共查询到20条相似文献，搜索用时 203 毫秒
1.
探讨沟垄二元覆盖对旱地土壤肥力及作物生产力的影响,对完善半湿润区作物微集水栽培技术具有重要的理论和实践意义。2007—2011年在渭北旱塬进行5年定位试验,设置垄上覆地膜,沟内分别覆普通地膜、生物降解膜、玉米秸秆、液体地膜和沟不覆盖等不同沟垄覆盖模式,以传统平作为对照。结果表明,2011年春玉米收获后各处理土壤有机质及速效养分含量随土层的加深而降低,与2007年试验处理前相比,沟垄二元覆盖各处理土壤养分含量明显增加,而垄覆地膜+沟不覆盖和传统平作处理有所下降。垄覆地膜沟覆秸秆处理0~20 cm层土壤有机质、碱解氮、有效磷和速效钾含量均显著高于对照,垄覆地膜沟覆地膜和垄覆地膜沟覆生物降解膜处理有机质和碱解氮含量较对照有所增加,而其有效磷和速效钾含量显著增加。20~60 cm层土壤有机质和速效养分含量各沟垄二元覆盖处理均略高于对照。各沟垄覆盖处理表层(0~20 cm)土壤脲酶、磷酸酶和蔗糖酶活性均较对照增加,且以垄覆地膜沟覆秸秆处理土壤酶活性最高,垄覆地膜沟覆生物降解膜和垄覆地膜沟覆地膜处理次之。垄覆地膜沟覆生物降解膜、垄覆地膜沟覆地膜和垄覆地膜沟覆秸秆处理较对照显著增产41.1%、42.1%、39.3%,水分利用效率显著提高38.0%、39.6%、37.0%。在渭北旱塬区进行沟垄二元覆盖对提高土壤肥力、酶活性及春玉米产量和水分利用效率有显著提高作用,以垄覆地膜沟覆秸秆处理最佳,垄覆地膜沟覆地膜和垄覆地膜沟覆生物降解膜次之。可见,垄覆地膜沟覆地膜、生物降解膜或秸秆的沟垄全覆盖种植在渭北旱塬雨养农业区春玉米生产栽培具有一定的可行性和应用价值。 相似文献
2.
斥水土壤很难被雨水湿润，影响种子发芽出苗而造成农业减产。由于地表干燥而引起风蚀水蚀，造成土地退化。这一问题在澳大利亚、荷兰、新西兰与美国引起重视。斥水土壤中水分分布往往是无规律的“指状”，到目前为止，没有成功的数学模型。作者从研究斥水土壤地区的耕作工程实践出发，采用沟种之后，水分的分布就有了规律性。开沟播种时，耕作机械把表层斥水性特别强的土壤推到垄上而形成几乎不透水的垄，下雨时雨水只能从沟中渗入形 相似文献
3.
近年来东北黑土区沟蚀吞食耕地现象加剧,养分流失、耕地质量下降等问题凸显。以宾县的糖坊镇和三宝乡为研究区,综合"3S"技术和统计学的模型方法,对研究区沟蚀对土壤中有机质、全氮、全磷和速效钾含量的影响及不同垄向耕作下沟蚀对各养分的影响及差异展开研究。其中横垄种植指作物垄的方向和地块坡向方向成垂直的种植方式,顺垄种植是作物垄的方向和地块坡向方向平行的种植方式。结果表明:沟蚀对土壤养分含量影响较大,有机质和全氮含量较无侵蚀区分别减少33.43%和46.67%,速效钾与全磷含量则变化不明显,在沟蚀区进行秸秆覆盖能够有效减少土壤养分的流失。沟蚀在造成养分含量下降的同时,也影响了土壤的理化结构,降低了土壤中有机质和全氮含量之间的相关性。横垄沟蚀、顺垄沟蚀及无沟蚀对照组土壤有机质和全氮含量大小均表现为无沟蚀区顺垄沟蚀橫垄沟蚀。无侵蚀区土壤养分含量最高,沟蚀区顺垄耕作较横垄耕作更具保肥意义。 相似文献
4.
