Effect of Tillage Systems on Wheat Productivity and Precipitation Use Efficiency under Dry Farming System in the North East of Syria.

The key problem of agricultural production in arid and semi-arid environments is the steady decline in the annual precipitation and soil fertility, especially under rainfed conditions. Implementing of the suitable agricultural practices help in improvement the utilization efficiency of the natural resources, and crops productivity, and as consequence the stabilization and sustainability of the agricultural production.Conservation agriculture (CA) system is considered as one of the most important adaptive approaches mitigating the vulnerability of the agro-ecosystems to climate change, and increasing the capability of the cropping systems to adapt with drought, where it helps to improve rainwater productivity (Precipitation use efficiency). This will help increasing the productivity of the precious rainwater by converting each rain drop into dry matter “More crop per drop”, thereby increasing field crops’ yield and yield stability, which are very important prerequisites for water and food security.Management of the frequency and type of tillage can stop soil degradation and improve soil quality, where tillage disrupts soil aggregates and enhances the oxidation of soil organic matter.A field experiment was conducted in the North East of Syria, during three consecutive growing seasons (2007/2008 – 2008/2009 – 2009/2010), to study the effect of three different tillage systems [No tillage (NT), double disc tillage (MT) and conventional tillage (CT)] on wheat crop yield, grown in a rotation with vetch. The experiment was laid in randomized complete block design (RCBD), with three replications.The highest grain yield was obtained with no- tillage system (5057 Kg . ha-1) compared with double disk and conventional tillage (4821, 4683 Kg . ha-1 respectively).Heads density and number of kernels per head increased significantly with no-tillage (841 heads . m-2, 48 Kernel . Head-1), but tillage practices had no significant effect on thousand kernel weight. Precipitation use efficiency was significantly higher under no-till (7.6 Kg.mm-1 . ha-1) compared with the other tillage systems (7.4 and 7.2 Kg.mm-1 . ha-1 respectively).Soil moisture content was significantly higher under no-tillage compared with minimum and conventional tillage systems, at different growth stages.