Nitrogen fertilizer in the form of urea is subject to ammonia volatilization through the activity of the urease enzyme found ubiquitously in soil (Kissel et al., 2008). Nitrate fertilizer is subject to leaching (Randall et al., 2008) or denitrification (Coyne, 2008), depending on the water content of the soil and water movement through the soil. Ammonium forms of N can be fixed (Kissel et al., ...

This review examines the effect of tillage on microbial habitat space, and the roles of microbes in in ̄uencing Ntransformation processes within a heterogeneous soil environment. Literature relating tillage to microbial processes is assessed critically focusing on (a) degrees of physical disruption and N-processes, (b) interactions between organisms and the soil pore network, and (c) the role of...

Due to the lack of good quality water for human consumption and industry, in many countries irrigated agriculture is exposed to increasing pressure to expand the use of brackish and even high-saline waters for crop production. The application of lower quality waters requires special management practices, which are not yet fully understood with respect to optimization of plant growth on saline s...

The goal of this paper is to identify the military geographic factors that affect the cross-country mobility (trafficability of the terrain) and to cite some standardised procedures for establishing of these factors. Classification of the crosscountry movement levels. Influence of the slope, vegetation, water, soil, weather, urban area, transportation, and another features on the cross-country ...

This paper describes the preliminary results of a study conducted by the California Department of Food and Agriculture which compares the soil distribution of herbicides in two ground water basins in the state. In a previous study, residues of several agricultural chemicals were detected in numerous wells in two inland ground water basins, while only one contaminated well was found in two coast...