为提高旱作区降水利用率,改善作物的水分有效性,于2007-2010年在陕西合阳县旱农试验站,设置了垄上覆地膜,沟内分别覆普通地膜、生物降解膜、玉米秸秆、液体地膜和沟不覆盖5个不同沟垄覆盖栽培模式。以传统平作为对照,研究了不同沟垄覆盖栽培模式对春玉米田土壤温度、水分及产量的影响,并对其经济效益进行了比较分析。4a结果表明,沟覆普通地膜和沟覆生物降解膜处理玉米苗期5～25cm平均土壤温度分别较对照增高2.4和2.1℃;沟覆玉米秸秆处理较对照降低1.7℃。不同集雨处理均能显著改善玉米前期土壤水分,而后期沟覆玉米秸秆、沟覆液体地膜和和沟不覆盖处理0～200cm土层土壤贮水量与对照无差异,沟覆普通地膜和沟覆生物降解膜处理下层土壤贮水量低于其他处理。沟覆生物降解膜、沟覆普通地膜和沟覆玉米秸秆处理增产效果显著,4a平均产量分别较对照增产35.2%、34.7%和33.6%,平均水分利用效率提高30.6%、30.2%和28.6%。沟覆玉米秸秆处理净收入最高,生物降解膜次之,4a平均净收入分别较对照增加3299和2752元/hm2。因此,垄覆普通地膜沟覆秸秆和垄覆普通地膜沟覆生物降解膜处理在改善土壤水温效应的同时能显著增产增收,是渭北旱塬区春玉米的高效栽培模式。 相似文献
5.
棵间土壤蒸发是农田土壤耗水的重要组成部分。该文采用两种规格的微型棵间蒸发皿(Micro-Lysimeter)分别测定沟灌夏玉米田沟、垄土面蒸发量,并对沟灌条件下夏玉米棵间土壤蒸发与作物蒸腾变化规律进行了试验研究,分析了相对棵间土壤蒸发强度与土壤含水率的关系以及棵间土壤蒸发强度与作物叶面积指数的关系。结果表明,沟灌条件下夏玉米棵间土壤蒸发量占全生育总耗水量的33.06%～34.35%,棵间土壤相对蒸发强度与表层土壤含水率和作物叶面积指数之间均呈现良好的指数函数关系,灌溉或降雨后2～3 d内土壤蒸发强度较大,受大气蒸发力影响明显。因此,在不影响作物蒸腾的条件下减少表层土壤的湿润面积和湿润次数是减少棵间土壤蒸发、提高作物水分利用效率的主要技术途径与措施。 相似文献
6.
利用野外模拟降雨试验，研究了不同垄沟（自然垄沟、盖膜垄沟、成垄压实）耕作条件下土壤水分分布特征和再分布规律。结果表明：垄沟耕作改变了农田微地形，利用垄上降雨顺垄流人沟中，从而拦蓄部分径流，相对增加了沟中土壤蓄水，有利于水分向下运移。相对于自然垄沟，膜垄的集雨效果明显，沟中土壤平均含水量显著高于垄中，20～100cm土层范围内平均土壤含水量分别为12．7％和9．1％；成垄压实土壤水分在剖面分布状况与盖膜垄沟的水分分布相似，水分向沟内集中，沟中土壤水分含量显著高于同一土层深度处垄中土壤含水量，且与盖膜垄沟处理下沟中土壤水分含量无显著差异，在集水和聚水方面表现出和膜垄的相似性。因此，在以集雨农业为主的半干旱地区，成垄压实可以替代盖膜垄沟，有效地富集和储存雨水资源于沟中，供作物吸收利用。 相似文献
7.
该论述了黄土高原土壤水资源的数量、性质和动态规律，提出了土壤水资源管理应从提高作物耗水量，水分利用效率和建立水分良性循环的植制度３个途径进行。 相似文献
8.
在宁南旱作农业区,采用沟垄相间、垄上覆膜、沟内种植、垄面产流、沟内集水的微集水种植方式,以期改善土壤供水能力和降水空间分配,增加局部水分供给,提高作物产量和水分利用率。１９９７－１９９８年试验结果表明,谷子耗水量增加９２．２％－１９９．３％,产量平均提高６８．６％－９８．１％,水分利用率平均达到７．７５－１２．６５ｋｇ／（ｍｍ．ｈｍ＾２）。处理中窄垄型增产效果优于宽垄型。 相似文献
9.
