红壤性水稻土施肥的产量效应及与气候、地力的关系

以23a红壤性水稻土化肥定位试验为对象，探讨了不同施肥措施下水稻产量变化及其与气候、地力的关系。结果表明：不同施肥措施的产量效应均显著受气候的年成变化及其交互作用的影响，气候的季相变化因不同施肥措施而异，对CK、NK、NPKM处理影响不大，而对N、NP、NPK处理有强烈的影响；红壤性水稻土基础地力贡献率较稳定，为46．3％，72．0％。随着施肥结构完善，对地力贡献的依赖性表现出NPKM〈NPK〈NK、NP〈N的趋势；各施肥管理水稻平均增产效果表现为NPKM〉NPK〉NK〉NP〉N。连续施用氮（N）肥，增产效果达持续显著水平的年限为17a，钾（K）肥的为98，而磷（P）肥不明显。N肥单施或与P肥、K肥配施，生产稳定性显著下降，且随时间的延长，增产效率均呈线性下降，其下降速率表现出NP〉N〉NK的趋势，至18～218后，产量水平相当或者低于无肥区（CK）。N肥与PK肥配施，可显著提高水稻生产的稳定性和产量，再配施有机肥，水稻增产效果更为明显。     

施肥结构对砂质潮土有机质及氮磷钾养分变化的影响

通过在砂质潮土上10年长期定位试验,研究了不同施肥结构对作物产量和土壤有机质及N、P、K等养分在土体中变化的影响。结果表明,单施N肥小麦减产21.1％～34.3％,玉米则增产155.9％～209.7％;单施P肥小麦增产29.3％～39.7％,玉米减产50.4％～63.0％;而N、P肥配施小麦、玉米分别增产3.43～5.79倍和3.04～4.23倍。施有机肥能显著提高作物产量和土壤养分含量,而N、P肥单施或配施仅能维持较低有机质水平,且土壤K耗竭严重。单施N肥N素易于下淋,而N、P肥配施有利于N在土壤上层的保持。有机肥配施N肥或N、P肥是较好的施肥结构。     

翻压绿肥后不同施肥方法对水稻养分吸收及产量的影响

通过大田试验研究了翻压等量紫云英后不同施肥方法对水稻养分吸收及产量的影响.结果表明,翻压紫云英22 500kg/hm2后配施80%化肥,与习惯施肥方法相比,其他施肥方法均有利于提高早稻茎秆中氮、磷含量,分别平均增加1.0%～13.7%、6.5%～26.2%,却降低水稻籽粒中钾含量6.0%～23.0%.底肥:分蘖肥:穗肥=0∶7∶3降低早稻籽粒中磷含量,但是增加早稻茎秆和晚稻籽粒中钾素含量.不施底肥,分蘖肥:穗肥=5∶5提高晚稻籽粒中氮素含量,而全部用作分蘖肥施用时显著增加晚稻籽粒中磷素含量;配施60%化肥,其他施肥方法分别平均增加早稻籽粒中氮、钾含量24.6%～34.6%、8.8%～15.7%和晚稻茎秆中磷含量5.2%～60.9%,但是降低早稻茎秆中磷含量10.7%～44.3%,不施底肥降低早稻茎秆中氮含量2.4%～47.4%.配施60%～80%化肥,与习惯施肥方法相比,底肥:分蘖肥:穗肥=0∶7∶3更有利于增加水稻有效穗数和产量.     

太湖地区黄泥土表层氮库变化与水稻产量间的关系研究

24年田间定位试验研究表明,长期不施肥处理和化肥PK配施处理土壤表层N呈下降趋势,而施入化肥N处理(包括化肥N、化肥NP配施、化肥NK配施、化肥NPK配施处理)N增加较缓慢,有机与无机肥结合处理土壤表层N增加迅速。以长期不施肥为对照,长期有机肥 NPK处理水稻增产最多,达35.94%。随着N肥的逐年施入,土壤表层全N含量与产量间由显著正相关关系变为相关性不显著。     

长期定位施肥对花生产量和品质的影响

在1997~2003年进行长期定位施肥的基础上,研究了氮、磷、钾配合施用对花生产量和品质形成的研究。结果表明:与不施肥处理相比,长期施用N肥可以提高花生籽粒产量和籽粒中蛋白质含量;施用NK肥,籽粒中粗脂肪含量降低,施用NP肥,降低了籽粒中蛋白质含量;施用PK肥,降低籽粒中蛋白质含量:施用NPK肥,显著地提高了籽粒产量和蛋白质含量,说明NPK肥配合施用有利于籽粒产量的提高和籽粒品质的形成,有利于保持和提高土壤肥力。     

