Effect of different tillage systems on the quality and crop productivity of a clay–loam soil in semi-arid north-western Turkey

A 2-year study was conducted to investigate the effect of three tillage systems on the properties of clay–loam soil (EutricVertisol) planted with winter wheat (Triticum aestivum L.) in the Canakkale province of north-western Turkey. Crop productivity was also evaluated. The three tillage treatments were: (1) conventional tillage involving mouldboard ploughing followed by two discings (MT); (2) shallow tillage consisting of rototilling followed by one discing (RT); (3) double discing (DD). In the first year of the study, bulk density (BD) was found significantly lower under RT at both 0–10 and 10–20 cm depths with 1.24 and 1.32 Mg cm⁻³, respectively, when compared to MT treatment. However, MT at 20–30 cm provided the highest BD, at 1.49 Mg cm⁻³. In the second year of the study, DD had the lowest BD at all depths followed by RT and MT. Based on the 2-year mean, aggregate size distribution (ASD) and mean weight diameter (MWD) were significantly influenced by tillage treatments. The greatest MWD was obtained with DD, followed by MT and RT. Increasing MWD and coarse aggregates decreased seedling emergence. Organic carbon increased after RT, DD, and MT by 58%, 30%, and 18%, respectively, when compared to the amount at the beginning of the study. Similarly, the total N in the soil and straw was higher after RT than the other treatments. At 1.76 MPa, penetration resistance at 18–30 cm was significantly higher during the growing period using DD, followed by RT with 1.35 MPa and MT with 1.33 MPa. There was no significant difference between treatments at 0–18 cm. Increasing OC and total N and decreasing BD and PR under RT increased grain yield to 4611 kg ha⁻¹, followed by MT and DD at 4375 and 4163 kg ha⁻¹, respectively, according to the 2-year mean.     

不同耕作方式对坡耕旱地土壤环境及小麦产量的影响

在长期定位试验的基础上,研究分析了免耕覆盖与深松覆盖保护性耕作技术对降水贮蓄率、入渗、容重、养分、温度等土壤环境因子及小麦产量的影响,结果表明,这2项技术可提高土壤养分含量,增加土壤饱和导水率,减缓地表温度的日变化幅度,提高土壤对降水的利用率及小麦产量。增产最高可达18.89%与20.87%,但其应用效果年际间差异较大。免耕覆盖降水贮蓄率为34.8%~77.4%,深松覆盖为38.7%~75.0%;免耕覆盖的小麦水分利用效率为1.04~1.82 kg/m3,深松覆盖为1.07~1.77 kg/m3。     

Impact of agronomic practices on populations of Fusarium and other fungi in cereal and noncereal crop residues on the Canadian Prairies

Fusarium head blight (FHB) is an important disease which has been causing damage to wheat and barley crops in western Canada. Because crop residues are an important source of inoculum, it is important to know the ability of Fusarium spp. to colonize and survive in different residue types, and how their populations might be affected by agronomic practices. Sampling of residue types on producers’ fields for quantification of Fusarium and other fungi was conducted in 2000–2001 in eastern Saskatchewan. Fusarium spp. were isolated from most fields, whereas their mean percentage isolation (MPI) was over 50% for cereal and pulse residues, and under 30% for oilseed residues. The most common Fusarium, F. avenaceum, had a higher MPI in pulse and flax (45–48%) than in cereal or canola (10–22%) residues. This was followed by F. equiseti, F. acuminatum, F. graminearum, F. culmorum and F. poae which were isolated from all, or most, residue types. Factors affecting Fusarium abundance in residues included the current crop, cropping history, and tillage system. In cereal residues, the MPI of F. avenaceum was higher when the current crop was another cereal (24%) versus a noncereal (4–8%). When the current crop was another cereal, the lowest MPI of F. avenaceum and F. culmorum occurred when the field had been in summerfallow (SF) two years previous (F. avenaceum: 17% for SF, 28% for a crop; F. culmorum: 1% for SF, 4% for a crop); in contrast, F. equiseti and Cochliobolus sativus were most common in residues of cereal crops preceded by SF (F. equiseti: 16% for SF, 10% for a crop; C. sativus: 22% for SF, 13% for a crop). The MPI of F. graminearum was higher when the crop two years previous was an oilseed (7%) versus a cereal (4%). In regards to tillage effects, when the current crop was a cereal, the MPI of F. avenaceum was higher under minimum (MT) and zero tillage (ZT) (22–37%) than conventional tillage (CT) (15%), that of F. graminearum was lowest under ZT (3% for ZT, 7–11% for CT-MT), whereas that of C. sativus was highest under CT (27% for CT, 6–11% for MT-ZT). Under ZT, previous glyphosate applications were correlated positively with F. avenaceum and negatively with F. equiseti and C. sativus. These observations generally agreed with results from previous FHB and root rot studies of wheat and barley in the same region. Percentage isolation of F. avenaceum from noncereal and of F. graminearum from cereal residues were positively correlated with FHB severity and percentage Fusarium-damaged kernels of barley and wheat caused by the same fungi.     