垄覆塑料地膜沟内覆盖集雨种植模式可影响土壤水热状况,促进作物生长,提高作物的产量和水分利用效率。为探讨旱作条件下沟垄二元覆盖的土壤水热效应对马铃薯产量的影响效果,于2015年在宁南旱区设置垄覆地膜沟内覆盖不同材料(普通塑料地膜、玉米秸秆、生物降解膜、麻纤维地膜及液态地膜),以垄覆地膜沟不覆盖为对照,研究沟垄二元覆盖模式对土壤水分、耕层土壤温度、马铃薯生长、产量及水分利用效率的影响。结果表明:垄覆地膜沟覆地膜处理在马铃薯前期、中期土壤蓄水量较对照显著增加(P0.05),垄覆地膜沟覆秸秆处理在马铃薯生育后期土壤蓄水量最高(P0.05)。垄覆地膜沟覆地膜处理增温效果明显,马铃薯全生育期0~25 cm土壤温度较对照显著增加(P0.05),而垄覆地膜沟覆秸秆处理较对照显著降低(P0.05)。在马铃薯整个生育期,垄覆地膜沟覆秸秆处理植株株高和茎粗均明显高于对照处理(P0.05),在马铃薯生育后期垄覆地膜沟覆秸秆处理的地上部生物量显著高于对照处理(P0.05)。沟垄二元覆盖模式下马铃薯增产效果以垄覆地膜沟覆秸秆处理最为显著,较对照增产56.1%(P0.05),且水分利用效率最高(81.1kg/(hm2·mm))。总之,垄覆地膜沟覆秸秆处理对改善土壤水热状况,提高马铃薯水分利用效率和产量的效果显著,建议在宁南旱区进行推广应用。 相似文献
10.
作者运用所建立的斥水土壤中水热运动的数值模型，模拟分析了以下因素对沟中时苗床不分散失与温度的影响：（１）不同的沟垄尺寸；（２）湿润剂；（３）镇压；（４）沟垄的走向。以此为当地的耕种工程设计提供了依据。一般认为土壤斥性严重影响产量，但采用沟种后，表层的斥水土壤形成的不透不的垄能促进雨水渗入沟中，又能阻止水分的蒸发，降低沟中的温度，有利于种子发育出苗，从而使不利因素变化成有利条件。 相似文献
11.
Traffic and tillage effects on runoff, soil water and crop production under rainfall were investigated over a period of 6 years on a heavy clay vertosols (vertisols) in Queensland, Australia. A split plot design was used to isolate traffic effects, while the cropping program and treatments were broadly representative of extensive grain production practice in the northern grain region of Australia. Treatments subject to zero tillage and stubble mulch tillage each comprised pairs of 90 m 2 plots, from which runoff was recorded. A 3 m wide controlled traffic system allowed one of each pair to be maintained as a non-wheeled plot, while the complete surface area of the other received a single annual wheeling treatment from a working 100 kW tractor. Mean annual runoff from controlled traffic plots was 81 mm (36.3%) smaller than that from wheeled plots, while runoff from zero tillage was reduced by 31 mm (15.7%). Traffic and tillage effects appeared to be cumulative, so the mean annual runoff from controlled traffic and zero tillage plots, representing best practice, was 112 mm (47.2%) less than that from wheeled stubble mulch plots, representing conventional cropping practice. Rainfall infiltration into controlled traffic zero tillage soil was thus 12.0% greater than into wheeled stubble mulched soil. Rainfall/runoff hydrographs show that wheeling produced a large and consistent increase in runoff, whereas tillage produced a smaller increase. Treatment effects were greater on dry soil, but were still present in large and intense rainfall events on wet soil. Plant available water capacity (PAWC) in the 0–500 mm zone increased by 10 mm (11.5%) and mean grain yields increased by 337 kg/ha (9.4%) in controlled traffic plots, compared with wheeled plots. Mean grain yield of zero tillage was 2–8% greater than that of stubble mulch plots for all crops except for winter wheat in 1994 and 1998. Increased infiltration and plant available water were probably responsible for increased mean grain yields of 497 kg/ha (14.5%) in controlled traffic zero tillage, compared with wheeled stubble mulch treatments. Dissipation of tractive and tillage energy in the soil is the apparent mechanism of deleterious effects on the soils ability to support productive cropping in this environment. Controlled traffic and conservation tillage farming systems appear to be a practicable solution. 相似文献
12.
季节性干旱是南方红壤地区旱地农业生产中的主要障碍因素。本文报道了田间条件下作物土壤水势关系及其对干旱胁迫响应。结果表明ＳＰＡＣ中水势梯度为：叶气系统〉叶土系统〉７０ｃｍ以上土层,且约以１００倍左右递减,水势日变化结果表明免耕较常耕,窄垄较宽垄叶土水势差下降,水分胁迫更强,花生的耐旱性较强,大豆和玉米的则较弱;作物叶水势与土壤基质势呈正相关,可以用二项式表示。作物叶水势与不同土层土壤基质势关系表明, 相似文献
13.
