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1.
耕作与施肥对甘蔗地土壤微生物量碳、氮的影响   总被引:2,自引:0,他引:2  
何瑞清  王百群    张燕 《水土保持研究》2015,22(5):118-121
通过野外调查与室内分析,研究了云南蒲缥甘蔗地赤红壤不同耕作与施肥土壤剖面微生物量碳、氮特征。结果表明:不同耕作与施肥对土壤微生物量碳、氮均有一定影响,其中耕作对土壤微生物量碳、氮的影响较为一致,表现为免耕 > 翻耕。施肥对0—20 cm土层中微生物量碳的影响表现为翻耕施肥 > 翻耕,对20—40 cm,40—60 cm土层中微生物量碳的效应呈现为翻耕 > 翻耕施肥,而施肥对土壤微生物量氮影响则与其对微生物量碳的效应相反。耕作和施肥对各个土层土壤微生物商具有显著的影响(p<0.05),表现为免耕 > 翻耕,翻耕施肥条件下0—20 cm土层的微生物商稍高于翻耕,而其他土层均为翻耕 > 翻耕施肥;土壤微生物量氮与全氮的比值与微生物量氮的变化趋势相近。在不同的耕作和施肥条件下,免耕有利于提高土壤微生物量,施肥在一定程度上也利于提高土壤微生物量。  相似文献   

2.
The effects of subsequent sugarcane ratooning on soil quality and the crop yields under four treatments [an absolute control (T0), application of recommended dose of nitrogen (N)–phosphorus (P)–potassium (K) (T1), application of sulfitation press mud (SPM), a sugar factory by-product (T2), and SPM along with Gluconacetobacter diazotrophicus (Gd, T3)] were evaluated for 7 years. In the control (T0) and NPK-fertilized (T1) plots, an increase in soil compaction (5.4%), decrease in infiltration rate (6.04%), lower microbial activities, and increased soil phenolic contents (72.4%) rendered the nutrients unavailable, leading to significant declines in the crop yields at the rate of 5.47 Mg ha?1 y?1 and 4.67 Mg ha?1 y?1, respectively. The crop yield declined from 53 kg ha?1 in plant crop to 18 kg ha?1 in the sixth ratoon crop under the absolute control. The rates of yield decline, however, were minimized in SPM (T2) and SPM + Gd (T3) plots to 3.54 and 3.51 Mg ha?1 y?1.  相似文献   

3.
通过设置在甘肃省定西市李家堡镇的保护性耕作措施长期定位试验,共设4个处理(T:传统耕作;NT:免耕无覆盖;TS:传统耕作+秸秆还田;NTS:免耕+秸秆覆盖),采用春小麦豌豆双序列轮作(即小麦→豌豆→小麦和豌豆→小麦→豌豆,本文中所指春小麦地、豌豆地分别指2008年种植春小麦、豌豆的轮作次序),于2008年3月中旬对春小麦、豌豆双序列轮作下的土壤有机碳、全氮、土壤微生物量碳及土壤微生物量氮含量进行了采样测定。结果表明,经过7a的轮作后,两种轮作次序下,0-30cm土层中土壤有机碳、全氮、土壤微生物量碳、土壤微生物量氮含量均有在免耕+秸秆覆盖、传统耕作+秸秆还田处理较免耕不覆盖、传统耕作处理高的趋势,且其含量均随着土壤深度的增加而降低。其中,土壤微生物量碳含量在两种轮作次序下的排序均为:免耕+秸秆覆盖(NTS)〉传统耕作+秸秆还田(TS)〉免耕不覆盖(NT)〉传统耕作(T);而土壤微生物量氮含量在春小麦地和豌豆地的排序则分别表现为:免耕+秸秆覆盖(NTS)〉传统耕作+秸秆还田(TS)〉传统耕作(T)〉免耕不覆盖(NT)和免耕+秸秆覆盖(NTS)〉传统耕作+秸秆还田(TS)〉免耕不覆盖(NT)〉传统耕作(T)。同时,微生物量碳、微生物量氮与有机碳和全氮均呈显著正相关,说明提高土壤有机质、全氮含量的保护性耕作模式有利于土壤微生物量碳与氮的积累。  相似文献   

