How do we cultivate in England? Tillage practices in crop production systems          下载免费PDF全文

T. J. Townsend  S. J. Ramsden  P. Wilson 《Soil Use and Management》2016,32(1):106-117

Reducing tillage intensity offers the possibility of moving towards sustainable intensification objectives. Reduced tillage (RT) practices, where the plough is not used, can provide a number of environmental and financial benefits, particularly for soil erosion control. Based on 2010 harvest year data from the nationally stratified Farm Business Survey and drawing on a sub‐sample of 249 English arable farmers, we estimate that approximately 32% of arable land was established under RT, with 46% of farms using some form of RT. Farms more likely to use some form of RT were larger, located in the East Midlands and South East of England and classified as ‘Cereals’ farms. Application of RT techniques was not determined by the age or education level of the farmer. Individual crops impacted the choice of land preparation, with wheat and oilseed rape being more frequently planted after RT than field beans and root crops, which were almost always planted after ploughing. This result suggests there can be limitations to the applicability of RT. Average tillage depth was only slightly shallower for RT practices than ploughing, suggesting that the predominant RT practices are quite demanding in their energy use. Policy makers seeking to increase sustainable RT uptake will need to address farm‐level capital investment constraints and target policies on farms growing crops, such as wheat and oilseed rape, that are better suited to RT practices.  相似文献   

Short-term responses of soil nutrients and corn yield to tillage and organic amendment     

Ruhollah Naderi  Mohsen Edalat  Seyed Abdolreza Kazemeini 《Archives of Agronomy and Soil Science》2016,62(4):570-579

Field experiments were conducted in 2010 and 2011 at the Agricultural College of Shiraz University to evaluate the effects of cattle manure and nitrogen (N) fertilizers on soil properties such as soil organic carbon (SOC), soil organic nitrogen (SON), soil electrical conductivity, soil pH and corn yield under two tillage systems. Treatments included tillage systems in two levels as conventional tillage and reduced tillage as subplots, cattle manure (0, 25 and 50 tons ha^?1) and N fertilizer (0, 125 and 250 kg N ha^?1) as sub-subplots. Results showed that SOC and SON were significantly affected by tillage system in both years of the experiment. SOC and SON were higher in reduced tillage compared to conventional tillage. Tillage system had no significant effect on grain yield, plant height and 1000 seed weight. Increased cattle manure rates at 25 and 50 tons ha^?1 increased grain yield by 27% and 38%, respectively, in 2010 and 25% and 25% in 2011. The results showed that application of cattle manure combined with N fertilizer might be an efficient management to increase soil productivity in southern Iran, in soils with poor organic content. Additionally, reduced tillage showed to be an efficient method to increase soil organic matter.  相似文献   

一膜两年覆盖条件下耕作方法对旱作玉米产量及土壤物理性状的影响   总被引：6，自引：1，他引：5  

谢军红  李玲玲  张仁陟  罗珠珠  蔡立群  柴强 《水土保持学报》2016,(3)

为了优化全膜双垄沟播玉米土壤耕作技术,实现土壤质量保育和增产增效,布设田间定位试验,比较研究了一膜两年全膜双垄覆盖条件下,少免耕对玉米产量、水分利用效率(WUE)、经济效益及土壤物理性状的影响。结果表明:一膜两年用条件下,深松耕—免耕较对照能显著提高玉米的籽粒产量、水分利用效率、收获指数、总产值及产投比,其籽粒产量、水分利用效率、收获指数、总产值及产投比分别较对照提高22.8%,22.0%,15.0%,17.4%,17.4%;深松耕—免耕具有降低表层土壤容重、紧实度,增加土壤总孔度、大团聚体含量及饱和导水率的作用,全膜双垄沟播玉米采用深松耕—免耕具有明显的稳增产增效及土壤结构改善的作用,建议在全膜双垄沟播玉米种植体系中推广应用。  相似文献   

