一次性根区施控释尿素对再生稻生长及产量的影响

Effect of one-time root zone application of controlled release urea on the growth and yield of ratoon rice

通过研究控释尿素不同的根区施肥方式对根区土壤无机氮含量及再生稻生长的影响,为实现再生稻轻简化施肥和氮肥高效利用提供理论依据。田间试验设置5个处理,分别为不施氮(CK)、农民常规分次施氮(FFP)、一次性根区5 cm浅施控释尿素(RF1)、一次性根区10 cm深施控释尿素(RF2)、一次性根区分层5和10 cm施控释尿素(RF3),分析了不同施肥方式对再生稻生长及产量的影响。结果表明,与FFP处理相比,RF1、RF2和RF3处理均可显著提高根区土壤的NH_(4)^(+)-N含量,且可保持到再生稻腋芽生长期(120 d)仍具有和FFP相似的NH_(4)^(+)-N含量,其中RF3处理在根区土壤出现NH_(4)^(+)-N分层,最利于再生稻生长。与FFP处理相比,RF2和RF3处理在两季成熟期株高上差异不显著;头季成熟期RF1、RF2、RF3处理的干物质积累量比FFP处理高3%~8%,且RF3与FFP处理差异显著,但再生季各施肥处理无显著差异。与FFP处理相比,RF3处理显著提高了头季和再生季齐穗期茎、叶和穗的氮积累量。在再生稻头季,RF1、RF2和RF3处理较FFP处理增产了1%~10%,且RF3处理显著高于FFP处理,但再生季的产量与FFP处理无显著差异。综上,控释尿素的一次性根区施用通过根区集中施氮并维持氮素的持久释放能够满足再生稻全生育期的养分需求,是一种值得推广的轻简化施肥模式,其中根区分层施控释尿素效果最佳。

The effects of different root-zone fertilizations of controlled release urea on soil inorganic nitrogen content and growth of ratoon rice were studied to realize simplified fertilization and high-efficiency utilization of nitrogen fertilizer.In this study,5 treatments were set up through field experiments,which were no nitrogen(CK),farmers’familiar practice(FFP),one-time application of controlled release urea at a shallow depth of 5 cm in the root zone(RF1),one-time application of controlled release urea at a depth of 10 cm in the root zone(RF2)and one-time application of controlled release urea in the root zone layered application fertilization with both 5 and 10 cm depth(RF3).The effects of different fertilization methods on the growth and yield of ratoon rice were analyzed.The results showed that compared with FFP treatment,RF1,RF2 and RF3 significantly increased the NH_(4)^(+)-N content around the root-zone soil,and the NH_(4)^(+)-N content could be maintained at a similar level with FFP for 120 days till the growth period of axillary bud.Among them,the soil NH_(4)^(+)-N of RF3 stratified around the root-zone soil,which could best meet the growth of ratoon rice.Compared with FFP treatment,there was no significant difference in plant height of RF2 and RF3.The dry matter accumulation of RF1,RF2 and RF3 was 3%~8% higher than that of FFP in the first harvest time(the difference between RF3 and FFP was significant),but there was no significant difference among the fertilization treatments in the second harvest time.Compared with FFP treatment,RF3 treatment significantly increased the nitrogen accumulation of stem,leaf and panicle at full heading stage in the first season and regeneration season.In the first rice season,RF1,RF2 and RF3 improved rice yield by 1%~10% compared with FFP,in which RF3 had significant higher yield than FFP,while in the regeneration season,RF1,RF2 and RF3 had similar rice yield with FFP.In conclusion,the one-time root zone application of controlled release urea can meet the nutrient requirements of regenerated rice in the whole growth period by the concentration and slow release of nitrogen,which is an easy and simplified fertilization model and worthy to popularize,and the root zone layered application of controlled-release urea has the best effect.