施钾水平对甘薯干物质积累与分配和钾效率的影响

在大田生产条件下,以紫色甘薯(宁紫1号)、食用甘薯(苏薯14)、兼用甘薯(苏渝303)、淀粉甘薯(苏薯11)4个甘薯品种为试验材料,测定了不施钾(K0)、施钾150 kg/hm2,K2O(K1)、施钾300 kg/hm2,K2O(K2)3个施钾水平下,甘薯干物质积累、蔓薯比以及甘薯植株钾的累积量、利用效率、收获指数。与不施钾处理相比,K2处理下苏薯11的干物质积累显著增加,宁紫1号和苏薯14的干物质积累显著降低。施钾处理显著提高了宁紫1号、苏薯14和苏渝303的蔓薯比。不施钾处理下宁紫1号和苏薯14的块根理论产量高于苏渝303和苏薯11,K2处理下苏薯11的块根理论产量高于宁紫1号和苏薯14。因此,为节约钾素资源,宜在土壤供钾水平较高的地区推广种植淀粉型甘薯苏薯11,在土壤供钾水平较低的地区推广种植紫色甘薯宁紫1号和食用型甘薯苏薯14。

Effects of potassium application rates on dry matter accumulation, dry matter distribution, and potassium efficiency of sweet potato

Three rates of potassium(0,150 kg/hm2,300 kg/hm2) were applied to four sweetpotato varieties,purple sweet potato(NZ1),food sweetpotato(SU14),food and starch sweetpotato(SY303),starch sweetpotato(SU11).The dry matter accumulation,ratio of vines to tuberous roots,plant potassium accumulation,plant potassium utilization and potassium harvest index of sweet potato were determined.Compared to no potassium treatment,300 kg/hm2 potassium application increased the dry matter accumulation of SU11 and lowered the dry matter accumulations of NZ1 and SU14.Potassium application improved the ratio of vines to tuberous roots of NZ1,SU14 and SY303.Without potassium application,the theoretical yields of NZ1 and SU14 were higher than those of SY303 and SU11.The theoretical yield of SU11 was higher than those of NZ1 and SU14 applied with 300 kg/hm2 potassium.Therefore,SU11 is preferential variety for soils with sufficient potassium,and NZ1 and SU14 are preferential varieties for soils with insufficient potassium.