Researches Concerning some Elements of Agroecological Monitoring in Codrilor Plateau from Republic of Moldova

Abstract

Several elements of agroecological monitoring have been investigated as component parts, and also subsystems of the integrated ecological monitoring, the first aiming to survey and control the agroecosystems in order to determine formation of highly effective agrocoenoses, ecologically balanced, able to harmoniously work with the agricultural environment, biotic and abiotic factors. Surveillance of the physical-mechanical indices in time and space in various ecosystems, including ecosystems without agricultural impact is an important and necessary component in controlling the overall condition of soil, in maintaining the productive capacity of lands on long term, in distinguishing changes in case of land degradation and application of regulation measures directed to the sustainable development of soils. Research of gray mollisols (greyzems, faeziom) and cambic chernozems belonging to the Central Moldavian Plateau has been complexly performed, by monitoring three groups of indicators - the diagnosis, seasonal changes (short-term) and long-term changes. Along with research of the physico-chemical properties of soil, the study of the physical-mechanical properties (plasticity, adhesion) has been realised in key polygons, included in the database monitoring network of soil quality. Were investigated soils of different textures within several agroecosystems - field crops in crop rotation, ecosystems as fruit growing, vegetables, fallow, as compared with natural ecosystems (forest), which can provide data for background monitoring. Research has shown that the clay-sandy varieties of the mollic gray soils recorded sensitive values passing from the lower to the higher limit of plasticity. The light varieties of soils are more affected by the processes of aridity degradation as compared to the clay loam varieties. Anthropogenic influence by tillage significantly alters the plasticity and adherence. In the mollic gray soil of the fruit growing ecosystem, the physical-mechanical indicators have worsened as a result of cleaning works and of surface work necessary for plantation maintenance. Soil adherence can be used as diagnostic parameter in assessing the level of human impact within agroecosystems. Highlighting the value of optimal humidity for soil tillage based on plasticity and adherence can provide methods for mitigation of land degradation, and measures for work, and subsequently - energy saving.