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1.
通过盆栽试验,研究了钙镁磷肥和过磷酸钙对土壤砷的生物有效性的影响。结果表明,施用钙镁磷肥和过磷酸钙能显著促进小白菜的生长,与对照相比生物量分别提高了约149%和119%;施磷可显著提高土壤有效态砷含量,其中钙镁磷肥高、低施肥量处理分别比对照增加了52.2%和20.9%,过磷酸钙高、低量施肥处理比对照分别提高了15.0%和5.5%;在同一施磷水平下,钙镁磷肥处理的土壤中有效态砷含量明显高于过磷酸钙处理,施磷可导致小白菜对砷的吸收总量显著增加（P〈0.05）,施用钙镁磷肥处理的小白菜砷吸收量的增加幅度较大。磷肥施用可在一定程度上提高土壤中砷的生物有效性,其中施用钙镁磷肥比过磷酸钙的效果更为明显。 相似文献
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深淹对狗牙根根际土壤酶活性及肥力的影响 总被引：2，自引：1，他引：1
以三峡库区消落带生境和非消落带生境生长的狗牙根(XC、FC)为试验材料, 研究了不同生境狗牙根经不同深度水淹胁迫后, 植株根际土壤酶活性和土壤肥力状况。结果表明: 未淹对照植株根际土壤的蔗糖酶活性明显大于不同深度淹水处理, 说明淹水处理不能给植物提供与未淹对照同样多的营养源; FC 根际土壤的脲酶和酸性磷酸酶活性都较XC 的高; 淹水处理后, FC 根际土壤的全氮含量明显低于XC; 淹水前FC 根际土壤的全磷含量明显高于XC, 表明在未进行淹水处理之前的生长时期, XC 可能较FC 利用更多的土壤营养进行生长, 储备更多的能量, 从而为淹水期间植株提供能量供应, 为增强其耐淹能力奠定较好的能量基础。以上结果说明不同生境狗牙根在不同水淹胁迫下, 植株根际土壤酶活性和土壤肥力的变化与其耐淹能力有关。 相似文献
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红壤酸化及石灰改良影响冬小麦根际土壤钾的有效性 总被引：8，自引：1，他引：7
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Brummell DA Watson LM Pathirana R Joyce NI West PJ Hunter DA McKenzie MJ 《Journal of agricultural and food chemistry》2011,59(20):10987-10994
Methylselenocysteine (MeSeCys) is an amino acid derivative that possesses potent anticancer activity in animals. Plants that can tolerate growth on soils with high Se content, known as Se hyperaccumulators, do so by converting inorganic Se to MeSeCys by the enzyme selenocysteine methyltransferase (SMT). A cDNA encoding the SMT from a Se hyperaccumulator was overexpressed in tomato (Solanum lycopersicum). Transgenic plants were provided with selenite or selenate to the roots during fruit development, and liquid chromatography-mass spectrometry was used to show that MeSeCys accumulated in the fruit but not in the leaves. Depending on the transgenic line and Se treatment, up to 16% of the total Se in the fruit was present as MeSeCys. MeSeCys was produced more effectively from selenite on a percentage conversion basis, but greater accumulation of MeSeCys could be achieved from selenate due to its better translocation from the roots. MeSeCys was heat stable and survived processing of the fruit to tomato juice. 相似文献
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《Archives of Agronomy and Soil Science》2012,58(1):96-109
ABSTRACTThe use of organic fertilizer is essential to ensure sustainable agricultural production. Because organic fertilizer normally acts as a slow-release fertilizer, improving its nutrient-use efficiency is important, particularly in terms of nitrogen (N) nutrition. In the present study, we attempted to increase the N-use efficiency of cattle farmyard manure (CM) in the cultivation of pasture grasses by mixed cropping with white lupin (Lupinus albus), which has been reported to decompose organic N in its rhizosphere. Timothy (Phleum pratense) and orchard grass (Dactylis glomerata) were cultivated with or without either lupin or soybean (Glycine max) in pots under three different N treatments (CM, ammonium sulfate, or no N). In the CM treatment, growth was higher in grasses cultivated with lupin than in those cultivated alone or with soybean. Moreover, decomposition of soluble organic N and protease activity in the rhizosphere soil of grasses with CM treatment were enhanced by mixed cropping with lupin. Analyses of microbial activity and bacterial community structure using Biolog EcoPlates suggested that the enhanced decomposition of soluble organic N was facilitated by lupin roots rather than by rhizosphere microorganisms. 相似文献
