Nutrient constraint and yield potential of rice on upland soil in the south of the Dahoumey gap of West Africa

With the objective of improving rice productivity and generating additional knowledge on rice production in Africa, field experiments were conducted for two consecutive seasons of 2005 and 2006 in Southern Benin. Terre de barre soils at the WARDA experimental station and Niaouli, and the plinthic Ferralsols of Cana were investigated. A complete fertilizer (Fc) composed of N, P, K, Ca, Mg and Zn was used to assess NERICA.4 (upland rice) root development and grain yield (GY). Similar observations were made in treatments with a specific nutrient excluded from Fc (Fc–N, Fc–P, Fc–K, Fc–Ca, Fc–Mg and Fc–Zn). A grain yield of up to 1.4 t ha^?1 (Fc–N) and higher root densities for Fc and Fc–Mg at 20–60 cm were attained. Maximum reductions in yield and rooting depth were observed for Fc–P (27%, 27%), Fc–K (30%, 14%) and Fc–Zn (32%, 2%). Drought occurrence, a high C/N ratio and soil acidity influence the effects of nutrients on rice. Removal of N from basal fertilizer was recommended to reduce the effect of mid-season drought. It is suggested that the critical level of K in the soils of West Africa be adjusted to 0.40 cmol kg^?1 for upland rice.     

稻田长期垄作免耕对水稻产量及土壤肥力的影响研究

不同耕作条件下的水稻生长发育、作物产量及土壤肥力状况的研究表明,稻田长期垄作免耕,水稻根系数量、白根率、根系活力比常规平作和水旱轮作高,分蘖时间早;垄作免耕水稻的株高、茎粗、穗长、穗粒数增加,11年水稻平均产量垄作免耕比常规平作和水旱轮作分别提高了10.3%和11.3%。垄作免耕改变了土壤的物理、化学性状,土壤容重、土壤养分含量明显提高,土壤微生物数量和酶活性增强,土壤表层松结态腐殖质含量比常规平作和水旱轮作高0.194和0.238个百分点,紧结态腐殖质降低0.098和0.037个百分点。垄作免耕有利于提高作物产量、培肥地力、改善土壤生态环境。     

稻田冬种绿肥对水稻产量和土壤肥力的影响

为探讨冬季种植绿肥作物改良土壤的生态作用, 以冬闲连作为对照, 通过连续8年的定位试验研究了冬种绿肥(紫云英、油菜和黑麦草)收获后翻压还田对后作水稻产量及土壤肥力的影响。结果表明: 连续8年冬种绿肥期间, 冬种绿肥各处理的水稻平均产量均高于冬闲对照, 但不同处理增产效果有所不同, 其中紫云英 早稻 晚稻处理增产效果最明显, 为10.48%, 其次是油菜 早稻 晚稻处理(7.31%), 黑麦草 早稻 晚稻处理的增产效果较差, 仅为5.76%。紫云英 早稻 晚稻处理的土壤pH和碱解氮含量最高, 与其他处理相比, pH增加0.58%~1.37%, 碱解氮增加6.59%~35.35%。黑麦草 早稻 晚稻处理的土壤有机质、有效磷、速效钾含量和C/N在各处理中最高, 分别较其他处理高2.99%~4.98%、19.25%~31.05%、16.97%~22.15%和0.97%~6.61%。相关性分析结果表明, 水稻产量与每穗颖花数、结实率、千粒重及土壤碱解氮、有效磷极显著相关(P<0.01), 与每穗粒数、有机质、速效钾显著相关(P<0.05), 而与穗长、有效穗数及土壤pH和C/N相关不显著; 水稻产量各构成要素与土壤养分之间的关系极为密切。综合来看, 稻田冬种绿肥有利于增加水稻产量和改善土壤肥力。     

