Comparative analysis of the field performances of a reversible animal-drawn prototype and conventional mouldboard ploughs pulled by a single donkey

The performance of two conventional animal-drawn mouldboard ploughs and a reversible prototype mouldboard plough were studied under field conditions in Kenya on previously ploughed and harrowed clay nitisol. The two mouldboard ploughs were a Victory plough, manufactured in the United Kingdom, and a cylindrical mouldboard plough manufactured by the Rumptstad factory of The Netherlands. The reversible prototype wooden mouldboard plough was developed at the Department of Agricultural Engineering of the Swedish University of Agricultural Sciences as a mouldboard type, modernized version of the ard type plough.

Simultaneous and dynamic measurement of forces, moments, ground speed and tillage depth were made. The results of the comparison between the three ploughs showed that both the horizontal and vertical components of forces resulting from the reversible plough were about 50 and 65% of the forces resulting from the Rumptstad and the Victory ploughs, respectively.

In the case of the reversible plough, the effect of a tail angle on horizontal and vertical forces was investigated. The results of field tests confirmed the laboratory results in that the form of graphs and equations describing the relationship between the forces and tail angle were similar to those obtained during the laboratory tests.

A single donkey was used to draw the implements throughout the experiment. It pulled about 25% of its body weight at an average speed of 0.8 m s⁻¹ and worked for 9 h per day.     

Effect of subsoiling on soil properties and winter wheat grain yield

A 2‐year field experiment was carried out in loessal soil in a semi‐humid climate to explore the integrative influences of subsoiling on soil properties and winter wheat grain yield. Results showed that it was essential to deepen the plough pan in loessal soil. The sharply increased soil penetration resistance (>7 MPa) in plough pan under dry soil condition was especially harmful for plant growth. In rotary tillage treatment, the waterlogging conditions caused by shallow plough pan slightly produced macropores and preferential water flow. Significantly, higher grain yield was obtained in the subsoiling tillage treatment, increased by 21.9% in 2016 and 11.3% in 2017, respectively. Subsoiling tillage improved the resilience of winter wheat under adverse climate conditions. Subsoiling tillage should be popularized in loessal soil with shallow plough pan in semi‐humid climate. This study may provide valuable information on soil sustainable use and management in loessal soil.     

SW—Soil and Water: Improvement of Whitish Oasis Soil, Part 1: Field Experiments with a Four-stage Subsoil Mixing Plough

A prototype four-stage subsoil mixing plough was designed in Japan and built in China for the improvement of whitish oasis soil. The machine was transported to two places in China for field tests where the whitish oasis soil is found. This paper presents the trash mixing rate into mixed layer of Bca and C horizons, the inverting rate of the Bca and C horizons and the draught of the plough in the whitish oasis soil.The results show that the rolling resistance of the tracked vehicle (T802), on which the plough was mounted, was about 8 kN and the draught of the first plough body which tilled the Ap horizon was about 4 kN with a working depth of 200 mm and a working width of 500 mm. The draught of the second plough body, which tilled the surface of the Ap horizon, was about 2 kN with a working depth of 50 mm. The draught of the third plough body increased steeply with greater working depths. The draughts were about 8, 14 and 24 kN, respectively, for working depths of 117, 239 and 300 mm. The draught of the fourth plough body also increased steeply with greater working depth. The draughts were about 7, 14 and 18 kN, respectively, for working depths of 117, 178 and 239 mm. When the whitish oasis soil was disturbed by the plough bodies, it was observed that the whitish oasis soil was very hard but comparatively brittle and easily broken up. This property explains the smaller draught requirements in the whitish oasis soil despite a greater soil strength. The values of the soil-inverting rate ranged between 0·45 and 0·6, and the average value was 0·5. Perfect inversion of the Bca and C horizons was not possible, but good mixing was achieved by the plough. The average trash mixing rate in Inner Mongolia was 0·85, and that in North of River was 0·95. These data show that even in Inner Mongolia where the trash material is long, a fairly uniform trash mixing was possible.     

Heavy soil loading its consequence for soil structure,strength, deformation of arable soils

The alteration of mechanical soil properties by a single stress application exceeding all previously applied stresses is analyzed for a conventionally tilled and a conservational managed (since 1992) Stagnic Luvisol. Despite the more pronounced compactness of the plough layer under conventional management, it turned out to be less rigid compared to the “relictic” plough layer under conservation management. We assume that wheeling with a sugar beet harvester (rear wheel 140 kPa, front wheel 110 kPa, total mass 37 Mg) resulted in a break up of the plough pan. This was most obvious in the conventionally tilled soil whereas under conservation tillage, the plough pan seemed to resist the induced forces. Our results suggest that a break up of the compact plough layer and the subsequent re‐arrangement of newly formed fragments results in a smaller mechanical stability of the deformed soil. Soil structural changes within the plough pan are also indicated by the alteration of the anisotropy of cohesion and precompression stress, respectively. Altered mechanical properties induced by heavy soil loading affects the soil response to subsequent loading events, which could be shown by finite‐element simulations of stress‐strain properties. The simulations showed that a decrease in soil stiffness reduces the stress attenuation within the plough pan causing compressive and shear stresses to be transmitted into deeper soil levels, while at the same time shear strain increased.     

