Effect of coated urea type and fertilization pattern on lodging resistance and yield of wheat following rice

The purpose of this study was to investigate the effects of coated urea on the lodging resistance of wheat following rice and evaluate the rational application of coated urea to coordinate the yield and lodging resistance of wheat following rice. Resin-coated urea (PCU) and sulfur-coated urea (SCU) were used as the experimental materials, and three fertilization patterns were designed: 100% coated urea applied before sowing (N1); 60% coated urea applied before sowing and 40% urea at jointing (N2); and 60% coated urea applied before sowing and 40% coated urea at regreening stage (N3). A control (CK), with 60% urea applied before sowing and 40% at regreening stage, was also included. The differences in stem morphological characteristics, lodging resistance, and grain yield of wheat following rice under different coated urea and fertilization patterns were analyzed. The results showed that, compared with CK, N1 significantly decreased the length of the basal second internode; increased the fullness, diameter, and wall thickness of the basal second internode; and enhanced snapping resistance and lodging resistance index. The actual field lodging coefficients in PCUN1 and SCUN1 were only 1.11 and 1.31, respectively. The yield in PCUN1 and SCUN1 was low but was not significantly different from that of CK. N2 significantly decreased the fullness of the basal second internode and lodging resistance index but significantly increased the field lodging rate and lodging coefficient compared with N1. N3 achieved the highest yield, which was significantly higher than that of N1, N2, and CK for PCU and SCU. The field lodging rate and lodging coefficient in N3 were not significantly different from those in N2 but were significantly lower than those in CK. In N3, the yield in PCU was the highest; it increased by 14.75% compared with that in CK. The length of the basal second internode in PCUN3 was significantly lower than that in SCUN3; and the fullness, diameter, and wall thickness of the basal second internode were significantly higher than those in SCUN3. Moreover, the field lodging rate and lodging coefficient of PCUN3 were lower than those of SCUN3. In conclusion, 60% PCU applied before sowing and 40% PCU topdressing at re-greening can limit the length of basal second internode, improve fullness and snapping resistance, decrease lodging coefficient, and increase yield, and this is beneficial for coordinating the high yield and lodging resistance of wheat following rice.