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%。

Design and experiment of anti-adhesion rototiller based on staggered double-roller scraping

In order to solve the serious problem of soil adhering blade roller in the middle and lower reaches of Yangtze River,the anti-adhesion rototiller based on staggered double-roller scraping(ARSDS)was designed by mechanical scraping methods.The volume equation for scraping the soil adhesion part with staggered rotary blades was constructed.The mechanical conditions for separation of soil adhesion part from blade roller were clarified,and the contact time between rotary blade and soil during rotary tillage was analyzed.By this way,the key parameters affecting soil adhering on and separating from the blade roller were determined,which were rotational speed,cutting pitch and tillage depth.The spatial and temporal trajectory changes for the sidelong section edge of staggered rotary blades were analyzed,so that the rotary blade arrangement was obtained.Combining the discrete element method,selecting the soil adhesion mass on the staggered blade rollers as the response value established prediction model by Box-Behnken design test.For example,taking the tillage depth of 14 cm for wheat cultivation in the middle and lower reaches of Yangtze River,the optimal combination of parameters was determined to be 230 r/min and 10 cm for rotational speed and cutting pitch,respectively.At this time,the soil adhesion mass was 4566.67 g.In the meantime,the process of soil particles adhering staggered blade rollers and rotary blades scraping off the adhering soil were clarified.Field experiments have shown that the operation quality of ARSDS met the requirements of rototiller performance indexes.In the rice stubble field of high water moisture,the soil adhesion mass was 13.455 kg and 38.215 kg for ARSDS and conventional rototiller,respectively,which indicated that ARSDS effectively reducing soil adhesion mass.The research results can provide technical support for the design of rototiller reducing soil adhesion in the agricultural areas of the middle and lower reaches of the Yangtze River.

耕作方式和稻草还田对双季稻田CH4和N2O排放的影响

稻田温室气体(甲烷和氧化亚氮)排放强度受多种田间管理的影响,以往对各种措施间的交互效应研究较少。为此,该研究利用改进的静态箱-气相色谱法进行了连续4个生长季的湖南典型双季稻田温室气体排放强度观测,旨在分析耕作和稻草还田2种措施的交互效应并探寻多措施联合减缓温室气体排放强度的途径。试验设4个处理:翻耕(CWS,conventional tillage without straw residue)、免耕(NWS,no till without straw residue)、免耕高茬还田(HN,no till with high stubble straw residue)和翻耕高茬还田(HC,conventional tillage with high stubble straw residue)。结果表明,耕作和稻草还田2种措施对稻田甲烷排放有显著的交互效应(P<0.05),但对氧化亚氮交互效应不显著。2种措施对稻田温室气体排放强度的影响有明显的季节和年际变异。多生长季平均而言,各处理甲烷排放顺序为HC>HN>CWS>NWS(HC显著高于HN,HN和CWS差异不显著),水稻产量顺序为CWS>HN>HC>NWS(HN和CWS差异不显著),而温室气体排放强度(greenhouse gas intensity)顺序为HC>CWS>HN>NWS(HN显著低于HC和CWS,P<0.05)。可见,"免耕高茬还田"模式能抵消翻耕处理的高温室气体排放,并能比NWS处理提高水稻产量,显著减缓双季稻田温室气体排放强度。在保护性耕作和农田碳库提升的需求下,该模式应被予以高度重视。该研究可为中国双季稻主产区温室气体排放强度减缓措施的选择提供科学支撑。

水稻及玉米茬口对强筋小麦品质性状的影响

以强筋小麦品种豫麦34号为试验材料,分析了种植在河南省5个地点水稻茬和玉米茬的豫麦34主要品质,同时测定了两种茬口下土壤含水量。结果表明,与玉米茬相比,水稻茬种植的豫茬34号品质差,表现为蛋白质含量、湿面筋含量下降,稳定时间缩短,评价值减小,以强筋麦适宜种植区的新乡点水稻茬小麦品质下降最多;土壤含水量高是水稻茬小麦品质变差的原因之一;提出了水稻茬不适宜种植强筋优质小麦的观点,即使在强筋麦适宜生态区内也是如此。

超高茬麦田套稻田间杂草防除效果研究

[目的]采用超高茬麦田套稻技术田间杂草危害严重,是其大面积推广应用的主要障碍之一,通过不同药剂的防效试验筛选最佳除草剂。[方法]选用35.5%丁.恶乳油等除草剂在水稻套播后和小麦收割后,用毒土法先后2次处理麦田套播水稻田,调查防效。[结果]除草效果以35.5%丁.恶乳油2 250 ml/hm2最佳,其后依次为30%丁.苄1 500 ml/hm2、50%杀草丹3 000 ml/hm2+10%苄磺隆225 ml/hm2、50%苯噻草胺750 ml/hm2+10%苄磺隆225 ml/hm2,而36%二氯.苄750 ml/hm2效果最差;用药时间越早,对禾本科杂草防效越好,供试药剂持效期均为45 d左右;中、后期可根据田间杂草发生情况辅以茎叶处理,效果更佳。[结论]以稗草和阔叶杂草为主的田块,5种药剂均可使用;以千金子和阔叶杂草为主的田块,除36%二氯.苄750 ml/hm2外,其他4种药剂均可使用;以莎草科和阔叶杂草为主的田块,可用含有苄磺隆的复配除草剂,或单用10%苄磺隆225～300 ml/hm2进行防除。供试药剂均对水稻安全。

水田秸秆还田整地机具研制进展

为改善水田耕整地作业效果,研制水田秸秆还田耕整机具。介绍水田秸秆还田的类型及质量要求,总结国内外水田秸秆还田机具的研究进展及主要成果,为提高相关技术发展水平提供理论参考。

稻秆还田与化肥配施对稻茬麦田土壤肥力和小麦产量的影响

在大田试验条件下,以水稻秸秆为研究对象,设置化肥水平(C)0、70%、100%,秸秆还田水平(S)0、50%、100%,共9个处理,研究不同秸秆还田量与化肥配施对不同时期土壤养分及冬小麦产量的影响。结果表明:在冬小麦的整个生育期内,秸秆还田与化肥配施能明显提高土壤有机质、碱解氮、速效钾含量,对土壤有效磷含量影响不大。其中处理S 100 C 70对土壤有机质的积累效果最佳,处理S 100 C 100对提高土壤碱解氮含量的能力最强,处理S 50 C 70对提高土壤速效钾含量作用最大。在相同施肥水平下,秸秆还田会提高产量,但秸秆还田量并不是越大越好。在C 70和C 100水平下,冬小麦的穗长、株高、穗粒数、千粒质量等产量构成要素随秸秆还田量的增加而增加。相关分析结果显示土壤速效钾含量对提高小麦产量及其构成要素具有至关重要的作用。运用主成分分析方法找出3个主成分,综合得分排名第1、第2的处理分别为处理S 50 C 100与处理S 100 C 100,因此在本试验条件下,处理S 50 C 100与处理S 100 C 100可维持较高的土壤肥力且促进小麦增产,实现废弃秸秆还田资源化合理利用。