横坡和顺坡耕作对紫色土土壤团聚体稳定性的影响

通过径流小区试验,分析探讨了紫色土横坡和顺坡两种耕作模式下表层(0~20 cm)土壤水稳性团聚体及有机碳含量的特征,为紫色土区坡耕地的有效改造和综合利用提供科学依据。试验结果表明,横坡耕作下土壤水稳性指数K值比顺坡耕作高38.99%,而土壤分散性D值为顺坡耕作的1.64倍,横坡耕作抗蚀性大于顺坡耕作。横坡耕作>0.25 mm水稳性团聚体含量比顺坡耕作增加3.62%,>5 mm、5~3 mm、3~2 mm水稳性团聚体含量横坡耕作均高于顺坡耕作,横坡耕作显著提高>2 mm水稳性团聚体含量。横坡耕作下团聚体结构体破坏率较顺坡耕作减少3.05%,团聚体平均重量直径为顺坡耕作的1.39倍。2种耕作模式下0.5~2 mm团聚体有机碳含量均最高,>0.25 mm不同粒级团聚体有机碳含量百分数均随粒径的减小而减小,均在0.5~0.25 mm粒级下达到最小。横坡和顺坡耕作模式下2~1 mm团聚体有机碳含量无显著差异。横坡耕作较顺坡耕作能够显著增加紫色土>2 mm水稳性团聚体含量,且对有机碳的固持作用更好,有利于土壤结构的改善。     

Improving animal drawn tillage system in Ethiopian highlands

In most smallholder farms in Ethiopian highlands, farmers still use the wooden ard plough (Maresha). This study was undertaken to understand and optimise the traction forces provided by the draught animals. An ard plough equipped with three load cells (one on the beam and one on each side of the yoke) was implemented to measure traction forces required for tillage of four Vertisol fields under wet and dry conditions. Tillage was performed at three different depths of shallow (0–5 cm), medium-deep (5–10 cm) and deep (10–15 cm). The interpretation of force measurement was done for equally and unequally strong pair of oxen. After tillage, soil samples were taken for the determination of bulk density and moisture content. The cross-section area of furrow profile (CSAFP) and depth were also measured.With the measurement of equally strong oxen, each ox provided 50% of the total traction force required for tillage. However, with unequally strong oxen, different contributions of each ox to the total traction force were found. The stronger ox moved faster than the weaker ox, creating an asymmetric position of the yoke. In this situation, the weaker ox had to work harder to overcome the force transferred from the strong ox and correct the asymmetric position of the yoke. Thus, the weaker ox had to provide a larger force to the total traction force compared to the stronger ox. A larger traction force was measured with the yoke asymmetric position for smaller depth, speed and CSAFP. Therefore, farmers in the Ethiopian highlands can improve the tillage efficiency of the Ethiopian ard plough by using equally strong pairs of oxen. However, with unequally strong oxen the weaker ox should be enhanced to walk a head of the stronger ox, allowing the latter to provide the larger required traction force.     

吉林玉米带现行耕作制度对黑土肥力退化的影响

该文从“体质”和“体型”两个方面探讨了吉林玉米带现行耕作制度对土壤肥力退化的影响。结果表明,现行的耕作制度下,土壤剖面中耕层与犁底层的界面为“波浪型”,而每年进行秋翻的玉米田,其耕层与梨底层的界面为“平面型”。“波浪型”犁底层的土壤容重、三相组成与“平面型”剖面相比有明显差异,而耕层中有机无机复合体及其有机碳分布特征无明显差异,与底层土壤有较大差异。但由于“平面型”剖面耕层的有效土量是“波浪型”有效土量的2倍,因此,在生产上“平面型”剖面土壤保水性能、玉米产量等多方面都普遍优于“波浪型”土壤。吉林玉米带黑土肥力退化的主要原因是耕层有效土量过少。     

Optimized soil inversion in the headlands with a novel section-controlled mouldboard ploughing system

