苹果树体磷素动态规律与施肥管理

以"富士"苹果树为试材,对果树体生物量和各器官及其皮层、木质部的磷含量和累积动态进行了研究,以期探讨果树磷素吸收、转运和分配规律.结果表明,3月26日至9月21日,树体生物量呈直线增加,果实采收后,生长缓慢,7月30日后,根系快速生长,植株、地上部及根系中磷累积迅速增加;枝、干和根系皮层内磷含量与累积7月30日最低,休眠期最高,皮层磷含量枝＞干＞根系;而木质部磷含量与累积4月30日达最低,木质部磷含量根系＞枝＞干;一年内,果树吸磷总量为28.72 kg/hm2,果实和叶片共带走磷素7.94 kg/hm2,7月30日至9月21日,吸收磷素18.32 kg/hm2,占吸收总量的63.8%,9月21日至1月15日,吸收磷素10.40 kg/hm2,占36.2%;苹果树(苹果产量48 t/hm2)年推荐施纯磷47.86 kg/hm2,果实收获后秋季基施磷17.33 kg/hm2,果实膨大期前追施磷30.53 kg/hm2.

Phosphorus dynamics and fertilization management of apple tree

Phosphorous fertilizer is an important factor for the yield and quality production in apple trees.Biomass,phosphor concentration and accumulation in the cortex and xylem in different parts of apple tree were studied in field-grown "Fuji" apple trees(M micromalus Makino) in 2004 and 2005 growing seasons in Shaanxi Province,China.The objective of this study was to find the dynamic variety of phosphor uptake,transportation and distribution in different parts of the apple tree.The results showed that biomass of plant and the parts above ground vegetated quickly from March 26 to September 21,and developed slowly after fruit harvested in September 21.Phosphor accumulation in the parts above ground,root system and plant rapidly increased after July 30.Phosphor content and accumulation in cortex of branch,trunk and roots reached lowest in July 30,they were highest in the dormant period,and phosphor content order in cortex was Branch > Trunk > Roots.But phosphor content and accumulation in xylem were lowest in April 30,phosphor content order in xylem was Root >Branch > Trunk.Total 28.72 kg/hm~2 phosphor was absorbed in a year and 7.94 kg/hm~2 phosphor was move away by fruits and leaves.From July 30 to September 21,18.32 kg/hm~2 phosphor was absorbed;it occupied 63.8% of total uptake.10.40 kg/hm~2 phosphor was still absorbed from harvested to January 15,accounted for 36.2% of total uptake.Total phosphor in orchard was 47.86 kg/hm~2 in one year,17.33 kg/hm~2 of phosphor was as base fertilizer in autumn,and the rest of 30.53 kg/hm~2 was used to topdressing before the fruit expanding time.