Soil activity behaviors after farming techniques application in The Chammak olive tree field

The olive tree arranges no more water reserve that can be exploited during extremely dry periods. A failure of the olive yields observed during the last two decades. The annual production decreased from 150 000 tons to 50 000 tons of olives in the south of Tunisia.  This degradation results, in fact from an obvious reduction in the biological activity of the ground. A new Strategy was employed to improve the organic status and restore the biological activity of the soil ground of the long-term. We have evaluated the effect of the of different plot treatment.  A plot of olive tree speeded with 200 m3/ha dose of  OMW during 10 years, P4;  a plot of olive tree treated with tillage accompanied by 50 m3/ha dose OMW spreading lasting only a one year, P5 and a plot of olive tree cultivated with the introduction of  the fig tree in parallel, P3.  Untouched ground was used as control plot, P0. A comparison of these plots with a degraded ground of olive tree implanted since 1900, P2 and other ground degraded during 10 years, P1. The plot treated with OMW showed an OM value close to the value founded with P0 (Control Plot). The Phytotoxcity measured via germination index GI (percentage) was determined; an   important increment ranged from 200% to 230% was obtained in the P3 and P5, respectively. Correlation analyses, among physiochemical parameters of soil and microbial biomass indicated several positive significant trends. The highest significant correlation was found between OM and TAMF (r=0.999, p<0.001). These results corroborate the notion that the microbial community structure is a good indicator of soil quality and the effects of different management practices, because the microorganisms respond against changes in soil management more rapidly than chemical or physical soil properties. However, in this work we found a negative correlation between respiration soil activity (Resp) and with OM (r=-0.533, p<0.05). In fact, CO2 sequestration took place. Indeed, increasing soil OM enhances the sequestering carbon dioxide (CO2) to mitigate anthropogenic greenhouse gas (GHG) emissions

Seasonal and depth variation of soil physical parameters irrigated with treated wastewater in the case of light textured soil

In places with scarce water supplies, treated wastewater (TWW) can be used for irrigation. This is the case in many places on the Mediterranean coast. In order to examine changes in soil physical proprieties irrigated with secondary-treated wastewater for >38 years, a study was conducted under real agricultural conditions and three different sampling seasons (Summer, autumn and winter). Five soil depth distribution (0-20, 20-40, 40-60, 60-80 and 80-100 cm was also investigated. The soil parameters studied were: salinity (EC), permeablity (K) and  structural stability (IS). The results demonstrate that K and IS depended significantly on the season and varied throught the soil profile. However, only the depth had an impact on the EC. The maximum EC and K were observed in summer at 0-60 and 0-20 cm, respectively. The highest IS, although, was detected during the winter at 40–60 cm depth layer. More interstingly, to take into consideration the interactions of both factors, a positive correlations were shown between K and EC, and IS (r =0.56***, r = 0.62***, respectively) and between EC and IS (r = 0.44**) in summer. In contrast, only K and EC showed a negative correlation (r = -0.35*) in the autumn, but no correlation was detected between all parameters in winter. The results indicate that treated wastewater is a suitable alternative during hot seasons, especially in sandy soils. Further research is required to investigate the effect of this wastwater on crops responses

Polygenic Olive by-products to Silage production by Anaerobic Digestion : a new alternative of sustainable agriculture security and socio-economic advantage impact

Olive by-products consisting of 40 % wood pruning and leaves, 40 % Olive pomace and 20 % OMW were ground and combined with preserving them by anaerobic fermentation (wet silage) for 4 months. The pH and total nitrogen/dry matter silage sample were 5.46 and 45 mg/g, respectively; the values comply with standards norms. After the silage process, a decreasing of phenol compound concentration of 67.85% was revealed and among 37 fatty acids compounds were identified with a valuable richness in mineralnutrients. The silage was devoid of total coliforms and fecal coliforms and yeast number doesn't exceed 489.95104 by gram of the silage. Correlation studies were done between the Silage and silage by-products parameters to evaluate the fermentation silage process. They showed different significant trends. A social-economic challenge was studied and discussed. Compared to that of using barley, the cost was 3 times less, with better quality for silage