4.
The objective of this study was to determine the influence of tillage methods (conventional tillage (CT) and minimum tillage (MT)) and N rates (0, 50, 150, 250 kg N ha?1) on crop yield, N uptake and soil organic carbon (SOC), bulk density (BD), total N (TN), electrical conductivity (EC), pH and soil nutrient contents on a clay-loam near Hashtgerd, Iran. A successive corn-based rotation (2012–2014) was conducted as a split-plot in a randomized complete block design in which tillage methods were considered as main plots, and N rates as subplots. Tillage had no significant effect on corn 2012 and canola 2012–2013 grain yields. CT and MT systems showed different critical N rates to reach their maximum grain yield in corn (2013) and wheat (2013–2014). MT system required more N application to reach its maximum grain yield. Tillage × N rate effect on none of the soil properties was significant. Tillage had no significant (P ≤ 0.05) effect on soil pH, BD, TN and SOC. However, soil EC of 0–5 cm depth in MT system was higher than CT system by 64%. MT system under higher N application could increase corn grain yield, but on the other hand probably adversely changes soil chemical properties.  相似文献   

5.
Quantifying trends in soil microbial biomass carbon (SMBC) under contrasting management conditions is important in understanding the dynamics of soil organic matter (SOM) in soils and in ensuring their sustainable use. Against such a background, a 60-day greenhouse simulation experiment was carried out to study the effects of straw placement, mineral N source, and tillage on SMBC dynamics in two contrasting soils, red soil (Ferrasol) and black soil (Acrisol). The treatments included straw addition + buried (T1); straw addition + mineral N (T2); and straw addition + tillage (T3). Straw was either buried in the soil or placed on the surface. Sampling was done every 15 days. Straw placement, addition of external mineral N sources (Urea, 46% N) and soil type affected SMBC. SMBC levels decreased with exposure durations (15 days, 30 days, 45 days, and 60 days). Rate of SMBC fixation was more in buried straw than in surface placed straw at all sampling dates in both soils. Addition of an external N source significantly increased SMBC level. Soil pH increased in both soil types, with a greater increase in black soil than in red soil. The study could not, however, statistically account for the effect of tillage on SMBC levels because of the limited effect of our tillage method due to the artificial barrier to mechanical interference supplied by the mesh bags, although differences in absolute values were quite evident between treatments T1 and T3.  相似文献   

6.
为了探讨黑河流域保护性耕作对土壤生产力的影响,设计20cm留茬(NS20),20cm留茬压倒(NPS20),40cm留茬(NS40),40cm留茬压倒(NPS40)和传统耕作(CT)5个处理,研究了黑河流域保护性耕作对农田土壤有机质、土壤微生物量C、土壤微生物量N以及作物产量和水分利用效率的影响。结果表明,保护性耕作农田0—20cm土层土壤有机质、土壤微生物量C和N的含量均高于传统耕作,且其在剖面中的变化趋势基本一致,即随土层深度增加下降;土壤微生物量N有明显的"表聚现象";相关分析表明土壤有机质和土壤微生物量C之间显著正相关(r=0.85,p0.05),与土壤微生物量N之间无明显的相关关系(r=0.47,p0.05);保护性耕作提高了春小麦的产量,NPS20和NPS40增产效果最好,较CT分别增产53.08%和46.59%,与CT之间差异达到极显著水平;保护性耕作提高了春小麦的水分利用效率(WUE),NPS20,NS40,NPS40,NS20分别较CT的WUE提高了58.02%,43.40%,47.27%,23.78%。  相似文献   

