不同降雨年型下种植密度对旱作马铃薯生长、水分利用效率及产量的影响

Effect of Planting Density on the Growth, Water Use Efficiency and Yield of Dry-farming Potato under Different Rainfall Year Types

为探索宁南半干旱偏旱区覆膜垄作马铃薯合理的种植密度,于2015和2016年设置37 500、45 000、52 500、60 000、67 500株hm^(–2) 5个种植密度,以当地传统种植密度37 500株hm^(–2)为对照,研究不同种植密度对土壤水分、马铃薯生长、水分利用效率及产量的影响。结果表明,不同种植密度可显著影响马铃薯生育前期和中期0~100 cm层土壤水分状况,以45 000和52 500株hm^(–2)处理土壤贮水量最高,均显著高于37 500和67 500株hm^(–2)处理。45 000和52 500株hm^(–2)处理较其他处理均显著提高马铃薯出苗率,促进马铃薯生育前期和中期的生长,而在马铃薯生育后期各处理间差异不显著。马铃薯产量和商品率均随种植密度的增加呈先增加后下降的变化趋势, 45 000和52 500株hm^(–2)处理两年平均降水利用效率分别较37 500株hm^(–2)处理显著提高15.3%和17.6%,作物水分利用效率分别提高11.1%和15.0%。通过两年数据拟合函数发现,在宁南半干旱偏旱区2015年平水年和2016年枯水年,旱作覆膜垄作马铃薯种植密度为51187~51 302株hm^(–2)时,其水分利用效率和块茎产量最高。

In order to explore the reasonable planting density of potato under plastic film mulching and ridge planting,a 2-year field experiment was conducted in semi-arid areas liable to droughts of southern Ningxia between 2015 and 2016,with five planting density treatments,including 37 500(A),45 000(B),52 500(C),60 000(D),and 67 500 plant ha–1(E).Local traditional planting density of 37 500 plant ha–1(A)was as the control.Different planting densities could significantly influence the water status of soil layer at 0–100 cm during the earlier and middle stages of potato growth.The soil water storages in treatments B and C were the highest,which were significantly higher than those in treatments A and E.The treatments B and C could significantly increase emergence rate of potato,and promote the growth of potato during the early stage and middle stage compared with other treatments,whereas there were no significant differences among the five treatments during the later stage of potato growth.The tuber yield and commodity rate of potato increased at first and then decreased with increasing planting density.Compared with treatment A,the 2-year mean rainfall use efficiency of treatments B and C were significantly increased by 15.3%and 17.6%,and mean water use efficiency were significantly increased by 11.1%and 15.0%,respectively.By function fitting with the two-year data,the highest tuber yield and water use efficiency of dry-farming potato under plastic film mulching and ridge planting was demonstrated in normal year and dry year in semi-arid areas liable to droughts of southern Ningxia,which was 51 187–51 302 plant ha–1.