不同耕作方式下覆草旱作稻田土壤肥力的特征

通过始建于2003年中国南方季节性干旱区(江西省余江县)的双季稻田定位试验,于2005～2007年研究了水稻覆草旱作和免耕覆草旱作对稻田土壤理化性质和生物学性质的影响。结果表明,覆草旱作、免耕覆草旱作的耕层土壤容重和总孔隙度与常规水作的差异不显著。与常规水作相比,免耕覆草旱作显著提高土壤有机质、全氮、碱解氮和土壤基础呼吸;与常规水作相比,覆草旱作和免耕覆草旱作均显著提高土壤微生物生物量碳含量、脲酶和蔗糖酶活性。由此可知,覆草旱作和免耕覆草旱作可以作为该区积极推行的具有培肥地力作用的节水型稻作栽培模式。     

菌渣对水稻生长性状、产量及土壤肥力的影响

利用菌渣进行水稻生产小区试验,以探索其对水稻的增产效果及土壤肥力的影响.试验设无肥、化肥、低量菌渣、中低量菌渣、中量菌渣和高量菌渣6个处理.经过2年的小区试验表明,施用菌渣可有效增加水稻的分蘖数、有效穗数,提高稻谷产量;有效增加稻田土壤的碱解氮、速效钾和有机质含量.在水稻生产中,菌渣的直接施用量以7 180 kg/hm2较为合适.     

长期施用绿肥对红壤稻田水稻产量和土壤养分的影响

通过对26年长期定位试验结果的统计分析,结果表明:绿肥与化肥长期配合施用有利于水稻稳产增产,减少化肥的使用量,提高化肥NPK养分的农学利用效率达60%以上。26年水稻平均产量以OM3处理(紫云英+猪粪)最高,比CK增产64.47%,比NPK处理增产6.86%;其化肥养分农学效率为16.33kg/kg,比NPK处理化肥养分农学效率高118.9%。绿肥与化肥长期配合施用土壤有机质、全氮和全磷均有所积累,积累的量与肥料施用量及有机肥种类相关,以紫云英+猪粪处理最优。土壤钾素均表现亏缺,土壤全钾和速效钾均低于试验前,亏缺幅度最小的是紫云英+稻草处理,其土壤全钾和速效钾分别比对照高4.28%和13.94%。通过对土壤有机质、全氮、全磷和全钾与水稻产量关性分析,相关系数最高的为土壤全钾(r=0.808**),说明缺钾已成为限制红壤稻田高产的主要肥力因子。     

改良剂对反酸田土壤性质与水稻产量的影响

采用盆栽试验研究了不同改良剂在反酸田土壤上的应用效果。结果表明,土壤pH在3.47~4.90范围内,pH与交换性H+和交换性Al3+呈极显著线性负相关关系,而与土壤有效铁和有效硫含量呈显著正相关。不同改良处理在提高作物产量和改良土壤性质方面较对照处理与NPK处理效果明显,且钙镁磷肥、自研改良剂、石灰及碱渣等无机改良剂改良效果显著高于添加腐植酸、精制有机肥、碱性有机肥处理。其改良效果主要体现在提高土壤pH,显著降低土壤交换性H+和交换性Al3+含量,明显增加土壤有效钙和有效镁的含量,改善根系生长环境,增加水稻地上部养分吸收和水稻籽粒产量。综上,初步认为酸害(包括活性酸和潜在酸)是反酸田土壤最主要的限制因子,钙镁磷肥、自研改良剂和石灰等偏碱性且富含有效钙或磷的无机矿物质是农业生产中改良反酸田的适宜改良剂。     

