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土垫时耕人为土是长期施用土粪,耕作,栽培等改良作用,定向培育使土垫表层逐渐增国的土壤。土垫表层厚度≥50cm约有3000年历史。它有物质迁移富集与淀积,大量侵入体进入,并有层次分化。土垫表层厚度变化与农业生产有密切的关系。据土垫表层,土垫表下层等诊断和诊断特性,土垫旱耕人为土划分五个亚类。 相似文献
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于文瑞 《农业新技术新方法》1997,(4):29-30
以前双孢菇采用工厂化生产。临朐县在引进双孢菇后,根据其生育特点,创造性地进行了土洞塔架分层栽培,不占土地,不减少效益,被农业部有关专家称为“地下农业”。 相似文献
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古水稻土与现代水稻土硝化活性的比较 总被引:2,自引:2,他引:2
根据最新的考古发现,中国种植水稻的历史可以追溯到公元前4000多年。据考证,位于长江三角洲的昆山市正仪镇绰墩山古水稻土遗址的地下42~57cm与100~116cm均为古水稻土层,历史耕作时间分别距今约3320a和6280a。硝化细菌在耕作土中的数量及其硝化强度被认为是土壤肥力的指标之一,在土壤氮素循环中起着重要作用,氨氧化细菌在硝化作用过程中将铵氧化为亚硝酸盐,实现亚硝化作用,是硝化过程中必不可少的步骤,同时也是其限速反应。本试验比较研究古水稻土与现代水稻土硝化活性的差别,观察氨氧化细菌沿土壤深度的分布规律,对揭示古水稻土在长期埋藏于土壤深层后的硝化功能演变具有积极的指示意义。 相似文献
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长期施肥条件下Lou土和黄绵土有机质氧化稳定性研究 总被引:15,自引:0,他引:15
从关中平原的头道塬、二道塬、三道塬以及延安地区的4个长期肥料定位试验地采集34个土壤样品对Lou土和黄绵土长期施用化肥和有机肥条件下有机质氧化稳定性和活性进行了较系统的研究。结果表明:长期施用有机肥或配施化肥,均能促进Lou土和黄绵土耕层土壤易氧化有机质和活性有机质积累,提高Kos值;长期施用化肥,只能促进土壤有机质的老化,提高难氧化有机质含量和Kos值,对易氧化有机质和活性有同无积极作用。相关分 相似文献
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重庆缙云山典型植被原状土与重塑土抗剪强度研究 总被引:4,自引:0,他引:4
为了从土壤力学方面探索防治水土流失的途径与措施,该文采用直剪仪对重庆缙云山5种典型植被的原状土和重塑土抗剪强度进行试验测定。通过比较相同植被同干密度、同含水率的原状土与重塑土在同一垂直荷载下的剪切差异,分析了根(极细根)在土壤-根系复合体(原状土)中的作用。研究结果表明:原状土剪切位移小于重塑土;在相同垂直荷载作用下,同一植被原状土的抗剪强度大于与其同干密度、同含水率的重塑土。原状土的剪切破坏近似于塑性破坏,而重塑土则属于弹性破坏;原状土的抗剪强度与含根量呈正相关,并以此建立关于原状土的抗剪强度回归模型。 相似文献
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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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长期施用有机肥对紫色水稻土铁锰铜锌形态的影响 总被引:55,自引:8,他引:47
以长期定位试验为基本材料 ,研究了 9年连续施用有机肥对紫色水稻土铁、锰、铜、锌形态的影响。结果表明 ,有机肥是土壤铁、锰、铜、锌的良好给源。紫色水稻土长期施用有机肥与单施化肥比较 ,土壤中的全铁、全锰变化不大 ,全锌提高了 5.5%~ 30.0% ,交换态铁、碳酸盐结合态铁、有机态铁、无定形结合态铁分别提高了1.5%~12.7%、2.4%~8.9%、11.6%~19.5%、32.5%~72.5%。锰、锌的各形态数量均有不同程度的增加。同时 ,长期施用有机肥增大了土壤铜的消耗 ,全铜含量有下降的趋势。 相似文献
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施肥结构对砂质潮土中微量营养元素空间变化的影响 总被引:11,自引:0,他引:11
本文通过长期定位施肥试验 ,分析了不同施肥结构对砂质潮土交换性钙、镁及有效硫、锌、锰、铜、铁等在 0~ 1 2 0cm土体中空间分布变化的影响 .结果表明 ,磷肥明显提高土壤交换性钙的含量 ,而有机肥与氮肥对土壤钙含量无明显影响 .但有机肥显著增加土壤交换性镁含量 ,各层镁含量与有机肥用量呈显著或极显著正相关 ,磷肥同样对土壤镁有提高作用 ,但氮肥无论是否与有机肥配施均降低了土壤各层交换性镁含量 .土壤 0~ 4 0cm有效锌、锰、铁均随有机肥增加而增加 ,并与有机肥用量呈极显著正相关 .而化肥无论是否与有机肥配施均降低土壤有效锌含量 ,但却增加了有效铁含量 .氮肥单施降低土壤有效锰含量 .在无有机肥情况下 ,施磷提高土壤有效铁含量 ,而在施有机肥条件下磷肥则降低耕层有效铁含量 .磷肥只在单施化肥时增加土壤有效锰含量 相似文献
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长期肥料试验对土壤和水稻微量元素及重金属含量的影响 总被引:23,自引:0,他引:23
长期肥料试验会影响土壤中微量元素和重金属状况以及作物对微量元素和重金属的吸收。本文研究了长期的不同施肥处理对土壤、糙米中微量元素Cu、Zn、Fe、Mn和重金属Pb、Cd含量的影响,结果表明:经17a连续施用猪粪及秸秆还田显著增加了土壤Cu、Zn和Cd全量,而土壤Fe、Mn和Pb全量在不同施肥处理间没有显著差异;施肥增加了土壤有效态Cu、Zn和Fe含量,其中施用猪粪及秸秆还田的3个处理显著增加了土壤有效态Cu、Zn和Cd含量,而土壤有效态Pb含量在不同施肥处理间没有显著差异。不同处理糙米Cu、Zn、Fe、Mn和Pb含量变化较小或没有显著性差异,而在3个施猪粪和秸秆还田处理中,糙米Cd含量均超过国家食品卫生标准(>0.2 mg kg-1)。水稻地上部吸收积累Cu、Zn、Fe、Mn、Pb和Cd总量与其地上部生物量呈正相关,土壤Cu、Zn、Cd有效态与全量含量呈极显著相关关系,而糙米中的镉含量与土壤镉含量有较好的相关关系。长期施用畜粪导致土壤Cd污染问题应引起高度重视。 相似文献
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长期施肥对菜田土壤微量元素有效性的影响 总被引:23,自引:5,他引:23
