Tillage practice in agroecosystems and their implications on in nitrification and denitrification pattern in soil.

Soil tillage management considerably influences abiotic as well as biotic properties of a soil. Mainly in arid and semiarid regions the possibilities to store carbon, which in turn improves water holding capacity and reduces soil erosion, significantly increased the popularity of no tillage or reduces tillage management in the last decades. While the positive implications on carbon balance in soil have been clearly described in the past, not much is known about the effects of different tillage systems on nitrogen (N) turnover and the corresponding microbial populations. In this paper we review the current state of knowledge about the consequences of different forms of tillage on microbes involved in denitrification and nitrification and the corresponding turnover rates in soil. The main focus is directed towards the effect comparison of different tillage management forms as well as the other parameters on soil microbes affecting N dynamic in the soil (e.g.type, quality of the fertilizer or crop rotation)