共查询到20条相似文献，搜索用时 31 毫秒
1.
2.
不同施氮量及分配对小麦生长发育和产量的影响 总被引：9，自引：0，他引：9
不同施氮量及分配试验表明,未施氮素较施用氮素的小麦早熟６天,施用氮素（Ｎ,下同）３００ｋｇ／ｈｍ＾２,倒伏严重,产量低。以每公顷施２４０ｋｇ氮素,基肥：追肥＝６：４最好,分蘖比对照多０．５４个／株,有效穗比对照、施氮素１８０ｋｇ／ｈｍ＾２、３００ｋｇ／ｈｍ＾２分别多５１、４５、２７万／ｈｍ＾２,每穗粒数分别多１０．７、０．５、０．９粒,产量达８９７１．２ｋｇ／ｈｍ＾２,比对照、施氮素１８０ｋｇ／ｈ 相似文献
3.
二元覆盖技术在玉米高产栽培中的应用 总被引：3，自引：0，他引：3
二元覆盖是针对玉米生产上单纯地膜覆盖消耗地力过重和单纯整秆覆盖又导致地温下降的新问题而提出的一项综合配套栽培新技术。１９９２年至１９９６年经验试验研究,肯定了二元单覆盖分别比整秆覆盖和对照增产１５０３ｋｇ／ｈｍ＾２和２７３９ｋｇ／ｈｍ＾２,增产１５．６％和３２．６％;二元双覆盖分别比地膜覆盖和对照增产１１２０．５ｋｇ／ｈｍ＾２和３４３０．５ｋｇ／ｈｍ＾２,增产１４％和６０．２％。 相似文献
4.
小麦高留茬的经济效益与配套技术 总被引：8，自引：1，他引：8
１９９２￣１９９４年度，在邹西平原潮土地研究了小麦高留茬的效益与技术。结果表明：高留麦茬３０ｃｍ并增施占麦茬量１．１％的纯Ｎ量氮素化肥，三年平均增产玉米１１．７％，增产小麦７．８％，纯收益较低茬（５ｃｍ）增加１２６１．５５元／ｈｍ＾２。且不同留茬方式、高度和麦茬密度的效果显著不同。高留麦茬具有抑制田间杂草、节省中耕灭茬用工、保墒坑旱、减轻水土流失、培肥土壤等效应。其配套技术主要是留茬高度和方式，配 相似文献
5.
安徽省全椒县「实施油菜＝西瓜－水稻、西瓜＝棉花－冬菜、蔬菜－水稻－蔬菜、冬菜－棉花＝蔬菜、小麦＝西瓜＝大豆、马铃薯＝西瓜＝棉花、西瓜＝玉米－水稻等多种立体复合种植模式及其配套栽培技术,１９９７年各类面积达１．３３万ｈｍ＾２,其中５６００ｈｍ＾２田粮食单产达７５００ｋｇ／ｈｍ＾２,产值达３万元／ｈｍ＾２,分别比传统种植模式（油菜－水稻,麦－稻）增长１２．４％和２４％,取得明显的社会、经济和生态效益。 相似文献
6.
小麦平衡配套施肥中氮素运筹 总被引：2，自引：0，他引：2
在小麦平衡配套施肥条件下研究了不同氮素运筹对氮肥的实际利用率及小麦量的影响。结果表明;在试验条件下,氮肥以６０％作基肥,２０％作壮蘖肥,２０％作拔节孕穗肥施用时肥料效益最高,小麦全生育期技术合理施氮量为２１０－２４０ｋｇ／ｈｍ＾２纯氮,施氮量在２４０ｋｇ／ｈｍ＾２纯氮时小麦产量最高。 相似文献
7.
8.
