Relationship between vertical distributions of Bray II P content and organic P content in the Ap horizon of paddy rice fields

Abstract

We examined the vertical distributions of total, Bray II and organic phosphorus (P) in the Ap horizons of five paddy rice fields including no tillage treatment. Soil samples were collected from the Ap horizons as nine thin layers of 0–1, 1–2, 2–3, 3–4, 4–6, 6–8, 8–10, 10–15 and 15–20 cm from the soil surface after harvest. In three lowland paddy soils of no-tillage Hachirogata (HA-NT), conventional-tillage Hachirogata (HA-T) and conventional-tillage Furukawa (FU-T), the total P (TP) content was relatively low. In these soils, the modified Bray II P (soil : solution = 1:20; shaking time 60s) content decreased and the organic P (OP) content increased at a depth of 0–1 cm compared with the underlying layers, possibly because of high microbial activities as suggested from the increased total C and N contents in this layer. In contrast, the decrease in Bray II P content and the increase in the OP content of the surface layer were not evident in two Andosols of the conventional-tillage Utsunomiya (UM-T) and conventional-tillage Kawatabi (KA-T). Even TP content fluctuated in the thin surface layers of 0–3 cm depending on the sampling site. Accordingly, percentages of Bray II P and OP to TP were calculated to compare the vertical distribution curves between Bray II P and OP. The percentage of Bray II P to TP of the 0–1 cm layer was lower and the percentage of OP to TP in the layer was higher than the underlying layers for HA-T, HA-NT and FU-T. The decrease in Bray II P was nearly compatible with the increase in OP for the surface of the 0–1 cm layers of HA-NT, HA-T and FU-T. This result suggests that a part of Bray II P was converted to OP in the thin surface layer of the Ap horizons in these paddy soils. This change in chemical form of P was more pronounced in the HA-NT by accumulating the effect of the microbial activities over a longer period of time because of no tillage compared with HA-T and FU-T. These findings add a new dimension to P behavior in submerged rice soils under field conditions, particularly near the soil surface. Moreover, we must be careful in soil sampling for P availability evaluation, and soil samples should represent the vertical distribution of P in the whole Ap horizon of a paddy field. Changes in OP with depth in UM-T and KA-T may have been masked by the high OP content as well as by the high TP content in these Andosols.     

Determination of water content in olive oil by 31P NMR spectroscopy

A method for moisture determination in olive oil using 31P NMR spectroscopy is developed. This method is based on the replacement of the hydrogen atoms of water molecules with the tagging agents 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane and diphenylphosphinic chloride. Both reagents were successful in determining moisture in olive oil. However, only the second reagent provided a clean and instantaneous reaction under mild condition with no side reactions as observed with the first reagent. A study comparison was made to assess the agreement between the present analytical NMR method and the well-established methods of Karl Fischer titration.     

长期不同施肥对棕壤微生物量磷及其周转的影响

研究棕壤定位试验27年后,长期不同施肥条件下土壤微生物量磷在玉米生长季内的变化及其对植物营养的贡献。结果表明,长期施用化学磷肥或有机肥均能增加土壤微生物磷的含量,尤以有机肥的作用更显著;长期单一的施用氮肥降低了微生物量磷的含量。玉米生长季内土壤微生物量磷的动态变化呈先上升后下降的趋势,其含量最大值出现在玉米生长中后期;一个生长季后,各处理微生物量磷的含量都较施肥前有所下降。长期施肥增加了土壤微生物体的供磷量,微生物体供磷量与玉米产量及吸磷量关系密切,占玉米植株体吸磷量的11.79%～34.46%。不同施肥处理土壤微生物量磷的周转期为0.68～1.61年,施肥延长了微生物量磷的周转期;但单施氮肥加速了其周转。土壤微生物量磷能反映土壤磷素肥力水平。     

Available phosphorus content of soil affected by P fertilization and its change in time

Abstract

For characterizing the rate of increase of the available soil phosphorus content applying superphosphate fertilization the slope of the linear regression curve in the range of 0–12–120 ppm P is used. The available phosphorus is determined by NH₄‐lactate and NaHCO₃ extractions. The rate of increase of available phosphorus is primarily influenced by the presence of CaCO₃ and is in close correlation with the pH, as well as the silt + clay content. The rate of decrease of available phosphorus in time after P fertilization in non‐calcareous soil is similar, in calcareous soil is different measured by the two extractions.     