免耕轮作对旱作区土壤水热动态及速效养分含量的影响   总被引：1，自引：0，他引：1       下载免费PDF全文

戴云仙  张向前  郭晓霞  杨彦明  王林  刘景辉 《中国土壤与肥料》2016,(6):14-20

免耕轮作对土壤性质有明显改善作用。在免耕秸秆覆盖基础上进行燕麦、玉米、大豆3种作物轮作2个周期的试验研究。结果表明,免耕秸秆覆盖结合不同作物轮作能调节土壤水热环境,增加土壤速效养分含量。土壤贮水量在不同处理间总体表现为免耕留高茬覆盖(NHS)免耕留低茬覆盖(NLS)免耕留高茬(NH)免耕留低茬(NL)常规翻耕(T),3种轮作方式中均以燕麦-大豆-玉米方式最高。轮作2个周期后NHS、NLS、NH、NL分别较T土壤贮水量在作物苗期增加了16.24%、12.16%、8.75%、5.56%,可见免耕覆盖能明显提高土壤水分蓄储能力。土壤温度在0~5 cm土层受外界环境影响最大;免耕覆盖在低温时起"保温作用",能提高土壤温度1.4~2.4℃;高温时起"降温作用",能降低土壤温度1.8~3.4℃;秸秆覆盖后土壤温度日变化平缓。同时免耕结合轮作处理能不同程度增加土壤有机质及速效养分含量,说明免耕轮作在该地区能较大程度的改善土壤性质,为提高作物产量提供了基础和有效保证。  相似文献   

Market‐level assessment of the economic benefits of atrazine in the United States     

Paul D Mitchell 《Pest management science》2014,70(11):1684-1696

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凸轮转子泵的流场及脉动特性数值分析     

刘忠族  王秋波 《排灌机械工程学报》2014,32(3):208-213

随着舰船减振降噪要求的进一步提高,管路噪声逐步成为这一目标的主要障碍,而泵类设备则是管路噪声最主要的噪声源.传统离心泵由其高转速及强烈的动静干涉决定了它在进一步降低自身诱导噪声上的局限性,而新型的凸轮转子泵则具有较大的优势.因此为研究该型泵的主要性能与流场特性,在系统分析凸轮转子泵的工作原理及技术特点的基础上,建立了该泵的二维、三维直翼、三维扭曲翼模型,通过基于动网格的CFD分析计算了凸轮转子泵的流场及脉动特性.计算结果表明:新型凸轮转子泵的流量与转速呈线性关系且呈现出周期性脉动;泵内压力分布稳定,各区域没有明显的压力梯度,在转子间隙及进出口区域存在旋涡及流动分离现象,此处流速较大;转子泵泵内压力脉动随转子叶片数的增大及采用螺旋翼型能够得到有效降低,而随着转速的增大也会迅速增大.  相似文献   

东北黑土区不同地形垄向坡度的相对水土保持效益研究   总被引：1，自引：1，他引：0  

赵玉明    姜洪涛    王世界 《水土保持研究》2014,21(5):28-34

垄作是东北黑土区一种非常普遍而重要的耕作措施,具有一定的水土保持效益,但几乎没有学者对其进行研究。探讨黑土区不同地形垄作方向在空间上的分布规律及其具有的水土保持效益具有重要研究价值。以黑龙江省宾县为研究区,用分层抽样的方法提取168个野外调查单元并进行实地填图调查,根据坡度因子和垄向坡度计算公式,利用ArcMAP、SPSS和Excel等软件进行了室内数据分析统计,结果表明:平原区、丘陵区、山区的平均地面坡度分别为1.92°,6.20°,8.27°;平均垄向坡度分别为1.33°,4.52°,6.45°,分别为平均地面坡度的70%,73%,78%;垄作坡度引起的平均土壤流失相对量分别为地面坡度的55%,69%,67%,垄作的相对水土保持效益明显。在此基础上,对垄作现状的原因进行了分析,并提出一些改进措施。研究成果有助于了解东北黑土区不同地形耕地垄作方向的分布情况及其水土保持效益状况,对当地水土保持措施的布设也具有重要的指导意义。  相似文献   