7.
为了探明耕作方式转变对土壤物理性质的影响,研究设置田间定位试验,监测长期旋耕转变为免耕和深松耕后土壤容重、水分和穿透阻力的变化特征。试验设免耕(no tillage,NT)、深松(subsoiling,SS)、旋耕(rotary tillage,RT)3个处理,在玉米生长季监测土壤含水量、容重和穿透阻力动态,定量并分析土壤穿透阻力对含水量和容重变化的响应。结果表明,玉米生育期NT处理的土壤容重保持相对稳定,RT和SS处理容重逐渐增大;与RT和SS处理相比,NT处理增加0—30 cm的容重、0—45 cm的含水量和0—15 cm的穿透阻力,但在干旱时期降低15—45 cm的穿透阻力,避免了土壤紧实对玉米的胁迫。基于含水量和容重参数,建立了预测土壤穿透阻力的指数模型,其P<0.001,R2为0.77。模型结果表明,当容重>1.4 g/cm3且含水量<0.13 cm3/cm3时,土壤穿透阻力将大于限制作物生长的阈值(2 MPa);在含水量<0.2 cm3/cm3时,土壤穿透阻力对含水量的敏感性显著高于容重,说明该区域干旱(水分)引起的土壤紧实度增加比压实更为重要。免耕有助于该区域保持土壤水分,同时降低容重增加导致的土壤紧实效应,有利于避免土壤紧实胁迫对作物生长的影响。  相似文献   

8.
通过分析裂区设计下的6个处理,即小麦季深耕和旋耕2个主处理×玉米季免耕播种、行间深松和行内深松3个副处理:(1)旋耕+免耕播种(RT—NT);(2)旋耕+行间深松(RT—SBR);(3)旋耕+行内深松(RT—SIR);(4)深耕+免耕播种(DT—NT);(5)深耕+行间深松(DT—SBR);(6)深耕+行内深松(DT—SIR),对土壤养分含量和作物产量影响,筛选适宜于小麦—玉米轮作体系的耕作模式。结果表明,各处理土壤养分含量在小麦、玉米两季中均随土层深度增加而降低。小麦季,旋耕处理0—10cm土层土壤全氮、碱解氮、有效磷含量、硝态氮含量显著高于深耕处理;但深耕增加当季30—40cm土层土壤有机质、全氮、碱解氮、有效磷、硝态氮、铵态氮含量。玉米季,DT—NT处理0—30cm土层有机质含量较RT—NT处理增加40.1%~64.3%。RT—SBR、RT—SIR处理显著提升土壤0—30cm全氮含量,其中RT—SBR处理0—10cm土层全氮含量最高,为1.4g/kg。RT—SIR处理显著增加0—20cm土壤碱解氮含量,较RT—NT显著增加15.0%~25.3%。在0—40cm土层,DT—SBR处理的有效磷含量最高,而RT—SBR处理的速效钾含量最高。DT—SIR处理显著提升20—50cm土层硝态氮和铵态氮含量,其中硝态氮含量为8.5~30.4mg/kg,铵态氮含量为2.6~8.9mg/kg。与小麦季相比,玉米季提升10—20cm土层有机质含量、0—50cm土层的碱解氮、有效磷、速效钾含量以及40—50cm土层的硝态氮、铵态氮含量。DT—SBR和DT—SIR处理穗长、百粒重、收获指数和产量显著高于其他处理,且二者产量较RT—NT处理显著增加6.4%~10.8%。玉米季DT—SIR处理的肥料偏利用率和经济效益最高。综上所述,深耕+行内深松处理有利于增加土壤养分含量,且增产效果较好,在本研究中最优。  相似文献   

9.
Field experiments (established in autumn 1979, with monoculture barley from 1980 to 1990 and barley/wheat–canola–triticale–pea rotation from 1991 to 2008) were conducted on two contrasting soil types (Gray Luvisol [Typic Haplocryalf] loam soil at Breton; Black Chernozem [Albic Agricryoll] silty clay loam soil at Ellerslie) in north-central Alberta, Canada, to determine the influence of tillage (zero tillage and conventional tillage), straw management (straw removed [SRem] and straw retained [SRet]), and N fertilizer rate (0, 50 and 100 kg N ha?1in SRet, and only 0 kg N ha?1in SRem plots) on seed yield, straw yield, total N uptake in seed + straw (1991–2008), and N balance sheet (1980–2008). The N fertilizer urea was midrow-banded under both tillage systems in the 1991 to 2008 period. There was a considerable increase in seed yield, straw yield, and total N uptake in seed + straw with increasing N rate up to 100 kg N ha?1 under both tillage systems. On the average, conventional tillage produced greater seed yield (by 279 kg ha?1), straw yield (by 252 kg ha?1), and total N uptake in seed + straw (by 6.0 kg N ha?1) than zero tillage, but the differences were greater at Breton than Ellerslie. Compared to straw removal treatment, seed yield, straw yield, and total N uptake in seed + straw tended to be greater with straw retained at the zero-N rate used in the study. The amounts of applied N unaccounted for over the 1980 to 2008 period ranged from 1114 to 1846 kg N ha?1 at Breton and 845 to 1665 kg N ha?1 at Ellerslie, suggesting a great potential for N loss from the soil-plant system through denitrification, and N immobilization from the soil mineral N pool. In conclusion, crop yield and N uptake were lower under zero tillage than conventional, and long-term retention of straw suggests some gradual improvement in soil productivity.  相似文献   