Mechanisms of increase in content of water-soluble P in Hachirogata reclaimed soils after NaCl washing

Abstract

In some of the drainage waters in Hachirogata reclaimed land, a very high concentration of inorganic P (up to 2 mg P L^-1) has been recently detected (Sato et al. unpublished). The drainage waters flow into the Lake Hachirogata that surrounds the land. Since the lake is also a reservoir, the water circulates through a closed system. Recently, the eutrophication of the lake has been found to be significant (Akita Prefectural Government 1989) and drainage water has been incriminated as one of the P sources of eutrophication. Therefore, it would be important to analyze the mechanisms responsible for the increase of P release from Hachirogata reclaimed land.     

高温焚烧对秸秆灰渣磷、钾养分变化的影响

生物质能是我国仅次于煤炭、石油和天然气的第4位能源资源,是可再生能源的一部分,在能源系统中占有重要地位[1]。农作物秸秆作为一种生物质能,也是我国广大农村中重要能源之一[2]。如何合理利用秸秆这一类生物质能已成为研究的热点[3]。自1988年丹麦建成世界第一座秸秆发电厂后,秸秆发电已成为秸秆能源化利用的新途径[4],目前,秸秆发电技术在发达国家如美国、欧洲、日本等已广泛采用。受世界能源危机的影响,近两年,我国许多省市引进国外技术,开始陆续上马秸秆发电建设项目。然而,秸秆发电过程中,会产生约占秸秆量15%左右的灰渣,由于发电厂秸…     

近红外光谱法快速测定土壤碱解氮、速效磷和速效钾含量

运用偏最小二乘法(PLS)和人工神经网络(ANN)方法分别建立了0.9 mm筛分风干黑土土壤碱解氮、速效磷和速效钾含量预测的近红外光谱(NIRS)分析模型。使用偏最小二乘算法建立的碱解氮、速效磷和速效钾校正模型的决定系数R²分别为0.9520、0.8714和0.7300，平均相对误差分别为3.42%、13.40%和7.40%。人工神经网络方法建立的碱解氮、速效磷和速效钾校正模型的决定系数分别为0.9563、0.9493和0.9522，相对误差分别为2.67%、6.48%和2.27%，测试集仿真的相对误差分别为5.44%、16.65%和7.87%。结果表明，人工神经网络方法所建立的校正模型均优于偏最小二乘法所建模型；用近红外光谱分析法预测土壤碱解氮含量是可行的，而速效磷、速效钾模型的测试集样品仿真的相对误差较大，其预测可行性还需做进一步研究。     

不同轮作模式农田磷养分表观平衡及其对土壤Olsen-P含量的影响

通过连续3年监测上海郊区43块定位农田研究,比较了50种作物以及5种不同轮作模式农田的磷养分表观盈余状况及其对土壤Olsen-P含量的影响。结果表明:(1)不同作物农田的磷养分盈余趋势为水生蔬菜类果树类旱作蔬菜≥草皮大田作物;不同轮作模式农田磷养分盈余趋势为菜菜轮作果树单作菜作轮作草皮单作作物轮作;(2)不同作物及轮作农田收获后土壤Olsen-P含量随土壤深度的增加而逐渐降低,磷养分盈余量多的农田土壤Olsen-P含量也高;(3)不同作物以及轮作农田磷养分盈余与收获时土壤表层(0~30cm)的Olsen-P含量呈显著正相关。     

Reactive natural phosphate enriched with filter cake enhances soil P content and noni seedlings growth*

