Effect of tillage and poultry manure application on soil infiltration rate and maize root growth in a sandy Alfisol

This study was carried out in Abeokuta, South-western Nigeria in 2008 and 2009 to assess the impact of tillage and poultry manure (PM) on soil infiltration rate and maize root growth. The experiment was a split-plot design with three replications. The main plot consisted of three tillage treatments: zero tillage (ZT), minimum tillage (MT) and conventional tillage (CT) while the sub-plot comprised three PM treatments (0, 10 and 20 Mg ha-1). Soil infiltration characteristics were determined on the field using disc permeameter while root mass was evaluated by excavation method. In 2008, the soil infiltration rate (IR) was significantly higher under MT than other tillage systems while the IR was higher by about11% under CT than ZT. Though, there was no significant difference in IR among the three tillage systems in 2009, IR was lower under CT by about 9% and 3% compared with MT and ZT, respectively. The IR of 10.87 cm hr-1 observed in 2008 under the plots treated with 20 Mg ha-1 of PM decreased to 6.19 cm hr-1 in 2009 possibly due to reduction in the large pores of the sandy soil by repeated application of 20 Mg ha-1 of PM. The implication of this is that nutrients are likely to be held against leaching when 20 Mg ha-1 PM is applied in a sandy soil. Root mass was insignificantly higher under MT than CT in both years of the study while root mass was lower under ZT than CT by about 26% in 2009. Plots treated with poultry manure gave significantly higher root mass than the control. Therefore, fast draining pores dominating sandy soil may be modified by application of large quantity (20 Mg ha-1) of PM to improve the soil water and nutrient holding capacities and maize root growth.Keywords: Disc permeameter; fast draining pores; infiltration rate; maize roo

An overview of Conservation Agriculture in the dry Mediterranean environments with a special focus on Syria and Lebanon

Conservation Agriculture (CA), comprising minimum or no mechanical soil disturbance through no-till seeding, organic soil mulch cover, and crop diversification is now practiced on some 157 million ha worldwide, corresponding to about 11% of the global cropped land. CA adoption in the Middle-East is low compared to other regions. Lack of knowledge on CA practices and systems discourages farmers from giving up ploughing. The main reason why farmers in the Middle-East have begun to apply the no-till system has been the cost reduction in fuel, labor and machinery required for land preparation. Soil and water conservation concerns do not appear to be the main drivers in the Middle-Eastern farmers’ decision to adopt or not to adopt CA. The adoption and uptake of CA by Middle Eastern farmers has been slow but it is nonetheless occurring gradually. Collection of information and research parameters related to agricultural practices are needed for designing a suitable soil and water conservation program for sustainable production intensification. Governmental policy encouraging the adoption and spread of CA systems in the Middle-East region is certainly a necessary condition for uptake. The objective of this article is to review the current status of adoption and spread of CA in the Middle-East, focusing mainly on Syria and Lebanon, and the potential beneficial consequences that can be harnessed through CA systems under rainfed conditions in both countries. The benefits include: higher factor productivity, yield and income; improved soil properties; climate change adaptation, including reduced vulnerability to the erratic rainfall distribution; and reduction in machinery, fuel and labor costs