Effect of shallow tillage, moldboard plowing, straw management and compost addition on soil organic matter and nitrogen in a dryland barley/wheat-vetch rotation

Crop residue and soil organic matter (SOM) management and their relation to tillage and crop rotation are of particular concern for dryland farming practiced in Mediterranean climates of North Africa and West Asia. In this study, the effect of tillage, straw management, and compost application on soil depth of SOM, labile and microbial carbon and nitrogen, and total organic nitrogen was measured. The addition of compost increased SOM and labile nitrogen and carbon. Shallow tillage also contributed to the increase in SOM and the subsequent increase in crop yields in dry years. However, amounts of straw required for compost production limits the viability of this system within an actual production setting in which straw would most likely be used for fodder. Thus, animal-integrated systems may not be able to achieve sufficient levels necessary to provide benefit.