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桂林市水稻土养分状况研究 总被引:3,自引:0,他引:3
1998年秋收后,我们对全市稻田进行了取样化验,共采集土壤农化样3536个,经经验与第二次土壤普查的养分状况相比较,结果表明:土壤有机质、全氮呈上升趋势,土壤速效磷无明显变化、速效钿略有下降;pH值呈下降趋势。本文对这些化验结果进行了比较分析,为今后桂林市稻田培肥地力和合理施肥提供了科学依据。 相似文献
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江西水稻土养分状况研究 总被引:4,自引:0,他引:4
为了解近年水稻土养分变化状况,于1997年采集原土壤普查点位的耕层土样142个,进行农化性状分析。结果表明:江西水稻土土壤有机质,全氮,碱解氮,速效磷含量呈上长这效钾含量稍有改善;pH值略有下降,并简略讨论了上述养分变化的主要原因。 相似文献
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长期施钾对红壤水稻土水稻产量及土壤钾素状况的影响 总被引:18,自引:7,他引:11
研究了长期定位施肥试验中连续27年(1981~2007)施用钾肥对水稻产量和土壤钾素状况的影响。本试验选择了其中5个处理:CK(不施肥)、NP(施氮、磷肥)、NPK(施氮、磷、钾肥)、NP+RS(施氮、磷肥和稻草)和NPK+RS(施氮、磷、钾肥和稻草)。结果表明,施钾能明显提高水稻产量,施钾肥的NPK和NPK+RS处理27年的早稻平均产量分别比NP和NP+RS处理增加15.2%和10.9%;晚稻增产17.2%和9.1%;在27年54季水稻种植期间,不同施肥处理早、晚稻产量的变化趋势不同。CK、NP处理的早、晚稻产量随时间的推移呈负变化趋势,而NPK、NP+RS和NPK+RS处理的早、晚稻产量呈正变化趋势。施钾的NPK和NPK+RS处理不同土层中土壤全钾、缓效钾和速效钾含量均高于NP和NP+RS处理的相同土层;除NPK+RS处理外,其它各处理表观钾平衡均为负值,其中CK和NP处理钾的负平衡值最大。长期施用钾肥能提高水稻产量和维持土壤钾素肥力。 相似文献
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1998年秋收后 ,我们对全市稻田进行了取样化验 ,共采集土壤农化样 35 36个 ,经化验与第二次土壤普查的养分状况相比较 ,结果表明 :土壤有机质、全氮呈上升趋势 ,土壤速效磷无明显变化、速效钾略有下降 ;p H值呈下降趋势。本文对这些化验结果进行了比较分析 ,为今后桂林市稻田培肥地力和合理施肥提供了科学依据。 相似文献
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在兰州构建了自然型稳定塘(自然塘)和人工型稳定塘(人工塘)的中试系统,研究了两种稳定塘中藻类生长状况及藻类生长对稳定塘污染物去除功能的影响。相比于自然塘,人工塘增加了折流式导流墙且悬挂了无纺布载体。结果表明,增设导流墙使得人工塘中水流速度比自然塘增加了2.4倍,这抑制了人工塘中藻类的生长繁殖。自然塘中藻类比人工塘中藻类生长更为旺盛,叶绿素a峰值分别出现在3月和4月,为279.44mg·m^-3和115.65mg·m^-3。藻类光合作用使得稳定塘出水DO和pH都明显高于进水,自然塘藻类生长更为旺盛,因此出水与人工塘出水相比具有更高的DO和pH。更高的pH使得自然塘具有更好的氨氮和总磷去除率,分别为56%和19%。 相似文献
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水分状况对水稻土某些性质的影响 总被引:4,自引:1,他引:4
对太湖地区水稻土进行了以土壤分布的地形部位和不同水旱轮作引起的土壤水分状况,对水稻土某些性质的影响研究。初步结果表明,地下水位较高的老稻田有利于有机质和全氮的积累,但其有机氮的矿化率却比旱作历史较久的水稻土为低,而矿化产物中的硝/铵比亦明显偏低。土壤水分状况还明显地影响土壤剖面中的pH、有机质和全氮的分布。 相似文献
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湖北省4种水稻土养分状况的系统研究 总被引:1,自引:0,他引:1
利用土壤养分状况系统研究法对湖北省4个不同地区典型水稻土的养分状况进行了综合评价.土壤化学分析结果表明,鄂东南蕲春县油-稻-稻三熟制区花岗片麻岩母质发育的水稻土(1#土)、鄂中荆门油-稻两熟区Q3母质发育的水稻土(2#土)、鄂北襄樊市麦-稻两熟区Q3母质发育的水稻土(3#土)、江汉平原洪湖市油-稻两熟区近代河流冲积物母质发育的水稻土(4#土),均主要缺乏N、P和K.并且4种土壤N的缺乏程度依次为3#>4#>1#>2#、P为1#>2#>3#>4#、K为1#>3#>4#>2#.以高粱为指示作物的生物试验结果表明,1#土主要缺乏N、P、K,Zn:2#、3#和4#土主要缺乏N、P,同时施K也有一定效果.生物试验结果表明4种土壤N缺乏程度为3#>2#>4#>1#,P为3#>1#>2#>4#.结果显示土壤化学分析和盆栽生物试验判定养分丰缺种类结果基本一致.但两种方法判定的养分缺乏程度顺序不一致. 相似文献
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Long-term paddy management promotes nitrogen (N) sequestration, but it is unknown to what extent the properties of the parent soil modify the management-induced N sequestration in peptide-bound amino acids (AA-N). We hypothesized that paddy management effects on the storage of AA-N relate to the mineral assembly. Hence, we determined contents and chirality of peptide-bound amino acids in paddy soils developed on contrasting parent material (Vertisols, Andosols, Alisols in Indonesia, Alisols in China, and Gleysol/Fluvisol in Italy). Adjacent non-paddy soils served as references. Selected samples were pre-extracted with dithionite–citrate–bicarbonate (DCB) to better understand the role of reactive oxide phases in AA-N storage, origin, and