Nutrients can enhance phytoremediation of copper-polluted soil by Indian mustard

An orthogonally designed experiment was conducted to study the single and combined effects of N, P and K on phytoremediation of Cu-polluted soil by Indian mustard. Addition of fertilizer N and P significantly increased Indian mustard shoot yield. Two high treatments combined with N resulted in the highest yields, followed by low-P combined with N. In contrast, high P with no N gave no yield increase and K had no effect on yield of Indian mustard. Nitrogen and P increased the amount of chlorophyll in the leaves, indicating that the yield increases were due to enhanced photosynthesis. Nitrogen application had no effect on plant Cu concentrations but addition of P slightly decreased plant Cu concentrations, likely a dilution effect resulting from the increase in yield. Among the treatments, N and P applied at 100 and 200 mg kg(-1) respectively with no K application resulted in the highest Cu uptake. Thus, a combination of low N and high P produced a yield increase in Indian mustard that was more than adequate to compensate for a slight decrease in Cu concentration, resulting in the highest Cu removal from the contaminated soil.     

不同施肥处理的养分利用率及甘蔗效益研究

在广西坡耕地赤红壤下,研究不同施肥处理对养分利用效率、甘蔗生长、单茎重、生物产量、蔗茎产量、锤度及经济效益的影响,寻求低成本、高经济效益和养分利用率的施肥模式.设5个处理,(1)不施肥的甘蔗对照(CK),(2)甘蔗常规施肥(SF),(3)80%的甘蔗常规施肥量(SF80%),(4)60%的甘蔗常规施肥量(SF60%),(5)甘蔗常规施肥+农家肥(SF+N).(SF+N)处理的甘蔗茎粗、株高、地上部干物质含量、生物产量、甘蔗产量、锤度、经济效益均最高,分别为33.93 mm、368.6 cm、82.78%、149.92 t/ha、139.58 t/ha、18.83BX、69 792.45元/hm2,与其它各处理相比,差异均达极显著水平;与SF处理相比,SF60%处理提高了N、P利用率,分别提高了4.87%、1.63%;与SF处理相比,(SF+N)处理提高P利用率42.04%,SF80%处理提高K利用率4.12%.(SF+N)处理的甘蔗产量和经济效益均最高.甘蔗K利用率最高的是SF80%处理,甘蔗N利用率最高的是SF60%处理.因此,在广西较肥沃的坡耕地上种植甘蔗,可以适当的减少化肥施用量,配施农家肥可以提高产量和经济效益,也能提高养分利用率.     

长期施肥对水稻土酶活性及理化特性的影响

为了明确不同施肥种类对水稻土土壤肥力与酶活性的影响,以30年（1981年至今）长期定位试验地为基础,研究不同施肥处理（CK,N,P,K,NPK,2倍NPK,NPK＋猪粪）水稻田耕层（0-20cm）土壤酶活性与养分的变化趋势及其相关性。结果表明：1）施P（配施或单施）增加土壤全P、速效P含量,平衡施肥配施有机肥（NPK＋猪粪处理）土壤的有机质、全P、速效P、全N、速效N均显著增加,所有施肥处理间pH值差异均不显著;2）除了NPK处理土壤脲酶活性最高外,平衡施肥配施有机肥土壤转化酶、酸性磷酸酶、过氧化氢酶活性均较其他处理显著增加;3）酸性磷酸酶活性与土壤全P量呈负相关,过氧化氢酶、脲酶、转化酶与全N、有机质、速效N、速效P呈显著或极显著正相关;因此,水田土壤长期平衡施肥配施有机肥,能显著提高土壤肥力,增加土壤酶活性,有益于土壤生产力的持续提高。     

Response of winter wheat yield and soil microbial biomass to fertilization with ridge mulching-furrow planting in the dry highlands of the Loess Plateau北大核心CSCD