长期施肥对红壤旱地玉米生物量及养分吸收的影响

基于江西进贤旱地长期施肥定位试验田,研究不同施肥模式下玉米不同器官的生物量、养分吸收与分配及其与土壤养分的关系.结果表明:(1)长期施用化肥导致土壤pH值下降,不合理施肥使土壤养分含量有不同程度的下降,有机无机肥配施能有效缓解土壤酸化,显著提高土壤有机碳和有效养分含量.(2)与对照相比,N处理降低了玉米籽粒、穗轴、秸秆和根茬的生物量,而均衡施肥(NPK、2NPK)及有机肥处理(NPKOM、OM)使玉米籽粒增产1.1～2.9倍,并提高了其他器官的生物量.土壤酸碱度、有机质及N、P养分对玉米籽粒的产量影响显著,土壤K养分对玉米生物量影响相对较小.(3)玉米对N的吸收主要集中在籽粒和秸秆,分别占总吸N量的41.8％～61.3％和30.3％～48.4％,P在籽粒中的吸收量高达61.8％～73.9％,K的吸收主要集中在秸秆,占总吸K量的51.4％～67.9％.有机无机肥配施模式则显著促进了作物各器官对养分的吸收和提高作物产量.作物养分的收获指数为P＞N＞K.     

长期施肥红壤稻田有机碳演变规律及影响因素

利用1981年起设置的水稻土长期施肥定位试验,分析了CK(不施肥)、N(单施氮肥)、NPK(氮磷钾配施)、NPK2(2倍氮磷钾配施)和NPKM(有机无机肥配施)等施肥措施下土壤有机碳的演变规律及其与作物产量和土壤养分(全氮、碱解氮、全磷、速效磷、全钾和速效钾)的相关性.结果表明:试验30年后,各个处理的土壤有机碳含量均有上升,其中CK、N、NPK、NPK2和NPKM的土壤有机碳在试验30年分别比试验前增加18.95％、17.72％、23.36％、16.92％和32.68％.与CK处理相比,NPK、NPK2和NPKM处理的土壤有机碳平均提高了4.09％、4.03％和25.68％.土壤有机碳含量与水稻产量呈显著相关(P＜0.001),相关系数r为0.410,这说明土壤有机碳含量的增加可以促进水稻增产.土壤有机碳与土壤养分中的碱解氮、速效磷和全磷含量均表现出极显著相关(P＜0.001),相关系数r分别为0.452、0.559和0.487,但是与钾含量相关不显著.这表明:有机无机肥配施可以持续快速提高红壤性水稻土的有机碳含量,同时在有机无机肥配施过程中应适当增施钾肥,从而促进土壤肥力平衡和维持作物高产稳产,实现农业可持续性.     

配方肥配施锌肥和硫肥对小麦的提质增效作用

为探明配方肥配施锌肥和硫肥对小麦产量和品质的影响,在安徽省小麦主产区宿州的西二铺村和湖町村分别设置了农民习惯施肥(CK)处理、配方肥处理、配方肥分别配施锌肥和硫肥处理以及同时配施锌肥和硫肥处理的田间试验。结果表明,与农民习惯施肥相比,配方肥显著增加了小麦产量,配方肥配施锌肥和硫肥进一步增加了小麦产量,进而提高小麦经济效益;同样,配方肥配施锌肥和硫肥提高了小麦氮、磷、钾肥偏生产力,平均增幅达到35.0%、107.0%、99.1%。配方肥配施锌肥和硫肥增加了籽粒锌和硫的积累量,对籽粒锌含量有一定促进作用,对籽粒硫含量影响不明显。不同处理小麦籽粒蛋白质含量及其组分、淀粉含量及其组分差异均不显著,但增施锌肥和硫肥提高了小麦籽粒的谷醇比,降低了直支比,有利于小麦品质的提高。因此,在土壤锌和硫含量较低的地区,配方肥配施锌肥和硫肥能促进小麦籽粒产量和品质的提高。     