长期施钾对红壤水稻土水稻产量及土壤钾素状况的影响

研究了长期定位施肥试验中连续27年（1981～2007）施用钾肥对水稻产量和土壤钾素状况的影响。本试验选择了其中5个处理:CK（不施肥）、NP（施氮、磷肥）、NPK（施氮、磷、钾肥）、NP+RS（施氮、磷肥和稻草）和NPK+RS（施氮、磷、钾肥和稻草）。结果表明,施钾能明显提高水稻产量,施钾肥的NPK和NPK+RS处理27年的早稻平均产量分别比NP和NP+RS处理增加15.2%和10.9%;晚稻增产17.2%和9.1%;在27年54季水稻种植期间,不同施肥处理早、晚稻产量的变化趋势不同。CK、NP处理的早、晚稻产量随时间的推移呈负变化趋势,而NPK、NP+RS和NPK+RS处理的早、晚稻产量呈正变化趋势。施钾的NPK和NPK+RS处理不同土层中土壤全钾、缓效钾和速效钾含量均高于NP和NP+RS处理的相同土层;除NPK+RS处理外,其它各处理表观钾平衡均为负值,其中CK和NP处理钾的负平衡值最大。长期施用钾肥能提高水稻产量和维持土壤钾素肥力。     

越南红河三角洲地区淹水稻田轮作蔬菜可改良土壤性质

Vegetable production in South East Asia often is in rotation with flooded rice. The puddling of the soil with flooded rice production may result in unfavourable soil conditions for the subsequent production of dry land crops. To establish whether permanent vegetable production results in favourable soil conditions for vegetables, the effects of five different permanent vegetable production systems and a system of vegetable production in rotation with flooded rice on soil properties after flooded rice were studied in a 2-year field experiment. Bulk density at 0.05–0.10 m depth layer decreased with permanent vegetable production and vegetable production in rotation with flooded rice. The decrease in bulk density was influenced by the application of organic manure and rice husks, and especially by the number of crops cultivated, suggesting that frequency of soil tillage had a major effect on bulk density. Ploughing with buffalo traction after flooded rice, in combination with construction of raised beds, could reduce or totally eliminate negative effects of puddling on soil structure. Bulk density at 0.15–0.20 m soil depth was not influenced. Soil acidity decreased significantly in all systems. Soil organic carbon increased in all systems, but significant increase was only found in two permanent vegetable production systems. Available phosphorus(P) significantly increased in two permanent vegetable production systems, with a positively correlation to the amount of P applied. The significant decrease in bulk density and increase in p H(H2O), after only 2 years, showed that soil conditions after flooded rice could be improved in a short time under intensive vegetable production.     

土壤改良剂对冷浸田土壤特性和水稻群体质量的影响

以南方典型冷浸田为研究对象, 在明沟排水的基础上, 通过田间定位试验, 以不施土壤改良剂为对照, 研究了施用不同土壤改良剂(自研的脱硫灰改良剂、生物活性炭, 市售的土壤改良剂石灰、硅钙肥、腐植酸)对冷浸田氧化还原电位、土壤呼吸强度、土壤微生物数量、水稻群体构建及产量构成因素的影响。结果表明, 施用改良剂能够改善土壤理化性状, 提升土壤速效养分和pH,但除脱硫灰处理外, 其他改良剂处理对土壤Eh未产生显著影响。施用不同土壤改良剂在水稻各生育期均能有效增强土壤微生物呼吸强度和放线菌数量, 并且放线菌数量达到差异性显著水平(P<0.05), 生物活性炭处理下土壤呼吸强度和放线菌数量分别较对照增加67.6%和127.6%。各土壤改良剂处理与CK相比较均有助于提高叶片SPAD、茎蘖数、水稻干物质积累量、成穗数、穗粒数、产量结实率和根系伤流速率。其中以脱硫灰和生物活性炭处理改良效果最佳, 抽穗后29 d时,根系伤流速率较CK分别提高45.4%和39.1%, 叶片SPAD分别增加27.4%和22.5%; 成熟期水稻成穗数较对照提高12.1%和10.7%,干物质积累量增加68.8%和50.5%,产量分别增加12.8%和10.3%。综上所述, 土壤改良剂可有效改善冷浸田土壤特性及水稻群体质量, 脱硫灰和生物活性炭处理的改良效果最明显, 增产幅度最大。     