composition. The results showed that topsoil N and AA-N stocks were significantly larger in paddy-managed Andosols and Chinese Alisols than in their non-paddy counterparts. In other soils, however, paddy management did not cause higher proportions of N and AA-N, possibly because N fixing intercrops masked the paddy management effects on N sequestration processes. Among the different soils developed on contrasting parent material, AA-N stocks were largest in Andosols, followed by Alisols and Fluvisols, and lowest in Vertisols. The N storage in amino acid forms went along with elevated d-contents of bacteria-derived alanine and glutamic acid, as well as with increasing stocks of DCB-extractable Fe, Mn, and Al. Other d-amino acids, likely formed by racemization processes, did not vary systematically between paddy and non-paddy managed soils. Our data suggest that the presence of oxides increase the N sequestration in peptide-bound amino acids after microbial N transformations. 相似文献
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As was shown in the previous reportl), a close connection between the photosynthetic autotrophs and nitrogen fixation in paddy soils was demonstrated. 相似文献
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长期定位施肥对太湖地区稻麦轮作土壤酶活性的影响 总被引:1,自引:1,他引:1
对太湖地区25年长期定位试验田的稻麦两季土壤酶活性进行了测定分析。结果表明,麦季不同施肥处理间的5种土壤酶活性变化没有明显的规律性;无论是仅施化肥还是施有机肥加化肥,稻季5种土壤酶活性的不同肥料配比处理之间绝大多数均无显著差异;成对比较显示,稻麦两季绝大多数相同肥料处理的酶活性之间没有显著差异,仅有稻季猪粪加氮磷钾全施(MNPK)处理的酸性磷酸酶活性极显著高于麦季。分析差异不显著的原因,可能与经过多年的长期定位培肥,土壤储积酶已经达到"饱和"水平,因此不会对外源肥料的施用产生显著响应有关。 相似文献
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长期不同量秸秆炭化还田下水稻土孔隙结构特征 总被引:1,自引:0,他引:1
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Md. Rashedul Islam Puneet Singh Chauhan Yoohak Kim Myungsook Kim Tongmin Sa 《Biology and Fertility of Soils》2011,47(5):599-604
Soil microbial community structure and function are commonly used as indicators for soil quality and fertility. The present
study deals with the effect of different long-term fertilizer management practices on community-level physiological profiles
(CLPP) and soil enzyme activities of paddy soils. Since 1954, chemical fertilizers have been applied in the fields as N–P2O5–K2O, and compost has been added as rice straw at 0, 7.5, 22.5, and 30.0 Mg ha−1 in NPK, NPKC750, NPKC2250, and NPKC3000 treatments, respectively. Community-level functional diversity was significantly
enhanced in the plots treated with both chemical fertilizer and compost as compared to only chemical fertilizer and untreated
control plots. Average well color development (AWCD) obtained by the Biolog Eco plate indicates that there were few differences
among soil samples. Shannon diversity and evenness indices were the highest in NPKC750-treated soil and the lowest in chemically
fertilized soil. Dehydrogenase, cellulose, β-glucosidase, and acid and alkaline phosphomonoesterase activities were significantly increased depending on the amount of
added compost with inorganic fertilizers; the alkaline phosphomonoesterase activity was the most sensitive to treatments.