As the typical planting pattern of winter wheat in the dry highlands of the Loess Plateau, ridge mulching-furrow planting (RMFP) has played an important role in fertilizer efficiency of different fertilizers, and the differences in fertilizer efficiency further influence the diversity of the structure of soil microbial communities. The effects of different fertilization practices on winter wheat yield formation, soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), and soil microbial biomass phosphorus (SMBP) were investigated by field experiments during 2014-2016 in the winter wheat growing region of the dry highlands in southern Shanxi. The treatments included four groups, farmer fertilization (FF), monitoring fertilization (MF), monitoring fertilization combined application of manure (MFM), and monitoring fertilization combined application of bio-organic fertilizer (MFB). Results showed a significant increase in winter wheat yield by optimized and balanced fertilization, and the grain yield of MFB was highest among all treatments, with a value of 4 107-5 400 kg/hm2, which was 14.5%-23.2% (P < 0.05) higher than that of FF. The effects of different fertilization treatments on the winter wheat yield formulation mainly depended on spike number; however, no effect was found on kernel number per spike and 1 000-grain weight. Soil microbial biomass was affected by both growth period and fertilization patterns, i.e., the content of SMBC from jointing to flowering stage was highest during the winter wheat growth period, whereas the maximum values of SMBN and SMCP were found during the jointing stage. Changes in the rates of SMBC, SMBN, and SMBP during the entire growth period were less than 50%; however, the average contribution rate of optimized fertilization on SMBC, SMBN, and SMBP reached 90%. Compared to single chemical fertilizer applications, the combined application chemical fertilizer and manure or bio-organic fertilizer significantly improved the contents of SMBC, SMBN, and SMBP; however, the contents of SMBC and SMBN between MFM and MFB had no significant difference, whereas the SMBP of MFB was 19.8%-47.1% (P < 0.05) higher than that of MFM owing to the effect of mixed phosphorus bacteria. The soil microbial biomass C/N and C/P of the different treatments were 6.9-9.8 and 14.4-41.0, respectively, and maximum values occurred during the flowering stage. Given the above, the combined application of reasonable chemical fertilizer and bio-organic fertilizer can effectively improve the winter wheat yield and soil microbial biomass under RMFP cultivation in the dry highlands of the Loess Plateau. © 2018 Science Press. All rights reserved.     

Sewage sludge ditch for recovering heavy metals can improve crop yield and soil environmental quality

• Indirect use of sludge in ditches alongside plants was tested in field experiments. • The dried and stabilized sludge in ditches was recovered with heavy metals. • Cd, Pb, Cu and Zn in the planted soil were all in a safe range. • The indirect use of sludge increased plant yield, soil N content and C storage. The treatment and disposal of municipal sewage sludge (MSS) is an urgent problem to be resolved in many countries. Safely using the nutrients within MSS to increase crop yield and enhance the fertility of poor soil could contribute to achieving sustainable development. An indirect use of MSS in ditches alongside Pennisetum hybridum plants was studied in field plots for 30 months and the contents of heavy metals and macronutrients were monitored in soil, sludge and plant samples. We found that the yield of P. hybridum was significantly increased by 2.39 to 2.80 times and the treated plants had higher N content compared with no sludge. In addition, the organic matter (OM) and N contents in the planted soil increased significantly compared with the initial soil. The OM content in the planted soil of the MSS treatment was 2.9 to 5.2 times higher than that with no sludge, and N increased by 2.0 to 3.8 times. However, MSS had no significant effect on the N, P and K contents in the soil at the bottom of the MSS ditch, and the content of heavy metals (Cd, Pb, Cu and Zn) were also within the safe range. Moreover, the moisture content and phytotoxicity of MSS after this indirect use were reduced and the heavy metal contents changed little, which is favorable to the further disposal of recovered MSS. Therefore, this indirect use of MSS is beneficial to agricultural production, soil quality and environmental sustainability.     