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为评价栽培年限对新建日光温室土壤供氮能力的影响,采用盆栽生物耗竭试验和间歇淋洗好气培养法相结合的方法研究了陕西杨凌不同年限新建日光温室(温室建造前的大田及温室建造后第2年和第3年取样)耕层(0~20 cm)土壤供氮能力的变化。结果表明:随着温室栽培年限的增加,番茄生物量和吸氮量与温室栽培前相比均显著增加,其中栽培年限为第2年和第3年的番茄株高、茎粗、地上及根系生物量、叶片SPAD值均显著高于温室建造前,而第2年和第3年间各指标无显著差异;第2年和第3年温室的番茄吸氮量分别是建造前大田的2.53倍和3.01倍;与种植前土壤相比,第3年温室土壤有机质、全氮和速效养分含量均显著增加,第2年及第3年温室土壤可矿化氮量分别是建造前大田的2.84倍和2.96倍,说明随栽培年限的增加,温室土壤供氮能力显著增强。相关分析表明,土壤有机质、全氮、初始矿质氮及累积矿化氮量与番茄吸氮量间呈极显著正相关关系,其中以土壤累积矿化氮量与番茄吸氮量间的相关系数最大,说明这些指标均可用于评价土壤供氮能力。随栽培年限的增加,日光温室土壤供氮能力显著提高,生产中应随温室栽培年限增加适当降低氮肥用量。 相似文献
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控释复合肥对番茄生长效应的影响研究 总被引：20，自引：2，他引：20
采用流化床包膜技术制作的控释期为90d的4种养分比例不同的控释复合肥与等养分量的普通复合肥进行了番茄肥效对比盆栽试验。试验结果表明,控释复合肥具有养分缓慢释放的特点,施肥后40d达到高峰,有利于番茄生殖生长对养分的需求。施用控释复合肥番茄株高、叶面积、叶片数和鲜果重明显优于普通复合肥,且对防止病虫害有良好效果。施用控释复合肥番茄鲜果产量平均比普通复合肥提高63.1％。在本试验条件下,以CRF3处理,N-P2O5-K2O用量为0.4-0.26-0.37g/kg(即N:P2O5:K2O养分比例为1:0.65:0.93)肥效最好。 相似文献
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Little information is available about the long‐term effects of deforestation and cultivation on biochemical and microbial properties in wet tropical forest soils. In this study, we evaluated the general and specific biochemical properties of soils under evergreen, semi‐evergreen, and moist deciduous forests and adjacent plantations of coconut, arecanut, and rubber, established by clear felling portions of these forests. We also examined the effects of change in land use on microbial indices and their interrelationships in soils. Significant differences between the sites occurred for the biochemical properties reflecting soil microbial activity. Microbial biomass C, biomass N, soil respiration, N mineralization capacity, ergosterol, levels of adenylates (ATP, AMP, ADP), and activities of dehydrogenase and catalase were, in general, significantly higher under the forests than under the plantations. Likewise, the activities of various hydrolytic enzymes such as acid phosphomonoesterase, phosphodiesterase, casein‐protease, BAA‐protease, β‐glucosidase, CM‐cellulase, invertase, urease, and arylsulfatase were significantly higher in the forest soils which suggested that deforestation and cultivation markedly reduced microbial activity, enzyme synthesis and accumulation due to decreased C turnover and nutrient availability. While the ratios of microbial biomass C : N and microbial biomass C : organic C did not vary significantly between the sites, the ratios of ergosterol : biomass C and ATP : biomass C, qCO2 and AEC (Adenylate Energy Charge) levels were significantly higher in the forest sites indicating high energy requirements of soil microbes at these sites. 相似文献
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丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)和根围促生细菌(plant growthpromoting rhizobacteria,PGPR)能降解有毒有机物,但分解土壤中残留甲胺磷农药尚未见报道。本试验旨在测定AMF和PGPR矿化甲胺磷的效应。试验设甲胺磷0、50、100和150μg g-1下,对番茄(Lycospersicon esculentum,品种金冠)接种AMF Glomus mosseae(Gm)、Glomus etunicatum(Ge)、PGPR Bacillus subtilis(Bs)、Bacillus sp.B697(Bsp)、Pseudomonas fluorescens(Pf)、Gm+Bs、Gm+Bsp、Gm+Pf、Ge+Bs、Ge+Bsp、Ge+Pf和不接种对照,共48个处理。结果表明,接种Gm显著增加了根区土壤和根内PGPR定殖数量,而Pf处理显著提高了AMF侵染率,表明Gm与Pf能够相互促进。甲胺磷100μg g-1水平下,Gm+Pf处理的番茄株高显著高于其他处理,地上部干重显著高于其他处理(Ge+Pf除外),根系干重显著高于对照、PGPR各处理和Ge处理;而根内甲胺磷浓度则显著低于其他处理,茎叶中的则显著低于其他处理(Gm+Bs、Gm+Bsp和Ge+Pf除外)。AMF、PGPR或AMF+PGPR处理均显著降低番茄体内甲胺磷浓度。甲胺磷50~100μg g-1水平下,Gm+Pf显著降低根区土壤中甲胺磷残留量,矿化率达52%~60.6%。AMF和PGPR显著提高了根区土壤中甲胺脱氢酶活性,其中以Gm+Pf组合处理的酶活性最高。表明AMF和PGPR均能促进土壤中残留甲胺磷的降解,Gm+Pf是本试验条件下的最佳组合。 相似文献
