氮肥施用方式对水稻产量以及氮、磷、钾养分吸收利用的影响

[目的]针对水稻氮肥施用量大、利用率低的现状，探索氮肥高效的一次根区施氮模式，比较改变施氮方式后水稻对氮、磷、钾养分吸收利用的差异，为水稻高效施肥提供理论指导。[方法]在环太湖单季中稻区（安徽省宣城市广德县邱村镇和江苏省泰州市姜堰区梁徐镇）开展大田试验，比较常规习惯施氮（FFP，40%作基肥，30%作分蘖肥，30%作穗肥）与根区一次施氮的3种施氮方式（BF，侧5 cm深5 cm条施；HF5，侧5 cm深5 cm穴施；HF10，侧5 cm深10 cm穴施）4个处理对水稻产量及氮、磷、钾肥吸收利用的差异。[结果]根区一次施氮相对FFP不减产，且HF10的产量比FFP分别显著增产24.5%（广德）和44.8%（姜堰）。HF10显著提高水稻茎、鞘、叶以及籽粒的氮含量和氮积累量，两地HF10的水稻总氮积累分别达164.1 kg？hm-2（广德）和196.4 kg？hm-2（姜堰），相对FFP分别增加了53.6%和114.3%。根区施氮对于水稻各器官磷含量和磷积累量也有显著提高，两地最高磷积累的HF10相对FFP平均增加45.1%。根区施氮对水稻钾含量的影响相对较小，钾的积累量的变化趋势与干物质相同。HF10的氮肥表观利用率平均由FFP的17.9%提高到54.0%，农学利用率也有显著的提高。[结论]根区一次施氮是一种节肥高效的施肥方式，两地综合结果均以水稻侧5 cm、深10 cm一次穴施氮肥效果最好，根区施氮显著提高了水稻磷、钾的吸收量，磷、钾肥施用量有待进一步调整，此施肥模式值得进一步研发施肥机械和推广应用。
[Objectives] The phenomenon of large amount of N fertilizer input and low N use efficiency in rice had become a common scene,and studying and researching an optimal one-time N root-zone fertilization method and comparing the effect of one-time N root-zone fertilization on N,P and K uptake and utilization of rice are important for increasing rice yield and fertilization use efficiency,and providing a theoretical guidance for rice fertilization. [Methods] This study was carried out at the middle-season rice area of around Taihu Lake(Qiucun Town,Guangde County,Xuancheng City,Anhui Province and Liangxu Town,Jiangyan Country,Taizhou City,Jiangsu Province. GD and JY for short),and compared the effects of four different N fertilization methods,which include farmer fertilization practice(FFP,40% as basal fertilizer,30% as tillering fertilizer and 30% as earing fertilizer),band fertilization at 5 cm lateral and 5 cm depth(BF),hole fertilization at 5 cm lateral and 5 cm depth(HF5) and hole fertilization at 5 cm lateral and 10 cm depth(HF10),on rice yield and N,P,K uptake and utilization. [Results] Result showed that there was no yield reduction for one-time N root-zone fertilization,also significant yield increase was observed at HF10 compared with FFP,and the yield increments were 44.8% and 24.5% at GD and JY,respectively. HF10 significantly increased N content and N accumulation of stem,sheath and blade of rice as well. The highest total N accumulations for HF10 were 164.1 kg？hm-2(GD) and 196.4 kg？hm-2(JY),and there were 53.6% and 114.3% increment compared with corresponding FFP,respectively. Significantly enhanced N,P,K content and accumulation was observed for N root-zone fertilization. The highest P accumulation was HF10 for both sites and it showed 45.1% averaged increment compared with FFP. Rice K content showed a little variation between different N fertilization patterns and the trend of K