Studies on soils in the transferring cultivation of paddy and upland field

The amount of paddy crop is usually increased by converting a continuous paddy field into a transferring cultivation between paddy and upland crops. To study the reasons for this increase, in Hokkaido a soil survey was made at 16 localities, where both types of cultivation were practiced. The survey was carried out on four different types of soil; peaty soils at Horomui (18,3),* Kurisawa (36,2), Ebetsu (23,2), and Iwamisawa (20,2); muck soil at Fukagawa (35,4); clay soils at Naie (28,3), Takikawa (31,1), Toyonuma (25,3) Fūen (80,2) and Higashiasahikawa (22,3); and sandy soils at Higashikawa (22,3), Pippu (30,2), Shimokawa (28,1), Kucchan (20,3), Kunneppu (16,2) and Ebetsu (30,2).     

旱作条件下水稻的生物效应及表层覆盖的影响

在田间研究了水稻旱作条件下不同覆盖物和常规淹水种植水稻 (简称水作 )条件下水稻生育期间土壤NH4+-N、NO3--N的动态变化 ;水作与旱作条件下水稻各部位的含氮量 ,水稻对氮素养分的吸收、积累的动态变化 ;产量及其构成因素以及灌溉水的利用效率。结果表明 ,旱作条件下土壤有效氮以硝态氮为主 ,旱作水稻的氮营养以硝态氮为主 ;水稻各部位的含氮量均大于水作。旱作水稻的氮素吸收、累积主要在拔节期以后 ,而水作水稻从移栽后就大量吸收氮素 ,灌浆期后很少吸收氮素 ;旱作水稻的产量以半腐解覆盖处理的最高。所有旱作处理的水稻产量均低于水作 ,但耗水量只占水作耗水量的 71.4% ,水分利用效率是水作的 12倍以上。     

生物炭对土壤磷素转化的影响及其机理研究进展

【目的】土壤中磷素总量及形态变化是其发挥营养元素作用和造成环境潜在威胁的重要因素。作为一种外源输入的新型功能材料,生物炭对调节土壤磷素转化及其功能发挥具有重要意义。本文重点针对农业生态系统中生物炭影响土壤磷素转化的研究进展进行综述,并对相应的影响机制进行探讨,旨在为生物炭在农田土壤磷素迁移转化方面的应用及调控提供理论依据。主要进展生物炭可有效增加土壤中有效磷的供给,不仅由于生物炭本身含有较高的磷,其施入土壤后,还可以调节土壤pH,吸附土壤磷素与金属的络合物,直接作为土壤微生物的碳素营养,提高土壤磷素的生物转化率等途径。展望生物炭研究应针对低肥力土壤进行生物炭适宜类型和添加量的研究,防止由于可能的磷素过多导致养分供应的不平衡。由于生物炭本身的含磷量较高,还应进行增施生物炭适当减少磷肥用量的试验,以提高生产效益。生物炭对根际土壤磷活性影响与实际生产相关更加密切,也应投入更多的注意力。此外,作为较为新兴的改土材料,生物炭施入土壤后的长期效应还有待观察和评估。     

有机物料与化肥配施提高黄泥田水稻产量和土壤肥力

农业有机物料具有资源化再利用的特点,与化肥配施既可以保证作物产量,也可以提升地力。为了建立最适宜的南方低产黄泥田培肥模式,该文在浙江金衢盆地开展3年田间试验研究化肥与不同有机物料(菇渣、紫云英、牛粪和秸秆)配施对水稻产量和土壤肥力的影响。结果表明:1)有机物料与化肥配施可以显著提高水稻产量,化肥+菇渣、化肥+紫云英、化肥+牛粪和化肥+秸秆处理下,水稻三年的平均产量分别比单施化肥提高了9.7%、9.5%、12.3%和9.5%;2)有机物料与化肥配合施用,土壤有机质、土壤养分(全氮、有效磷、速效钾和CEC)及土壤容重较单施化肥处理有一定程度的改善,其中,化肥+牛粪效果最明显,有机质质量分数提高了12.5%,土壤有效磷质量分数提高了37.7%,CEC提高了16.1%;3)与单施化肥相比,化肥+菇渣、化肥+牛粪处理下5 mm机械稳定性大团聚体分别提高了10.4%和6.7%,各配施处理均显著降低了团聚体破坏率。总得来讲,连续三年有机物料与化肥配施较单施化肥处理提高了水稻产量、改善了土壤肥力状况、增加了土壤团聚体稳定性,其中又以牛粪与化肥配合施用效果最佳。     