小麦是吕梁地区的主要粮食作物之一。建国５０年来，全区小麦生产取得了辉煌的成就，单产由建国初期的５２５ｋｇ／ｋｍ＾２增长到３６００ｋｇ／ｈｍ＾２，总产达２．１１亿ｋｇ，是建国初期的３．１倍，但在发展的同时也暴露出种植面积连年下降，生产水平较低，年际产量减幅较大，总量不足、品种更新换代速度慢等问题。为了在短期内大幅度提高小麦产量，力争到２００５年实现全区供需基本平衡，应从充分挖掘小麦增产潜力，加快中低 相似文献
9.
小麦—玉米轮作制度下潮土硝态氮的分布及合理施氮肥研究 总被引：13，自引：3，他引：10
利用田间小区试验研究了小麦－玉米轮作中在不同施氮量和不同时期潮土１ｍ土层中硝态氮的分布状况。结果表明：３年不施氮肥的土壤仍有６～１６ｋｇ／ｈｍ＾２的硝态氮,其中０－２０ｃｍ支占２０％～３４％,８０％～１００ｃｍ土层占１０％～１８％;每季施氮量小于２２５ｋｇ／ｈｍ＾２时,１ｍ土层中各时期硝态氮含量变化不大,在１１．４～４１．３ｋｇ／ｈｍ＾２之间;当施氮量增加到３７５ｋｇ／ｈｍ＾２时,１ｍ土层的硝态氮 相似文献
10.
紫云英压青对水稻产量的影响 总被引：7，自引：0，他引：7
对水稻产量与紫云英压青量关系的一元二次回归方程和４年多点田间对比试验分析结果表明,紫云英压青对水稻具有显著的增产作用,其适宜压青量为１５０００￣２２５００ｋｇ／ｈｍ＾２,可使早稻增产７．１％￣１０．４％,晚稻增产２．６％￣４．５％。 相似文献
11.
安阳市近10年来建成的水土保持工程的主要建设管理方式可分为3种,即:乡村组织治理,完成后分配给农户分散经营;乡村组织治理,由村成立专业队代表村集体管理;把小流域或荒山承包给个体或私人经济组织,由其自行治理和经营管护。3种建管方式中以后者为最优,其经济效益是分散经营管理的5倍、专业队经营管理的3.5倍。针对水保工程建设管理中存在的问题和适应农村税费改革等要求,提出了加快安阳市水保生态建设的建议。 相似文献
12.
我国滑坡、崩塌的区域特征、成因分析及其防御 总被引：2，自引：0，他引：2
论述了我国滑坡、崩塌的区域分布特征,滑坡和崩塌的危害程度,滑坡和崩塌类型和成因分析,并且提出了灾害的防御措施,以期达到环境保护成为社会发展过程中的一个重要组成部分。 相似文献
13.
为探讨硒、钴在提高苜蓿生长影响,在河南省沿黄滩区,开展了硒、钴单施和配施下对紫花苜蓿生长以及产量和品质影响研究。结果表明,硒、钴单施和配合基施均能够显著提高苜蓿从现蕾到开花期的净光合能力,降低呼吸消耗,提高单位叶面积干物质的生产速率,有利于苜蓿花前青干草生产和果实发育;其中,以硒570 g/hm2、钴762g/hm2配施下效果显著,青干草增产8.06%,种子千粒重可提高12.85%。单施钴和硒钴配施还能促进0—20 cm耕层苜蓿根瘤菌的生长和积累,增强苜蓿的固氮能力。说明硒钴合理基施对苜蓿青干草和优质种子生产具有很好的应用效果。 相似文献
14.