In inversion tillage systems, the mouldboard plough is fundamental for producing a desirable seedbed. The desired ploughing quality is achieved when the plough layer is inverted homogeneously. This is, however, difficult to obtain in the main-headland intersection zone where the plough is lowered and elevated, as ploughed and unploughed triangles are formed. This results in zones where the soil is inverted twice, which may result in poor residue and weed incorporation and a poor seedbed quality. The design of the three-point linkage-attached mouldboard plough has not changed since the 1950s, but the number of furrows has increased, which has increased the size of the aforementioned triangles. A novel ploughing system was introduced to meet these headland challenges, where each plough section can be lowered and elevated independently. The aim of this study was to evaluate the effects of using a section-controlled mouldboard plough. Two similarly designed, randomized, field plot experiments were conducted on two different soil types (sandy loam and loamy sand) on a stubble field and grass field. The study showed that the section-controlled plough reduced the main-headland overlap area by ~98%. The results of a range of soil physical properties measurements and seedbed quality analyses showed that the section-controlled plough created a homogeneous loosened seedbed quality, improving the incorporation of crop residues and leaving fewer residues on the soil surface. Furthermore, the section-controlled plough showed additional benefits, for example wedge operations and visual line marking.     

红壤坡耕地耕层土壤质量特征及障碍因素研究

为探究红壤坡耕地耕层质量特征及其障碍因素,通过野外调查、资料查阅及室内土壤理化性质分析等综合性研究手段,对江西红壤坡耕地耕层土壤质量统计特征、演变特征及主要障碍因素进行分析。结果表明:(1)红壤坡耕地田面坡度主要分布在2~16°之间,耕层平均厚度13.40 cm,有效土层厚度平均88.30 cm,土壤容重平均为1.17 g/cm~3;耕层土壤有机质平均含量19.37 g/kg,土壤pH值平均5.36。(2)红壤坡耕地耕层质量近20年有明显提高,田面坡度从6°降至4°,耕层厚度从13.68 cm增至16.42 cm;耕层土壤有机质含量24.63 g/kg,提高33.93%,全氮、有效磷和速效钾含量分别增加10.53%、230.98%、44.18%。(3)红壤坡耕地低产耕层土壤质量的主要障碍因素是土壤养分贫瘠化、粘重化和酸化;花生和木薯低产耕层的土壤容重和粘粒含量均大于高产耕层,而土壤孔隙度、田间持水量、有机质含量及pH值均小于高产耕层,表明高产坡耕地耕层土壤质量优于低产坡耕地。研究结果可为江西红壤坡耕地耕层质量改善和合理耕层构建提供科学参考。     

Land‐use change and urbanization of Adana,Turkey

This study analyses land‐use/land‐cover (LULC) changes in Adana city, Turkey, using satellite data of 1984 and 2000. Study of the expansion of the city over adjacent agricultural fields and semi‐natural areas was the major focus. The satellite images were classified using supervised classification prior to comparison of LULC on two different dates. The change map was produced by pixel‐to‐pixel comparison of the classified images. Urban and built‐up area increased by a factor of 2ċ07 during the 16 years; about 30 per cent on agricultural land and 70 per cent on previously semi‐natural land. Permanent immigration and urban development strategies were the main driving forces. Some policy perspectives are also given. Copyright © 2003 John Wiley & Sons, Ltd.     

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。     

Specific draught for mouldboard plough, chisel plough and disc harrow at different water contents

The objective of the present study was to measure the specific draught (force per cross-sectional area of worked soil) and energy use for soil fragmentation for different tillage implements and soil conditions. Draught was calculated from measurements of fuel consumption and speed during tillage with a mouldboard plough and a chisel plough set to working depths of 13, 17 and 21 cm, and a disc harrow. Tillage was carried out at three different water contents (“Wet”, “Moist” and “Dry”) on two sites. The average working depth was calculated from weighing the loose soil within a 0.25-m² frame. Specific area of the soil was determined by sieving. Soil strength was measured in situ using a shear vane and a penetrometer. Average working depth was much less than the set working depth for the chisel plough. Specific draught was generally the lowest for the mouldboard plough and the highest for the chisel plough, and increased with decreasing soil water content. The specific draught was strongly correlated to soil cohesion, but not to penetration resistance. The proportion of coarse aggregates after tillage was the highest for the mouldboard plough and the lowest for the moist soil. The energy use for soil fragmentation was in most cases the lowest for the disc harrow, while there were small differences between the chisel and the mouldboard ploughs. The results show that the mouldboard plough is energy efficient for loosening soil, while the disc harrow is energy efficient for soil fragmentation during primary tillage. Tillage at an intermediate water content, close to the plastic limit, gave the largest proportion of small aggregates and consequently the lowest energy use for soil fragmentation.     

