Diversity in Dryland Winter Wheat Cropping Systems.

Water is a deciding and foremost limiting factor of crop production in rain-fed semi-arid environments. General conception is that replacement of fallow with a rotation crop in wheat wheat cropping systems affects the soil water content for the following crop. Although it is true to some extent, the possible moisture losses from fallow through evaporation in the peak precipitation months and water use of weed populations can be even more substantial. In addition to that, the possible negative effects posed by fallow cultivation under dryland conditions can be even more damaging both in terms of natural resource efficiency and long-term sustainability. However, the replacement of fallow with suitable crop needs a careful considerations of water and nutrient use, yield potential, and other rotation compatibility factors before making any recommendations to the producers. Possible rotation options of improving dryland winter wheat diversity, productivity, and sustainability will be discussed.