The effects of long-term different soil tillage methods on some of hydrophysical properties of a soil

In this thesis, the effects of 7 different long-term tillage methods on the hydrophysical properties of the soil were investigated in the experimental field where two crops were grown per year in Çukurova conditions. As soil tillage applications; conventional tillage with stubble (CT-1), conventional tillage with stubble burnt (CT-2), reduced tillage with heavy disc harrow (RT-1), reduced tillage with rototiller (RT-2), reduced zero tillage with heavy disc harrow (RT-3), strategic zero tillage (ST) and zero tillage with direct cultivation (NT) methods were used. In the long term (13 years) soil hydrophysical properties of 7 different tillage methods in 21 separate plots are weighted average diameter, volume weight, water retention, capacity, porosity, penetration resistance and hydraulic conductivity were determined. STI, which is one of the protected tillage methods, increased the weighted average diameter value by 253% and 509% at 0-15 cm, 222% and 152% at 15-30 cm, compared to traditional cultivation methods CT-1 and CT-2. The water retained values in the soil were found to be generally close to each other at both depths in all cultivation applications. Reduced zero tillage method with heavy disc harrow significantly reduced total and macroporosity at 0-15 cm surface depth (P<0.05). It has been determined that reduced and no-till applications increase the volume weight at 15-30 cm depth, and therefore soil compaction, compared to conventional tillage applications. Traditional tillage methods were reduced and soil compaction was significantly reduced in 0-45 cm soil profile compared to protected tillage methods, and the lowest penetration resistance value was obtained as 1.50 Mpa in the CT-2 method, which is the traditional tillage application in which the stubble was burned. On the other hand, the highest value was obtained as 1.92 Mpa in the RT-3 method. The highest hydraulic conductivity values were obtained as 2.64 x10-1 cm hr-1 and 5.91 x10-1 cm hr-1 in the mean of 5 cm and 10 cm water head, respectively, in CT-1 and CT-2 methods. The lowest hydraulic conductivity value was obtained as 0.39 x10-1 cm h-1 in the direct sowing notill method. Compared to conventional tillage methods, reduced tillage methods that do not destroy soil aggregates too much can be preferred to improve hydrophysical properties. Keywords: Conventional tillage, Reduced tillage, No till, Aggregate, Water holding capacity, Hydraulic conductivity, Hydrophysical property