10.
A study was conducted to examine the impact of land use on soil fertility in an Entisol in the Jalpaiguri District of humid subtropical India. The natural forest served as a control against which changes in soil properties were compared. Soil samples were collected from four different depths (0–25, 25–50, 50–75, and 75–100 cm) of soil from four land uses (viz. forest, home garden, arecanut plantation, and agriculture) and examined for pH, organic carbon (OC), electrical conductivity (EC), cation exchange capacity, available nitrogen (N), phosphorus (P), exchangeable calcium (Ca), magnesium (Mg), potassium (K), aluminum (Al), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and dehydrogenase activity (DHA). Soil pH (5.7), OC (2.29%), N (386 kg ha?1), and P (22.54 kg ha?1) were greatest in forest soil, followed by soil from arecanut plantation, agriculture, and home garden. The greatest Ca (0.892 cmol kg?1), Mg (0.527 cmol kg?1), and Al (1.86 cmol kg?1) were found in the arecanut plantation, whereas K (0.211 cmol kg?1) was greatest in forest. The greatest content of diethylenetriaminepentaacetic acid–extractable copper, zinc, manganese, and iron (2.25, 1.66, 4.86, and 7.65 ppm, respectively) were found in forest. MBC (558 mg kg?1), MBN (26.67 mg kg?1), and DHA (33.03 μg TPF 24 h?1 g?1) was greatest in forest soil. Soil fertility index varied from 13.13 in arecanut plantation to 18.49 in forest. The soil evaluation factor ranged from 5.32 in agriculture to 6.56 in forest. Pearson's correlation matrix revealed strongly significant positive correlation of soil fertility index and soil evaluation factor with soil properties.  相似文献   

11.
针对南方丘陵区季节性干旱这一区域问题,以节水稻作模式为研究对象,以常规稻作模式为对照,通过田间定位试验,研究了稻基农田土壤微生物数量和土壤微生物量碳氮的变化规律.结果表明,与该区常规稻作模式相比,节水稻作模式的土壤微生物数量和土壤微生物量碳氮差异显著;节水稻作模式有利于土壤细菌和放线菌的增殖,但抑制了真菌的增殖;土壤微生物量碳和微生物量氮的显著增加,以水旱轮作双季稻模式最佳,说明采用节水稻作模式可有效提升土壤细菌数量、放线菌数量、微生物量碳和微生物量氮含量.因此,在南方丘陵季节性干旱区,采用节水稻作模式,可促进稻田生态系统健康持续发展.  相似文献   

12.
为明确深耕培肥对瘠薄黑土的改土效果,采用大田对比方法,以依安地区黑土为供试土壤,开展深耕培肥对瘠薄黑土土壤理化性质影响及对大豆产量的调查研究。结果表明:深耕培肥可以有效降低10~30 cm土层土壤容重、硬度,提高土壤通气性,容重第1年和第2年分别下降0.09 g cm~(-3)和0.05 g cm~(-3),通气系数分别提高为34.01×10~(-5) cm s~(-1)和10.89×10~(-5) cm s~(-1),10 cm以下土层土壤硬度与对照相比呈明显下降趋势;同时,深耕培肥后20~30 cm土层有效磷含量显著提高,两年增加幅度为15.05~16.23 mg kg~(-1);深耕培肥可以提高土壤速效钾含量,增加幅度为10.19~10.38 mg kg~(-1);并且深耕培肥提高了大豆产量,两年平均提高大豆产量达9.61%。  相似文献   

