不同生态区丰产型马铃薯品种氮素优化管理分析

Strategies for Optimal Nitrogen Management of Productive Potato Varieties in Different Ecological Zones

针对内蒙古马铃薯主产区氮肥利用率普遍较低的现状,选择阴山南麓地区(乌兰察布市察哈尔右翼前旗)和阴山北麓地区(呼和浩特市武川县)两个典型生态区,研究不同施氮量下马铃薯叶片SPAD值变化、SPAD值与施氮量的关系以及与马铃薯产量的关系。结果表明:不同氮素处理下马铃薯叶片SPAD值随着生育期进程的推进呈现逐渐降低的趋势;随着施氮量的增加,各生育期马铃薯叶片SPAD值呈线性增加的趋势,马铃薯产量呈现先增后减的变化趋势,表明马铃薯叶片SPAD值与产量之间为二次函数关系,当叶片SPAD值超过一定值后,马铃薯增产幅度不再显著。武川县施氮量为225 kg·hm^(-2),产量达到最高为46.2 t·hm^(-2);前旗施氮量为350 kg·hm^(-2),产量达到最高为61.7 t·hm^(-2);马铃薯苗期、块茎形成期、块茎膨大前期、块茎膨大后期以及淀粉积累期阴山北麓地区的临界SPAD值分别为43.4、41.5、40.7、34.6、32.0,阴山南麓地区的临界SPAD值则分别为49.3、49.1、44.9、37.8、35.6;基于马铃薯叶片SPAD值建立了两个生态区的马铃薯主要生育期氮肥追施模型。

In view of the low nitrogen use efficiency in the main potato producing areas in Inner Mongolia,two typical ecological areas,namely,the southern foothills of Yinshan Mountain(Chahar Right Wing Front Banner,Wulanchabu City)and the northern foothills of Yinshan Mountain(Wuchuan County,Hohhot City),were selected to study the changes of SPAD value of high-yield potato leaves under different nitrogen application rates,and the relationship between SPAD value and nitrogen application rates and potato yield.The results showed that the SPAD value of high-yield potato leaves under different nitrogen treatments decreased gradually with the advancement of growth period;With the increase of nitrogen application rate,the SPAD value of potato leaves increased linearly,and the yield of potato increased first and then decreased,which indicated that the relationship between SPAD value of potato leaves and yield was quadratic function.When SPAD value of potato leaves exceeded a certain value,the yield increase of potato was no longer significant.In Wuchuan,the nitrogen application rate was 225 kg·hm^(-2),and the highest yield was 46.2 t·hm^(-2);Nitrogen application rate was 350 kg·hm^(-2)in Qianqi,and the highest yield was 61.7 t·hm^(-2);The critical SPAD values were 43.4,41.5,40.7,34.6,32.0 at the northern foot of Yinshan,49.3,49.1,44.9,37.8,35.6 at the southern foot of Yinshan,respectively at seedling stage,tuber formation stage,early tuber expansion stage,late tuber expansion stage and starch accumulation stage;Based on the SPAD value of potato leaves,the topdressing model of nitrogen fertilizer in main growth stages of high-yield potato in two ecological regions was established.