长期定位施肥对土壤有效硼含量的影响

试验研究长期定位施肥对土壤有效硼含量的影响结果表明,无肥、N、NP、NPK、N 有机肥和N 秸秆6个不同施肥处理0~20cm土层土壤有效硼含量与肥料定位研究年限呈r=0.8094~0.8847的正相关关系,且不同施肥处理土壤有效硼含量均增加,为试验基础数值的2.9~4.7倍。各处理土壤有效硼含量依次为N 有机肥处理>N、P配施处理>N 秸秆处理>单施N肥处理>N、P、K配施处理>无肥处理。N、P、K配施处理在获得较高产量的同时,有效硼累积较少。耕作、施肥等是影响土壤有效硼累积的重要因素。     

鄱阳湖地区长期施肥双季稻田生态系统净碳汇效应及收益评估

以江西省红壤所长期施肥红壤水稻土双季稻农田生态系统为研究对象,利用不同施肥处理作物产量及土壤有机质含量等测定数据结合调查获得的生态系统物质和管理投入资料,估算了不同施肥处理（不施肥（CK）、单施氮肥（N）、单施磷肥（P）、单施钾肥（K）、氮磷肥配施（NP）、氮钾肥配施（NK）、氮磷钾配施（NPK）、两倍氮磷钾配施（2NPK）、有机肥与氮磷钾肥配施（NPKM））双季稻生态系统的碳汇效应和经济效益。结果表明,有机肥和化肥配施（NPKM）既提高了系统的作物固碳量又显著增加了土壤的固碳量,使得其净碳汇效应最大,为8．78tC·hm^-2·a^-1;两倍氮磷钾配施（2NPK）系统的净碳汇效应为8．11tC·hm^-2·a^-1,二者均高于氮磷钾配施（NPK）处理的7．03tC·hm^-2·a^-1,不施肥及单施一种或两种无机肥配施系统的净碳汇效应均明显减弱,其中不施肥处理（CK）最小为4．52tC·hm^-2·a^-1,单施N肥比单施P、K肥在提高系统净碳汇效应上作用明显。配施有机肥（NPKM）稻田的作物产量和经济效益也高于无机肥配施处理（NPK和2NPK）,不施肥、单施一种或两种无机肥配施稻田的作物产量和经济效益明显偏低。因此,稻田施用一定量的无机肥是提高稻田生态系统碳汇效应和经济效益的保证,而配施有机肥可以明显提高稻田生态系统的碳汇效应和经济效益。     

高沙土小麦高产施肥技术研究

连续3年茎蘖动态分析表明,高沙土麦作区在10月底～11月初播种,基本苗180～270株/m2情况下,播后25～30天茎蘖达到预期成穗数390～450株/m2;小麦产量由主茎及主茎1叶、2叶、3叶产生的分蘖成穗构成。最高产量时的氮肥施用水平为213.2kg/hm2,产量为5782.5kg/hm2。拔节期施用NPK三元素肥料具有显著提高实粒数,增加千粒重等作用,增产效果显著。     

Potassium Buffering Capacity of Sandy Soils from Thua Thien Hue Province,Central Vietnam,as Related to Soil Properties

Most agricultural production in central Vietnam relies on sandy soils distributed along the sea coast. Because of their low exchangeable potassium (K) and low cation exchange capacity (CEC), careful adjustment of K fertilization on these soils is needed to minimize K leaching. Quantity/intensity curves were established on 24 sandy soils from Thua Thien Hue Province from which K buffering capacity (PBC) was calculated and compared with basic soil properties. Potassium buffering capacity was found to correlate best with soil texture and only a little with humus content, although these two characteristics are responsible for CEC. A simple equation based on sand content, which is easier to determine than clay content, is proposed to calculate optimum exchangeable K level as a function of target K level in soil solution.     

施氮量对皖南砂壤土烤烟碳氮代谢动态变化的影响

选取皖南典型植烟土壤,对不同施氮(N)量烤烟生长发育过程中硝酸还原酶、转化酶活性和碳氮代谢产物含量的变化动态进行了测定分析。结果表明,随施N量的增加,硝酸还原酶活性提高,活性高峰下部叶出现在移栽后40天;中、上部叶出现在移栽后55天,高峰值处理N8(N8kg/667m2)N7(N7kg/667m2)N6(N6kg/667m2)N5(N5kg/667m2)。在烟叶生长发育过程中转化酶活性达到最大值后明显下降。烟株地上部总N累积量、烟碱含量和烟碱累积量不断增加,施N量愈高增加幅度愈大。总糖含量随施N量的增加而减少,上部叶总糖含量的积累水平低于中部叶和下部叶,上部叶中N8处理总糖含量最低。     