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Precise estimation of vegetable nitrogen (N) status is critical in optimizing N fertilization management. However, nondestructive and accurate N diagnostic methods for vegetables are relatively scarce. In our two-year field experiment, we evaluated whether an active canopy sensor (GreenSeeker) could be used to nondestructively predict N status of bok choy (Brassica rapa subsp. chinensis) compared with a chlorophyll meter. Results showed that the normalized difference vegetation index (NDVI) and ratio vegetation index (RVI) generated by the active canopy sensor were well correlated with the aboveground biomass (AGB) (r=0.698-0.967), plant N uptake (PNU) (r=0.642-0.951), and root to shoot ratio (RTS) (r=-0.426 to -0.845). Compared with the chlorophyll meter, the active canopy sensor displayed much higher accuracy (5.0%-177.4% higher) in predicting AGB and PNU and equal or slightly worse (0.54-1.82 times that of the chlorophyll meter) for RTS. The sensor-based NDVI model performed equally well in estimating AGB (R2=0.63) and PNU (R2=0.61), but the meter-based model predicted RTS better (R2=0.50). Inclusion of the days after transplanting (DAT) significantly improved the accuracy of sensor-based AGB (19.0%-56.7% higher) and PNU (24.6%-84.6% higher) estimation models. These findings suggest that the active canopy sensor has a great potential for nondestructively estimating N status of bok choy accurately and thus for better N recommendations, especially with inclusion of DAT, and could be applied to more vegetables with some verification. 相似文献
14.
Reducing nitrogen pollution while improving tomato production by controlled-release urea application
Jungang Yang Shangqiang Liao Yanmei Li Bing Cao Yanxin Sun Guoyuan Zou 《Soil Science and Plant Nutrition》2013,59(5):632-641
Considerable nitrogen (N) losses from intensive vegetable systems have become an important source of environmental damage. A high-efficiency N application to minimize N pollution and improve production is urgently needed. Here, we conducted field experiments to identify the effects of a single application of controlled-release urea (CRU), conventional urea (CU), and chicken manure (CM) on N losses and yields improvement in a greenhouse tomato system in Beijing, China. Five treatments were carried out: no N control (CK), lower rate of CRU with CU and CM (CRN1), medium rate of CRU with CU and CM (CRN2), higher rate of CRU with CU and CM (CRN3), and conventional fertilization (CN). The results showed that the single application of CRU, CU, and CM reduced the nitrate N concentration and N2O emissions by 22 to 79% and 39 to 51%, respectively, compared with the conventional fertilization . Based on the N application rate, the average nitrate N concentration showed an exponential increase, and the cumulative N2O emissions showed a linear increase. Compared to the CN treatment, the CRN1, CRN2, and CRN3 treatments decreased fertilization cost by 44%, 22%, and 3.4%, while raising yields by 9.6%, 17%, and 2.0%, respectively. The apparent N surplus of the CRN1 and CRN2 treatments was reduced by 39% and 13% relative to the CN treatment, whereas the CRN3 treatment was as high as that of the CN treatment. It can be concluded that applying CRU, CU, and CM at the higher rate hardly improved the yield but increased the risk of N losses, whereas the lower and medium rates of CRU could reduce N pollution and improve production. The CRN2 treatment, reducing the CRU rate by 25%, with the highest economic efficiency, was the best choice to achieve greater yields with less environmental impacts in greenhouse tomato systems.Abbreviations: CRU, controlled-release urea; CU, conventional urea; CM, chicken manure; DAT, days after transplanting. 相似文献
