Abstract
Unsustainable agricultural practices put global food security at risk by threatening the productivity and health of agricultural soils. Diverse cropping systems have been proposed as a way of intensifying agricultural output around the world. However, the impacts of diversifying cropping systems on the health of soils are poorly understood, particularly in arid agricultural ecosystems (agroecosystems which require irrigation to maintain productivity). Since arid agriculture is disproportionately important to maintaining global agriculture, it is of particular importance to understand the ways that diverse cropping systems impact arid agriculture. The following research assessed the impacts of diverse cropping in the form of crop rotations and intercropping on soil health in an arid agricultural setting in Aberdeen, Idaho under full and deficit irrigation regimes. Two experiments were conducted, with the first assessing the impact of diverse cropping on soil C, N, and microbial biomass, and the second assessing the influence of diverse cropping on respiration from soil (Rs). The results showed little effect of diverse cropping on soil labile C (in the form of POXC), but reduced N depletion in crop rotations relative to other treatments. Microbial biomass was consistently higher in the control. Rs did not differ between treatments, but was reduced in deficit irrigation levels. A comparison between respiration and aboveground biomass showed a relative advantage for intercropping over the control, indicating higher aboveground productivity relative to belowground metabolic demand. The results showed increased biomass yield from diverse treatment, but limited effects on soil health metrics.