滴灌水肥一体化下施钾量对宁夏春玉米叶绿素荧光特性与产量的影响

通过2018—2019年田间试验,研究不同施钾量对宁夏春玉米叶绿素荧光特性及产量的影响。以天赐19号为试验材料,采用随机区组试验设计,设6个梯度钾肥量处理,K0(0 kg· hm^-2)、K1(60 kg·hm^-2)、K2(120 kg·hm^-2)、K3(180 kg·hm^-2)、K4(240 kg·hm^-2)、K5(300 kg·hm^-2)。结果表明,施用钾肥可增强玉米的荧光特性,提高宁夏春玉米产量,施钾180 kg·hm^-2时,叶绿素相对含量(SPAD)、最大荧光(F_m)、PSⅡ潜在活性(F_v/F_o)、PSⅡ最大光化学效率(F_v/F_m)、PSⅡ综合性能指数(PI)、单位反应中心吸收的光能(ABS/RC)等指标均达到最优;施钾量为0~180 kg·hm^-2时,玉米产量随着施钾量的增加而增加,当施钾量超过180 kg·hm^-2,春玉米产量开始下降。相关分析表明,产量与SPAD、F_m、最小荧光(F_o)、F_v/F_o、F_v/F_m、PI、ABS/RC均有不同程度的正相关关系,因此,施钾量180 kg·hm^-2是该区最佳的钾肥施用量。

Effects of potassium application rate on chlorophyll fluorescence characteristics and yield of spring maize in Ningxia under integrated drip irrigation

Through two-year field experiments in 2018-2019, the effects of different potassium application rates on the chlorophyll fluorescence characteristics and yield of Ningxia spring maize were studied. Using Tianci 19 as the test material, a random block test design was adopted, with six gradient potassium fertilizer treatments, K0 (0 kg·hm^-2), K1 (60 kg·hm^-2), K2 (120 kg·hm^-2), K3 (180 kg·hm^-2), K4 (240 kg·hm^-2), K5 (300 kg·hm^-2).The results showed that potassium fertilizer can enhance the fluorescence characteristics of maize and increase the yield of spring maize in Ningxia. When potassium was applied at 180 kg·hm^-2, SPAD, maximum fluorescence(F_m), potential activity of PSⅡ(F_v/F_o), the primary maximum photochemical efficiency of PSⅡ(F_v/F_m), PSⅡcomprehensive performance index(PI), light energy absorbed by unit reaction center (ABS/RC) and other indicators all reached the optimum. In the range of 0-180 kg·hm^-2, the yield of maize increased with the increase of potassium application. When the amount of potassium application exceeded 180 kg·hm^-2, the yield of spring maize began to decline.Correlation analysis showed that the yield was related to SPAD, F_m, minimum fluorescence (F_o), F_v/F_o, F_v/F_m, PI, ABS/RC, which showed different degrees of positive correlation. Therefore, the best application amount of potassium was 180 kg·hm ^-2.