Effect of Fertilization on Plant Growth and Nutrient Uptake in Oilseed Rape Under Varying Boron Supply

Abstract

Both pot experiment and solution culture were conducted with two contrasting oilseed rape cultivars to investigate the effects of NPK fertilization with varied boron (B) status on plant growth, nutrient uptake, root activity (as TTC reducing capacity by fresh roots) and root cell plasmalemma H+-ATPase activity. The tolerant and sensitive cultivars used were ZY 821 and WY 324, respectively. The soil used for pot experiment was an alluvial soil. The pot experiment consisted of two nitrogen–phosphorus–potassium (NPK) levels (mg kg−1 air-dried soil): high NPK with N 335; P2O5 150 and K2O 150; low NPK with N 285; P2O5 100 and K2O 100 and two B levels (as borax, mg kg−1 air-dried soil): 16 (+B) and 0 (−B, no B supply). The solution culture consisted of two B levels: 0 (−B, no B added) and 100 μmol/L (+B, added as H3BO3). Compared to the treatment with no B added, the incorporation of B into the B-deficient soil significantly increased shoot and root dry weight (DW), ratio of root to shoot (RRS), seed yield (SY), and uptake of nutrients [N, P, K, calcium (Ca), magnesium (Mg), and B], irrespective of NPK supply levels. Increasing rate of NPK could significantly decrease the parameters described above, regardless of B status. In contrast to −B treatment, addition of B to the solution obviously enhanced root activity and plasmalemma H+-ATPase activity. Under the same conditions, cultivar ZY 821 produced more DW, larger RRS, higher SY, more nutrient uptake, higher root activity and H+-ATPase activity than cultivar WY 324. It is suggested that RRS, root activity and plasmalemma H+-ATPase activity be used as useful parameters to screen oilseed rape cultivars, which are genotypically different in response to B deficiency.