免耕玉米田杂草群落消长初探   总被引：1，自引：0，他引：1  

樊翠芹 《中国农学通报》2014,30(27):119-126

为了研究“小麦-玉米”一年两熟制农田,连续免耕对玉米田杂草群落演替及对玉米产量的影响,进行了田间小区试验,采用倒置“W”取样法调查不同耕作方式玉米田杂草种类和数量,用生测法测杂草鲜重,玉米成熟后测产。结果表明：免耕覆盖麦秸和免耕玉米田的杂草种类由12种增加到13种,旋耕玉米田杂草种群构成没有变化,有11 种杂草。免耕覆盖麦秸1~5 年,其玉米田杂草数量比旋耕田少,6~7年,二者杂草数量差异不大;免耕1~4 年,免耕玉米田的杂草数量与旋耕田相比互有消长,从第5 年开始免耕田杂草数量一直比旋耕田多;免耕覆盖麦秸的玉米田牛筋草所占比率明显降低,而马唐所占比率呈增加趋势。连续免耕3 年后,免耕覆盖和免耕田玉米产量均下降,前者的降低幅度低于后者。免耕覆盖麦秸能减少玉米田杂草发生数量,而随免耕年限的延长抑制效果下降;免耕年限越长玉米田杂草发生越严重。  相似文献   

The impact of management on weeds and aquatic plant communities in Hungarian rice crops     

G Pinke  J Csiky  A Mesterházy  L Tari  RW Pál  Z Botta‐Dukát  B Czúcz 《Weed Research》2014,54(4):388-397

This study assessed the cultural and weed management factors influencing the weed communities of Hungarian rice fields. Hungary is situated at the northern limit of rice production with a history of about 300 years of rice culture. We surveyed the weed flora and 25 background variables in 100 active rice fields. Using a minimal adequate model containing 11 terms, 48.5% of the total variation in weed species data could be explained. The net effects of nine variables on species composition were significant. Crop cover was found to be the most important explanatory variable, which was followed by the herbicides penoxsulam and azimsulfuron, tillage depth, phosphorous and potassium fertilisers, years after last rotation, water depth in May, sowing type, pendimethalin and water conductivity. Filamentous algae, as the most abundant group of weeds, were positively associated with deep tillage, deep water and surface sowing. Echinochloa crus‐galli, one of the most troublesome grass weeds, was associated with low rice cover, shallow water and later years after crop rotation, while weedy rice favoured high crop cover, deep water and soil sowing. These findings can be used to design improved weed management strategies. The occurrence of red list species and charophytes in diverse micro‐mosaic patterns deserves attention from a conservation perspective, as well. The maintenance of these unique charophyte communities can be facilitated by shallow tillage without soil inversion.  相似文献   

Identifying the effect of density dependence,agricultural practices and climate variables on the long‐term dynamics of weed populations     

D García de León  R P Freckleton  M Lima  L Navarrete  E Castellanos  J L González‐Andújar 《Weed Research》2014,54(6):556-564

Quantifying the impacts of climate change on weed populations requires an understanding of the relative contributions of endogenous and exogenous factors on their numerical fluctuations. Here, we have used long‐term data (26 years) of seven weed species growing in a cereal–legume rotation from a locality in central Spain to determine the importance of endogenous (density dependence) and exogenous (tillage system, crop rotation, temperature and precipitation) factors. Density dependence was the main driver of the population dynamics studied, and it was exhibited more frequently under zero tillage (86% of the species) than under minimum tillage (57% of the species). Our results confirmed previous findings and provided stronger support for density dependence under zero tillage than under minimum tillage. Under the latter, temperature negatively affected the population growth rate of Descurainia sophia and positively Atriplex patula. We found no effect of either precipitation or crop rotation on population dynamics. Our findings could underpin an awareness campaign aimed at farmers to prevent them from drawing unwarranted conclusions regarding the efficacy of the particular control method used in a given year.  相似文献