Effects of Zero Tillage and Residue Retention on Soil Quality in the Mediterranean Region of Northern Syria

Abstract

How to cite this paper: Sommer, R., et al. (2014) Effects of zero tillage and residue retention on soil quality in the Mediterranean region of northern Syria.

Potential for Conservation Agriculture in the Dry Marginal Zone of Central Syria: A Preliminary Assessment

“…Hydraulic conductivity or permeability is the capacity of the soil to allow water to pass through its pores or voids. This is likely an indication of increased pore volume and thus soil water retention capacity [29], a result which was also found by [8] in relative comparisons between a no-till system and conventional tillage system. Figure 5.…”

“…It has been estimated [36] that the shadow value of straw in a drought year is 3-fold the price of grain, signifying its importance to crop-livestock farming communities for which crop-livestock integration is based on pastoralists relying on access to fodder produced by settled farmers. The value of fodder during the growing season and of straw during the dry season, particularly in a drought year, may however further complicate the problem noted by [8], where difficulties were found in farmers adopting CA in Syria as a result of competing uses of biomass for livestock. Thus, [5] notes the importance of conducting research to determine the "optimum quantity of crop residues" that can be retained for ground cover without restricting the amount of biomass needed for livestock, whilst also ensuring that enough residues are left on the soil surface to capture the full productivity, socio-economic and environmental benefits that can occur over time.…”

“…Contesting this argument, recent research work in Syria [8] has shown favorable impacts of a no-till system with respect to the potential for biomass retention for ground cover as well as for soil properties and moisture retention.…”

“…Similarly, low levels of organic matter, nitrogen and plant-available phosphorous within soils in other areas of Syria have been documented [8]. Table 2.…”

“…Moreover, the soil moisture content was significantly higher under CA relative to TA (p < 0.05) at different water potential levels observed (see Table 3). The higher soil moisture under CA, measurable immediately in the first 2 years during the period of transition, provides an indication of improved water infiltration and moisture retention capacity under CA conditions, albeit under transition, relative to TA conditions, with an implication for reductions in water runoff and soil erosion [3,4,8]. Given the relative assessment between CA and TA treatments at the same point in time in the growing season, the impact of the higher-than-average rainfall of 197.5 mm on productivity observed during the 2011/2012 season (see Tables 4 and 5) may improve further with time because of the possible further improvements in rainfall infiltration, water retention, and consequently crop growth, which may occur with further improvement in the soil quality over time.…”