氮肥施用时期对马铃薯干物质积累转运及产量的影响

Effects of Nitrogen Application Time on Dry Matter Accumulation and Translocation and Tuber Yield of Potato

在相同施氮水平下,通过小区试验研究不同时期追施氮肥对马铃薯中晚熟品种克新13干物质积累、转运及块茎产量的影响。结果表明,在N 150 kg/hm2用量条件下,与全部氮肥作基肥相比,将2/3氮肥作基肥施入,1/3氮肥在块茎形成末期施用,可使块茎产量提高9.5%,商品薯产量提高19.3%(P<0.05,收获指数提高13.2%(P<0.05;将2/3氮肥作基肥施入,1/3氮肥在块茎形成初期施用或将全部氮肥分别在苗期和块茎形成末期施用则使块茎产量有不同程度下降,而商品薯率有所提高,但差异未达显著水平(P>0.05)。研究还表明,与全部氮肥作基肥相比,在苗期至块茎形成末期追施氮肥,都不会降低块茎中的淀粉含量和干物质含量。

A plot experiment was carried out to study the effects of nitrogen （N） application time on dry matter accumulation and transloeation in potato plant as well as on tuber yield. Cultivar KX 13 was grown at one N application level （150 kg/hm^2） and four application patterns. Compared with applying all N at planting, applying 2/3 of all N at planting while 1/3 at the end of tuber formation stage can boost the translocation of dry matter from vine to tuber and the tuber yield increased from 34.8 t/hm^2 to 38.1 t/hm^2, marketable tuber yield increased from 23.3 t/hm^2 to 27.8 t/hm^2 （P 〈 0.05）, harvest index increased from 0.76 to 0.86（P 〈 0.05）. The treatment with the 2/3 of all N applied at planting while the other 1/3 applied at early tuber formation stage or all N applied at the seedling stage and the end of tuber formation stage depressed tubers yield though marketable tuber ratio increased slightly. The results also demonstrated that the dressing N in season could not decrease the starch content and dry matter content of tuber.