利用田间试验研究了长期定位施用有机肥和氮、磷、钾化肥对菜田土壤重要微量元素有效性的影响。结果表明,长期施用氮肥会提高土壤有效态铁、锰、锌、铜含量,随着氮肥用量增加,土壤酸化程度加重,土壤中铁、锰、锌、铜有效性亦随之增强。磷、钾化肥能够提高土壤有效铁、锰含量,对土壤锌有效性不会产生明显影响,在一定范围内可以提高土壤有效性铜含量,但效果不明显。长期施用有机肥对土壤微量元素的影响与配施的化肥种类有关。土壤有效铁、锰、铜含量与土壤pH呈极显著负相关,而有效锌含量与pH相关性不明显,而且关系比较复杂。总之,影响微量元素有效性的首要因素是土壤酸碱度。 相似文献
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Impacts of biochar and processed poultry manure,applied to a calcareous soil,on the growth of bean and maize 下载免费PDF全文
Direct use of poultry manure on agricultural lands may cause environmental concerns, so there is a need to establish the suitability of the application of biochar derived from poultry manure for calcareous soil chemical properties and plant growth. The purpose of this study was to evaluate the effects of processed poultry manure (0, 5, 10 and 20 g/kg) and its biochar (0, 2.5, 5, 10 and 20 g/kg) on soil chemical properties of a calcareous soil and growth of bean (Phaseolus vulgaris) and maize (Zea mays) plants. In the incubation experiment, both processed poultry manure (PPM) and biochar decreased pH and the concentration of plant‐available Fe of soil but increased plant‐available P, Zn, Cu and Mn concentrations. PPM and biochar increased the concentrations of exchangeable cations (K, Ca and Mg) in soil. PPM and biochar applications increased the growth of maize and bean plants. PPM and biochar resulted in increased concentrations of N, P, K, Ca, Fe, Zn, Cu and Mn in bean plants. In maize plants, PPM and biochar applications increased the N, P, K, Zn, Cu and Mn but decreased the Ca and Mg concentrations. Results of this study reveal that poultry manure biochar can be used effectively for agricultural purposes. 相似文献
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Micronutrient deficiencies are common in many parts of China's Loess Plateau. The objective of this experiment was to study the effects of long-term cropping and fertilization practices on soil properties and micronutrient availability in this region. The field plot experiment began in 1984. It included five cropping systems and four fertilizer treatments. In September 2002, soil samples were collected and soil pH, organic matter content, available P, and CaCO3 were measured. Total and available Zn, Cu, Mn, and Fe were also determined. The relationship between soil properties and available micronutrients was determined by correlation and path analysis. After 18 years, soil pH and CaCO3 levels were lower in the cropped and fertilized treatments compared to the fallow treatment. In contrast, soil organic matter and available P levels were higher in cropped compared to fallow treatments. A comparison of unfertilized treatments indicated that available Zn and Cu levels in cropped treatments were lower compared to the fallow treatment, probably due to the removal of these micronutrients from the system through crop uptake and harvest. In contrast, available Mn and Fe levels were higher in cropped treatments compared