磷肥施肥方式对长白落叶松苗木生长的影响

Effect of Phosphorus Application Mode on Growth of Larix olgensis Seedlings

为提高磷肥利用率,找到磷肥最佳施肥方式,以长白落叶松2年生(1-1)移栽苗大苗为试验材料,在底施磷肥的基础上,进行生长期水施追肥。试验采用裂区设计,主区为磷肥量(163、326、489 kg.hm-2),副区为水施追肥比例(0、25%、33.3%、50%、100%)。结果表明:苗高、地茎、I级侧根数(根茎D>1 mm)、各组织生物量在不同磷肥量和不同水施比例间的差异均达到显著水平;在489 kg.hm-2磷肥处理下,苗木各生长指标最大,显著优于其他两个磷肥处理,因此,最佳磷肥量为489 kg.hm-2;而在不同水施比例中,大部分指标在33.3%水施比例下最大,显著优于其他4个水施比例处理;在326、489 kg.hm-2磷肥处理下,33.3%水施比例处理的磷肥利用率分别为12.42%、19.10%,显著高于其他水施比例处理。因此,在本试验设定范围内,最佳施肥方式为在489 kg.hm-2磷肥量下,将磷肥总量的1/3用于水施追肥。

An experiment was conducted to study the effects of phosphorus application mode on the growth of Larix olgensis, with the aim to improve the phosphorus efficiency and find the best phosphorus application mode. Two-year-old transplanted seedlings （1-1） of L. olgensis were used as experimental materials. After applying some phosphorus to the soils as basal fertilizer, other phosphorus was applied by fertigation as topdressing for three times during the growth of seedlings. The split spot design was conducted in this experiment, with amounts of phosphorus （163,326,489 kg · hm^-2） as main treatment and fertigation ratios （0, 25%, 33.3%, 50%, 100% ） as side treatment. Results show that height, diameter, firstorder lateral root in diameter at junction greater than lmm and biomass of seedlings are affected by phosphorus amounts and fertigation ratios significantly. All the growth indexes of the seedlings were highest at the amount of phosphorus of 489 kg · hm^-2 , which were significantly better than those of the seedlings at other amounts of phosphorus, so the proper amount of phosphorus is 489 kg · hm^-2. The growth indexes of seedlings reached their maximum values under the fertigation ratio of 33.3%, which were significantly better than those of the seedlings under the other four fertigation ratios. Besides, under the amounts of phosphorus of 326 and 489 kg · hm^-2, the phosphorus use efficiency were 12.42% and 19.10% respectively, which were significantly higher than those under other fertigation ratios. It proves that 33.3% is the optimal fertigation ratio. The optimum mode for phosphorus application to the transplanted seedlings （ 1- t ） of L. olgensis is that the amount of phosphorus is 489 kg · hm^-2 and 33.3% of the total amount is applied by fertigation during the growth.