The effects of compost prepared from waste material of banana plants on the nutrient contents of banana leaves

In this study, the possible utilization of removed shoots and plant parts of banana as compost after fruit harvest were investigated. Three doses (15-30-45 kg plan(-1)) of the compost prepared from the clone of Dwarf Cavendish banana were compared with Farmyard manure (50 kg plant(-1), Mineral fertilizers (180 g N + 150 g P + 335 g K plant(-1)) and Farmyard manure + Mineral fertilizers (25 kg FM + 180 g N + 150 g P + 335 g K plant(-1)) which determined positive effects on the nutrient contents of banana leaves. The banana plants were grown under a heated glasshouse and in a soil with physical and chemical properties suitable for banana growing. The contents of N, P, K and Mg in compost and in farmyard manure were found to be similar. Nitrogen, phosphorus and potassium contents of leaves in all applications except control, and Ca, Mg, Fe, Zn, Mn, Cu contents in all applications were determined between optimum levels of reference values. There were positive correlations among some nutrient contents of leaves, growth, yield and fruit quality characteristics. Farmyard manure, Farmyard manure + Mineral fertilizers and 45 kg plant(-1) of compost increased the nutrient contents of banana leaves. According to obtained results, 45 kg plant(-1) of compost was determined more suitable in terms of economical production and organic farming than the other fertiliser types.     

氮钾配合施用对亚种间杂交水稻养分吸收及产量影响的研究

氮促进亚种间杂交稻的分蘖和对磷、钾的吸收,钾也能促进氮、磷的吸收,但对分蘖似有抑制的趋势。稻株各生育期氮、磷、钾含量以分蘗盛期最高。随后迅速下降,至幼穗形成期下降速率减缓。齐穗后,累积在茎、叶的氮、磷大部分向穗部转移,而钾则很少运送到穗部。每生产100kg稻谷约需吸收1.71kg N、0.77kg P_2O_5、2.30kg K_2O,三者比例为1:0.45:1.35。氮、钾配合施用的增产效果大于单施氮或钾的效果;在施用量为82.5kg N ha~(-1)和75.0kg K_2O ha~(-1)的基础上,增施氮肥或钾肥,其增产效果相近,表明在施用适量氮肥的前提下,亚种间杂交稻对钾的反应甚为敏感。     

Effects of cadmium on nutrient uptake and translocation by Indian Mustard

Plants that hyperaccumulate metals are ideal subjects for studying the mechanisms of metal and mineral nutrient uptake in the plant kingdom. Indian Mustard (Brassica juncea) has been shown to accumulate moderate levels of Cd, Pb, Cr, Ni, Zn, and Cu. In this experiment, 10 levels of Cd concentration treatments were imposed by adding 10-190 mg Cd kg(-1) to the soils as cadmium nitrate [Cd(NO3)2]. The effect of Cd on phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and the micronutrients iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in B. juncea was studied. Plant growth was affected negatively by Cd, root biomass decreased significantly at 170 mg Cd kg(-1) dry weight soils treatment. Cadmium accumulation both in shoots and roots increased with increasing soil Cd treatments. The highest concentration of Cd was up to 300 mg kg(-1) d.w. in the roots and 160 mg kg(-1) d.w. in the shoots. The nutrients mainly affected by Cd were P, K, Ca, Fe, and Zn in the roots, and P, K, Ca, and Cu in the shoots. K and P concentrations in roots increased significantly when Cd was added at 170 mg kg(-1), and this was almost the same level at which root growth was inhibited. Zn concentrations in roots decreased significantly when added Cd concentration was increased from 50 to 110 mg kg(-1), then remained constant with Cd treatments from 110 to 190 mg kg(-1). However, Zn concentrations in the shoots seemed less affected by Cd. It is possible that Zn uptake was affected by the Cd but not the translocation of Zn within the plant. Ca and Mg accumulation in roots and shoots showed similar trends. This result indicates that Ca and Mg uptake is a non-specific process.     