辽西地区土壤耕层及养分状况调查分析

目前,东北地区农田土壤耕层中明显存在的“浅、实、少”问题,已成为制约区域农业发展的主要限制因素。本文对辽西地区主要作物农田土壤耕层和养分状况进行了调查分析,结果表明：辽西地区的平均耕层为15.17 cm,比我国土壤平均耕层（16.5 cm）低1.33 cm。阜新、铁岭、朝阳、赤峰的有效耕层土壤量分别为2.27×106、1.97×106、1.95×106、1.79×106 kg/hm2,均低于正常有效耕层土壤量（2.72×106 kg/hm2）,分别低16.5%、27.6%、28.3%、34.2%。但阜新、铁岭、朝阳、赤峰的土壤体积质量平均值分别为1.32、1.38、1.33、1.33 g/cm3,均高于作物生长适宜的土壤体积质量范围（1.1 ~ 1.3 g/cm3）。同时,辽西地区土壤养分状况也较为低下,其中速效P总变异趋势最大,pH值总变异趋势最小。     

石羊河流域农田休闲期耗水规律研究

通过微型蒸渗器和diviner2000土壤水分测定仪测定了不同耕作及储水灌溉条件下农田休闲期土壤水分动态变化规律,并结合气象数据比较不同耕作方式和灌水处理的优越性,分析了休闲期不同耕作方式及储水灌溉措施对土壤水分及降水利用的影响。研究结果表明,春耕可减少农田表层土壤蒸发,保水效果较好;低定额储水灌溉既没有造成深层渗漏,且蒸发损失小;冬季大定额储水灌溉产生43.86 mm的深层渗漏和121.11mm的土壤水分蒸发,形成了水资源的无效流失;而春耕+免储水灌溉只产生54.41 mm水分损失,节水效果显著。土壤蒸发和深层渗漏产生的土壤水分损失大小顺序为:传统冬季储水灌溉>低定额储水灌溉>秋耕+免储水灌溉>春耕+免储水灌溉,低定额储水灌、秋耕+免储水灌溉、春耕+免储水灌溉处理土壤水分损失较对照分别减少53.44 mm、97.52 mm和110.56 mm(土面蒸发+深层渗漏)。石羊河流域春耕+免储水灌溉处理可有效减少休闲期水分损失,提高休闲期水分利用效率。     

Ergebnisse zur bodenverlagerung durch bearbeitungserosion in der jungmoränenlandschaft Nordostdeutschlands: Investigations of soil movement by tillage as a type of soil erosion in the young moraine soil landscape of Northeast Germany

Soil translocation by soil tillage can have a considerable importance on arable land. These results were published in the international literature. The aim of the experiments is to quantify the translocation of soil due to tillage with different typical tools. A mouldboard plough and a disc harrow were tested in field experiments on a slope (4° inclination) with sandy soil. The average movement of soil particles of the top soil was determined about the changed tracer concentration. The tracer coloured gravels were most suitable of all tested tracer. The comparison of the tools showed more soil translocation caused by mouldboard plough (145?kg) than by disc harrow (12?kg). The transport was also different: plough 0.50?m and disc harrow 0.11?m average distance.     

秸秆心土混合犁改良白浆土效果

为将表层秸秆施入心土,改善贫瘠的心土层创造有利条件,该文设计了将白浆土"上翻20 cm,下混30~40 cm,同时将有机物料施入心土层"的秸秆心土混合犁。该研究通过设置秸秆心土混合区和浅翻深松区田间对比试验,调查机械作业后土壤理化性质,指示作物农艺性状以及产量指标等,明确秸秆心土混合的改土增产机理,进一步拓宽白浆土改良途径,为机械改土技术的广泛应用提供技术支撑。研究结果表明:与浅翻深松相比,秸秆心土混合改善心土层土壤物理性质,20~40 cm土层土壤含水率提高2.69~4.90个百分点;硬度降低44.45%左右,且没有出现峰值;改善土壤通透性,固相降低幅度为4.51~2.14个百分点,液相增加幅度为1.17~4.13个百分点,气相增加幅度为0.38~0.98个百分点,容重下降幅度为0.16~0.11 g/cm~3;提高心土层养分含量,碱解氮提高17.33%,有效磷提高116.39%,速效钾提高37.86%,有机质提高36.66%,同时提高心土层全量养分含量,缓解土壤酸性。连续2 a调查大豆产量,秸秆心土混合区比对照区增产15.77%~16.33%,一次改土后效时间长,增产效果显著。该研究结果可为白浆土及其同类低产土壤改良及作物高产提供技术支撑。     

Performance of low-draft tillage implements on a hard setting Alfisol of the SAT in India

Abstract. Four bullock-drawn tillage implements (mouldboard plough, chisel plough, sweeps, and shovels) were evaluated on a hard-setting Alfisol. Measurements included draft requirement, bulk density, cone index, soil crust strength, water content of the plough-layer and crop yield. Changes in bulk density and cone index due to tillage decreased with time and were negligible by the end of the growing season. After tillage with a mouldboard plough the crust was stronger than after tillage with other implements. The shovel cultivator enabled the soil to store more water, and required least draft per unit effective area of cut.     

