高茬黏重稻茬田油菜直播埋茬防堵深施肥复合装置研究

针对长江中下游稻油轮作区油菜直播作业时,因土壤黏重板结,地表前茬水稻留茬高、留存秸秆量大,导致旋耕部件易缠绕,秸秆埋覆率低,致使深施肥铲易挂草壅堵,作业厢面拖堆不平,难以实现深施肥作业。本文设计一种适应高茬黏重稻茬田的油菜直播埋茬防堵深施肥复合作业装置,确定埋茬防堵部件深旋弯刀、浅旋弯刀、防堵直刀和深施肥铲的结构参数及刀片和深施肥铲排列安装方式。利用EDEM仿真分析了机具作业后的秸秆埋覆、空间分布及颗粒肥料深施后的分布深度,结果表明:作业速度为2.5 km/h、耕作深度为150 mm、埋茬防堵部件刀辊转速为345 r/min时,秸秆埋覆率为86.53%、施肥深度为83~106 mm。开展了油菜直播机4种田间作业工况验证试验,结果表明:埋茬防堵深施肥复合作业装置田间作业性能良好,实现了肥料深施,秸秆埋覆率为86.69%~90.35%、厢面平整度为16.48~22.65 mm、施肥深度为87.4~109.5 mm、碎土率为81.24%~92.13%。

黏质土稻茬麦田土壤封闭防除硬草研究

东辛农场稻麦连作田杂草群落改变后,硬草发生量和发生面积逐年扩大,成为大麦、小麦共生性恶性杂草。本研究设置了绿麦隆·异丙隆、异丙隆、丙草胺、氟乐灵4种药剂不同剂量的播后苗前土壤处理,进行防效研究。结果表明:绿麦隆·异丙隆125、180 g/667 m2安全性高,防效好,增产效果明显,建议早播草重田块采用土壤封闭以大幅度降低硬草基数,抑制其扩展蔓延速度,降低茎叶处理成本。

Starch RVA Profile Properties for Cold Tolerant and Sensitive Cultivars of Japonica Rice at Different Altitudes

[Objective] By investigating of change rule rice starch RVA profile properties and the influence of cold tolerance on rice quality,the aim was to provide scientific references to the breeding of new cold-tolerant japonica rice varieties with high quality in the Yunnan plateau.[Method] Four cold-tolerant and five cold-sensitive japonica rice cultivars were grown at three locations with different altitudes in Yunnan plateau to investigate rice starch RVA profile characteristics.[Result] The results showed that with increasing altitude,the setback viscosity in cold-sensitive cultivars increased significantly,while the peak viscosity and breakdown viscosity decreased significantly.However,the peak viscosity and breakdown viscosity in cold-tolerant cultivars initially decreased and then gradually increased with rising altitude,whereas the setback viscosity initially increased and then decreased.[Conclusion] The starch RVA parameters of cold-tolerant cultivars were less sensitive to different environments than those of cold-sensitive cultivars.Cooking and eating quality of cold-tolerant cultivars had relatively stable trends with rising altitude,whereas cooking and eating quality of cold-sensitive cultivars had a trend toward inferior.

Effects of Nitrogen Fertilizer on Grain Quality of Different Cultivars of Japonica Rice

Three cultivars of Japonica rice:hybrid Japonica rice,inbred Japonica rice and soft Japonica rice,were used to study the effects of recommended nitrogen fertilizer on grain quality including milling,appearance,nutrition,cooking and eating quality,pasting property and their relationships in direct seeding rice.Recommended nitrogen fertilizer improved the brown rice rate,the milled rice rate,and the protein content;increased the chalky grain rate and the chalkiness,and reduced the amylose content,palatability and pasting viscosity.The nitrogen fertilizer caused the appearance,the cooking and the eating quality to deteriorate.Lower amylose content and protein content were found in soft Japonica rice compared to those in hybrid Japonica or inbred Japonica rice under the condition of the recommended rate of nitrogen fertilizer,contributing to high cooking and eating quality.Correlation analysis indicated that palatability was negatively correlated with amylose content,protein content,hardness and gelatinization temperature,and was positively correlated with stickiness,peak viscosity and breakdown.Therefore,the decreased amylose and protein content of the soft Japonica rice cultivar planted under the condition of the recommended rate of nitrogen fertilizer is beneficial to achieving high taste quality.