One of the major challenges in crop production is increase efficiency of non-renewable P sources, or replace them with renewable sources. The objective of this study is to evaluate the effects of phosphorus (P) fertilization using reactive natural phosphate, filter cake, peat and biofertilizer on soil P content, foliar P content and growth of noni seedlings. The treatments were: control (without P fertilization); phosphorus; filter cake; phosphorus?+?filter cake; phosphorus?+?filter cake?+?peat; and phosphorus?+?filter cake?+?peat?+?biofertilizer. All treatments were replicated four times and arranged in a completely randomized design. The treatments phosphorus?+?filter cake; phosphorus?+ filter cake?+?peat; and phosphorus?+?filter cake?+?peat?+?biofertilizer increased phosphorus content in soil and in leaf, and the growth of noni seedlings. Our results indicates that natural reactive phosphate enriched with filter cake can be used as phosphate fertilizer on noni seedlings cultivation.     

Phosphorus pools in sulfuric acid sulfate soils: influence of water content,pH increase and P addition

Journal of Soils and Sediments - Acid soils often have low P availability limiting plant growth, which is addressed by application of inorganic fertilizers and neutralizing agents. However, little...     

不同比例化肥与猪粪肥配施对稻穗不同部位磷含量分布的影响

为了综合评价中国南方施用猪粪肥对稻穗不同部位籽粒磷素积累的影响,本研究在水稻施肥量N 180kg/hm~2,N∶P_2O_5∶K_2O=3∶1∶2.5情况下,比较施用化肥(NPK)、70%化肥配施30%猪粪(F7M3)、50%化肥配施50%猪粪(F5M5)、30%化肥配施70%猪粪(F3M7)的稻穗不同部位籽粒含磷量。结果发现,化肥配施猪粪肥能有效促进水稻产量的增加与稻穗含磷量的下降,但猪粪肥配施与NPK处理的水稻籽粒吸磷量无明显差异;与NPK处理相比,猪粪肥配施可以显著降低一次枝梗与穗上部二次枝梗含磷量,并能有效降低不同穗位的籽粒含磷量。故猪粪肥能有效影响稻穗不同部位的磷含量,猪粪肥资源的合理利用有利于水稻的高产稳产。     

氮磷钾和有机肥配合施用对马铃薯淀粉含量和产量的影响

采用分 3 个正交区组的 4 因素 2 次正交旋转组合设计方法,研究了乌兰察布地区施用 N、P、K 和有机肥对马铃薯淀粉含量和淀粉产量的影响.研究结果表明:N、P、K 和有机肥的合理配合施用能使马铃薯淀粉含量和淀粉产量明显提高.在本试验条件下,得到较高淀粉含量和淀粉产量的最佳配方施肥方案是:N 208.12 kg/hm2,P2O5 87.97 kg/hm2,K2O 128.9 kg/hm2,有机肥 22898 kg/hm2.     

Variation in content of available P and K (bray I) in soil samples from a cropped N,P, and K fertility experiment over 8 years

Abstract

Plots from a N, P, and K field fertility experiment were soil sampled each spring and fall from 1971 to 1979 to study the effect of cropping and different rates of added P and K on the content of available soil P and K (Bray I). Phosphorus and K fertilization was in the spring after soil sampling and before planting in 1971, 1972,and 1973 and in the fall after sampling in 1974, 1975, 1976, 1977, and 1978. Over the 8‐year period, available soil P increased 1 kg/ ha for every 2.3 kg/ha of added P; while available soil K increased 1 kg/ha for every 5.7 kg/ha of added K. However, within a growing season and between growing seasons, contents of available soil P and K showed cyclic patterns, increasing and decreasing to a greater extent than the long‐term response. Changes in available P and K from spring to fall and from fall to spring are presented. Variability in the content of available soil P and K for 32 plots receiving a similar treatment of either P or K was greater for P as compared to K.     