Monitoring the variation of soil quality with sewage sludge application rates in absence of rhizosphere effect

Agricultural soils in semi-arid regions have frequently been degraded due to adverse climatic conditions, organic matter depletion, and poor farming practices. To enhance soil quality, this study examines the reuse of sewage sludge (SS) as an available source of organic matter in a typical Mediterranean sandy-loam soil. Accordingly, we studied the cumulative effect of two annual applications of 40, 80 and 120 tons of sludge per ha on soil quality in absence of vegetation. The dose-dependent improvement of organic matter content was the most significant event that reflected sludge application rates, and consequently influenced other soil properties. Accordingly, soil structural stability increased by 13.3%, 28.8% and 59.4% for treatments SS-40, SS-80 and SS-120 respectively as compared to unamended control. Structural stability improvement was also confirmed by the dose-dependent variation of other edaphic factors including calcium content, the microbial quotient as well as Welt and C:N ratios. These parameters are involved in cementing soil aggregates by cation bridging, the formation of microbial mucilage, and clay-humic complexes. Soil magnetic susceptibility (SMS) was measured in situ as a possible rapid tool to evaluate soil condition. SMS showed significant correlation with sludge dose and stability amelioration testifying to the aggregation role that can play Al2O3 and particularly Fe2O3 minerals added by the hematite-rich sludge. Besides, analytical results and field observations revealed no trends of soil salinization or acidification by excessive sludge amounts. By avoiding the rhizosphere effect, outcomes could reflect the resilience and intrinsic capacity of the soil to cope with excessive sludge loads.This study was financially supported by a research grant from the Tunisian Ministry of Higher Education and Scientific Research. The authors would like to thank the National Sanitation Utility (ONAS) for providing urban sewage sludge. The technical support of Rym Ghrib is hereby acknowledged

Soil activity behaviors after farming techniques application in The Chammak olive tree field

The olive tree arranges no more water reserve that can be exploited during extremely dry periods. A failure of the olive yields observed during the last two decades. The annual production decreased from 150 000 tons to 50 000 tons of olives in the south of Tunisia.  This degradation results, in fact from an obvious reduction in the biological activity of the ground. A new Strategy was employed to improve the organic status and restore the biological activity of the soil ground of the long-term. We have evaluated the effect of the of different plot treatment.  A plot of olive tree speeded with 200 m3/ha dose of  OMW during 10 years, P4;  a plot of olive tree treated with tillage accompanied by 50 m3/ha dose OMW spreading lasting only a one year, P5 and a plot of olive tree cultivated with the introduction of  the fig tree in parallel, P3.  Untouched ground was used as control plot, P0. A comparison of these plots with a degraded ground of olive tree implanted since 1900, P2 and other ground degraded during 10 years, P1. The plot treated with OMW showed an OM value close to the value founded with P0 (Control Plot). The Phytotoxcity measured via germination index GI (percentage) was determined; an   important increment ranged from 200% to 230% was obtained in the P3 and P5, respectively. Correlation analyses, among physiochemical parameters of soil and microbial biomass indicated several positive significant trends. The highest significant correlation was found between OM and TAMF (r=0.999, p<0.001). These results corroborate the notion that the microbial community structure is a good indicator of soil quality and the effects of different management practices, because the microorganisms respond against changes in soil management more rapidly than chemical or physical soil properties. However, in this work we found a negative correlation between respiration soil activity (Resp) and with OM (r=-0.533, p<0.05). In fact, CO2 sequestration took place. Indeed, increasing soil OM enhances the sequestering carbon dioxide (CO2) to mitigate anthropogenic greenhouse gas (GHG) emissions

Effect of different soil amendments on irrigation and crop yields in the oases of southern Tunisia

