栅条式液压翻转调幅犁设计与试验

随着大功率拖拉机在新疆地区的推广使用,与其相配套农机具的研制相对滞后,使得大功率拖拉机的优势难以充分发挥。研制开发与大功率拖拉机相配套使用的栅条式液压翻转犁,对该犁的主犁体、悬挂装置、调幅装置等关键部件进行设计,通过该型犁的田间实地测试,对试验结果和机具工作状况进行记录分析。田间试验结果表明,栅条犁作业速度9.1 km/h,耕深350 mm,耕宽2 700 mm,运行平稳、翻垡均匀,各项指标均达到或者超过国外同类机具水平,为大功率拖拉机在新疆地区的应用起到积极的推进作用。     

晋西黄土丘陵沟壑区土壤抗侵蚀能力的试验研究

通过大量的野外试验及调查,探讨了晋西黄土丘陵沟壑区土壤抗蚀性的时空变化规律、天然撂荒地的抗冲刷性能以及表土生物结皮、农耕地的犁底层等对土壤抗侵蚀能力的影响。结果表明:(1)晋西黄土丘陵沟壑区小流域的坡地土壤抗剪力及抗蚀性存在明显的时空变化规律。总体上,旱季的土壤抗蚀性高于雨季;峁顶缓坡地的土壤抗蚀性高于梁坡下部陡坡地。(2)只要土壤的整体结构不被破坏,即便水流冲刷力很大,黄土易蚀的特点也不易表现。尽量避免人为破坏黄土的整体结构,也是减少黄土侵蚀的重要手段。(3)黄土生物结皮,可大大增强土壤的抗侵蚀能力,减沙效应同结皮覆盖率成正比;犁底层在黄土地区的农耕地普遍存在,且会加剧耕作层的侵蚀作用。     

三段式心土混层犁及其改良白浆土效果的研究

三段式心土混层犁为改造白浆土土体构型实现了“上翻20 cm，下混30～40 cm”的农艺要求，白浆层与淀积层的土壤混拌率M_x达到0.7，白浆层向淀积层的土壤转移率T_Aw→B达到了0.3。0～40 cm土层土壤物理性状明显改善，疏松透水，硬度下降，农田表涝现象得到缓解，效果持久稳定，连续4年测定，耕翻一次后至第4年其土壤硬度仍然明显低于常规耕作田块。1996年～1998年大面积示范试验，使用该犁耕翻地块作物增产达10%～27.9%。该犁作业幅宽50 cm，深度60 cm，总牵引阻力30～35 kN。     

The role of clay, organic carbon and long-term management on mouldboard plough draught measured on the Broadbalk wheat experiment at Rothamsted

Despite a high energy requirement, the mouldboard plough remains the dominant tillage tool in northwest Europe. The aim of this work was to evaluate the relative influences of soil texture (clay content), soil organic carbon (SOC) and long‐term management on soil‐specific draught (S), where S is the force per cross‐sectional area of worked soil. Measurements were made during autumn 2000 on the then 157‐year‐old Broadbalk wheat experiment at Rothamsted, UK, where clay contents vary from 19 to 39% and the different cropping history, mineral and organic fertilizer treatments lead to SOC values of 0.7–3.2%. Minimum SOC values increased with increasing clay and were associated with zero or low mineral N inputs, while higher SOC values (>2%) were associated with long‐term applications of farmyard manure (FYM), despite these being on the lighter (<24% clay) soils. S values ranged between 52 and 142 kPa, with higher values co‐located in areas with high clay contents. Contour maps were generated to illustrate the spatial variability of S and show similarity to those for clay. Where FYM had been added, S was 66 kPa compared with 74 kPa where only mineral or no fertilizer was applied on soils of the same texture. Increasing applications of mineral N resulted in relatively small increases in SOC but up to 12% reduction in S.     

Land management effects on the near-surface physical quality of a clay loam soil

Although agricultural land management is known to affect near-surface soil physical quality (SPQ), the characteristics of these affects are poorly understood, and diagnostic SPQ indicators are not well-developed. The objective of this study was to measure a suite of potential SPQ indicators using intact soil cores and grab samples collected from the 0–10 cm depth of a clay loam soil with the treatments: (i) virgin soil (VS); (ii) long-term continuous bluegrass sod (BG); (iii) long-term maize (Zea mays L.)—soybean (Glycine max (L.) Merr.) rotation under no-tillage (NT); (iv) long-term maize–soybean rotation under mouldboard plough tillage (MP); (v) short-term (1–4 years) NT after long-term MP; (vi) short-term MP after long-term BG; (vii) short-term MP after long-term NT. Organic carbon content, dry bulk density, air capacity, relative water capacity and saturated hydraulic conductivity appeared to be useful SPQ indicators because they were sensitive to land management, and proposed optimum or critical values are available in the literature. Soil macroporosity was also sensitive to land management, but optimum or critical values for this parameter are not yet established. Soil matrix porosity and plant-available water capacity did not respond substantially or consistently to changes in land management, and were thus not useful as SPQ indicators in this study. Converting long-term BG to MP caused overall SPQ to decline to levels similar to long-term MP within 3–4 years. Converting long-term NT to MP or vice versa caused only minor changes in overall SPQ. With respect to the measured SPQ indicators and their optimum or critical values, both VS and BG produced “good” overall SPQ in the near-surface soil, while long-term maize–soybean rotation under NT and MP produced equally “poor” SPQ.     

拖拉机阻力控制系统实验分析与动态性能评价指标体系探讨

以拖拉机阻力控制系统为对象，进行了大量的室内模拟实验，测定出系统存在三个不同的响应频段以及低幅阻力扰动的不响应区。在此基础上，分析了系统性能。最后提出一套新的系统性能指标评价体系     

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.     

高略契金阻力公式的BASIC程序设计与应用

利用前苏联院士高略契金计算犁耕阻力的有理公式．分析建立教学模型，设计ＢＡＳＩＣ程序，用计算机运行，使其分析简化、准确，并就其应用，说明该程序的实用性与广泛性．     

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.     

心土混层耕改造白浆土效果研究

 经过7年系列试验和两年心土混层耕改良白浆土效果试验证明：设计心土混层耕犁的理论依据是保持耕层，改造白浆层。淀积层与白浆层按1∶1或0.5∶1混拌，应用心土混层耕犁的农艺参数为上翻20cm，下混30-40cm。心土混层耕具有持续改土增产效果，粮豆作物第一年增产15.6%,第二年增产11.4%；心土层土壤硬度降低，抗穿透阻力从25kg/cm#+2降到5-10kg/cm#+2，土壤饱和透水系数提高1.7-7.3倍,土壤抗旱涝能力提高。心土混层耕改土经济效益显著，改土效益期内（两年）每台犁可获纯收益18.7万元。