粤东龙眼立地土壤养分限制因子系统调查

用“土壤养分状况系统研究法”对粤东８ 片龙眼园土壤进行大、中、微量营养元素含量测定、土壤吸附试验及盆栽诊断试验。结果表明,全部供试土壤均缺 Ｎ 和 Ｐ,８８ ％ 土壤缺 Ｋ 和 Ｍｇ ,７５ ％ 土壤缺 Ｃａ 和 Ｓ,６３ ％ 土壤缺 Ｃｕ ,５０ ％ 土壤缺 Ｂ。在缺素土壤中若不配施这些元素,指示作物（ 高粱） 的干物产量分别下降 Ｎ ６０ ．３ ％ , Ｐ６５ ．３ ％ , Ｋ ２９ ．５ ％ , Ｃａ ４６ ．２ ％ , Ｍｇ ３３ ．５ ％ , Ｃｕ １９ ．３ ％ , Ｓ１７ ．９ ％ , Ｂ１５ ．５ ％ 。综合各营养元素的施肥效应及缺乏的普遍性显示,粤东龙眼立地土壤养分限制因子排序为： Ｎ ＞ Ｐ＞ Ｍｇ ＞ Ｋ ＞ Ｃａ ＞ Ｃｕ ＞ Ｓ＞ Ｂ;碱性紫色土则富 Ｃａ 。     

Efficacy of rapeseed residue and eggshell waste on enzyme activity and soil quality in rice paddy

Addition of plant residue into soils improves soil physiochemical properties and its fertility. Rapeseed residue is an emerging N source to paddy soils via rice-rape double-cropping practice. The objective of this study was to evaluate the effects of rapeseed residue and eggshell waste on chemical changes and enzyme activity in the rice paddy soil. The powdered eggshells at 0, 1, 3, and 5% were applied once to 7.0 kg paddy repacked soils in each pot treated with the rapeseed residue or the conventional N, P, and K fertilisers. Eight rice seedlings (Oriza sativa L. cv. Ilmibyeo) (40 days after sowing) were transplanted to the treated each pot. The contents of total C (TC) and N (TN), and organic matter (OM) were significantly increased in soils treated with the rapeseed residue compared to the N, P, and K fertilisers. With the addition of eggshell containing ～92% CaCO₃, a considerable increase of soil pH was observed in soils treated with the rapeseed residue and the N, P, and K fertilisers, compared to the untreated soil. Activities of β-glucosidase, urease, and arylsulfatase enzymes were higher in soils treated with the rapeseed residue than soils treated with the N, P, and K fertilisers. The eggshell additions at 1, 3, and 5% into soils treated with the rapeseed residue increased enzyme activity mainly resulting from N mineralisation, whereas no change in enzyme activity was observed in the soils treated with the NPK fertiliser. The combined use of the rapeseed residue and the eggshells can be beneficial to improve soil environment.     

Effects of organic and inorganic fertilisation on soil nutrient dynamics in a Savannah region (DR Congo)

Very few studies have considered the residual effect of inorganic and organic fertilisation on oxisol chemistry and plant productivity while studying the response of maize to fresh fertiliser application. The purpose of the present study was to examine the effects of five treatments of inorganic and organic fertilisers on maize productivity and soil fertility under field conditions in a Savannah region. The trials were conducted from 2009 to 2011 and the treatments included inorganic nitrogen–phosphorus (NP), Entada abyssinica, Tithonia diversifolia, inorganic NP combined with E. abyssinica, and inorganic NP combined with T. diversifolia, and no fertilised plots. The combination of NP with T. diversifolia or E. abyssinica leaves resulted in the highest increase in grain yields during the first crop season.The positive residual effects of fertilisers on maize grain yield were strong and significant in the immediate succeeding season and decreased during the second year following fertilisation. The highest residual effect was observed in plots fertilised with E. abyssinica combined with NP, followed by T. diversifolia combined with NP, and E. abyssinica and T. diversifolia without NP, respectively. The lowest residual effect was observed in plots fertilised with inorganic NP. Analytical results revealed that total nutrients in the soil matrix are not dominantly in forms available for plant uptake. There were significant residual effects for total potassium in the site with low initial nutrient levels. The soil content of bioavailable phosphorus, nickel, zinc, copper, and cobalt was in general below detectable levels.     

