The use of hydrogel in afforestation of postindustrial areas
Some areas intended for afforestation are characterised by a lack of moisture and mineral nutrients. One of the approaches to improve water retention capacity of soils is the use of hydrogels (polymer soil conditioners). The presented experiment was performed with 4 different methods of hydrogel applications and control in a post-industrial area - a dumping ground of the Brown Coal Mine Bełchatów (Forest District Administration Bełchatów). The Aquaterra product (pure hydrogel) and hydrogel with nutrients (Terra Vit) produced by Terra-Gubin company were used in all experiments. From 292 to 306 one-year old seedlings of Pinus sylvestris L. of an average height of 80-101 mm were planted in each plot. The influence of hydrogel application method on successful afforestation and growth of seedling was analyzed after the first vegetation year. Maximum number of survived seedlings (93.3%) was observed for hydrogel applied through roots coating, minimum (72.4%) for hydrogel with fertilizers applied under plants. Results obtained for pure hydrogel surface application (89.1%) and pure hydrogel applied under plants (85.3%) can be compared with results from control plot (89.7%). Mean heights of surviving seedlings were similar (128-130 mm) for root coating, and both methods of hydrogel application under plants, in contrast with surficial hydrogel application (117 mm) and control where they were minimal (111 mm). Mean height increments in surviving seedlings were minimum in control plot (31 mm), and similar (38-40 mm) for root coating and surface application. The best results of height increments (47 mm) were obtained when hydrogel mixed with fertiliser was applied under plants. To sum up, in view of plant survival the best method of polymer soil conditioner (hydrogel) application was root coating; this method gave also satisfactory increments of plant height.
In the past, rural society has always been able to implement some forms of community management of space, water and land that have served as a support for the survival of populations that are often too large for the available resources. The mountainous region of Béni-Snous offers a wide variety of strategies for water and soil fertility conservation management; it presents a form of adaptation of man to the strong physical constraints and thus constitutes a hydro-agricultural and cultural heritage which unfortunately has not yet aroused all the interest it deserves and of which one can be inspired. The ingenuity of these traditional systems, which have survived throughout history, challenges us to analyse and study these systems more seriously, particularly from the technical and organizational side. Our study was conducted in this context. The present work aims to evaluate the traditional systems of water and soil fertility conservation management, which are encountered on the mountains of Béni-Snous, which is characterized by a semi-arid climate. These systems represent a kind of creativity that is, at the same time, practical, organizational and social. The assessment of the state of water and soil management and conservation structures showed that 78% of them are currently functional and valorised. Given their importance, all mobilization and water management structures are still functional; they showed a good cost-effectiveness ratio.