Effect of corn leaf sampled on N,P, K,Ca and Mg content and calculated DRIS indices

Abstract

The indices calculated from the Diagnosis and Recommendation Integrated System (DRIS) are used to interpret previously published data on the variation in N, P, K, Ca and Mg content in corn leaves. The results indicate that the DRIS approach is able to make consistent diagnoses of the order of requirement of the above elements by the plant irrespective of position of the leaf on the plant and portion of leaf sampled within certain limits. The diagnoses are completely consistent if any whole leaf from the middle of the plant is sampled.     

Effect of arbuscular mycorrhizal fungi on rhizosphere organic acid content and microbial activity of trifoliate orange under different low P conditions

ABSTRACT

Arbuscular mycorrhizal (AM) fungi can improve plant phosphorus (P) uptake; however, information about how AM fungi affect rhizosphere organic acid and microbial activity to alleviate citrus low P stress is limited. Here, a pot experiment was conducted to evaluate the effect of AM fungi (Rhizophagus intraradices, Ri) inoculation on rhizosphere organic acid content, microbial biomass (MB) and enzyme activity of trifoliate orange (Poncirus trifoliata L. Raf.) seedlings grown under three low P conditions. The results showed that mycorrhizal seedlings all recorded higher P concentrations, plant biomass and better root morphology with more lateral and fine roots, but lower root mass ratios, irrespective of P conditions. Mycorrhizal P absorption contribution did not differ significantly among three P conditions. Mycorrhizal seedling rhizosphere soil exhibited lower organic acid content, soil organic P content and ratio of MB-carbon (C)/MB-P, but higher MB and enzyme activity. Additionally, the main organic acids showed a negative relationship with mycorrhizal colonization rate and hyphal length; however, phosphatase and phytase activity had a significantly positive relationship with MB. Therefore, the results suggest that AM fungi inoculation may help citrus to efficiently utilize organic P source by improving microbial activity under low available P conditions.     

化肥减量配施黄腐酸降低盐渍农田NaCl含量提高氮磷养分有效性的协同效应

  【目的】  土壤盐渍化以及肥料过量施用严重限制着黄河三角洲盐渍化地区农业的可持续发展。综合分析氮、磷肥优化减量及其与黄腐酸配施对盐渍农田土壤肥力、冬小麦产量以及养分吸收利用的影响,可为该区盐渍农田化肥减施增效提供理论依据。  【方法】  以黄河三角洲中度盐土[pH 7.73、电导率 (EC) 1.18 dS/m]为研究对象进行室内盆栽试验,试验设5个施肥水平,分别为常规氮磷肥用量 (N100P100)、氮肥常规用量的85% (N85P100)、氮肥常规用量的70% (N70P100)、磷肥常规用量的85% (P85N100)、磷肥常规用量的70% (P70N100);每个处理下又分为添加、不添加黄腐酸 (H) 两个处理,并且以不施肥料和黄腐酸的处理为对照(CK) ,共11个处理。在冬小麦苗期和收获期,分别采集0—10 和10—20 cm土层土壤样品,测定土壤有效磷、硝态氮、EC、pH和盐分离子组成。在收获期,测定冬小麦籽粒产量、全氮及全磷含量。  【结果】  化肥减量配施黄腐酸处理降低了冬小麦苗期和收获期0—10 cm土层硝态氮含量,提高了收获期10—20 cm土层硝态氮含量。0—10 cm土层土壤有效磷含量随着氮肥施用量的增加呈现降低的趋势。随着施氮量的增加,土壤溶液EC、Na+、Ca2+、Cl－含量增加,而Mg2+含量减少。与N100P100相比,N85P100、N70P100、P85N100、P70N100处理下的土壤Na+含量分别降低了29.74%、55.84%、28.62%和43.25%,Cl－含量分别降低了37.68%、43.81%、26.11%和14.53%。与相同养分量处理相比,N100P100+H、N85P100+H、N70P100+H、P85N100+H、P70N100+H处理下的Na+含量分别下降了64.63%、31.20%、5.14%、32.66%、30.59%,Cl－含量分别下降了66.74%、55.07%、35.93%、53.56%、70.44%。处理N85P100、N70P100、P85N100、P70N100的冬小麦产量与N100P100没有显著差异,N70P100+H和P85N100+H的冬小麦产量显著高于N70P100和P85N100。氮、磷素吸收效率均随着氮肥施用量的增加而减少,与N100P100相比,N85P100、N70P100处理下的氮素吸收效率分别提高11.22%、29.37%。与单施化肥处理相比,化肥减量配施黄腐酸处理均能够提高冬小麦产量、氮、磷素吸收效率和偏生产力。通过相关分析发现,土壤盐分是降低作物产量的直接原因,其中,Na+、Cl－和EC与氮素吸收效率、偏生产力及磷素吸收效率、偏生产力呈显著负相关。  【结论】  黄河三角洲盐渍农田的主要盐分是NaCl,Na+、Cl－含量决定着EC值,与氮素吸收效率、偏生产力及磷素吸收效率、偏生产力呈显著负相关。化肥减量可显著减少土壤盐分含量,配施黄腐酸能够显著降低土壤中的Na+和Cl－含量,缓解盐碱胁迫对作物的影响,提高冬小麦产量、氮、磷素吸收效率和偏生产力。减施氮肥能够提高冬小麦苗期和收获期0—10 cm土层的有效磷含量,减施氮肥30%时的土壤有效磷含量高于减施氮15%和常规施氮量。     