香蕉组培苗的营养和施肥

较系统地研究了香蕉组培苗的营养与施肥，试验方案包括了ＮＰＫ１３种用量水平、１０种不同ＮＰＫ配比和中微量元素混施．试验结果表明，在一定的ＮＰＫ施肥基础上．再增施ＮＰＫ均能获得不同程度的增产，其中增施Ｎ的增产幅为４．７％－１５．０％，增施Ｐ、Ｋ的分别为３．４％－１５．１％和６．６％－１２．６％．增Ｎ有利于植株增高、茎围增粗、长叶增快和提早吐蕾；增Ｐ对植株增高和提早吐蕾也有一定的作用；增Ｋ主要有利于茎围增粗，但在高Ｎ高Ｐ下增Ｋ也同样具有增Ｎ的多种效果．增Ｋ的另一效应是延缓吐蕾期而使吐蕾期较集中一致，这有利于田间管理和收获；施用中微量元素的增产效果显著，同时也改善和提高了果实品质．应提倡应用和推广．     

烤烟优质高产施肥技术研究初报

１９９７～１９９８年在广东省五华县的紫色土田进行了烤烟优质高产施肥试验。结果表明，在一定的氮磷施用量条件下，烤烟的产量、质量及产值都是随着施钾比例的提高而提高。在一定的配比下，烤烟的产量及产值在施氮 １６５ ｋｇ／ｈｍ~２以下均随施氮量的增加而提高；均价和优级烟率以中等氮水平（ １３５ ｋｇ／ｈｍ~２）的为最高。本文还提出烤烟的最佳施肥方案。     

施用化肥对砂姜黑土碳库管理指数的影响

针对安徽省砂姜黑土的不良属性,在安徽蒙城砂姜黑土上进行了4年的施肥定位试验,施肥方式为年施氮量（以 N计）0、360、450、540、630、720 kg·hm-2,玉米季占55%,通过研究连续施肥措施下砂姜黑土耕层土壤活性有机质组分的变化特征,分析了单施化学氮肥对土壤有机质组分及碳库管理指数的影响。结果表明：施用化学氮肥有利于提高土壤总有机质质量分数和活性有机质质量分数,变化幅度分别为17.49~19.46、3.10~3.52 g·kg-1,化肥施用水平之间差异不显著,相比不施肥,施肥土壤的总有机质质量分数增加1.53~3.53 g·kg-1、活性有机质质量分数增加0.10~0.52 g·kg-1、稳定态有机质增加1.02~4.30 g·kg-1。处理间高活性有机质质量分数变化范围为0.46~0.62 g·kg-1,施用化肥后降低,高量氮肥与不施肥处理间差异显著（P＜0.05）;中活性有机质质量分数在2.21~3.25 g·kg-1之间,且与氮肥施用水平有关,年施氮量（以N计）高于540 kg·hm-2时其值增加,但各施用水平间无显著差异（P＞0.05）。施氮对CMI的影响不显著,土壤总有机质增加的有机质组分主要为稳定性有机质。施氮处理的玉米籽粒产量明显高于不施氮处理,年施氮（以N计）720 kg·hm-2的玉米籽粒产量最高,达11137.90 kg·hm-2。相关性分析结果显示,3种活性有机质之间,活性有机质和高活性有机质相关性最高,关系最为密切;碳库管理指数与活性有机质呈极显著正相关,相关系数为0.910;总有机质含量与活性有机质含量显著正相关（P＜0.05）,与碳库管理指数无显著相关性（P＞0.05）;玉米籽粒产量与总有机质、活性有机质极显著正相关（P＜0.01）,与碳库管理指数显著相关（P＜0.05）。由此可知,化学氮肥可促进砂姜黑土耕层土壤总有机质和活性有机质的提高,且二者均能够反映砂姜黑土施用化肥后的肥力变化情况;提高砂姜黑土总有机质的有机质组分主要是稳定态有机质;要提高玉米产量需要较高的氮肥用量。     