13.
Within the Mediterranean basin, soil tillage enhances the mineralisation of soil organic matter. We assessed the short‐term impact of shallow tillage [field cultivator (FC), rotary tiller (RT) and spading machine (SM)] on some soil quality indicators [bulk density, water‐stable aggregates, total and labile organic C pools (microbial biomass and extractable organic C), soil respiration and related eco‐physiological indexes] in a Sicilian vineyard. Also no tillage was included. We hypothesized that (i) RT and FC worsened soil quality indicators more than SM, and (ii) within the same tillage system, labile C pools, soil respiration and eco‐physiological indexes will respond more efficiently than chemical and physical soil properties since the tillage starts. The experiment started at March 2009, and each tillage type was applied three times per year (March or April, May and June), with soil tilled up to 15‐cm depth. Soil was sampled (0–15 and 15–30‐cm depth) in March 2009, April 2010, May 2012 and June 2014. SM was very effective in preserving soil organic matter pool and in improving any monitored soil quality indicator, similarly to no tillage. By contrast, RT was the most deleterious machine as it worsened most investigated indicators. Such deleterious effects were due to drastic disruption of soil aggregates and consequent exposition of protected soil organic matter to further microbial mineralization. Labile organic C pools and microbial quotients were the most responsive soil parameters for assessing the impact of shallow tillage on soil quality, even in the short term (<5 years). Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

14.
针对黑龙江省西部风沙土区干旱频繁发生、土壤风蚀严重的特点,采取打茬播种、旋耕播种、免耕等不同保护性耕作措施,与当地传统耕作的玉米进行对比试验。结果表明:旋耕措施对土壤含水量具有显著改善作用。旋耕处理土壤结构较好,能够有效接纳降水,增大储水库容;免耕条件下对土壤水分的影响主要表现在玉米生长前期及中期,免耕处理耕作次数较其它处理少,在春季保持了底层土壤水分。旋耕处理的玉米产量最高,与对照相比增加了31.2%;其次为打茬播种处理,产量比对照增加了13%;免耕处理的玉米产量最低,与对照相比产量降低了20.4%。  相似文献   

15.
春玉米覆膜垄作沟灌条件下土壤水热效应及对产量的影响   总被引:2,自引:0,他引:2  
为探究河套灌区玉米覆膜垄作沟灌种植模式下土壤温度与含水率的变化规律、两者响应关系及对玉米产量的影响,以灌区玉米常规覆膜宽度(70cm)及当地常见农用宽膜(110cm)进行对比研究。结果表明:土壤温度变化主要受外界因素和含水率的影响,两种覆膜条件下土壤温度具有相同的日变化规律,且深层较表层土壤具有明显的滞后效应;玉米生育前期宽膜具有更好的保温效果,且表层5,10cm处地温变化具有显著或极显著性差异;全生育期内110cm较70cm膜具有明显的保墒效果,5—25cm土壤平均含水率高5.06%,6.83%,3.89%,5.28%和3.44%;各时刻不同土层与温度可以拟合为对数函数,但早晚相关性较差,说明此时段地温变化的机制更为复杂;玉米生育后期5cm处土壤平均含水率与土壤温度呈现反比关系,20cm处呈现正比关系,且低水分条件下土壤温度变幅更大;生育期内玉米生长性状及产量指标也达到显著性水平,且110cm较70cm膜平均产量高14.86%;研究成果可为灌区玉米覆膜垄作沟灌模式下适宜地膜宽度的选择提供科学依据。  相似文献   

16.
[目的]探究不同果草套种模式下0—10cm土层土壤微生物量碳、氮及酶活性的差异,为改善土壤肥力条件、促进桂林旅游城市生态循环农业经济的发展提供理论依据。[方法]在桂林潮田河流域大山口农业综合示范区内设置样地,采集表层(0—10cm)土壤样品,测定与分析不同果草套种模式下表层土壤微生物量碳、氮及酶活性的差异。[结果]0—10cm土层土壤氮磷钾、土壤微生物量碳氮和土壤酶活性大小基本表现为:阳朔金桔+牧草桂橙1号+牧草翠冠梨+牧草对照样地。其中,阳朔金桔+牧草模式对0—10cm土层土壤微生物量碳、氮含量和土壤酶活性的影响最为明显(p0.05)。相关性分析表明,土壤微生物量碳氮和3种土壤酶活性存在极显著正相关关系。[结论]果草套种模式特别是阳朔金桔+牧草模式对南方丘陵山地表层土壤肥力条件的改善作用较为明显。  相似文献   

