长期稻-稻-绿肥轮作对水稻产量及土壤肥力的影响

为探讨湘南红壤稻田多熟制增产潜力,不断提高经济效益和土壤肥力,促进农业可持续发展,从1982年开始,对红壤稻田布置了冬种紫云英(T1)、油菜(T2)、黑麦草(T3)翻压还田对水稻产量和土壤肥力影响的长期轮作制度定位试验。30年的研究结果表明：(1)与冬闲(T4)处理相比,绿肥还田能促进水稻增产,其平均增产效果和年均增产率为：T1> T2> T3,且其增产稳定性较好;(2)与T4处理相比,绿肥还田能显著增加土壤有机质含量,其中T1处理下活性有机质含量显著高于其他处理,且在有机质中所占比例最大;(3)与T4处理相比,绿肥还田能提高土壤全氮、碱解氮含量,加速土壤矿化,促进水稻对磷素和钾素吸收,其中,T1处理下土壤全氮、碱解氮含量显著高于其他处理,T2和T3处理显著高于T4处理,T1处理比T2和T3处理更能促进土壤磷素释放与吸收,致使T1处理土壤全磷累积相对缓慢,也更需要补充外界钾素;(4) 稻-稻-紫云英轮作是一种较好的轮作模式。     

秸秆还田对豆-稻-菜循环耕作模式下作物产量和土壤肥力的影响

豆-稻-菜循环耕作模式是中国南方地区最重要的轮作模式之一,但秸秆还田对该耕作制度下作物产量和土壤肥力的影响尚不明确。通过连续7年的田间定位试验（2009—2015年）,研究秸秆还田对豆-稻-菜循环耕作模式下作物产量和土壤养分状况的影响。结果表明：秸秆还田对浙江省豆-稻-菜轮作模式下作物产量的影响显著：与单施化肥相比,秸秆还田有效提高了水稻和小萝卜的产量,且水稻和小萝卜年均增产10%以上;此外,秸秆还田对豆-稻-菜循环种植区域土壤肥力也有较大影响：提高了土壤有机质、全氮、有效磷、速效钾含量和土壤pH值,此外,秸秆还田区域土壤全氮、有效磷和速效钾含量呈逐年增加趋势。由此可见,多熟制耕作制度下秸秆还田仍具有作物增产和土壤培肥作用,可作为耕地质量提升的有效手段长期实施。     

稻棉轮作

我县是粮棉兼作区。近几年,在“农业学大寨”的群众运动中,随着农田水利建设的不断完善,部分社、队试验推广了稻棉轮作制度,收到了较好的增产效果。马口公社胜利大队过去是一个旱作地区,目前水田已扩大到1100亩,早地1399亩,常年植棉1200亩。从1972年开始搞稻棉轮作试验,第八生产队144亩棉田有70亩是水田改种的,亩产皮棉155斤,较老棉田增产63.1%;而棉田改种双季稻,亩产1160斤,较老水田增产34.2%。县农科所1972、1973年稻棉轮作试验也证明:轮作棉田增产46.2%和54.4%。轮作水田较老水田水稻增产34.6%和34.5%。(一)稻棉轮作能增产的原因:     

直播稻田杂草发生与防除研究进展

随着水稻直播技术的推广,稻田出现杂草发生严重、除草剂用量加大等问题,而杂草发生种类、优势种群出现多样化,增加了杂草对除草剂的抗性,导致杂草防除困难,影响了直播稻的丰产与稳产;同时直播稻田除草剂的过量使用带来的生产安全性问题值得关注。本文从杂草发生种类、数量及成灾时期、发生差异性（稻作区域、种植方式、直播方式与播种期）、生态学效应及对直播稻生长发育影响等方面综述了直播稻田杂草的发生特性,分析了不同种类杂草的防除途径（化学除草、耕种制度与栽培措施）,提出我国目前在直播稻田杂草发生与防除方面研究存在的问题,并对未来直播稻田杂草防治的发展方向进行探讨与展望,旨在提高我国直播稻田杂草的防除效果,促进直播稻生产的轻简高效发展。     

稻-稻-菜的几种种植模式

<正>双季稻区采用稻-稻-菜种植模式,每亩可增收1000元以上,复种指数从200%提高到300%,还能起到促进后作增产,实现水旱轮作,改善稻田生态环境,改良土壤等作用,是农户脱贫致富的好门路,但必须合理安排好     