to the fallow treatment. The impacts of fertilization on available micronutrients varied with cropping systems. Generally, available Zn and Fe were higher in fertilized compared to unfertilized treatments, but available Cu was not significantly influenced by fertilization. Fertilization tended to increase available Mn in continuous wheat and maize, but reduced available Mn in continuous clover and the crop–legume rotation. The total (plant available + unavailable) micronutrient contents were lower in the four cropped-treatments compared to the fallow treatment. The addition of manure or P fertilizer increased total Zn, Fe, and Mn, but had no significant effect on total Cu. The results of correlation analysis and path analysis indicated that soil organic matter exerts a significant and direct effect on the availability of Zn, Mn, and Fe, but has little influence on available Cu. The effects of available P, CaCO3, and pH on micronutrient availability were indirect, passing through soil organic matter. The results of this study suggest that long-term cropping and fertilization altered several important soil properties and increased the plant available micronutrient content of this loess-derived soil. 相似文献
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本文对甘肃省主要农业土壤中Cu、Zn、Mn、Fe的形态及其有效性进行了研究。结果表明,供试土壤的全Cu含量范围为22-24mg/kg,全Mn为542-772mg/kg,全Fe为35685-38355mg/kg。四种元素均以灌漠土的含量最低,褐土最高。土壤中Cu、Zn、Mn、Fe的大部分以残留矿物态和氧化铁结合态存在。生物试验和统计分析表明,Cu、Zn、Mn、Fe的交换态和松结有机态对植物最为有效, 相似文献
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The effect of elemental sulphur (S) and S containing waste applications on soil pH treated with 0–2,000 kg ha‐l elemental S, and 0–100 tons ha‐1 of waste was determined in the field and the pots. Sorghum (Sorghum bicolor L.) was grown in a Lithic Xerorthent soil which was taken from where the field experiment was conducted in pots receiving 5 kg soil. Plants were harvested 20 weeks after planting or 30 weeks after the applications for determination of dry matter yield and phosphorus (P), iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) uptake by shoots. EC, NaHCO3‐extractable P, and DTPA‐extractable Fe, Zn, Mn, Cu also were measured in pot soil at the 5th, 10th, and 30th weeks. All treatments led to a decrease in soil pH though pH tended to increase again during course of time in both field and pot experiments. The both elemental S and waste applications in pot experiment caused an increase in dry matter yield and P, Fe, zinc (Zn), Mn and Cu uptake (mg pot‐1) by shoots in sorghum plant. There was also an increase in EC of soil due to both applications of S. The concentration of available P extracted by NaHCO3 in the pot soil, though not significantly different, was slightly higher compared with the control. Waste applications increased DTPA‐extractable Fe content of the soil, DTPA‐extractable Mn and DTPA‐extractable Cu. DTPA‐extractable Zn content, however, was reduced by the same applications. 相似文献