Much evidence has indicated that the occurrence of montmorillonite and vermiculite containing Al-interlayers is very common in solis, particularly acid soils. Viewed in the light of soil clay minerology, it would be required to investigate the properties of their original minerals. For the latter purpose, the Al-interlayer has been removed prior to the Mg-glycerol,K-saturation and heating tests for identification of montmorillonite and vermiculite. Its removal has been accomplished in sevsral ways; KOH plus KCl (1), NH4F, KCl plus HCl (2), Na-citrate (3),400C de hydroxylation-NaOH (4) dissolution. Although these methods are effective for the removal of Al-interlayers, they seem drastically to affect the minerals or are time-consuming. Inthe course of the study of hydroxy-Al interlaid complexes of expanding 2:1 layer lattice clay minerals, the authors have noticed the difference between the (001) spacings of hydroxy-Al complexes of montmorillonite and vermiculite; the former exhibited the 20 A basal spacing at room temperature against the 14 A spacing of the latter. This difference might be useful for differentiating montnmorillonite-chlorite intergrades in soils. 相似文献
15.
16.
平原地区河道堤防滩地的水土流失,直接淤积河床,影响行洪安全。堤防滩地的水土流失是自然因素和人为因素共同作用的结果,以新修堤防的水土流失最为严重,对其防治须实行工程措施、植物措施和人为预防相结合。 相似文献
17.
18.
The effects of biochar (maize biochar – MBC, wood biochar – WBC) and unfermented or fermented hydrochar (HTC) on the euedaphic Collembola Protaphorura fimata and on spring wheat were investigated in greenhouse experiments. The impact of char type, amount of fermented HTC, and MBC-Collembola interactions were assessed. Generally, shoot and root biomass as well as abundance of P. fimata were not affected by the different chars. However, with increasing amounts of fermented HTC the abundance of P. fimata declined, whereas shoot biomass of wheat increased. Moreover, MBC altered root morphology and resulted in thicker roots with higher volume. The latter was not apparent when Collembola were present. 相似文献
19.
Potatoes (Solarium tuberosum L.) and carrots (Daucus carota L.) were grown in the field on Tasmanian ferrosols (humic eutrudox) which had been limed either 2, 3, or 5 years earlier, and where tuber cadmium (Cd) concentrations in potatoes grown a few months after the liming had shown no lime response. In the current crops lime decreased potato tuber Cd by about 30% and carrot root Cd by about 50%. We attributed the decrease to more even and deeper mixing of the lime with the soil by the harvest of the first potatoes. Phosphorus (P) fertilizer residues from the earlier potato crops did not significantly affect tuber or root Cd, but there was a positive effect at 1 site where some high Cd P fertilizer had earlier been used. Neither lime nor P fertilizer residues affected potato or carrot yields. Analysis at one site of potato tubers from the upper part of the soil ridges showed that they had slightly higher Cd concentrations than did deeper tubers near the fertilizer band, whether P fertilizer was in the band or not. This suggests that either the Cd in the fertilizer band was relatively unimportant as a Cd source for the current crop, or that Cd was redistributed within the plant during the season, or both. Liming may be a suitable medium to long‐term strategy for decreasing Cd uptake by root crops, but site to site and seasonal variation can still be great, and knowledge of other major influences is needed for assurance of produce quality. Our observations need to be extended to sites which gives rise to higher Cd concentrations in agricultural produce, and to other soil types. Potato common scab was severe in the limed plots at one site. However, this site had grown 3 potato crops in 5 years, which probably exacerbated the disease. Potato processors in Tasmania demand a minimum of 5 years between successive crops which should slow any build up of scab due to liming, but more work on possible interactions between lime and rotation length on scab incidence is needed before liming can be recommended as a Cd control measure for potatoes. 相似文献
20.
水土流失动态监测与评价研究现状与问题 总被引：16，自引：3，他引：13
美国等国家已将遥感、ＧＩＳ技术广泛应用于水土流失动态监测与预报,并开发出基于物理过程的土壤侵蚀预报模型。中国在水土流失地面观测、遥感监测方面已取得许多成果,但在区域土壤侵蚀评价、预报模型开发方面,缺少系列化观测与统计数据,已有的坡面土壤侵蚀模型等在通用性、适用性方面还存在不少问题。当前急需解决的问题是建立水土流失监测与评价指标体系,开发评价模型系统,建立国家水土保持信息系统 相似文献