中国云南省滇池盆地东南区由于土地利用方式的变化（从水田变为旱地或温室土壤）导致土壤理化性质的变化研究

Paddy fields in the southeastern basin of Dianchi Lake have rapidly changed to greenhouses since 1999. A total of 61 surface soil samples, including 43 greenhouse soils, 12 upland soils, and 6 paddy soils, were collected from a flat lowland area mainly used for agricultural production fields in the southeastern basin of Dianchi Lake. Analyses of the soil samples indicated that the greenhouse soils were characterized by a lower organic matter content, lower pH, and higher soluble nutrients than the paddy soils in the area. The lower organic matter content of the greenhouse soils was ascribed to environmental or management factors rather than the clay content of the soil. Accumulation of soluble nutrients, especially inorganic N, was due to over-application of fertilizers, which also caused soil acidification. The average amount of readily available N, P, and K accumulated in the greenhouse soils was estimated to be equal to or higher than the annual input of these nutrients as a fertilizer, indicating that a reduction in fertilizer application was possible and recommended. In contrast, a very low available Si content was observed in the paddy soils, suggesting the need for Si application for rice production.     

过量施用磷肥对红壤发育的水稻土化学性质的影响及其与水稻生长的关系

A filed experiment with an early rice-late rice rotation was carried out on a paddy soil derived from red soil in the southern part of Zhejing Province to elucidate the effect of excess P application on some important characteristics of soil properies and its relation to nutrient status and grain yields of rice crops.The experimental results indicated that adequate fertilizer P(15 kg P hm^-2)could increase the content of soil available P at the tillering stage of early rice,the contents of N,P and K in the shoots of early rice at primary growth stages,and the grain yield of early rice by increasing valid ears per hectare and weight per thousand grains,which,was mainly related to the higher contents of reduced,non-reduced and total sugar in the shoot at the heading stage, And early rice supplied with excessive P could not yield more than that applied with adequate, P de to the reduction in the valid grain percentage and weight per thousead grains. In addition,one-time excess P supply at a rate as high as 90 kg P hm^-2 could not improve the soil P fertility in case the soil available P content was lower than the initial(3.74mg kg^-1 soil) after an early rice-late rice rotaion,and made a decline in the grain yield increased by per kilogram fertilzer P.Thus,one-time excess P supply should not be adopted for soils with a large P fixation capacity like the paddy soils derived from red soils.     

不同施肥模式对赤红壤旱地作物产量和土壤肥力的影响

采用长期定位田间试验,研究不同施肥模式对赤红壤旱地花生一甘薯轮作制产量和土壤肥力的影响.5年定位试验表明,平衡施肥平均产量最高,花生和甘薯比常规施肥增产13.1％～13.5％,净增收提高14.0％;氮磷钾对花生和甘薯的增产率逐年提高,但花生和甘薯分别对缺磷和缺钾较敏感.年际间产量变化趋势表明,常规施肥对花生和甘薯产量的变异系数大于平衡施肥;不施肥区和氮磷钾缺素区的产量均呈现逐年下降,但缺氮对花生产量的敏感性大于甘薯,甘薯缺磷或缺钾对产量的敏感性高于花生.平衡施肥的氮磷钾利用率平均分别为40.9％、17.7％和24.2％;缺素区的土壤供肥量比不施肥区提高了近1倍;土壤有机质都有所提高,施用氮肥都使土壤酸度有所增加;不施肥区和氮磷钾缺素区都使相应的土壤速效养分明显下降;常规施肥使土壤有效磷下降22.5％,碱解氮和速效钾则基本维持不变,但平衡施肥使土壤有效磷含量基本不变,碱解氮和速效钾则分别提高26.2％和38.4％.     