The effects of deep tillage, straw mulching, and irrigation on corn ( Zea mays L.) yield on a loamy sand (mixed, hyperthermic, Typic Ustipsamment) were studied for early (high evaporativity) and normally sown (relatively low evaporativity) crop for 3 years in a semi-arid sub-tropical monsoon region at Punjab Agricultural University, Ludhiana, India. Treatments included all combinations of two tillage systems (conventional tillage — harrowing the soil to a 10-cm depth; deep tillage — chiselling 40 cm deep, 35–40 cm apart), two irrigation regimes (75 mm irrigation when net open pan evaporation accumulated to 75 mm or 50 mm), and two straw mulch rates (0 and 6 Mg ha −1). Deep tillage significantly reduced soil strength (cone index) and caused deeper and denser rooting than conventional tillage, more so in the dry season and with the infrequent irrigation regime than in the wet season and frequent irrigation regime. Mulch also improved rooting by influencing the hydrothermal regime of the soil. Better rooting with deep tillage and/or mulch helped the crop to extract stored soil water more efficiently, which was reflected in a favourable plant water status (indicated by canopy temperature). Averaged across years, irrigation, and mulch, deep tillage increased grain yield by 1.6 Mg ha−1 for the early season and 0.5 Mg ha−1 for the normal season crop over the yield of 2.0 Mg ha−1 achieved with conventional tillage regardless of season. Yield increase with mulching was also greater for the early season crop. Crop response to deep tillage and mulching was generally linked to the interplay between water supply (rain + irrigation) and demand (seasonal evaporativity) during the growing season. Increasing irrigation frequency increased crop yield when evaporativity exceeded rainfall early in the growing season. The results show that higher corn yields on coarse-textured soils in these regions may be achieved by advancing the seeding time and by using a proper combination of deep tillage, mulch, and irrigation. 相似文献
14.
The influence of tillage, herbicide (paraquat), evaporation retardents (white opaque polythene and hexadecanol) and straw mulch, applied in the post-monsoon pre-seeding period, on soil moisture conservation and yield of chickpea ( Cicer arietinum L.) was studied in a 2-year field experiment. These practices all proved to be useful in conserving more soil moisture in the 180 cm deep soil profile. Opaque polythene conserved most moisture, followed by straw mulch with an average increase of 47 mm (24%) and 32 mm (16%) over the control. Polythene and straw mulch greatly improved moisture in the seeding zone; tillage, hexadecanol and paraquat were also useful. Soil moisture conservation treatments improved plant stand, profile water use, yield and yield components. The effect of treatments varied with crop season rainfall. In the first year, with low rainfall (51 mm), polythene and straw mulch significantly increased the grain yield over other treatments. Hexadecanol, tillage and herbicide also tended to increase yields. In the second, wetter crop season (rainfall 139 mm), the differences in yield between treatments were not significant though the trend was similar to the dry year. Polythene and straw mulch increased yields over the control by 690 and 536 kg/ha in the first year and 399 and 281 kg/ha in the second year. Polythene and hexadecanol being costly, straw mulch, tillage and herbicide offer scope for adoption at field scale. 相似文献
15.
为探究保护性耕作与施肥对渭北旱地春玉米田土壤耗水量和水分利用效率的影响,达到高效生产的目的。于2013—2015年在渭北旱塬实施了春玉米耕作与施肥田间试验,共设置6种耕作与施肥处理:翻耕+低肥(A1)、免耕+高肥(A2)、深松+平衡施肥(A3)、翻耕+无肥(B1)、免耕+无肥(B2)和深松+无肥(B3),测定了春玉米休闲期与生育时期0~200 cm土层土壤蓄水量和收获时籽粒产量。结果表明:1)保护性耕作能显著提高旱地玉米田土壤蓄水保墒能力。与传统翻耕处理B1相比,休闲期,B2和B3播前土壤蓄水量分别提高23.39 mm和27.73 mm(P0.05);耕作处理区,B2和B3全生育期土壤蓄水量平均提高13.41 mm和15.70 mm;耕作施肥处理区,A2、A3土壤蓄水量较A1分别提高13.15 mm、19.54 mm。2)平衡施肥能有效提高玉米全生育期平均土壤蓄水量,与不施肥处理相比,全生育期土壤蓄水量平均提高6.79 mm(P0.05)。3)保护性耕作与施肥能提高玉米籽粒产量与水分利用效率。耕作无肥处理区,与B1比较,B3处理产量提高212~576 kg×hm~(-2),水分利用效率提高0.83~2.21 kg×hm~(-2)×mm~(-1);耕作施肥处理区,A3产量与水分利用效率提高最为显著,产量较A1提高659~1 495 kg×hm~(-2),水分利用效率提高0.65~3.82 kg×hm~(-2)×mm~(-1)(P0.05)。3种施肥方式下以氮、磷、钾平衡施肥产量与水分利用效率提高幅度最大。4)对耗水量与产量进行相关性分析发现,抽雄—灌浆生育阶段土壤耗水量与产量呈显著正相关,保护性耕作提高玉米生长初期土壤蓄水保墒能力,提高春玉米抽雄—灌浆期土壤水分,增加作物生长关键时期对水分的利用效率,利于玉米籽粒产量的提高。因此在渭北旱地春玉米田,深松与平衡施肥组合能提高春玉米产量与水分利用效率,是该地区玉米高效生产较为适宜的种植模式。 相似文献
16.
