To explore the appropriate amount of phosphorus (P) fertilizer and improve economic yield and P use efficiency of edible sweetpotato, we took Xushu 32 as an example and compared the effects of different P application rates on yield, quality, P accumulation and P use efficiency of edible sweetpotato based on a two-year field experiment (soil available P content was 31.70 mg·kg-1) from 2018 to 2019. There were five P application levels (P2O5), including 0 (P0), 25 (P25), 50 (P50), 75 (P75) and 100 kg·hm-2(P100). The results showed that, 1) compared with P0, P application significantly increased the yield of fresh sweetpotao and commodity potato, with the effects being the stongest under P75 treatment, followed by P50 treatment. However, there was no significant difference between the two treatments. 2) P application significantly increased the contents of starch and reducing sugar in storage root. The contents of soluble sugar and protein increased significantly under P50 treatment. 3) Du-ring the growth period of 90 to 120 d, P fertilizer supply significantly increased P accumulation and dry matter accumulation of sweetpotato. 4) The apparent P use efficiency (APUE) decreased with increasing P application rates, while P agronomic efficiency (PAE) increased first and then decreased with the increases of P application rates, which was significantly higher under P50 than other treatments. Taking into account the yield, quality, economic yield and P utilization rate of edible sweetpotato, the optimal dosage of P2O5 is 50 kg·hm-2 under the experimental conditions.
为了探索适宜的磷肥用量,提高鲜食型甘薯的经济产量和磷肥利用率,以徐薯32为例,于2018—2019年进行两年的田间试验(土壤有效磷含量为31.70 mg·kg-1),比较了不同施磷量对鲜食甘薯产量、品质、磷积累和磷利用效率的影响。试验设置5个施磷水平(P2O5),分别为0(P0)、25(P25)、50(P50)、75(P75)和100 kg·hm-2 (P100)。结果表明: 1)与P0相比,施磷显著提高了鲜薯产量和商品薯产量,以P75处理最高,其次为P50处理,两处理间差异不显著。2)施磷显著提高了薯块中淀粉和还原糖含量,在P50处理下可溶性糖和蛋白质含量显著增加。3)在生育期90～120 d,施磷显著提高了甘薯的磷积累量和干物质积累量。4)磷表观利用率随着施磷量的增加而下降,磷农学效率则随着施磷量的增加先升后降,在P50处理下显著高于其他处理。综合考虑鲜薯产量、品质、经济产量和磷肥利用率,本试验条件下P2O5的适宜用量为50 kg·hm-2。.
Keywords: commodity potato yield; edible sweetpotato; phosphorus application rate; phosphorus use efficiency.