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减氮及硝化抑制剂对菜地氧化亚氮排放的影响 总被引：7，自引：1，他引：7
利用静态暗箱—气相色谱法,周年监测集约化菜地四种蔬菜种植过程中N2O的排放和蔬菜产量变化,探究减氮(640、960 kg hm-2 a-1)以及施用硝化抑制剂氯甲基吡啶(CP)对菜地N2O排放的影响。结果表明,与常规施氮(Nn)处理相比,减量施氮(Nr)在不显著降低产量的情况下平均降低菜地N2O排放27.1%;与仅施用尿素的处理相比,在减量和常规施氮水平的基础上添加硝化抑制剂又分别能降低菜地N2O排放总量29.4%、26.0%,降低N2O排放系数60.9%、42.4%,而对蔬菜产量没有显著影响,因此显著降低菜地单位产量N2O排放量32.1%、30.3%,以减氮结合CP(CP-Nr)处理减排效果最佳。因此,减氮结合CP应用于集约化蔬菜生产是一种有效的菜地减排农业措施。 相似文献
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ZHANG Xinyu XIE Juan YANG Fengting DONG Wenyi DAI Xiaoqin YANG Yang SUN Xiaomin 《土壤圈》2018,28(3):488-496
Mineral nutrient inputs to soil may alter microbial activity and consequently influence the accumulation of microbial residues. In this study, we investigated the effects of application rates and ratios of mineral fertilizers on the microbial residue carbon(MRC) of reddish paddy soils after long-term(15-year) fertilizer applications in southern China. Contents of three soil amino sugars as microbial residue contents were determined and MRC were calculated based on amino sugars. Results showed that three individual amino sugar contents increased as fertilizer application rates increased until maximum values were reached at a rate of 450-59-187 kg ha~(-1) year~(-1)(N-P-K). The three amino sugar contents then declined significantly under the highest mineral fertilizer application rate of 675-88-280 kg ha~(-1) year~(-1)(N-P-K). In addition, to enhance the microbial residue contents, it was more beneficial to double P(N:P:K= 1:0.26:0.41) in fertilizers applied to the P-deficient reddish paddy soils than to double either N(N:P:K = 2:0.13:0.41) or K(N:P:K= 1:0.13:0.82). The contents of the three individual amino sugars and microbial residues under different fertilizer application rates and ratios were significantly and positively correlated with soil organic carbon(SOC), total N, total P, and p H. Increases in values of the fungal C to bacterial C ratios showed that soil organic matter(SOM) stability increased because of the fertilizer applications over the past 15 years. The contents and ratios of amino sugars can be used as indicators to evaluate the impact of mineral fertilizer applications on SOM dynamics in subtropical paddy soils. The results indicated that fertilizer applications at a rate of 450-59-187 kg ha~(-1) year~(-1)(N-P-K) may improve crop yields, SOC contents, and SOC stability in subtropical paddy soils. 相似文献
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Previous studies showed that wide genotype differences in nitrogen (N) efficiency exists among cultivars of rapeseed (Brassica napus L.), but the mechanisms behind those differences are still unknown. In the present study, our aim was to analyze the adaptability mechanism of N-efficient rapeseed to low-N stress by employing two genotypes of natural variation in N efficiency. Nitrogen-efficient genotype, ‘BG51’, and N-inefficient genotype, ‘BG88’, were grown in a solution culture experiment under conditions of high-N (6.0 mM N) and low-N (0.6 mM N) supply. After growing 30 d, roots and shoots were sampled for the analysis of dry weight, N concentration and accumulation, N use efficiency (NUE), N transport efficiency (NTE), root system vigor parameters, nitrate redutase (NR) activity, and glutamine synthetase (GS) activity. Nitrogen deficiency decreased shoot and root dry weight significantly, but ‘BG51’ exhibited a significantly lower decrease in shoot dry weight and had significantly higher biomass production than ‘BG88’. Under low N supply ‘BG51’ accumulated more N in shoot, root and whole plant than ‘BG88’, and