黔北稻虾共生综合种养示范效果

为提升黔北地区稻田综合种养的经济效益和生态效益,2016-2018年连续3年在湄潭县大庙场村实施"稻虾共生"绿色增产增效示范,示范面积33. 3 hm2。结果表明,稻虾模式与传统单季稻模式相比,水稻产量同期下降10%左右,但均价和产值均翻了一番,田间施肥量减少42. 8%～50%,施药次数和种类也大幅减少,产出投入比显著增加,稳产、增收、增效显著,取得了良好的示范效果。     

齐齐哈尔市水稻田杂草群落变化趋势的分析

为明确齐齐哈尔市水稻田杂草种类、群落组成及危害状况,为高效防治水稻田杂草提供依据。采用倒置“Ｗ”形9点取样方法,进行定点系统观测与田间普查,田间调查方法为定点计数法与随机目测法,田间调查主要为杂草类别、群落组成结构和危害级别程度。结果表明：异型莎草、芦苇、稻稗、针蔺等杂草在稻田杂草群落出现频率在20年间明显下降,野慈姑、雨久花、鸭舌草、泽泻、稻李氏禾、葡茎剪股颖在杂草种群中的出现频率明显上升,杂草的危害程度随着其出现频率的变化而变化,造成很大危害。水稻田杂草群落模式由“禾本科杂草+莎草科杂草+阔叶类杂草”演替为“阔叶类杂草+禾本科杂草+莎草科杂草”,其中难治的恶性杂草种类增加且危害严重。     

稻乐思防治水稻田杂草试验简报

稻乐思是由江苏汽巴农化有限公司提供的新型稻田除草剂，该药的特点是活性高，用量少，杀草谱广，对稻田多种杂草有高度防效。为探讨稻乐思在我区稻田的防除效果及应用前景，特进行其防效试验。试验设亩用72％稻乐思（江苏汽巴农化有限公司提供）10ml、15ml，对照药剂稻田乐（贵州农科院生产）10ml及空白对照共4个处理。3次重复，小区面积133．4m2，随机排列。试验地设在遵义县南白镇青山村，选择在常年杂草发生较多田块，于1996年6月11日水稻插秧后7天（秧苗已返青），每处理拌干土4kg均匀撒施，药后保持水层3—5cm，一周内不排水。药效调…     

绿肥-烟-稻轮作与烟叶产量品质及后茬晚稻产量效应

摘要 连续三年采用绿肥-烟-稻轮作田间定位试验与室内分析相结合的方法,研究绿肥还田对提高土壤肥力和烟叶产量、品质及后茬作物晚稻产量的作用,取得良好效果。绿肥还田其养分释放可明显提高土壤速效氮磷钾养分含量,促进烤烟植株对土壤养分的吸收利用,显著提高烟叶产量。且改善烟叶品质,其烟叶外观表现为结构疏松,成熟度好,光泽强,颜色均匀,杂色少。三年结果统计,黑麦草区烟叶平均产量为2644kg/hm 2,油菜区烟叶平均产量为2626kg/hm 2,分别比对照增产14.6%、14.1%。上、中等烟叶比例分别为92.1％、93.6％,烟叶内在化学成分接近或达到优质烟叶标准。后茬作物晚稻分别比对照增产43.2%、29.6%。     

紫云英还田对土壤养分和重金属含量的影响

为提高六合稻麦轮作土壤质量,2018—2020年采用绿肥还田方式,设计开展紫云英-水稻轮作田间定位试验。设计紫云英-水稻轮作、小麦-水稻轮作2个耕作模式处理,研究紫云英还田对稻田耕层土壤养分含量、重金属的影响。结果表明,与小麦-水稻轮作相比,紫云英-水稻轮作可有效增加土壤养分,包括土壤全氮、有机质、速效钾、交换性钙、有效硫、有效锰、有效锌、有效钼;同时可改善土壤结构,土壤容重从1.32 g/cm³降低到1.21 g/cm³;还可减缓土壤酸化,土壤从pH 6.36升高到pH 6.51;可降低土壤重金属总铬、总铅、总砷、总汞的污染。综合考虑,紫云英还田可以有效减少冬季麦田肥料用量,并提高土壤质量,是六合水稻种植区较好的施肥模式。     