氮、磷、钾肥配施对烤烟化学成分和致香物质含量的影响

田间试验以烤烟(Nicotiana.tabacum.L.)品种K236为材料,研究了氮、磷、钾肥配施对烤烟化学成分和致香物质含量的影响。结果表明,不施肥处理烟叶内在化学成分协调性差,致香物质总量及不同种类致香物质含量都较低;单施氮、磷、钾一种肥料或任意两种肥料配施可以不同程度改善烟叶化学成分,提高烟叶中类西柏烷类和类胡萝卜素类致香物质含量;而氮、磷、钾配施处理烟叶的化学成分协调,致香物质总量和不同种类致香物质含量高。表明平衡施肥是改善烟叶化学成分,提高烟叶香气质量的基础。     

气量法测定尿素中水分含量的研究

建立气量失重法和气量体积法两种方法测定尿素中水分含量。利用尿素中的水分极易与碳化钙反应,生成的乙炔气体质量或体积与尿素中水分质量成正比关系,来分析计算尿素中水分含量。通过试验确定水分和碳化钙完全反应时间为10 mim的条件下,气量失重法加标回收率为96.0%~101.8%,平行测定结果的变异系数为1.05%~3.86%;气量体积法加标回收率为97.5%~100.6%,平行测定结果的变异系数为1.22%~4.16%。并通过与国标检测方法测得结果相比较、验证,气量失重法和气量体积法两种方法都可以快速、准确地测定尿素中水分含量,可满足基层实验室日常检测尿素中水分含量的工作需求;气量失重法和气量体积法相比较,气量失重法所需仪器更为简单,操作更为简便。     

土壤氮、磷营养过剩对微量元素锌、锰、铁、铜有效性及植株中含量的影响

土壤过量施用肥料,使部分菜地特别是保护地土壤中氮、磷养分积累过剩,导致蔬菜品质变劣,肥效下降,病虫害增多[1-2]。上世纪80年代日本已报道菜地过剩营养的不利影响,发现在土壤磷过高时,微量元素锰和铁出现异常[3]。据统计,京郊菜地土壤氮、磷养分已有明显积累,全市平均保护地土壤有效磷(P)含量达97·1mg/kg,个别区县高达165·8 mg/kg;土壤NO3-N含量平均为88·8 mg/kg,个别区县高达168 mg/kg[4]。在这种高氮、磷含量的土壤中,其它养分的变化也有必要进行研究。相对于大量元素,菜地土壤微量元素的研究较少[5],而且一般都是在常规施肥量的条…