菊芋生长后期生物产量及营养价值

选择适时种植的当年生菊芋(Helianthus tuberosus)产区,根据不同生长期,于块茎收获期(霜降)前第0、14、28、42、56和70天,分6个时间点取样。每次取样根据大田地形和土质,选择5个不同地块,每个地块选取1 m2,收获地上和地下部分。测定植株地上(下1/3,中1/3和上1/3)和块茎(地下)产量,取样测定营养成分及生物总能。结果表明,菊芋生长后期,新鲜、风干和绝干物质产量的地上不同部位、地上、地下部分、全株以及地上/地下的比例,都随着生长期发生极显著的变化(P0.01)。整个地上生物粗蛋白产量霜降前两周最高,地下部分霜降最高,全株分析霜降前两周最高(P0.01)。整个地上生物总能产量霜降前两周最高,地下部分霜降最高,全株分析霜降前两周最高(P0.05)。菊芋生物蛋白产量为3 206 kg·hm-2,比玉米+小麦总生物蛋白质产量(3 146 kg·hm-2)高2%。菊芋生物总能为8.33×105MJ·hm-2,比玉米+小麦总生物总能产量(6.06×105MJ·hm-2)高37%。从饲料产量来看,菊芋块茎收获前两周,生物产量最大,是用作饲料用途的适时收获期。菊芋种植生物产量优于玉米和小麦总生物产量。种植菊芋是解决生物能源紧缺的重要途径之一。

Effect of Helianthus tuberosus late growth stage of on biological yield and nutritional value

This study aimed to the right time for harvesting Helianthus tuberosus in an area of 6 6 7 hm2.Accord-ing to the different growth periods,the time of harvest was allocated to six sampling points before tuber har-vest (i.e.,10,8,6,4,2,0 weeks).Based on the topography and soil texture,five different plots were select-ed for each sampling,and each plot was selected by 1 m2to allow harvest of the aboveground and underground parts.Plant aboveground parts (lower one-third,middle one-third,and upper 1/3),tuber yields,nutrient components,and gross energy were measured.The results showed that the yield of fresh,air-dried H.tuberosus and its dry matter content in the late growth stages,the yield of different aboveground parts,and underground parts,and whole plants,and the proportion of aboveground and underground changed significant-ly (P<0.0 1).The crude protein yield of underground parts was the highest (P<0.0 1)at the first incidence of frost.The crude protein yield of aboveground parts and whole plant was the highest (P<0.01)at 2 weeks be-fore the first frost.The gross energy yield of aboveground and whole plant was the highest (P<0.01)at 2 weeks before the first frost.However,the yield of underground parts was the highest (P<0.05)at the first frost.The crude protein yield of Helianthus tuberosus was 3 206 kg?ha—1,which was 2% higher than the total protein yield of maize and wheat (3 146 kg?ha—1).The gross energy yield of H.tuberosus was 8.33×105 MJ?ha—1,which was 37% higher than the total protein yield of maize and wheat (6.06×105MJ?ha—1). Judged from the perspective of feed production,the biological yield of H.tuberosus was the maximum;in addi-tion,the most suitable harvest period for feed was 2 weeks before the first frost.The biological yield of H.tu-berosus was better than the total of corn and wheat.H.tuberosus'cultivation is one of the important ways of mitigating bioenergy shortages.