Effect of reduced fertilizer nitrogen application rates on yield and nitrogen recovery of sugar beet and potatoes.

Abstract

Data from 150 sugarbeet and 98 potato field trials in the Netherlands were used to calculate the effects on yield and N recovery of applying 0-90% of recommended N fertilizer rates. Av. sugarbeet root tuber yields were 63.8, 63.5, 62.9, 61.2 and 53.3 t/ha with 100, 90, 75, 50 and 0% of recommended N rate, resp.; corresponding potato tuber yields were 56.8, 56.5, 55.9, 54.4 and 45.1 t. Av. fertilizer N recovery by potato tubers ranged from 33.2% with the recommended N rate to 44.3% with 50% of the recommended N rate. On the assumption that the probability of serious yield deficits should not exceed 5%, current recommended N rates could not be reduced for sugarbeet but could be reduced by 25% for potatoes giving an av. yield deficit of 1.7% and 40% fertilizer N recovery by tubers. The effects of changes in the ratio of fertilizer cost to the price of produce is discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)