Dry Matter Accumulation and Phosphorus Utilization Efficiency in Sugar Beet (Beta vulgaris) under Varied Irrigation and Phosphorus Supply

The present study investigated the effects of irrigation and phosphorus fertilizer on dry matter accumulation and phosphorus use efficiency in sugar beet for two growing seasons during 2016 and 2017, using H003 cultivar. The experiment was comprised of four treatments including NP0K-rainfed (C1), NPK-rainfed (C2), NP0K-irrigation (C3), and NPK-irrigation (C4) using 105 kg P ha-1 compared with 0 kg P ha-1. The results showed that during the whole growth period of crop, chlorophyll contents was in the order of C4 > C3 > C2 > C1. The sugar contents were higher in irrigation treatments than rain-fed. At harvest, 105 kg P ha-1 under NPK-irrigation treatment had the highest sugar yield up to 11.59 and 10.64 t∙hm-2 in 2016 and 2017 respectively. The percent increase in yield was 20.19–27.07%, 15.79–21.62% and 14.57–14.93% than C1, C2 and C3 treatments, respectively. In C4 treatment, the dry matter accumulation in roots and leaves were 25.36 and 27.48 t∙hm-2, 9.22 and 10.67 t∙hm-2 in 2016 and 2017 respectively, with 0.39% and 5.53, 11.61 and 25.02% higher than in C2 treatment. The phosphorus accumulation in roots of C4 treatment at harvesting was 9.46 and 9.97 t∙hm-2 while phosphorus accumulation in leaves of same treatment was 3.58 and 3.80 t∙hm-2 in 2016 and 2017, respectively. In irrigation treatments, the utilization efficiency of phosphate fertilizer was 16.97 and 17.33% in 2016 and 2017, respectively, with 25.52 and 29.02% higher than corresponding rainfed treatment, indicating that irrigation could significantly improve the utilization efficiency of P fertilizer. © 2021 Friends Science Publishers