耕作方式对土壤理化性状及夏玉米生长发育和产量的影响

研究耕作方式对土壤理化性状、夏玉米生长发育及籽粒产量的影响,为黄淮海北部地区土壤结构改善和籽粒产量提高提出有利的科学依据。试验设夏玉米前茬深松、翻耕、隔年深松和传统耕作旋耕4个处理。研究结果表明,深松、隔年深松、翻耕能够显著降低10 cm以下土层的土壤紧实度;提高各生育时期土壤含水量,尤其以20～40 cm土层表现最为明显;增加20～60 cm土层速效钾含量;有利于维持夏玉米灌浆中后期叶面积指数,干物质的积累量增加7．79％～18．09％;提高籽粒最大灌浆速率、平均灌浆速率,每公顷产量提高4．1％～9．3％。各处理间以深松和隔年深松处理表现最好,且两处理无显著差异。本试验条件下,隔年深松是兼顾高产节能高效的耕作方式。     

河北省保护耕作的区域战略与技术需求分析

综合分析了河北省与土壤耕作有关的农业资源环境问题,指出河北省推广保护耕作应以解决区域性的土壤沙化、水土流失、资源利用率低等突出的资源环境问题为主要出发点, 以经济效益、社会效益及生态效益的综合提高为目标。     

基于离散元软件的大豆垄上深松铲仿真试验分析

为了合理优化大豆垄上深松铲的作业性能和作业效果,对传统大豆垄上圆弧式深松铲进行理论分析,通过分析深松铲正常作业时的耕作阻力以及对土壤的作用确定深松铲结构参数,并借助计算机离散元软件对深松铲进行仿真试验,研究深松铲结构参数对于其耕作阻力及土壤扰动面积的影响,从而优化深松铲结构。理论分析得到深松铲切削角范围为30°~60°,入土角范围为19°~23°。2因素5水平正交旋转组合离散元仿真试验得到:影响深松铲耕作阻力的主次因素为切削角、入土角;影响深松铲土壤扰动面积因素的主次顺序为深松铲切削角、入土角;理论上当深松铲切削角34.39°、入土角20.24°时,耕作阻力为804.799 N,扰动面积为418.42 mm^2。验证试验结果表明,优化后的深松铲与理论值相比,耕作阻力增加7.92%,土壤扰动面积增加7.54%,均与理论值偏差较小,仿真优化结果可靠。优化后的深松铲作业性能与作业效果优良,为大豆垄上深松铲的优化设计提供一定依据。     

不同机械耕作模式对土壤理化性状及小麦产量的影响

为解决多年秸秆还田和单一旋耕模式使土壤耕层变浅、土壤持水能力变弱、土壤容重加大及土壤速效养分提升慢等问题,连续6年选择有代表性土壤,以常规旋耕作业为对照,开展小麦播种前机械深松、深翻、旋耕不同耕作技术模式作业试验,探究其对土壤及小麦产量的影响。结果表明,土壤深翻、深松都不同程度地降低土壤容重,提高土壤通透性,小麦穗数、千粒质量均高于对照旋耕作业,较旋耕小麦产量分别增产5.66%和3.87%。     

Effect of seedbed cultivation and soil macrostructure on the establishment of winter wheat (Triticum aestivum)

Soil physical properties affect the establishment of crops; these properties are influenced by cultivation incurred during seedbed preparation and vary greatly depending upon the intensity of applications. However, there is little quantified data concerning the influence of cultivation upon the precise soil structural arrangement and the effects of this on crop establishment. The dynamics of soil macrostructure properties on a range of seedbeds and how they relate to crop establishment are considered in this paper. Significant interactions between cultivation techniques, soil physical properties, the soil macropore structure of the seedbed and the interaction with crop establishment were identified. The relationship between soil structure and crop establishment was highly significant, with increased pore space reducing final establishment numbers. An improvement to a previously developed model (soil quality of establishment (SQE)) was developed following the addition of soil macrostructure properties, accounting for improved predictability of between ca. 6% and 19% of the variation accounted across soil types, environmental conditions.     

夏玉米残茬覆盖与耕作方式的研究

对小麦机械收获后残茬覆盖与不覆盖两种条件下免耕、翻耕和间隔深松三种土壤耕作方式夏玉米的营养生长及籽粒产量进行了研究。结果表明,残茬覆盖和深松耕作玉米播种后出苗率高,次生根条数多,株高增加而基部节间缩短,叶面积系数提高,最终产量显著高于其他处理。