Effect of alternate partial root-zone drying (PRD) on soil nitrogen availability to alfalfa

Available soil N is critical for N fertilizer management in crop production but the effects of alternate partial root zone drying (PRD) on the dynamics of N and the impact of these effects on perennial crops such as alfalfa (Medicago sativa L.) have not been evaluated. A field experiment was conducted to compare two irrigation modes (PRD and conventional furrow irrigation (CFI)) in combination with four irrigation levels (70% ETc (evapotranspiration), 85% ETc, 100% ETc, and 115% ETc). PRD improved the mineralization of organic matter to increase available N and the NO3--N/NH4+-N ratio. Thus, it increased N uptake, water productivity and maintained seasonal forage yield. The combination of PRD and irrigation level (100% Etc) produced maximum NO3--N stock. These results present an evaluation of how PRD influences soil N availability to N-fixing perennial crops.

Automated summary

The effects of alternate partial root zone drying (PRD) on nitrogen dynamics and its impact on perennial crops like alfalfa were evaluated in a field experiment. Results showed that PRD improved soil N availability, increased N uptake, and water productivity while maintaining seasonal forage yield. The combination of PRD and 100% ETc irrigation level produced the highest NO3--N stock.