Yield Quality Parameters and Chemical Composition of Peanut as Affected by Potassium and Gypsum Applications under Foliar Spraying with Boron

A field experiment was carried out at El-Khattara region (Sharkia Governorate, Egypt) during the 2009 season to study the effect of potassium (K) fertilization, gypsum addition rates, and foliar spraying with boron (B) and combinations of them on growth, yield, yield components, oil quality, and uptake of some macro- and micronutrients by peanut (Arachis hypogaea L. cv. Giza 6) grown on a sandy soil. Biological yield (pod + hay) as well as hay and seed yields were increased significantly as a result of K and gypsum application, but there was no significant increase under foliar spraying with B. The greatest values of 7788, 6585, and 954 kg fed^?1 for biological, hay, and seed yields corresponded to 20.8 kg K fed^?1 + 0.5 ton gypsum fed^?1 without foliar spraying with B. For hay, the greatest value of N uptake was obtained with 20.8 kg K fed^?1 + 1.0 ton gypsum fed^?1, whereas the greatest values for P and K uptake (70.1 and 131 kg fed^?1) were obtained when 20.8 kg K fed^?1 + 0.5 ton gypsum fed^?1 was applied under spraying with B. For seeds, the greatest value of K uptake was obtained when 20.8 kg K fed^?1 + 1.0 ton gypsum fed^?1 was applied, whereas for N and P uptake the greatest values (60.8 and 15.2 kg fed^?1) were obtained when 20.8 kg K fed^?1 + 0.5 ton gypsum fed^?1 were applied under spraying with B. The oil yield of peanut seeds using the Soxhelt extraction method was found to be in the range of 23.1 to 35.2%. The greatest B uptake in hay was obtained without spraying with B, whereas in seeds it was obtained under spraying with B. In both of them was obtained upon application of 20.8 kg K fed^?1 + 0.5 ton gypsum fed^?1. Apparent K recovery (AKR) and K-use efficiency (KUE) were markedly decreased with increasing K addition rates.     

Influences of organic fertilization and solarization in a greenhouse on particle-size fractions of a Mediterranean sandy soil

 The effects of a composted organic amendment and solarization on the organic matter (OM) of a sandy soil were determined by means of particle-size fractionation and analysis of carbon and nitrogen contents. After 2 years, total soil carbon increased under organic fertilization but did not significantly change with solarization. As a consequence of the climatic conditions in the greenhouse, the carbon concentrations (g kg^–1 fraction) of the particle-size fractions were lower than those found for temperate soils and closer to those for tropical soils. The carbon amounts (g kg^–1 soil) and carbon:nitrogen ratios, which were highest in fractions >200 μm, reflected the short-term influence of the industrially processed organic amendment, rich in composted coarse plant debris. In contrast, the characteristics of the OM associated with each fraction were not significantly affected by solarization. In comparison with other coarse-textured temperate or tropical soils, carbon concentrations in fine silt (2–20 μm) and clay (0–2 μm) fractions were very low. This suggests a "greenhouse effect", together with a high rate of carbon mineralization affecting fine silt and clay fractions. Received: 19 November 1999     

Effects of two contrasting agricultural land‐use practices on nitrogen leaching in a sandy soil of Middle Germany

The objective of this study is to evaluate different agricultural land‐use practices in terms of N leaching and to give recommendations for a sustainable agriculture on sandy soils in Middle Germany. Soil mineral N (N_min) and leachate N were quantified at a sandy soil in N Saxony during 3 years. Two treatments were applied: intensive (I)—using inorganic and organic fertilizer and pesticides, and organic (O)—exclusively using organic fertilizer, legume‐based crop rotation, and no pesticides. Split application of mineral fertilizers did not result in substantial N losses at treatment I. Legumes induced a considerable increase of soil mineral N and particularly of leachate mineral N (N_{min_perc}) at treatment O. High N_{min_perc} concentrations (up to 78 mg N L^–1) were observed during as well as after the cultivation of legumes. These high N_{min_perc} concentrations are the reason why clearly higher N_{min_perc} losses were determined at treatment O (62 kg N ha^–1 y^–1) compared to treatment I (23 kg N ha^–1 y^–1). At both treatments, the quantity of N losses was strongly affected by the precipitation rates. Concentrations and losses of dissolved organic N (DON_perc) were assessed as above average at both treatments. The results suggest that the DON_perc concentration is influenced by precipitation, soil coverage, and organic fertilizers. Higher values were determined in the percolation water of treatment O. The average annual DON_perc losses amounted to 15 kg N ha^–1 at I and to 32 kg N ha^–1 at O. The average monthly percentage of DON_perc losses on the loss of the dissolved total N of percolation water (DTN_perc) ranged between <1% and 55% at O and between 2% and 56% at I. For the whole measuring period of 29 months, the relative amounts of DON_perc of DTN_perc (21% at O and 25% at I) were more or less the same for both treatments. The results show that DON_perc can contribute significantly to the total N loss, confirming the importance to consider this N fraction in N‐leaching studies. It was concluded that at sandy sites, a split application of mineral fertilizers, as applied at treatment I, seems to be more expedient for limiting the N leaching losses than legume‐based crop rotations.     

