Conservation tillage enhances crop productivity and decreases soil nitrogen losses in a rainfed agroecosystem of the Loess Plateau, China

Abstract Conservation tillage has been recommended as one of the effective soil management practices for mitigating the negative environmental effects of synthetic ammonia application and achieving cleaner agricultural production. However, information about how long-term conservation tillage affects agroecosystem nitrogen balance in dryland winter wheat-summer maize cropping is limited. Based on a long-term (>9 yr) field tillage experiment and in-situ observation, we assessed the effects of different tillage practices, including two conservation tillage methods (i.e., chisel plough tillage (CPT) and zero tillage (ZT)) and conventional ploughing tillage (PT) as the control, on soil nitrogen balance and crop productivity in the 2016–2017 and 2017–2018 growing seasons. Each tillage practice was exposed to a local widely adopted N application rate (240 kg ha−1 yr−1) in both seasons. Our results indicated that, compared with PT, CPT and ZT significantly (P