针对渭北旱塬降水少、季节性差异大及长期采用单一土壤耕作制度等制约作物增产增收的因素,该研究探索有利于提高旱作农田土壤质量及作物生产能力的轮耕模式。2007-2012年在陕西合阳实施了渭北旱塬春玉米连作田6种不同轮耕模式的长期定位试验,设置以免耕(NT,no-tillage)、深松(ST,sub-soiling)和翻耕(CT,continuous tillage)3种耕作处理组合集成的6种轮耕模式(NT?ST、ST?CT、CT?NT、NT?NT、ST?ST和CT?CT),测定各轮耕模式下春玉米田土壤容重和有机碳储量,分析各轮耕模式下春玉米籽粒产量、水分利用效率和经济效益的变化规律。结果表明:1)在疏松土壤、减少耕作机械碾压次数,改善土壤结构和降低容重等方面,6种轮耕模式以NT?ST表现最佳,ST?ST次之,差异显著(P0.05)。2)6种轮耕模式在0~60 cm土层土壤有机碳平均储量较试验前均增加幅度6.6%~17.4%。NT?NT轮耕模式对增加表层土壤有机碳储量具有优势,且与各处理间差异显著(P0.05)。NT?ST轮耕模式可改变耕层土壤有机碳储量分布特征,进而使土壤营养均匀分布。3)6种轮耕模式5年春玉米籽粒产量、水分利用效率和经济效益综合评价分析,NT?ST轮耕模式最高,分别为9 338.8 kg/hm2、22.6 kg/(hm2·mm)和7 600.5元/hm2;其次是ST?CT,其中NT?ST轮耕模式下春玉米籽粒产量、水分利用效率和经济效益较其他处理增加幅度分别为3.7%~15.7%、17.6%~45.8%和10.1%~40.4%,差异显著(P0.05);且5种轮耕模式下作物籽粒产量、水分利用利用效率和经济效益均高于传统CT?CT模式。综上所述,在6种轮耕模式下,以NT?ST(免耕与深松逐年轮换)轮耕模式下土壤容重和有机碳储量最佳,生产能力最强,水分利用率最高,是渭北旱塬地区春玉米连作田最佳适宜轮耕模式,其次是ST?CT(深松与翻耕逐年轮换)轮耕模式。 相似文献
17.
Eight conservation tillage methods were evaluated for maize ( Zea mays L.) production and were related to water conserved, soil strength, plant stand, plant nutrient status, and methods of managing crop residues on Norfolk loamy sands (Typic Paleudults) in the U.S. southeastern coastal plain. This study summarizes 10 site-years of data collected from 1978 through 1982. Seasonal soil-water balance and crop residue management largely determined the success of maize production under conservation tillage. Autumn subsoiling increased winter forage and maize production under both conventional and conservation tillage. When early-season rainfall was limited, water extraction by a winter cover crop or winter weeds often reduced early-season growth and yield of maize under conservation tillage. For adequate stands, increased seeding rates and effective weed-, rodent-, bird- and insect-control were all necessary. Under adequate water regimes, conventional tillage resulted in greater yields at low levels of nitrogen, but maximum yields occurred regardless of tillage system, when 200 kg ha−1 were applied. Conventionally-tilled maize generally resulted in higher yields than conservation tillage production. The only significant increase for conservation tillage occurred under non-irrigated conditions in 1981 during severe drought. The interactive soil and climatic factors which have impact on conservation tillage in this physiographic region were identified. 相似文献
18.