Soil Organic Carbon and Nitrogen Stocks under Tropical Organic and Conventional Cropping Systems in Northeastern Brazil

Soil organic matter (SOM) is an essential ecosystem component whose dynamics are affected by soil management practices. To evaluate the impact of two agricultural systems (organic and conventional) on soil organic carbon (C) and nitrogen (N) stocks in a sandy soil, samples were collected from the Amway Nutrilite Brazil farm and from the Central Pivot Horticultural Farmers Association farm, both situated in the Chapada da Ibiapaba region, Ceará State, Brazil. The first area has a large‐scale Caribbean Cherry fruit production system under organic management, whereas the second represented a conventional soil cultivation condition, characterized by the use of chisel plow and disc plow, mineral fertilization, and herbicides application. Plots with and without green manure fertilization were compared in the organically cultivated systems by using soil samples collected in the rows and between the rows. Areas under native forest were also sampled to determine the steady‐state condition. Total organic C and N contents in the soil (SOC, TN) and in the humic substances were determined at the 0‐ to 5‐, 5‐ to 15‐, 15‐ to 30‐, and 30‐ to 50‐cm soil layers. In addition, oxidizible organic C fractions were measured to calculate the carbon management index (CMI). In general, total SOC levels were low, ranging from 2.5 to 12.6 g kg^?1 in the whole soil profile among the organic systems. In the upper soil layer, SOC and TN stocks were greater in the rows in response to organic fertilization. The conventional system presented lower variation on the SOC contents throughout soil layers when compared to the native forest area, indicating the direct effect of plowing on the downward SOC distribution. The CMI data confirmed the reestablishment of SOM levels in the rows of the organic managed systems in relation to the reference area, whereas the reduction of the CMI in the conventional system suggests a decline in the soil quality and greater potential for increased C losses to the atmosphere.     

Effects of nitrogen fertilization and irrigation on N2O emissions from a sandy soil in Germany

The aim of this study was to investigate the effect of supplemental irrigation on the amount of N₂O emissions on a sandy soil in north-east Germany. N₂O flux measurements were carried out over two vegetation periods from the emergence of plants to harvest. The level of N₂O emissions was low, which is typical for sandy soils in north-east Germany. In both periods, irrigation had no increasing effect on N₂O emissions. Relevant factors were the soil temperature and the soil water-filled pore space (WFPS), which were mainly influenced by weather conditions. This may indicate that nitrification was the main source of N₂O emissions. In conclusion, this study has confirmed that sandy soils under weather conditions of north-east Germany generally have a very low potential for N₂O emissions.     

毛乌素榆林沙区沙产业发展战略研究

分析了毛乌素榆林沙区发展沙产业的资源优势、技术优势和区位优势,并根据该区沙产业发展现状及存在的问题,提出加速该区沙产业发展的对策。     

我国沙地水分分布状况及其意义

按生物气候带、干燥度、沙地土壤水分平均含量和降水量组合等特点,将我国沙地和沙漠分为荒漠带、半荒溴带、干草原带、半湿润带和南方湿润带五个沙漠区（青藏高原区除外）归纳分析各沙区水分运动基本规律、稳定含水率和有效储水量等项目,探讨影响我国沙地水分分布状况的主要因子,提出了我国不同沙带固沙造林具体措施和适宜选用的植物种。最后讨论各沙地开发和农业生产方向以及灌溉农业的经济效益和未来的发展趋势。