presented higher NUE in both shoot and root. Low-N stress induced an increase in maximum root length by 28.3% for ‘BG88’ and 55.1% for ‘BG51’ compared with the high-N treatment. And ‘BG51’ presented larger root volume, higher root vigor, larger root total absorbing area and root active absorbing area than ‘BG88’ in low-N treatment. Furthermore, ‘BG51’ had significantly higher NR and GS activity in both leaf and root in low N treatment than ‘BG88’, while there was no evident difference between them in high N treatment. These results suggested that N-efficient rapeseed germplasm of natural variation involves an integrated adaptability mechanism responding to low-N stress. Namely, N-efficient genotype could form more developed root system to accumulate more N, and presented efficient N assimilation by higher NR activity and GS activity than N-inefficient genotype. These ultimately resulted in high tolerance of N-efficient genotype to low-N stress and high biomass production. 相似文献
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ABSTRACT Boron (B) toxicity is an important disorder that can limit plant growth on soils of arid and semi arid environments throughout the world. Although of considerable agronomic importance, our understanding of B toxicity is rather fragmented and limited. The effects of increasing levels of B (0, 0.5, 5, 50 mg kg? 1) on plant growth, proline accumulation, membrane permeability, nitrate reductase activity (NRA), and mineral nutrient interactions of tomato and pepper plants were investigated in greenhouse conditions. Increasing levels of B increased the B contents of plants. Boron toxicity symptoms occurred at 5 and 50 mg kg? 1 levels. Fresh and dry weights of the plants clearly decreased with the application of the 50 mg kg? 1 level of B. Membrane permeability and proline accumulation were significantly increased by the 50 mg kg? 1 level of B. Nitrate reductase activity of tomato plants was increased with increasing levels of B. With the exception of potassium (K) and calcium (Ca) in pepper and magnesium (Mg) in tomato, B treatments significantly affected nutrient concentrations of tomato and pepper. Except for sulfur (S) and Ca in tomato, the highest rate of B applied increased the N, phosphorus (P), and K concentrations of tomato and N, P, Mg, and S concentrations of pepper. 相似文献
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EDTA对铅污染土壤上芥菜生长及铅积累特性的影响 总被引：5，自引：0，他引：5
采用盆栽实验研究了EDTA对Pb污染土壤上芥菜生长及Pb积累特性的影响。结果表明,单独Pb处理对芥菜生物量没有明显的影响,但高Pb处理(2000mg kg-1 Pb)芥菜地上部含水量显著降低;Pb处理芥菜体内Pb含量随土壤Pb浓度的增加而明显增加,根系Pb含量高于地上部Pb含量;3mmol kg-1 EDTA处理能促进土壤Pb溶解,增加土壤有效Pb含量,影响芥菜的正常生长,芥菜地上部生物量下降,高Pb浓度处理比低Pb浓度处理更明显;EDTA处理14天芥菜地上部和根系Pb积累量都比不加EDTA的对照明显增加,地上部Pb总量增加到对照的13.1～80倍;EDTA处理芥菜地上部与根系Pb含量的比值上升,表明EDTA处理促进Pb向地上部运输,这种促进作用因土壤Pb浓度的不同而略有差异。 相似文献
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连作番茄根区病土对番茄生长及土壤线虫与微生物的影响 总被引：4，自引：0，他引：4
探索连作番茄根区病土对番茄根结线虫病的诱导效果及引起连作障碍的微生态机制,可为深入了解番茄连作障碍发生机理及探究番茄连作障碍防治方法提供科学依据。本研究利用盆栽试验,测定了番茄在健康土壤及接种病土土壤中生物学特性变化及根结线虫侵染状况,并分析鉴定了土壤中微生物及线虫的种类与数量。结果表明,接种连作番茄根结线虫病株根区病土会对番茄生长及根结线虫侵染产生影响:1)番茄苗期根系根结数达9个?株~(-1),健康土壤无根结;土壤线虫数量较健康土壤增加390.4%;收获期番茄根结线虫侵染率达62.7%,病情指数为80.0%。2)番茄生长受到抑制,叶片防御酶活性降低,收获期茎叶及根系鲜质量较健康土壤分别减少50.2%及33.1%,苗期番茄叶片PPO活性较健康土壤降低15.8%,POD活性较健康土壤增加24.0%,差异均达显著水平(P0.05)。3)番茄根系更易感染有害菌,根系内病原菌甘蓝假单胞菌数量较健康土壤增加463倍,根区土壤细菌、真菌及放线菌总数分别增加46.3%、94.5%及134.0%。4)食细菌线虫、食真菌线虫及植物寄生性线虫数量分别为健康根区土壤的3.3倍、1.6倍及7.3倍,其中的植物寄生线虫95.6%为根结线虫。综上所述,接入连作番茄根结线虫病株根区病土不仅导致番茄遭受根结线虫侵染,而且会导致土壤线虫总量及植物寄生线虫所占比例大幅增加,并使番茄根系内有害细菌数量显著增加,对番茄生长造成显著抑制作用,同时影响番茄的生理生化特性,受线虫侵染番茄防御性酶活性降低,使其更易被根结线虫及病原菌侵染,番茄根区土壤线虫、微生物及根系内优势细菌的种类与数量及其之间的作用发生改变。 相似文献