Subsoil loosening does little to enhance the transition to no-tillage on a structurally degraded soil

Long-term cropping with conventional cultivation on New Zealand’s easily compacted soil causes soil structure degradation. The objective of this study was to ascertain if soil physical properties, and crop establishment and yield could be improved by subsoil loosening in the first year of conversion from conventional tillage to no-tillage. Plots on a Milson silt loam (Argillic Perch-Gley Pallic Soil, Typic Ochraqualf) were Paraplowed (PP), straight-legged subsoiler (SL), mole ploughed (M), or left as non-loosened controls (C) in the autumn of 1997. Forage brassica was sown with a Cross-Slot™ no-tillage drill. Wheat was established on the plots in the spring of 1997. Subsoil loosening resulted in some transient improvements in measured soil physical properties. Initially, subsoil loosening significantly reduced soil strength. Shortly after subsoil loosening, cone indices showed disruption to 300 mm with PP, 350 mm with SL and 100 mm with M. About 80% of profile cone indices from the PP and SL treatments were less than the critical value of 2 MPa compared to 48% for C and M. At 267 days after subsoil loosening, PP continued to have significantly lower cone index values than C and M. In May, the bulk density of PP plots was significantly lower than SL, M and C although reconsolidation in all plots was observed 9 months later after the wheat was harvested. Air permeability for PP, SL and M was significantly greater than C in June. Subsoil loosening did not increase plant populations or yield of the brassica or wheat crops. Vertical rooting depth was greater in the PP treatment. Few significant differences in wheat rooting patterns were found at depth.     

不同施肥技术对双季稻土壤微生物的影响

为了探明农业技术措施对土壤生物学特征的影响,为制定合理的耕作制度,保障土壤的可持续性利用提供依据,进行了一次性全层施肥法对双季稻土壤微生物的影响研究.结果表明,施肥技术没有引起土壤微生物的变化.土壤中几类微生物的数量变化主要受水稻生育期的影响.     

1SL-2/3型多功能鼠道犁的研制与应用

鼠道排水是盐碱地改良和涝害治理的有效技术措施,目前急需研制鼠道排水作业机具。研究设计1SL-2/3型多功能鼠道犁,介绍其结构及主要技术指标,分析其应用效益,以期为提高农田排水治渍机械化作业技术水平提供装备保障。     

花生收获机械化技术研究

作为辽西地区农民增收的主要经济作物,花生种植备受关注。针对花生全程机械化中收获环节相对薄弱的情况,介绍花生收获机的机型及特点,分析目前花生收获机存在的问题,提出相应的技术要求,为花生机械化发展提供技术参考。     

用于构建肥沃耕层的秸秆还田机具发展研究

在详细介绍秸秆还田机具的分类及型号编制方法的基础上,探讨秸秆粉碎还田机、深翻犁、水田埋茬搅浆机对农业生产的作用及研究发展现状,为秸秆还田技术及相关机具的研究设计提供理论依据。     

基于最小数据集的东北旱作区耕层质量评价与障碍诊断

为准确评价东北旱作区耕层质量特征,针对全部初选指标采用主成分分析法（PCA）建立了东北旱作区耕层质量评价的最小数据集（Minimum data set, MDS）,并运用最小数据集耕层质量指数（MDS-Plough horizon integrated quality index, MDS-PHIQI）和障碍因子诊断模型对研究区耕层质量及主导障碍因子进行分析。结果表明：东北旱作区耕层质量评价的最小数据集由土壤有机质含量、全氮含量、有效磷含量、粘粒含量、耕作层穿透阻力和压实层厚度组成,最小数据集可替代全部初选指标对东北旱作区耕层质量进行评价;东北旱作区耕层质量指数分布在0.10~0.53之间,均值为0.30,整体处于低和中等水平。东北旱作区合理耕层指标参数的适宜范围为：有机质质量比大于等于37.16g/kg,全氮质量比大于等于1.75g/kg,有效磷质量比大于等于26.38mg/kg,粘粒质量分数为4.60%~6.19%,耕作层穿透阻力小于等于364.56kPa,压实层厚度小于等于8.18cm。东北旱作区粮食产量低产区耕层多存在结构型障碍,中产区耕层结构型障碍和养分限制共存,而高产区耕层主要表现为养分限制型障碍。整体来看,研究区耕层质量的主要障碍因素为耕作层穿透阻力、土壤全氮含量、有机质含量,需针对上述指标采取针对性的耕作和培肥措施。     

通过研究犁体曲面的设计方法论曲面的实体建模

通过分析犁体曲面的设计方法,使用三维参数化建立水平直元线型犁体曲面的数学模型。在Pro/E中构造曲面的实体模型,弥补了平面作图设计中的缺陷和不足,较好地分析了曲面的质量,为后继犁体曲面的动力学仿真分析奠定了良好的基础。     

开沟合垄深施肥耕耙犁的设计

为提高肥料的利用率,开发设计一种开沟合垄深施肥耕耙犁.介绍机具的主要结构组成和工作原理,探讨传动系统、碎土器和工作部件的选型和设计思路,为肥料深施作业提供性能可靠的实用机具.     

基于Solidwork的拖拉机耕犁装置的设计与仿真

犁耕装置是农业生产过程中非常重要的土壤耕作机具,其核心部件是犁片结构,但犁片是曲面形状,其设计和优化过程较为困难。为此,提出了一种基于Solid Works软件的耕犁装置设计和仿真优化方法,有效地提高了犁耕装置的设计效率。以30系列悬挂铧式犁耕装置为例,对其结构和参数性能进行了分析,然后根据其结构参数建立了犁耕装置的三维模型,并以犁片为研究对象,对其进行了运动仿真。由建模和仿真结果可以看出:采用Solid Works软件可以成功实现犁耕装置犁片和土壤的三维建模,运用其运动仿真功能成功实现了耕犁作业的运动动画的制作,为耕犁装置的优化设计提供了一种新的方案。