机插秧同步施用噁草酮-复合肥缓释颗粒剂的研制及其田间应用

Development and application of oxadiazon-fertilizer slow-release granule for synchronous application in mechanical transplanting rice

稻田草害是影响中国机插秧生产最严重的限制因素之一,研发机插秧时可同步施用的除草剂产品和杂草防控技术是移栽稻亟需解决的问题。本文以噁草酮和复合肥为核心,采用聚乳酸进行包膜,制得3种具有不同缓释时间的噁草酮-复合肥缓释颗粒剂(噁草酮有效成分含量0.25%);在田间小区试验条件下,比较了该缓释颗粒剂在机插秧时同步施药对秧苗的安全性及对杂草的封闭防除效果。结果显示:具有不同缓释时间的噁草酮-复合肥缓释颗粒剂按180 kg/hm^(2)(含噁草酮有效成分450 g/hm^(2))于机插秧当天施用到田间,3~7 d后崩解释放,插秧后35 d时秧苗株高、地上部分鲜重及分蘖数显著高于对照药剂噁草酮乳油和吡嘧磺隆·西草净·扑草净可湿性粉剂在机插秧5 d后拌肥毒土法施用。噁草酮-复合肥缓释颗粒剂180 kg/hm^(2)剂量下对田间主要杂草稗草、鸭舌草等的防效达90%以上,与两种对照药剂封闭处理杂草的防效相当。当噁草酮-复合肥缓释颗粒剂降低至80%用量(144 kg/hm^(2))时,对机插秧苗的安全性及田间杂草的防效与推荐剂量下的无显著差异。所有试验处理对机插秧苗无明显药害产生。此外,本研究还对噁草酮-复合肥缓释颗粒剂大面积机械化的应用技术进行了探索,采用改良的侧深施肥插秧机按180 kg/hm^(2)的施药剂量在插秧的同时将该药肥颗粒均匀撒施在土壤表面,可实现机插秧同步精准机械用药,满足机插秧生产日益增长的省时省工需求。

Weed infestation is a serious problem in mechanical transplanting rice in China.Developing pre-emergent(PRE)herbicide-fertilizer slow-release granule and its assorted application technology is one of the most effective way to improve the efficiency.In this work,three types of slow-release oxadiazon-fertilizer granule(SROG)coated with poly-lactic acid with a core-shell structure were developed(contained 0.25%oxadiazon active ingredient).The efficacy and rice safety of SROG were evaluated in mechanical transplanting rice fields.The results indicated that,when transplanting was applied in the same time at 180 kg/hm^(2)(450 g a.i./hm^(2) of oxadiazon),the three types of SROG(with different concentration of coating material)disintegrated 3 to 7 days after the application,and had over 90%control efficacy against Echinochloa spp.and Monochoria vaginalis 35 days after transplanting,which were similar to regular PRE application(combined with fertilizer)of oxadiazon EC and pyrazosulfuron-ethyl+simetryne+prometryn WP 5 days after the transplanting.The plant height,aboveground fresh weight and tiller number were greater for the three SROG treatments compare with treatments of the two regular PRE herbicides 35 days after transplanting.Similar weed control efficacy was obtained when the dosage of SROG declined to 80%(144 kg/hm^(2) or 360 g a.i./hm^(2)).No herbicide injury was observed in all the experiments.The mechanical application of SROG synchronized with the improved side deep fertilizing rice transplanter(just broadcast the SROG on the soil surface)was also systematically investigated.The mechanical transplanting synchronized with SROG application technology could be an effective tool for rice cultivation systems to reduce labor input and herbicide application in the future.