Effects of Cadmium on Nutrient Uptake and Translocation by Indian Mustard

Plants that hyperaccumulate metals are ideal subjects for studying the mechanisms of metal and mineral nutrient uptake in the plant kingdom. Indian Mustard (Brassica juncea) has been shown to accumulate moderate levels of Cd, Pb, Cr, Ni, Zn, and Cu. In this experiment, 10 levels of Cd concentration treatments were imposed by adding 10–190 mg Cd kg^–1 to the soils as cadmium nitrate [Cd(NO₃)₂]. The effect of Cd on phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and the micronutrients iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in B. juncea was studied. Plant growth was affected negatively by Cd, root biomass decreased significantly at 170 mg Cd kg^–1 dry weight soils treatment. Cadmium accumulation both in shoots and roots increased with increasing soil Cd treatments. The highest concentration of Cd was up to 300 mg kg^–1 d.w. in the roots and 160 mg kg^–1 d.w. in the shoots. The nutrients mainly affected by Cd were P, K, Ca, Fe, and Zn in the roots, and P, K, Ca, and Cu in the shoots. K and P concentrations in roots increased significantly when Cd was added at 170 mg kg^–1, and this was almost the same level at which root growth was inhibited. Zn concentrations in roots decreased significantly when added Cd concentration was increased from 50 to 110 mg kg^–1, then remained constant with Cd treatments from 110 to 190 mg kg^–1. However, Zn concentrations in the shoots seemed less affected by Cd. It is possible that Zn uptake was affected by the Cd but not the translocation of Zn within the plant. Ca and Mg accumulation in roots and shoots showed similar trends. This result indicates that Ca and Mg uptake is a non-specific process.     

蚯蚓在植物修复铜、镉污染土壤中的作用

以红壤和高砂土为供试土壤,分别加入3个浓度的重金属铜离子Cu2 (100,200,400 mg kg-1)或镉离子Cd2 (5,10,20 mg kg-1),每钵接种6条蚯蚓(Pheretimasp.),种植黑麦草(Lolium multiflorum),以不加蚯蚓为对照(CK),研究蚯蚓活动对Cu、Cd污染土壤中黑麦草生长及铜、镉生物有效性的影响.结果表明,添加蚯蚓显著提高了Cu2 、Cd2 污染的高砂土中黑麦草地上部分的生物量,增幅为33%~96%;仅增加了Cu2 污染浓度低于200 mg kg-1的红壤中黑麦草地上部分的生物量;添加蚯蚓显著增加了两种土壤中速效N的含量,促进了黑麦草地上部分对N的吸收,对速效P、K的含量以及黑麦草中P、K含量无显著影响;添加蚯蚓显著提高了红壤中铜(Cu)、镉(Cd)DTPA提取态的含量,对高砂土中DTPA提取态Cu、Cd的含量无显著影响;增加了高砂土中和添加Cu污染浓度低于200 mg kg-1的红壤中黑麦草地上部分吸收Cu的总量,而对黑麦草吸收Cd的量无显著影响.加入蚯蚓可以不同程度地改善植物修复技术应用中受制的两个主要因素.表4参30     