紫云英和稻草还田免耕抛栽对水稻产量和土壤肥力的影响

【研究目的】研究紫云英和稻草还田免耕抛栽对水稻产量和土壤肥力的影响,为南方稻区免耕抛秧栽培技术的推广应用提供参考。【方法】2007-2008年在连续两年双季稻免耕抛栽定位试验的基础上,以翻耕抛栽处理为对照,探讨紫云英和稻草还田免耕抛栽对土壤物理性状、养分、土壤酶活性、土壤微生物和水稻产量的影响。【结果】连续免耕两年以后,免耕水稻产量低于翻耕处理,施用有机肥能够提高水稻单位面积的有效穗数和每穗粒数,从而提高水稻产量;随着稻田免耕时间的延长,土壤物理性状变差,紫云英和稻草还田可以降低土壤容重,改善土壤孔隙性;免耕稻田的土壤养分在表层土壤富集,紫云英和稻草还田对提高翻耕处理土壤养分的效果更明显;脲酶,过氧化氢酶、多酚氧化酶、过氧化物酶的活性均与土壤全氮含量呈极显著相关;土壤微生物总量免耕处理小于翻耕处理,免耕土壤细菌的数量增加,而放线菌和真菌的数量减少,施用有机肥后三大类微生物数量均有所增加。【结论】紫云英和稻草还田可以提高水稻产量,降低土壤容重,改善土壤孔隙性,缓解长期免耕导致的土壤板结,有利于土壤养分含量和土壤酶活性的提高,改善微生物的生存环境。     

烤烟-绿肥轮作对烤烟产量和品质的影响

为评价并筛选出适宜与烤烟轮作的最佳绿肥品种,采用田间定位试验设4个处理,分别为烤烟-冬闲、烤烟-光叶紫花苕、烤烟-肥田萝卜、烤烟-黑麦草,探讨4种轮作模式下的烟叶产量、产值、农艺性状、化学成分及植烟土壤的养分变化情况。结果表明,不同绿肥轮作显著提升了烟叶均价和产值,其中光叶紫花苕、肥田萝卜和黑麦草轮作处理的烟叶均价分别相对冬闲处理提高15.37%、20.04%和17.72%,产值分别提高23.6%、24.1%和18.3%,光叶紫花苕处理增加了中上等烟比例。光叶紫花苕和肥田萝卜轮作处理烟叶的烟碱含量、两糖差和非烟碱氮/总氮达到了优质烟叶的水平。综上,种植光叶紫花苕和肥田萝卜能够显著提高烤烟的均价和产值,并能使烟叶的化学成分更加协调,多项化学品质达到优质烟叶的标准,是云南烟区值得推广的冬绿肥轮作模式。     

绿肥轮作对早稻生长动态及氮素吸收利用的影响

综合评价南方稻区不同冬季绿肥种植下水稻对氮素的吸收利用特性,为水稻高产栽培中氮肥的合理运筹和水稻氮素营养性状改良提供依据。比较不同冬季绿肥紫云英、油菜、黑麦草及混播绿肥对后作水稻产量、生长动态及氮素吸收利用的变化。结果表明：（1）处理紫云英—早稻—晚稻(MV-R-R)的早稻产量分别比黑麦草—早稻—晚稻(RG-R-R)、油菜—早稻—晚稻(RP-R-R)、混播绿肥—早稻—晚稻(MS-R-R)高6.61%、3.29%及0.78%。（2）在分蘖期、孕穗期、抽穗期和成熟期植株含氮率均是处理MV-RR达到最大,较其他处理平均分别高9.68%、19.72%、6.23%和8.66%。在分蘖期、孕穗期、抽穗期和成熟期植株吸氮量均是处理MV-R-R最高,处理RP-R-R最低。（3）处理MV-R-R在分蘖期至孕穗期、孕穗期至抽穗期及抽穗期至成熟期各处理的吸收量较其他处理平均分别高出21.81%、68.73%和286.5%,且绿肥轮作条件下水稻氮素阶段吸收量及其占总吸收量的比例均以抽穗至成熟期最小,最大值所处的生育阶段则是分蘖前。因此,MV-R-R处理具有较高的增产潜力,有利于提高氮肥利用效率,改善稻田氮素循环。     

