Identifying the position of the compacted layer by measuring soil penetration resistance in a dryland farming region in Northeast China     

Zhiqing Zhuo  An Xing  Meng Cao  Yong Li  Yunze Zhao  Xiaoli Guo  Yuanfang Huang 《Soil Use and Management》2020,36(3):494-506

Topsoil is disturbed by ploughing, the effects of infiltration, the movement of fine particles from the topsoil to the subsoil, and direct pressure from agriculture machinery, all creating an abrupt delineation in the form of a compacted layer with very low permeability. Spatial variability of soil properties, such as soil structure and penetration resistance (PR), can help identify the compacted layer. However, there are no quantitative methods to describe this layer. In this study, PR was used to survey different soil types. A Mann–Kendall (M-K) test of PR data was used to identify the presence and position of the compacted layer in a dryland farming region of Northeast China. Our results demonstrated that PR was mainly affected by bulk density and soil water content. Compared with the topsoil, PR was more significantly affected by water content in deeper soil layers. An M-K test of the PR curve can provide a more reliable and objective assessment of the thickness of the plough layer and location of the compacted layer than field observation. Our data indicated that there was a compacted layer in the soil profile in the study areas and the spatial variability of the compacted layer was heterogeneous. The plough layer was shallow, and the compacted layer was thicker in areas with frequent use of agricultural machinery. Moreover, frequent use of agricultural machinery resulted in a PR of the plough and compacted layers that was greater than that in other areas. Information on identifying the position and thickness of the compacted layer and the factors influencing their spatial distribution can be used to create effective soil management options and improve conditions for the development of plant roots in dryland farming regions.  相似文献   

秸秆覆盖量对旱地小麦结实期抗氧化性的影响     

王贺正  黄明  张均  马超  吴金芝  李友军  陈明灿  付国占 《草业学报》2019,28(11):96-104

为了阐明秸秆覆盖对小麦结实期活性氧代谢的影响,筛选适宜豫西旱地小麦高产栽培的秸秆覆盖量。以豫麦49-198为材料,采用大田试验,设置5个秸秆覆盖量[不覆盖为对照(Ⅰ)、2000(Ⅱ), 4000(Ⅲ), 6000(Ⅳ)和 8000 kg·hm^-2(Ⅴ)],研究了小麦抽穗期后不同时间(0、10和20 d)旗叶主要活性氧、抗氧化酶、抗氧化物质、渗透调节物质和产量的变化。结果表明,与对照相比,秸秆覆盖降低了抽穗后小麦旗叶超氧阴离子($O^{-·}_{2}$)、过氧化氢(H₂O₂)和丙二醛(MDA)含量,处理Ⅳ降幅最大,抽穗后20 d,两年分别比对照平均下降了43.0%、32.2%和30.4%;增加了可溶性糖、氨基酸、谷胱甘肽(GSH)和抗坏血酸(AsA)含量以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性,处理Ⅳ增幅最大,抽穗后20 d,两年分别比对照平均增加了28.3%、120.5%、110.5%、11.6%、44.7%、47.6%和57.5%;Ⅳ处理的各测定指标均优于其他覆盖处理且与对照差异显著。在一定秸秆覆盖量范围内(2000~6000 kg·hm^-2)各测定指标随覆盖量而增幅(降幅)明显,但覆盖量超过一定水平后,各指标增幅(降幅)不明显。试验表明,适量的秸秆覆盖能够提高活性氧清除能力,减缓活性氧积累,增加小麦产量;在豫西旱地生态条件下,6000 kg·hm^-2为最佳秸秆覆盖量。  相似文献   

