temperature is 9,5 oC and the mean annual precipitation is 544 mm. Soil samples were taken in the spring and summer of 2018. The first soil sampling was done immediately after the snow was melted, from 10 cm to 10 cm and on the depth range 0-100 cm. Soil samples were taken from the plowed strips of ground and strips of grass. During this period, it is considered that the soil moistening takes place up to the level of the field capacity, and losses of water through direct evaporation to the soil surface are insignificant. Soil sampling was also done during summer, one month before harvesting of sunflower. Study of soil water distribution at the end of vegetation is useful for highlighting the lateral movement of water and hence the heterogeneity of improved soil units. The main criteria of sampling sites selection were based on the slope category of the land. The obtained analytical data showed that under the same climatic characteristics, soils from slope land retain a smaller amount of water than those found on flat or low slopes lands. The data analysis revealed that following the processing of the obtained results it was seen as the retention of the water in the soil was influenced by the land use and soil characteristics such as soil texture and state of compaction. Two or more water accumulation peaks recorded on soil profiles are well correlated with the changes of size particles of soil horizons and lithological deposits.