Our results demonstrated that enzyme activities can be used as sensitive and liable indicators in long-term managed rice-paddy
ecosystems. 相似文献
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A pot experiment was conducted to study the effects of rice cropping on elemental sulfur (S0) oxidation in three paddy soils under flooded conditions. Unaltered wet samples of paddy soils derived from cinnamon soil, black soil and red soil, respectively, were used. Repacked soils were incubated for 14, 28 and 42 days with or without addition of 2,000 mg kg-1 S0 (particle size of 0.075 cm) and with or without cropping. Substantial amounts of oxidized S0 were found to be immobilized into organic S or taken up by plants. The apparent mass of oxidized S was calculated as the sum of the net increase of the sulfate-S and organic-S pools, and S taken up by plants. Under flooded conditions and in the absence of rice, the oxidation rates in all three soils were the greatest during the initial 14 days and then declined with progressive incubation. Incubation for a 42-day period resulted in oxidation of 5.58-10.15% of applied S0. Meanwhile 3.23-5.60% of the applied S0 was converted into organic S. Cropping with rice could significantly increase S oxidation and conversion of S0 into organic S in soils. Incubation for 42 days resulted in the oxidation of 10.28-14.87% of the applied S0, and conversion of 5.74-8.06% of applied S0 into organic S in the three soils. The results suggest that S0 fertilizers should be applied to the soil horizon rich with rice roots (i.e. the rhizosphere) in flooded paddy soils in order to increase the efficiency of S0 oxidation and plant availability. 相似文献
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液体培养研究不同土壤中硝化活性 总被引:2,自引:0,他引:2
A red soil, a fluvo-aquic soil and a permeable paddy soil were used in a long-term investigation to study changes in nitrification with treatments: 1) soil incubation, 2) liquid incubation inoculated with soil samples, and 3) liquid incubation inoculated with ammonia-oxidizing bacteria (AOB) from the soils. There were significant differences (P < 0.001) in nitrification rates among the three soils when measured for 28 days by adding (NH4)2SO4 at the rate of 154 mg N kg-1 dry soil to fresh soil. However, the amounts of nitrifying bacteria in the three soils were not related to soil nitrification capacity. When the soil samples or the isolates of AOB enriched from the corresponding soil were incubated in liquid with pH 5.8, 7.0 and 8.0 buffers and 10 mmol L-1 ammonium nitrogen, there were no significant nitrification differences in the same soil type at each pH. The ability to oxidize ammonia through AOB from different types of soils in a homogeneous culture medium was similar, and the soil nitrification capacity could reflect the inherent properties of a soil. Altering the culture medium pH of individual soil type also showed that acidification of an alkaline fluvo-aquic soil decreased nitrification capacity, whereas alkalinization of the acidic red soil and permeable paddy soil increased their nitrification. For a better insight into factors influencing soil nitrification processes, soil properties including texture and clay composition should be considered. 相似文献
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依托湖北武汉、重庆北碚、湖南望城、湖南祁阳、江西南昌、浙江杭州6个水稻土壤肥力长期定位试验历史样品及数据,分析和讨论了土壤有机质含量变化趋势及对施化肥和有机肥的响应差异。施有机肥提升土壤有机质含量显著高于施化肥的效果。施化肥NPK处理,6个试验点土壤有机质含量都呈现提升趋势;但是,有机质平均年增量、有机质累计增量与累计有机肥施用量的比值都是逐年下降的,固定施肥方法提高土壤有机质含量是有限的,最高达到平衡点,施化肥的有机质含量的平衡点低于施有机肥的,土壤有机质含量提升不仅对施有机肥有响应,而且与累积产量也有一定的相关关系。 相似文献
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E. V. Shein T. Sakunkonchak E. Yu. Milanovskii D. D. Khaidapova M. A. Mazirov N. F. Khokhlov 《Moscow University Soil Science Bulletin》2009,64(4):194-201
The main physical properties of soddy-podzolic soils in a long-term field experiment have been studied. It is shown that their
changes under the impact of a century-long application of lime, fertilizers, and manure have been relatively small. Reliable
differences in the parameters of approximation of the dependence of penetration resistance on the soil water content in the
variant with regular application of organic fertilizers have been revealed. This attests to stronger interparticle bonds (within
the studied moisture range) in this variant. Interparticle bonds in the control variant and in the variant with lime application
tend to increase with a decrease in the soil water content more significantly than those in other experimental variants. This
may be due to the coarser texture of the soil in the control variant and to the aggregation of soil particles under the impact
of lime in the variant with lime application. 相似文献