旱地玉米不同覆盖栽培模式的土壤水热特征及产量品质效应   总被引：2，自引：0，他引：2  

李尚中  樊廷录  赵刚  党翼  王磊  张建军  唐小明  程万莉 《草业学报》2018,27(4):34-44

揭示不同覆盖时间、覆盖方式和覆盖材料调节土壤水热环境、影响玉米产量和品质的差异,为旱地玉米高产优质栽培提供依据。试验采用裂区设计,主区为秋季覆盖和播前覆盖2个处理,裂区为垄沟和平面2个处理,裂裂区地膜、秸秆和露地3个处理。测定不同处理玉米生育期耕层土壤温度,玉米主要品质指标,播前和收获0~2 m土层土壤贮水量,结合玉米籽粒产量分析水分利用效率。结果表明,冬春休闲期,不论是地膜还是秸秆覆盖都可以提高玉米播前0~2 m土层土壤贮水量,依次为42.2和43.7 mm,垄沟覆盖和平面覆盖播前贮水量差异不显著。玉米全生育期,地膜覆盖较露地可平均提高地温 1.4 ℃,而秸秆覆盖降低了 2.9 ℃,平面覆盖平均温度为23.2 ℃,较垄沟覆盖提高1.8 ℃。地膜覆盖产量和水分利用效率较秸秆覆盖依次提高42.8%和38.2%,较露地分别提高47.3%和36.0%,秋覆盖产量和水分利用效率较播前覆盖分别提高7.1%和4.5%,垄沟地膜覆盖平均产量和水分利用效率较平面地膜覆盖增产6.3%和5.2%,而垄沟秸秆覆盖和垄沟露地均表现出减产效应。秋覆盖提高了玉米容重、脂肪、蛋白质和淀粉含量,但与播前覆盖差异不显著。地膜覆盖提高了玉米容重和脂肪含量,降低了蛋白质,对淀粉含量影响差异不显著,秸秆覆盖提高了脂肪,降低了容重和蛋白质含量,垄沟覆盖提高了玉米淀粉含量,降低蛋白质含量,对容重和脂肪含量影响差异不显著。可见,覆盖时间、覆盖方式和覆盖材料对玉米播前土壤水分、耕层土壤温度、产量、水分利用效率和品质均有一定的调控作用,总体表现为覆盖材料>覆盖方式>覆盖时间。在生产实际中,应根据生产目标选择适宜的覆盖栽培模式。  相似文献   

Forage and Food Legumes in a Multi‐Year,Wheat‐Based Rotation Under Drought‐Stressed Conditions in Northern Syria’s Medium Rainfall Zone     

S. Christiansen  J. Ryan  M. Singh 《Journal of Agronomy and Crop Science》2011,197(2):146-154

Long‐term crop rotation trials were designed to assess sustainability of alternatives to traditional fallow and monocropping. The trial described here (6 years) involved wheat (Triticum aestivum L.) in rotation with lentil (Lens culinaris L.), forage vetch (Vicia sativa), pasture medic (Medicago spp.), fallow and watermelon (Citrullus vulgaris). Barley (Hordeum vulgare L.) was compared with wheat for an additional 2 years. Cereal grain and straw yields were highest with fallow and watermelon followed by vetch, lentil and medic; the latter showed no differential effect of variable grazing intensity. Fertilizer N increased yields except in the low‐rainfall years (less than 250 mm). Barley out‐yielded wheat in terms of grain, but not straw. Medic yielded highest in dry matter, whereas lentil produced highest seed yield. Despite the difficulty of assessing crop and animal‐oriented rotations because of non‐commonality of outputs, economic considerations are foremost, but other benefits of rotations (soil quality, water‐use relations) are also relevant to the overall assessment of cereal‐based Mediterranean rotations. The study suggested barley rather than wheat as the desired cereal in rotation with legumes in this marginal‐rainfall (350 mm) environment and provided support for the viability of vetch and lentil in the cropping system. Given the importance of sheep in the region’s farming system, vetch is likely to have a major role in crop rotations.  相似文献   

Fertilizer Best Management Practices: A Perspective from the Dryland West Asia–North Africa Region     