Effects of different application methods of fertilizer and manure on soil chemical properties and yield in whole crop rice cultivation

ABSTRACT

Whole crop rice (WCR) is expected to establish a cultivation method using manure produced from animal wastes. Meanwhile, application methods of fertilizer and manure in the WCR cultivation are affected by availability of manure, available time for its application, and field drainage, and low market price of WCR. This raises concerns about soil fertility deterioration and yield reduction in the WCR cultivation. The objectives of this study were to investigate how different application methods of fertilizer and manure affected soil chemical properties and yield in the WCR cultivation. Field surveys were conducted in 2013 and 2014 at 10 fields cultivated by five different farmers in the Itoshima region, Fukuoka Prefecture, Japan. The surveyed fields included two application methods of manure (M) alone and chemical fertilizer (CF) alone. Clay plus silt content was significantly correlated with total nitrogen (TN), total phosphorus (TP), and exchangeable potassium (Exch. K), which indicated that soil texture partly contributed to the variations of these soil chemical properties. Meanwhile, clear gaps of TN, TP, Exch. K, K saturation degree, and available N between CF and M at around 40% of clay plus silt content strongly suggested that manure application contributed to increases in the soil chemical properties. Yearly differences of available N had relatively large negative values in CF fields. This result suggested a possible decrease in mineralizable part of soil TN in the WCR cultivation with CF alone, which needs to be clarified through long-term study. Significant relationships between potential N supply and straw weight (r = 0.698, p < 0.05 for 2013; r = 0.873, p < 0.01 for 2014) or yield of whole crop (r = 0.852, p < 0.01 for 2014) indicated that N mineralized from soil, which was enhanced by manure application, increased straw weight, resulting in an increase in yield of whole crop. However, excessive amounts of manure applied in surveyed fields can cause groundwater and surface water pollution. Thus, nutrient balances in a paddy field need to be analyzed further to determine an appropriate application amount of manure.     

长期不同施肥对红壤性水稻土产量及基础地力的影响

利用长期定位施肥试验并结合盆栽试验,研究长期不同施肥模式对双季稻产量和土壤基础地力的影响,并分析水稻产量和肥料贡献率对土壤不同基础地力的响应。结果表明:长期施用氮磷钾肥(NPK)或氮磷钾肥配施稻草(NPKS)有利于双季稻产量的增加。NPK处理的早稻产量、晚稻产量和年总产量分别较对照(CK)处理增产100.7%、67.0%和81.9%,NPKS处理分别增产113.8%、77.7%和93.7%。CK处理早稻基础地力产量随试验年限的增加呈极显著下降趋势(p0.01),晚稻基础地力产量在试验的前9年随年限增加呈极显著下降(p0.01),之后基本维持稳定。长期施用氮磷钾肥或氮磷钾肥配施稻草有利于土壤基础地力的提升。土壤基础地力产量和基础地力贡献率均表现为NPKSNPKCK。NPK和NPKS处理早稻基础地力产量分别较CK提高38.5%和68.1%,晚稻分别提高25.8%和49.0%。NPK和NPKS处理早稻基础地力贡献率分别较CK提高21.4%和54.9%,晚稻分别提高12.8%和22.8%。无论施肥或不施肥,早晚稻产量均随土壤基础地力产量提高而增加;肥料对早晚稻产量贡献率随基础地力产量提高而极显著降低。土壤有机质、全氮、速效钾是影响土壤基础地力的主要养分因子,土壤全磷、全钾、碱解氮、有效磷对土壤基础地力也产生重要影响。