Replacing bare fallow with cover crops in a maize cropping system: Yield,N uptake and fertiliser fate

Cover crops in dry regions have been often limited by low nutrient and water-use efficiency. This study was conducted during 3.5 years to determine the effect of replacing bare fallow by a cover crop on yield, N uptake, and fate of labeled fertiliser in an intensive maize production system. Three treatments were studied: barley (Hordeum vulgare L.), vetch (Vicia villosa L.) and bare fallow during the intercropping period of maize (Zea mays L.). All treatments were irrigated and fertilised following the same procedure, and a microplot in each plot was established with 210 kg N ha^?1 of double labeled ammonium nitrate. Crop yield and N uptake, soil mineral N (N_min), and recovery of ¹⁵N in plant and soil were determined after maize harvest and killing the cover crop. Replacing bare fallow with cover crops did not affect subsequent maize yield but affected N uptake. Vetch increased N supply by legume residues after the second year, and the N content in grain by the third. Nitrogen recover from fertiliser was not affected by treatment and averaged 46%. Barley recovered more ¹⁵N during the autumn–winter period than vetch or fallow. Under representative conditions, average barley N content was 47, vetch 51, and spontaneous vegetation content 0.8 kg N ha^?1. Recovery of ¹⁵N in barley comprised 19% of total N content in aerial biomass, while only 4% in vetch. Vetch enhaced soil ¹⁵N recovery more than other treatments, suggesting its presence in a fairly stable organic fraction unavailable for maize uptake or lost. Replacing bare fallow by a cover crop only reduced fertiliser losses in a year with abundant precipitation. Nevertheless, reduction in soil N_min in vetch and bare fallow treatments was similar, showing that N losses can be reduced in this cropping system, either by replace bare fallow with barley or smaller N fertiliser applicationto maize.     

冬种绿肥对早稻病虫草发生及产量的影响

研究不同冬种绿肥对后茬早稻病虫草发生和产量的影响,为南方稻区种植模式的筛选提供技术支持。以马铃薯、油菜和紫云英为绿肥植物,以冬闲田处理作对照,研究冬种绿肥翻压后早稻病虫草发生变化特征及产量变化趋势。结果表明,不同冬种绿肥翻压后,对水稻病虫草发生种类无影响,主要病虫草害均为纹枯病、二化螟、稻纵卷叶螟、鸭舌草和稗草,而对纹枯病、鸭舌草和稗草发生程度有显著影响,对二化螟和稻纵卷叶螟发生量无显著影响。在水稻孕穗期,纹枯病株发病率表现为马铃薯—水稻油菜—水稻冬闲田—水稻紫云英—水稻处理,至黄熟期表现为冬闲田—水稻马铃薯—水稻油菜—水稻紫云英—水稻处理;鸭舌草和总草密度均以冬闲田—水稻紫云英—水稻马铃薯—水稻油菜—水稻,而稗草则以冬闲田—水稻油菜—水稻马铃薯—水稻紫云英—水稻。冬种绿肥对水稻有效穗数、穗粒数和结实率无显著影响,但可显著提高千粒重,从而提高水稻产量。在病虫草发生初期,选用适当的农药可有效控制冬种绿肥翻压后早稻病虫草发生,提高水稻产量。在江西红壤稻区,冬种绿肥可抑制纹枯病和杂草发生,提高水稻产量;绿肥选择上以紫云英对水稻产量和病虫草害控制综合效果最好。     

不同品种紫云英对镉污染土壤水稻生长累积效应的研究

旨在研究不同品种紫云英绿肥对镉污染地区水稻生长及土壤质量的影响。结果表明,与2个对照组相比,翻压紫云英显著提高了土壤溶液pH,降低Eh(P<0.01),也使土壤有效态镉的含量显著降低,减少了水稻在生长过程中对镉的累积,以‘湘紫3号’紫云英品种效果最为明显,与单施化肥处理相比,土壤有效镉含量降低了21.9%,植株稻草镉含量降低了39.1%,稻谷镉含量降低了43.5%,在4个品种中降幅均为最大值。不同品种紫云英翻压均能促进水稻的生殖生长,能有效提高水稻的产量,各处理间水稻的农艺性状指标和产量指标均无显著性差异。因此,选择降镉效果最佳的‘湘紫3号’紫云英品种,能够更好地降低农作物对镉的吸收,提高产品的安全性。     