J. Ryan  R. Sommer  H. Ibrikci 《Journal of Agronomy and Crop Science》2012,198(1):57-67

Chemical fertilizer use has contributed significantly to increased global food output in the past half century, especially in climatically favourable regions of the world. However, in drier agro‐ecological zones, such as in West Asia and North Africa (WANA) with a Mediterranean‐type climate, fertilizer use has been low but has increased rapidly in the past few decades. Chemical fertilizer use is now widely adopted in rainfed and irrigated agriculture. As elsewhere, fertilizer use is underpinned by concerns about biological and economic efficiency. Fertilizer use efficiency is central to the current concept of fertilizer best management practices (FBMP), which embraces right source, right place, right timing and right application method. In this brief review, we highlight such FBMP concepts as related to agriculture of the WANA region, with emphasis on the key nutrients for crop production. Rainfall has a dominant influence on dryland crop yields. Nitrogen (N) use efficiency increases with increasing rainfall and is influenced by crop rotation. Under rainfed conditions, modest N losses by volatilization can occur. Leaching losses are usually minimal. Phosphorus use (P) efficiency is higher with band application than with broadcasting. Balanced fertilization, especially involving potassium (K) and micronutrients, is fundamental to efficient nutrient use. Fertilizer efficiency is also influenced by soil test values and agronomic factors that influence crop yields, e.g. sowing date and varietal differences. Rational fertilizer application rates are guided by calibration–response trials. Effective fertilizer use in the region is also dictated by external factors such as government policies and a functioning extension service. In contrast to other regions of the world, environmental impacts from the overuse of fertilizers are relatively minor, while developments in fertilizer formulations that promote efficiency have yet to have impact. Despite the relatively low fertilizer use intensity in dryland areas such as the WANA region, the FBMP comprehensive approach is a logical framework within which to achieve the most efficient management and use of fertilizer in the region’s agriculture.  相似文献   

Tree planting for dryland salinity control in Australia   总被引：1，自引：0，他引：1  

N. J. Schofield 《Agroforestry Systems》1992,20(1-2):1-23

Dryland salinity is emerging as a major form of land and water degradation in southern Australia, particularly in Western Australia, South Australia and Victoria, and to a lesser extent in New South Wales, Tasmania and Queensland.Tree planting, in combination with other vegetation treatments, is regarded as a leading solution to dryland salinity. Research has now shown that planting trees can significantly lower groundwater tables, and thereby reverse the causal process of salinisation. Substantial progress has been made towards answering the basic questions of which species to grow, how to plant, where to plant, at what density and configuration to plant, and how much area to plant. The economic potential for commercial tree planting has given impetus to partial reforestation in higher rainfall (> 600 mm yr^–1) areas. Even so, serious constraints are apparent, relating primarily to cost, uncertainty and attitude. The future should bring increasing community input and control, technical refinement and gradual adoption, provided all aspects of the issue are well researched, relevant information is well communicated and programmes are well administered. Some specific requirements for future research are identified in this review.  相似文献   

Plant community and ecological analysis of woodland vegetation in Metema Area, Amhara National Regional State, Northwestern Ethiopia     

Haile Adamu Wale  Tamrat Bekele  Gemedo Dalle 《林业研究》2012,23(4):599-607

We studied woodland vegetation in broad-leaved deciduous woodlands of Metema in northwestern Amhara regional state,Ethiopia to determine plant community types and species distribution patterns and their relationships with environmental variables,including altitude,pH,cation exchange capacity,electrical conductivity(EC),and moisture.We used a selective approach with a systematic sampling design.A total of 74 quadrats,each 25m × 25m at intervals of 150 200 m were sampled along the established transect lines.For herbaceous vegetation and soil data collection,five subquadrats each 1m × 1m were established at the four corners and the center of each quadrat.Three community types were identified using TWINSPAN analysis.All three community types showed high diversity(Shannon-Weiner index),the highest in community type II at 3.55.The highest similarity coefficient was 0.49(49%) between community types II and III,reflecting 0.51(51%) dissimilarity in their species richness.The canonical correspondence ordination diagram revealed that the distribution pattern of community type I was explained by moisture while that of community types III and II was explained by EC and altitude and moisture,respectively.Altitude was the most statistically significant environmental variable,followed by moisture and EC in determining the total variation in species composition and distribution patterns while pH and cation exchange capacity were non significant.In conclusion,we recommend that any intervention should take into account these three discrete community types and their environmental settings to make the intervention more successful.  相似文献   