犁底层深度对膜下滴灌土壤水盐运移影响的模拟研究

为了探寻膜下滴灌条件下犁底层深度对土壤水盐运移的影响规律,采用室内土柱模拟试验与数值模拟相结合的方法,对不同犁底层深度（无犁底层,CK;25 cm深度,PB25;30 cm深度,PB30;35 cm深度,PB35;40 cm深度,PB40;45 cm深度,PB45）下土壤水盐运移规律进行了研究,结果表明:犁底层可以阻碍水分运移,降低水分入渗速率且有一定的阻水性,蒸发结束后PB处理表层10 ~ 20 cm土壤含水率比CK处理大;犁底层有一定的抑盐作用,CK处理上部10 ~ 20 cm土层的“洗盐”效果比PB处理好,蒸发结束后上部10 ~ 20 cm土层盐分最大的是PB30处理,最小的是PB45处理;利用HYDRUS-1D模型对膜下滴灌条件下犁底层对土壤水盐运移的变化规律进行模拟,经过实测数据验证,模拟效果较好。在现行以旋耕为主的传统耕作模式下,可根据不同作物根系吸水和耐盐的特点适度深耕打破犁底层,为作物生长创造适宜的水盐环境。研究结果可为新疆地区盐碱地改良、农业生产可持续发展提供参考。     

黄河三角洲地区浅层地下水与耕层土壤积盐空间分异规律定量分析

为研究黄河三角洲地区地下水作用条件下耕层土壤的积盐规律，运用GIS和地统计学的原理与方法，结合地下水埋深的空间分布以及临界埋深的划分标准对研究区域进行分区，并从空间尺度对各分区地下水矿化度与耕层土壤积盐规律进行了定量分析。结果表明：地下水埋深、矿化度和耕层土壤盐分均属于中等变异强度，在东西方向和南北方向上均具有2阶的趋势效应；受结构性因素和随机性因素的共同作用，地下水埋深呈中等的空间自相关性，地下水矿化度与耕层土壤盐分呈弱空间自相关性；耕层土壤盐分与地下水矿化度的空间分布具有一定的相关性，与地下水埋深呈负相关性。对空间尺度上的地下水矿化度与耕层土壤盐分定量分析结果表明，耕层土壤积盐与地下水矿化度呈极显著的相关关系，而地下水埋深增加使其相关性减弱，采用分区研究法使地下水矿化度对耕层土壤积盐规律分析更加客观准确。该结果对研究黄河三角洲地区土壤盐渍化的发生机理以及预测与评估该地区土壤盐渍化的发生发展具有重要意义。     

秸秆焚烧对不同耕层土壤酶活性、微生物数量以及土壤理化性状的影响

以秸秆焚烧后覆盖的耕层土壤为对象,研究秸秆焚烧对不同耕层土壤酶(过氧化氢酶,磷酸酶,脲酶和多酚氧化酶)活性、微生物数量的影响,并探讨土壤有机质含量、含水量、速效养分、微生物数量的增减程度与土壤酶活性增减程度的相关性。结果表明:过氧化氢酶、磷酸酶、脲酶和多酚氧化酶活性在焚烧秸秆后有不同程度的降低,其中耕层0-2cm,2-5cm土壤酶活性在焚烧前后都形成极显著性差异,5-13cm耕层的酶活性变化较小,13-20cm耕层的酶活性没变化。在微生物数量方面,焚烧秸秆导致0-2cm耕层的微生物数量大幅度减少,减少程度在80%左右,2-5cm耕层的微生物数量也有43%～52%的减少,5-13cm和13-20cm耕层的微生物数量没有变化。相关性分析表明,只有脲酶活性的降低程度与速效磷含量的增加程度达到显著相关,相关系数是0.959*。多酚氧化酶活性的降低程度与细菌、放线菌、真菌数量的降低程度均呈极显著相关性,相关系数分别是0.998**,0.999**,0.998**。同时脲酶活性的降低程度与细菌、放线菌、真菌数量的降低程度均呈显著相关性,相关系数分别是0.977*,0.974*,0.954*。