Impact of conservation tillage and nitrogen on sugarbeet yield and quality

Abstract

Conventional intensive tillage (CT) is widely practiced in sugarbeet (Beta vulgaris L.) growing regions. However, CT uses more labor and machinery and has negative impacts on soil and environment. Limited information exists for the performance of sugarbeet in reduced tillage compared to CT systems. A three-year field experiment was conducted to evaluate yield and quality of sugarbeet under no-till (NT), and strip-till (ST) systems compared to CT. The response of sugarbeet to the increasing rate of nitrogen (N) from 56 to 224 kg ha−1 in each tillage system was also studied. Sugarbeet plant stand, root yield, root impurities (sodium, potassium, and amino-N concentration in the root), sucrose loss to molasses (SLM) and recoverable sucrose yield were measured. Tillage had no significant effect on plant stand, root yield, and recoverable sucrose yield. The estimated cost of tillage operation showed that growing sugarbeet under NT was 111 US$ ha−1 less than that in CT, which could be translated into 111 US$ ha−1 higher net benefit for growers considering the similar yields in both systems. Sugarbeet root yield linearly increased in response to increasing rate of N, however, sucrose concentration decreased and root impurities increased with increasing N input. Overall, little increase of recoverable sucrose yield was observed with N rate increasing from 56 to 224 kg ha−1. Response to N rate occurred irrespective of tillage method.