Assessment of different soil management practices on soil physicalproperties, microbial respiration and crop yield(A case study: Rain-fed agricultural lands of Kalale district, Golestan province)

ABSTRACT: Soil is regarded as a renewable natural body and its protection or degradation depends on the way it is used such as agricultural management. Soil surface degradation and erosion has caused reductions in soil fertility and therefore plant growth.The location of this study is taken place, is some of agricultural fields in the town Kalale in the east of Golestan province. First, various applied tillage systems were examined, and then 9 agricultural units in arable land according to the applied management systems were selected. For the recognition of physical, chemical, and biological properties in the considered arable land, soil samples were collected randomly by Auger in the depth of 0-20 and 20-40 cm of the soil profile. In the considered area three tillage systems will be examined including: conventional tillage (plow plus two times disk), minimum tillage (chisel and disk), and no-tillage systems. Physical properties considered in this study include soil texture, bulk density and saturated soil water content. As the results of this study indicate, application of no-tillage system in comparison with conventional tillage leads to a reduction of bulk density whilesoil porosity increased. Moreover, reduction of soil moisture content and saturated soil water content has also been attributed to the reduction of soil disturbance by tillage operations. Of the biological properties examined here, microbial respiration was selected and the samples taken were incubated for one, three and eight-day time steps. Soil samples, under the exposed to minimum tillage and no-tillage systems, have shown the least carbon dioxide emissions for different incubationʹs times. For the mentioned tillage systems, the highest yield is achieved by the implementation of the no-tillagesystem; while on the other hand, the least amount is attained for the conventional tillage.