Identifying resource competition in maize-based soil conservation systems using 13C and 15N isotopic discrimination

摘要: Soil conservation measures such as establishing grass barriers or cover crops effectively control erosion but also provoke competition, which reduces yields of companion crops. We used 13C and 15N natural abundance profiles to identify the causes competition soil on a field with 59% slope in Northwest Vietnam three years after establishment. Treatments were maize under farmer’s practice (T1, control), Guinea (T2), minimum tillage (MT) Pinto peanuts crop (T3), MT relay cropped Adzuki beans (T4). A pretest using data from zero-N plots revealed that water limited nitrogen availability induced low grain N concentrations, enriched leaf δ13C, reduced yield. Similar concentrations elevated δ13C values observed growing close frequently pruned positive balance conditions, indicating yield decline these rows can b...