种植密度和施肥量对紫花苜蓿生长特性的影响

Effects of planting density and fertilization on growth characteristics of alfalfa

摘要:

【目的】 探究种植密度和有机肥施用量互作机制对科尔沁沙地紫花苜蓿生长的影响，明确科尔沁沙地紫花苜蓿高产优质生产中适宜的种植密度和有机肥施用量。【方法】 以公农1号紫花苜蓿 （Medicago sativa cv Gongnong No. 1）为研究材料，采用田间小区试验，研究2个种植密度（15、12.5 kg/hm²）和5个有机肥施用量（0、200、400、600、800 kg/hm²），对其生长特性和饲草产量的影响。【结果】 种植密度和有机肥施用量以及二者互作对紫花苜蓿的株高、茎粗、分枝数、生长速度、产量等指标有显著影响，各指标在低种植密度处理下（12.5 kg/hm²）均好于高种植密度处理（15 kg/hm²），且随着有机肥施用量的增加呈现先增大后减小的趋势。在种植密度为12.5 kg/hm²，有机肥施用量为600 kg/hm2处理下，茎粗、分枝数、株高、生长速度、茎叶比、干鲜比及饲草年产量均显著高于其他处理（P＜0.05），饲草年产量达最大值，为17 519.53 kg/hm²。【结论】 种植密度和有机肥施用量互作对紫花苜蓿生长影响较大，合理的种植密度和有机肥施用量可以促进紫花苜蓿生长，增加紫花苜蓿产量。

Abstract:

【Objective】 The study is carried out in order to explore the interaction mechanism of planting density and organic fertilizer application rate on the growth of alfalfa in Horqin sandy land，and to determine the suitable planting density and organic fertilizer application rate in high yield and high quality production of alfalfa in Horqin sandy land.【Method】 A field plot experiment was conducted to study the effects of two planting densities （15 kg/hm²， 12. 5 kg/hm²） and five organic fertilizer application rates （0，200，400，600，800 kg/hm² ） on the growth characteristics and forage yield of alfalfa （Medicago sativa cv Gongnong No. 1）.【Result】 The results showed that planting density，organic fertilizer application rate and their interaction had significant effects on plant height，stem diameter， branch number，growth rate and yield of alfalfa. Each index under low planting density treatment （12. 5 kg/hm²） was better than that under high planting density treatment （15 kg/hm²）. And each index increased first and then decreased with the increase of organic fertilizer application rate. Under the treatment of planting density of 12. 5 kg/hm² and organic fertilizer application rate of 600 kg/hm² the stem diameter，branch number，plant height，growth rate，stem leaf ratio and dry-fresh ratio were significantly higher （P＜0. 05 ） than other treatments. The annual yield of forage reached the maximum value of 17 519. 53 kg/hm2，which was significantly higher （P＜0. 05 ） than other treatments. 【Conclusion】 The interaction between planting density and organic fertilizer application rate has a great influence on the growth of alfalfa. Reasonable planting density and organic fertilizer application rate can promote the growth of alfalfa and increase the yield of alfalfa.