In the oasis agro-system, salinization and hydromorphy are the principal degradation factors that negatively affect the soils. These two processes are the result of the rise of the water table caused by the overdose of irrigations. To counteract soil degradation and restore field productivity, the oasis farmers turn to use sandy and manure amendments. Therefore, three treatments (Control (C), sandy amendment (T1) and   combined amendments composed by sand and manure (T2)) has been applied in Nefzaoua oasis to evaluate the effect of different amendments on oasis soil fertility, irrigation parameters, and barley yield. Results showed that T2 enhanced yield parameter (3,07 t/ha) compared to control treatment (1.85 t / ha) thanks to the improvement in the total nitrogen concentration (1.38 g kg -1), soil organic carbon (28.74 g kg- 1) and therefore C / N ratio (20.78) for T2 treatment at the level of the 0-20 cm layer. The results revealed that sand + manure combination (T2) enhanced the irrigation dose that can be effectively applied for the barley plants (19.61 mm) compared to the control treatment (15.49 mm) and T1 treatment (12.26 mm). In addition, the combined treatment T2 declined significantly the oasis soil bulk density leading to rise the porosity of the top layers (0-20 cm). Our results obtained confirmed the effectiveness of the combined amendment composed of sand and manure in improving the fertility and productivity of the amended oasis soil.Keywords: Soil amendments, irrigation, agro-system, soil degradatio

Effect of different soil amendments on irrigation and crop yields in the oases of southern Tunisia

In the oasis agro-system, salinization and hydromorphy are the principal degradation factors that negatively affect the soils. These two processes are the result of the rise of the water table caused by the overdose of irrigations. To counteract soil degradation and restore field productivity, the oasis farmers turn to use sandy and manure amendments. Therefore, three treatments (Control (C), sandy amendment (T1) and   combined amendments composed by sand and manure (T2)) has been applied in Nefzaoua oasis to evaluate the effect of different amendments on oasis soil fertility, irrigation parameters, and barley yield. Results showed that T2 enhanced yield parameter (3,07 t/ha) compared to control treatment (1.85 t / ha) thanks to the improvement in the total nitrogen concentration (1.38 g kg -1), soil organic carbon (28.74 g kg- 1) and therefore C / N ratio (20.78) for T2 treatment at the level of the 0-20 cm layer. The results revealed that sand + manure combination (T2) enhanced the irrigation dose that can be effectively applied for the barley plants (19.61 mm) compared to the control treatment (15.49 mm) and T1 treatment (12.26 mm). In addition, the combined treatment T2 declined significantly the oasis soil bulk density leading to rise the porosity of the top layers (0-20 cm). Our results obtained confirmed the effectiveness of the combined amendment composed of sand and manure in improving the fertility and productivity of the amended oasis soil.Keywords: Soil amendments, irrigation, agro-system, soil degradatio

Mixed organic and bentonite based amendments improve soil hydrological conditions and irrigation efficiency in oasis soils

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

Polygenic Olive by-products to Silage production by Anaerobic Digestion : a new alternative of sustainable agriculture security and socio-economic advantage impact

Olive by-products consisting of 40 % wood pruning and leaves, 40 % Olive pomace and 20 % OMW were ground and combined with preserving them by anaerobic fermentation (wet silage) for 4 months. The pH and total nitrogen/dry matter silage sample were 5.46 and 45 mg/g, respectively; the values comply with standards norms. After the silage process, a decreasing of phenol compound concentration of 67.85% was revealed and among 37 fatty acids compounds were identified with a valuable richness in mineralnutrients. The silage was devoid of total coliforms and fecal coliforms and yeast number doesn't exceed 489.95104 by gram of the silage. Correlation studies were done between the Silage and silage by-products parameters to evaluate the fermentation silage process. They showed different significant trends. A social-economic challenge was studied and discussed. Compared to that of using barley, the cost was 3 times less, with better quality for silage