干旱季节渭北果园土壤水分时空变化特征   总被引：2，自引：0，他引：2  

张露  王益权  石宗琳  焦彩强  喻建波  冉艳玲  高航 《干旱地区农业研究》2012,30(1):83-89

针对渭北旱塬干旱季节主要发生在春季到夏初,制约苹果早期生长发育的客观实际,对渭北旱塬苹果园和农田从3月初到5月底,0～100 cm土壤含水量时空变化进行了研究。结果表明:冬春季渭北果园土壤含水量明显高于农田,进入春季随着果树萌发并进入生长旺盛季节,果园土壤水分消耗较小麦农田更为明显,在0～100cm果园土壤耗水量显著,其中5月份0～60 cm土壤水分消耗更加明显。而农田土壤水分消耗层主要在0～30 cm。相对于农田而言,冬春季渭北果园土壤表现出极为明显的保墒性,有助于缓解春旱的威胁;而春季到夏初则表现为极为显著的土壤耗水性,土壤干燥化趋势明显,5月初为果园土壤水分管理的关键时期。  相似文献   

旱地小麦休闲期深翻覆盖配套不同播种方式对幼苗抗旱性的影响   总被引：1，自引：0，他引：1  

刘庆建  高志强  赵红梅  李光  任爱霞  孙敏 《山西农业科学》2012,(9):946-949

采用大田试验方法,研究旱地小麦休闲期深翻深施有机肥、覆盖和不覆盖下不同播种方式对幼苗抗旱性的影响。结果表明,覆盖可显著提高越冬期0～60 cm土壤蓄水量,增加分蘖数、单株叶面积和干物质量;显著降低越冬期幼苗POD,SOD的活性以及幼苗脯氨酸含量,提高越冬期幼苗丙二醛的含量。结果还表明,无论覆盖或不覆盖,全膜覆土穴播提高了0～60 cm土壤蓄水量,增加了单株叶面积、分蘖数和干物质量;采用全膜覆土穴播的POD,SOD活性降低、脯氨酸含量减少、丙二醛含量提高,且差异与其他处理达到显著水平。可见,旱地小麦休闲期深翻覆盖配套全膜覆土穴播的栽培措施有利于提高土壤蓄水量,促进旱地小麦生长。  相似文献   

垄作覆盖下小麦、玉米产量、土壤碳素转化及水分研究   总被引：2，自引：0，他引：2  

吕军杰  李俊红  檀尊社  丁志强  张洁  吴剑峰  杨妮娜  姚宇卿 《河南农业科学》2012,41(2):68-72

研究了旱地小麦、玉米一年两熟制下垄作覆盖对土壤溶解性有机碳和微生物量碳含量、水分及作物产量的影响。在洛阳市农林科学院内防渗精确水分池内,设置垄作覆盖、秸秆覆盖、传统耕作(对照)3个处理,结果表明,(1)垄作覆盖下作物增产显著,小麦较对照增产11.05%,玉米增产32.40%;小麦水分利用效率提高0.36 kg/(mm.hm2),玉米水分利用效率提高2.72kg/(mm.hm2)。(2)垄作覆盖提高了0～200cm土壤含水量,为小麦、玉米生长提供充足的水分。(3)垄作覆盖下0～5cm、5～10cm土层溶解性有机碳含量,小麦田分别较对照增加了39.7mg/kg、27.5mg/kg,玉米田分别较对照增加了52.1%、61.2%。(4)垄作覆盖下微生物量碳含量:小麦田0～5、5～10、10～20cm土层分别较对照增加了120.7mg/kg、158.6mg/kg和132.2mg/kg;耕层微生物量碳平均含量较对照高94.1%;玉米田0～5cm、5～10cm土层分别较对照高167.2mg/kg、78.2mg/kg,10～20cm与对照比差异不明显。垄作覆盖技术既可提高0～200cm土壤含水量和水分利用效率,又可显著提高0～5cm溶解性有机碳和微生物量碳含量,利于小麦、玉米高产稳产。  相似文献