Comment on "Tillage effects on certain physical and hydraulic properties of a loamy soil under a crop rotation in a semi-arid region with a cool climate." by Z. Gozubuyuk, U. Sahin, I. Ozturk, A. Celik, M. Cemal Adiguzel

The influence of different tillage practices (conventional tillage, reduced tillage, and no-till on bulk density, total porosity, penetration resistance, field capacity, field water content and infiltration rate) on samples of loamy soil in a semi-arid region were investigated by Gozubuyuk et al. (2014). There is need to further discuss some of the main issues raised in Gozubuyuk et al. (2014) study. One of such issues is the consideration of pore size distribution into two classes of micro-pores and macro-pores. In this paper, the basic classes of soil pores were not taken into consideration, including aeration pores/macro-pores (>30 mu m diameter), capillary pores/medium-pores (0.2 to 30 pm diameter) and micro-pores (<0.2 mu m diameter), in order to discuss field capacity; especially, plant available water content. Another problem deals with the conclusion where authors stated that "the no-till system increased winter wheat germination due to higher water content". The paper did not analyze the effective role of biological activity and plant nutrition, above all, organic input (mulch effect on temperature) effect was ignored. Therefore, it could not be concluded that the increased winter wheat germination under no-till practice is only due to higher water content. The discussion is inconsistent about the probable reasons of higher infiltration in no-tillage. Moreover, while the infiltration rate is increased under no-tillage, a problem was raised during interpretation regarding the concept of infiltration improvement, especially in a semi-arid region. This commentary elaborates on the earlier mentioned issues. (C) 2016 Elsevier B.V. All rights reserved.