在冬小麦季设置秸秆不还田翻耕(CT)、秸秆还田翻耕(CTS)、秸秆还田旋耕(RTS)和免耕秸秆覆盖(NTS)4种处理,研究耕作方式对华北小麦-玉米两熟区作物周年产量和水分利用的影响。结果表明:耕作方式对当季冬小麦产量和水分利用影响显著,对夏玉米产量和水分利用影响不大,但秸秆还田提高了夏玉米产量。RTS、CTS、CT 3个处理小麦季产量差异不显著,而NTS由于有效穗数不足,产量显著低于其他处理;与CT相比,NTS周年产量平均减产5.13%,RTS增产2.69%,CTS增产2.33%。耕作方式对当季小麦土壤水分含量影响大,而对后茬夏玉米土壤水分含量的影响较小。NTS提高了小麦季土壤水分含量,增加了土壤储水量,与CT相比,0~60 cm土壤储水量2010年和2011年分别增加39.07 mm和26.65 mm。从耗水构成来看,土壤水在冬小麦耗水中所占比例最大,其次为灌水和降水;而夏玉米耗水以降水为主,且降水中有一部分转化为土壤水储存起来。NTS提高了冬小麦季土壤储水量,降低了土壤水分的消耗,冬小麦季耗水最少。与CT相比,NTS小麦季平均节水22.40 mm,周年耗水量也以NTS最少;但NTS冬小麦产量降低导致其小麦季和周年水分利用效率均最低。从作物周年产量和水分利用的角度来看,如何提高免耕秸秆覆盖小麦季产量,进而提高周年产量,发挥其节水优势,是该耕作模式在华北地区冬小麦?夏玉米两熟区推广应用亟需解决的关键问题。 相似文献
19.
The recent adoption of conservation farming systems in the semi-arid Canadian prairies opens up the possibility of replacing the traditional fallow period with non-cereal crops (oilseeds, legumes). However, information on changes to soil water regimes by inclusion of these crops, especially in combination with zero tillage, is sparse. A study was initiated in 1984 on a sandy clay loam soil at Lethbridge, Alberta, to investigate the performance of winter wheat ( Triticum aestivum L.) under conventional, minimum and zero tillage in monoculture and in 2-year rotations with fallow, canola ( Brassica campestris L.) or lentils ( Lens culinaris Medic.)/flax ( Linum usitatissimum L.). Conventional tillage in the Lethbridge region is shallow cultivation (10 cm) with a wide-blade (sweep) cultivator. Continuous cropping greatly depleted soil water reserves, resulting in some crop failures. Averaged over 10 years, available water for establishment of winter wheat in fall was least after canola (45 mm), followed by continuous winter wheat (59 mm), lentils/flax (74 mm) and fallow (137 mm). In this semi-arid region, the effect of rotation on soil water was much greater than that of tillage. Zero tillage had relatively little impact on available water to 1.5 m depth. However, once the experiment had been established for 6–7 years, available water in the 0–15 cm depth under winter wheat in spring was greatest under zero tillage. Precipitation storage efficiency during the fallow year was generally unaffected by tillage system. 相似文献
20.
为研究不同轮作模式对渭北旱作冬小麦?春玉米一年1熟轮作田土壤物理性状和产量的影响,于2007—2014年在陕西省合阳县冬小麦?春玉米轮作田连续7年实施了保护性耕作定位试验,测定和分析了免耕/深松、深松/翻耕、翻耕/免耕、连续免耕、连续深松和连续翻耕6种轮耕模式下麦田0~60 cm土层物理性状、0~200 cm土层土壤湿度和小麦产量的变化。结果表明:1)不同轮耕模式0~40 cm土层土壤容重、孔隙度和田间持水量差异显著,其中以免耕/深松效果最显著;0~60 cm土层免耕/深松轮耕处理平均田间持水量较连续翻耕处理提高12.9%;2)轮耕对土壤团聚体特性影响明显,免耕/深松0.25 mm水稳性团聚体含量(R0.25)最高,结构体破碎率和不稳定团粒指数(ELT)最低,水稳性均重直径(WMWD)最高,水稳性和力稳性团聚体分形维数(D)均最低;3)小麦生育期间免耕/深松处理0~200 cm土层土壤蓄水量和小麦产量较连续翻耕分别增加17.7 mm和9.5%。综合可知,轮耕有利于耕层土壤物理结构改善,免耕/深松更有利于耕层土壤大团聚体形成和土壤结构稳定,利于土壤蓄水保墒和作物增产,为渭北旱塬区麦玉轮作田较适宜的轮耕模式。 相似文献
|