Uranium Accumulation of Crop Plants Enhanced by Citric Acid

Citric acid was applied to soil to enhance U accumulation in four crop plants. While the highest enhanced U accumulation of aboveground tissues (a.c. 2000 mg kg⁻¹ dry weight) occurred in the leaves of Indian mustard (Brassica juncea), the highest enhanced U accumulation of roots (a.c. 3500 mg kg⁻¹ dry weight) occurred in canola (Brassica napus var. napus). Uranium translocation among tissues of test plants is in the relation of roots>shoots ≅ leaves. The flowers of sunflower (Helianthus annuus) contained similar or higher U concentrations than those found in shoots, but concentrations in seeds are close to zero. In conclusion, Indian mustard is recommended as a potential species for phytoextraction for U-contaminated soil due to its high U accumulation of aboveground biomass (a.c. 2200 μg per plant). There is no evidence that two types of soils cause a significant difference of the enhanced U accumulation (p<0.05). Results, however, indicate that additional citric acid may result in downward U migration that may contaminate groundwater. Speciation of U that is taken up by plants is also discussed in the end.     

粉煤灰钝化污泥人工土壤上高麦草生长发育及营养状况研究

通过温室盆栽试验研究不同比例粉煤灰钝化污泥人工土壤上高麦草的生长发育及营养状况，试验结果表明：土壤中加入粉煤灰钝化污泥显著增加了高麦草的干物重．脱水污泥加入其鲜重的10％粉煤灰钝化后再按1∶1和1∶5体积比与土壤混合配成的人工土处理和加入其鲜重的35％粉煤灰钝化后再按1∶1体积比与土壤混合配成的人工土处理高麦草的产量都显著高于自然土壤施用化肥的处理，高麦草的发芽率也不受影响．随着粉煤灰加入量的增加，高麦草地上部Ca，Mg和B的浓度（w／％或w／mg．kg－1）增加而K，Fe，Mn和Zn的浓度下降，高麦草根中Fe，Mn，Cu和Zn的浓度显著高于其地上部中的浓度．所有粉煤灰钝化后污泥人工土壤高麦草都没有出现N和P的缺乏和重金属毒害，说明合适比例的粉煤灰钝化污泥人工土壤是高麦草的良好生长介质．     

Role of arbuscular mycorrhizal fungi on the performance of floodplain Phragmites japonica under nutrient stress condition

A pot experiment was conducted to evaluate the potential effects of arbuscular mycorrhizal fungi (AMF) on growth, nutrient uptake, and inoculation effectiveness on Phragmites japonica. Spores of AMF strains (Gigaspora margarita Becker &; Hall) were collected from the commercial product ‘Serakinkon’. Four treatments, namely, natural soil (NS), natural soil inoculated by AM fungi, sterilised soil (SS) inoculated by AM fungi, and SS without AM fungi inoculation were selected to determine the effects of applied and indigenous AMF on P. japonica. The average colonisation level of P. japonica was 24–33%, whereas no colonisation was found in the SS. AMF colonisation increased the chlorophyll content (r?=?0.84, p?r?=?0.89, p?相似文献   

长期施肥对土壤有机质积累的影响

20年的NPK施肥定位试验,有利于深刻揭示土壤肥力特征与营养平衡规律。以位于黄淮海平原的中国科学院禹城综合试验站为例,探讨和估算了长期定量施肥对冬小麦（TriticuspaestvumL．）、夏玉米（ZeaMaysL．）生长和土壤有机质（SOM）的影响。结果表明,长期的N、P肥配施或N、P、K均衡施肥,可显著增加SOM储量,并且后者要优于前者;SOM增加主要集中在0-20cm深度的土层,40-60cm基本不变;生物量对SOM储量变化影响明显,NPK,NP处理作物生长良好,作物残体输人明显优于其他处理;0-40cm可以代表该区用以计算土壤固碳潜力,并且在N、P、K均衡施肥条件下,0-40cm土层中SOM储量长期以来持续增加,并未达到上限,每年的平均固碳速率（以C计）达182．8kg·hm-1,约是全球平均水平的1．5倍,全国平均水平的1．1倍。华北平原若按N、P、K均衡施肥,农田土壤每年固碳潜力将达到1．6-2．4Tg·a-1。