不同喷灌水氮组合对马铃薯耗水、产量和品质的影响

为了探讨黑龙江省克山县圆形喷灌机条件下不同水氮组合对马铃薯的耗水规律、产量和品质的影响,同时确定节水、节肥、高产目标下适宜的水氮组合方式,试验设置了2个灌水水平:灌水总量W1(80 mm)和W2(100 mm);4个追氮量水平:F1(45 kg/hm²),F2(56.6 kg/hm²),F3(70 kg/hm²)和F4(86.6 kg/hm²);2个施氮频次:C1为块茎膨大期1次施入,C2为块茎膨大期分2次施入,并选择雨养区作为对照.结果表明:马铃薯全生育期耗水量为313~332 mm,块茎膨大期耗水量最大,占全生育期耗水总量63.4%~66.0%,幼苗期和块茎形成期是需水关键期,应结合马铃薯生长状况和当地雨水情况,适当进行补充灌溉;相比于其余处理,W2F4C2处理产量最高,达到46 525 kg/hm²;不同水氮组合间马铃薯的淀粉、维生素C、粗蛋白含量及商品薯率无显著差异,粗蛋白含量随着施氮量的增加呈现先降低后升高的趋势.综合比较,建议在黑龙江半湿润地区,可采用高水(100 mm)高肥(86.6 kg/hm²)高频次(块茎膨大期分2次施入)的方案.

Effects of different water-nitrogen combinations on potato water consumption,yield and quality under sprinkler irrigation

To investigate the appropriate combination of water and nitrogen for the potatoes, two irrigation levels(W1 and W2)and four nitrogen application rates F1(45 kg/hm²), F2(56.6 kg/hm²), F3(70 kg/hm²)and F4(86.6 kg/hm²)were conducted to evaluate the effects of combinations of water and nitrogen on water consumption, yield and quality of potatoes under center-pivot irrigation system at Keshan County, Heilongjiang Province. For assessing the effects of frequency of nitrogen application on the growth, yield and quality of potato, two frequencies of nitrogen application were also compared(C1:the nitrogen topdressing was applied once in the tuber enlargement stage; C2:the nitrogen topdressing was applied twice in the tuber enlargement stage). This study designed rainfall-fed zone as control. The results show that the total water consumption of the potato is ranged from 313 to 332 mm during the growing season. The tuber enlargement obtains the highest stage water consumption, which accounts for 63.4%-66.0% of the total water consumption. The seedling stage and the tuber formation stage are the critical periods for the potato water requirement, which indicates that the appropriate irrigation should be supplemented according to the local rainfall. The treatment of W2F4C2 obtains the highest yield, reaching 46 525 kg/hm². No significant differences exists in starch, vitamin C, crude protein content and commodity rate of potatoes among the different treatments. The crude protein content of potatoes decreases first and then increases with the increment of nitrogen application rates. Therefore, the irrigation amount of 100 mm, nitrogen application rate of 86.6 kg/hm² and nitrogen topdressing applied twice in the tuber enlargement stage are recommended for potato producers in semihumid areas of Heilongjiang province.