Modeling the requirement of nutrients by table beet crop

The nutritional balance system may be more accurate in estimating the fertilization of crops compared to fertilizer recommendation tables. For its efficiency, the construction of the model needs information related to the requirement of nutrients by the crop and yield. The objective of this study was to generate models that best correlate the requirement of each nutrient by beet crop (Beta vulgaris L. var. vulgaris) and dry matter harvest index with root yield, in addition to determining the order of total nutrient accumulation and nutrient export index. The study was conducted in the Alto Paranaíba region, MG, Brazil, during the 2017 season. Forty-seven commercial areas of beet, with 'Boro' and 'Betty' hybrids, were sampled. The average yield of beet roots was 68.9 Mg ha-1, ranging from 38.4 to 98.6 Mg ha-1. The linear model was the most appropriate to express the relationship between yield and dry matter harvest index, as well as the relationship between yield and nutrient accumulations, except for the total accumulations (root + shoot) of Mn and Zn, which were described by the model of decreasing increments. The order of total nutrient accumulation in beet crop was: K > N > Ca > Mg > P > S > Fe > Zn > Mn > B > Cu. Beet export index follows the order: Zn > P > Cu > N > Mg > K > S > B > Ca > Fe > Mn.