17.
对中层黑土上连续监测了6年的玉米免耕和秋翻两种耕作处理下的耕层土壤有机碳、全氮和速效氮、磷、钾进行了分析。结果表明:耕作处理对土壤养分的影响主要表现在不同的土壤深度上,免耕造成了土壤有机碳和全氮的分层化,即表层0~5 cm有机碳和全氮含量明显高于亚表层,而秋翻土壤有机碳和全氮分布则比较均匀。免耕处理的速效养分均表现为表层与亚表层存在明显差异。免耕处理下有机碳、全氮和速效氮、磷、钾在土壤表层发生明显富集。  相似文献   

18.
The chloroform fumigation-incubation method was used to measure the soil microbial biomass C (SMBC) and N (SMBN) in 16 loessial soils sampled from Ansai, Yongshou and Yangling in Shaanxi Province. The SMBC contents in the soils ranged from 75.9 to 301.0 μg C g-1 with an average of 206.1 μg C g-1, accounting for 1.36%~6.24% of the total soil organic C with an average of 3.07%, and the SMBN contents from 0.51 to 68.40 μg N g-1 with an average of 29.4 μg N g-1, accounting for 0.20%~5.65% of the total N in the soils with an average of 3.36%. A close relationship was found between SMBC and SMBN, and they both were positively correlated with total organic C, total N, NaOH hydrolizable N and mineralizable N. These results confirmed that soil microbial biomass had a comparative role in nutrient cycles of soils.  相似文献   

19.
以浙江省凤阳山常绿阔叶林和针阔混交林为例,通过野外调查和室内测定土壤容重、土壤孔隙度及土壤含水量等,研究了中亚热带主要林分类型的土壤水分物理性质及其海拔影响.结果表明,在0-60 cm土层中,随着深度的增加土壤容重逐渐增大,土壤总孔隙度、毛管孔隙度、最大持水量、毛管持水量、最小持水量逐渐减小.在海拔300~I 355 m高程范围随着海拔升高土壤容重平均值逐渐减小,土壤总孔隙度、毛管孔隙度、最大持水量、毛管持水量、最小持水量、土壤贮水量平均值均增大;土壤排水能力平均值为:海拔900 m>海拔600 m>海拔1 355 m>海拔300 m.同一海拔4种林分类型土壤容重平均值:人工杉木林>针阔混交林>人工柳杉林>常绿阔叶混交林;土壤总孔隙度、土壤最大持水量、毛管持水量、最小持水量、土壤贮水量平均值均表现为人工柳杉林优于其他3种林分类型;土壤排水能力平均值表现为:常绿阔叶混交林>人工杉木林>人工柳杉林>针阔混交林.综合分析,同一海拔常绿阔叶林水源涵养及保持水土能力要高于人工柳杉林.  相似文献   

20.
The present investigation was carried out in coastal Sundarbans of India to study the effects of farm yard manure, green leaf manure, and vermicompost on biological attributes of soils and yield in rice–tomato, rice–sunflower, and rice–chili cropping system over conventional farmer’s practices (control) by a strip-plot technique for the two consecutive years. The partial substitution of inorganic fertilizers through organics significantly increased the yield of various cropping systems. The use of organic materials significantly improved microbial biomass carbon, fluorescein diacetate hydrolyzing activities, dehydrogenase, and β-glucosidase activity over control, which varied in the tune of 51.6%, 67.4%, 50%, and 62.7%, respectively, due to variation in electrical conductivity (EC) of these soils. The improved soil microbial biomass and enzyme activities act as key driving factor for organic matter decomposition and nutrient transformation in organically amended soils which lead to better yield under such cropping sequences.  相似文献   

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