Nitrogen use efficiency and fertiliser fate in a long-term experiment with winter cover crops

The use of winter cover crops enhances environmental benefits and, if properly managed, may supply economic and agronomic advantages. Nitrogen retained in the cover crop biomass left over the soil reduces soil N availability, which might enhance the N fertiliser use efficiency of the subsequent cash crop and the risk of depressive yield and pre-emptive competition. The main goal of this study was to determine the cover crop effect on crop yield, N use efficiency and fertiliser recovery in a 2-year study included in a long-term (10 years) maize/cover crop production system. Barley (Hordeum vulgare L.) and vetch (Vicia sativa L.), as cover crops, were compared with a fallow treatment during the maize intercropping period. All treatments were cropped following the same procedure, including 130 kg N ha⁻¹ with ¹⁵N fertiliser. The N rate was reduced from the recommended N rate based on previous results, to enhance the cover crop effect. Crop yield and N uptake, soil N mineral and ¹⁵N fertiliser recovered in plants and the soil were determined at different times. The cover crops behaved differently: the barley covered the ground faster, while the vetch attained a larger coverage and N content before being killed. Maize yield and biomass were not affected by the treatments. Maize N uptake was larger after vetch than after barley, while fallow treatment provided intermediate results. This result can be ascribed to N mineralization of vetch residues, which results in an increased N use efficiency of maize. All treatments showed low soil N availability after the maize harvest; however, barley also reduced the N in the upper layers before maize planting, increasing the risk of pre-emptive competition. In addition to the year-long effect of residue decomposition, there was a cumulative effect on the soil’s capacity to supply N after 7 years of cover cropping, larger for the vetch than for the barley.     

Forage and Food Legumes in a Multi‐Year,Wheat‐Based Rotation Under Drought‐Stressed Conditions in Northern Syria’s Medium Rainfall Zone

Long‐term crop rotation trials were designed to assess sustainability of alternatives to traditional fallow and monocropping. The trial described here (6 years) involved wheat (Triticum aestivum L.) in rotation with lentil (Lens culinaris L.), forage vetch (Vicia sativa), pasture medic (Medicago spp.), fallow and watermelon (Citrullus vulgaris). Barley (Hordeum vulgare L.) was compared with wheat for an additional 2 years. Cereal grain and straw yields were highest with fallow and watermelon followed by vetch, lentil and medic; the latter showed no differential effect of variable grazing intensity. Fertilizer N increased yields except in the low‐rainfall years (less than 250 mm). Barley out‐yielded wheat in terms of grain, but not straw. Medic yielded highest in dry matter, whereas lentil produced highest seed yield. Despite the difficulty of assessing crop and animal‐oriented rotations because of non‐commonality of outputs, economic considerations are foremost, but other benefits of rotations (soil quality, water‐use relations) are also relevant to the overall assessment of cereal‐based Mediterranean rotations. The study suggested barley rather than wheat as the desired cereal in rotation with legumes in this marginal‐rainfall (350 mm) environment and provided support for the viability of vetch and lentil in the cropping system. Given the importance of sheep in the region’s farming system, vetch is likely to have a major role in crop rotations.     

施用控释氮肥对油菜产量、农艺性状及土壤肥力的影响

为了探讨控释氮肥对油菜的肥料效应,通过池栽试验,选取洞庭湖区3 种主要土壤在连续4 年“稻—稻—冬闲”后将冬闲改种油菜施用旱作控释氮肥,研究控释氮肥对油菜产量、农艺性状、生长性状及土壤肥力的影响。结果表明,在紫潮泥及河沙泥2 种土壤中施用控释氮肥促进了油菜植株的生长发育,可获得较高油菜产量,比施等N量尿素处理分别增产12.2%和9.8%,70%控释氮肥效果明显降低。施用控释氮肥后河沙泥土壤碱解氮和有机碳含量比油菜试验前分别增加25.0%和3.2%,紫潮泥碱解氮含量提高13.5%,并均高于尿素和70%控释氮肥2 个处理。而红黄泥施用控释氮肥对油菜产量和土壤肥力的影响均不及等N量尿素处理,70%控释氮肥处理的效应则更小。施用控释氮肥对紫潮泥及河沙泥的油菜生产具有显著增产效果及土壤氮素肥力提升作用。