Gast ::
| Hauptseite > Publikationsdatenbank > Mixed organic and bentonite based amendments improve soil hydrological conditions and irrigation efficiency in oasis soils |
| Hauptseite > Publikationsdatenbank > Mixed organic and bentonite based amendments improve soil hydrological conditions and irrigation efficiency in oasis soils |
| Poster (After Call) | FZJ-2019-02711 |
; ; ; ; ;
2019
Abstract: The major constraint for sustainable agriculture in arid regions of the world is the availability of (suitable irrigation) water. The quantity and quality of irrigation water, as well as the application technique and intervals between irrigation are important due to the useful amount of water brought to the soil and their direct influence on crop production. The oasis systems in southern Tunisia also suffer from scarcity of irrigation water resources because of low precipitation and limited available ground water. Organic matter (OM) application to improve soil fertility and enhance water holding capacity (WHC) is the traditional method in Tunisian oasis systems, but because of regional climatic conditions (dry and hot weather) the degradation of applied OM in the soils is very fast and consequently the WHC decreases too. The objective of this study was to examine the WHC of new alternative soil amendments in the oasis systems in a state of degradation. The soil studied is a gypsum soil. We compared these sandy soils amended either with (i) manure (MS), (ii) compost (CS), (iii) manure and bentonite (MBS) and (iv) compost and bentonite (CBS). The treatments were compared with untreated original oasis sandy soil (U). These five treatments were compared with the most degraded regional soil, i.e. that of the salt plain Chott Djerid (CD). To estimate the soil hydraulic parameters (including WHC) retention curves were measured and van Genuchten parameters fitted to the data. The results of soil water retention curves revealed that the untreated soil (U) retained less water at any matric potential compared to the amended soils. The soil hydraulic conductivity decreased with the use of bentonite combined with organic matter. The saturated hydraulic conductivity for untreated soil was higher than the amended soil with CBS and MBS by 11 and 18 times, respectively. These results suggested that the soil amendments significantly improved the soil water retention. Therefore these soil mixed amendments are appropriate for their potential wider use in sandy (oasis) soils to improve irrigation efficiency amounts and to reduce irrigation frequency.
|
The record appears in these collections: |