浅述三种新优藤本植物及其应用价值

主要介绍了三叶木通、南蛇藤及蓝果蛇葡萄三种木质藤本植物的特性及应用价值。     

除草剂减量施用对麦田杂草的防治效果及对叶绿素SPAD值的影响

探讨除草剂减施对麦田杂草的防治效果,以及对小麦生长过程中叶绿素SPAD值变化的影响。结果表明,药后45 d,10%苯磺隆WP 9.00 g/hm~2处理(减施60.00%)、10%苯磺隆WP 9.00 g/hm~2+5%(唑啉草酯+炔草酯)EC 30.00 g/hm~2处理(减施60.00%)、7%双氟·炔草酯OD 63.00 g/hm~2处理(减施25.00%)和28%唑草·苯磺隆WP 16.80 g/hm~2处理(减施33.33%)对麦田阔叶杂草的鲜质量防效分别为98.64%、98.99%、98.54%和98.68%,表明除草剂减量施用对麦田杂草仍具有较好的防效。施用除草剂后,小麦叶片叶绿素SPAD值呈现先下降再上升的趋势。药后3 d、5 d、7 d,28%唑草·苯磺隆WP 33.60 g/hm~2处理(增施33.33%)小麦叶片叶绿素SPAD值显著低于7%双氟·炔草酯OD 63.00 g/hm~2处理(减施25.00%)、10%苯磺隆WP 9.00 g/hm~2处理(减施60.00%)和空白对照(CK)的叶绿素SPAD值,低于其他处理的叶绿素SPAD值。     

基于RGB颜色空间的早稻氮素营养监测研究

针对双季稻区水稻过量施肥带来环境污染和成本提高问题,设计不同品种氮肥梯度大田试验,应用数码相机获取早稻冠层数字图像,研究不同色彩参数及早稻氮素营养指标的时空变化特征,以期确立双季早稻氮素营养预测模型。结果表明:不同品种同一氮肥处理下图像色彩参数差异不大;拔节期数字图像参数对氮素营养指标敏感;模型构建结果显示,图像参数INT与水稻氮素营养指标构建的模型决定系数(R2)最大,模型预测效果最佳,R2分别为0.895 7和0.924 7;进一步采用多元回归分析和BP神经网络分析法进行预测,预测效果均较好。对预测结果进行检验,发现品种对于模型的构建影响不大,以BP神经网络分析法构建的叶片氮浓度(LNC)模型和以INT为敏感色彩参数构建的叶片氮积累量(LNA)回归模型效果最优,而多元回归分析方法则效果不佳。早稻冠层RGB颜色空间敏感参数与氮素营养指标间相关性较好,可以实现氮素营养的无损监测诊断。     

光氮互作对芹菜幼苗生长及生理特性的影响

光质和施氮量是影响芹菜生长发育的关键因素,适宜的光氮组合能有效提升芹菜幼苗质量。为优化芹菜工厂化育苗,本试验设置2种光质(白光,W;蓝光,B)和2种施氮量(8mmol/L KNO_3,高氮,H;4mmol/L KNO_3,低氮,L),以WH为对照,研究光氮互作对芹菜幼苗生长、生理代谢和元素积累的影响。结果表明:与WH相比,WL和BH处理的芹菜全株干重分别显著减少43.18%和55.07%,WL处理的叶片和叶柄中硝酸盐、可溶性蛋白质和总游离氨基酸质量分数均显著降低,BH处理的叶片和叶柄中硝酸盐、可溶性蛋白质和矿质元素质量分数显著增加,而叶片中可溶性糖、丙氨酸族和丝氨酸族氨基酸质量分数均显著降低。然而BL处理的芹菜全株干重比WH显著增加32.18%,叶片可溶性蛋白质、叶柄组氨酸(His)和脯氨酸(Pro)质量分数均显著增加。利用隶属函数分析对芹菜幼苗生长发育进行综合评价发现,BL处理表现最优。综上所述,蓝光和低氮组合能促进芹菜干物质积累,提高可溶性蛋白质和游离氨基酸质量分数,进而促进芹菜幼苗生长发育。     

玉米-大豆间作和减量施氮对玉米生长、产量及土壤硝态氮含量的影响

通过大田试验，研究玉米单作（MM）、玉米-大豆间作1∶2（IMS1，玉米1行，大豆2行）、2∶2（IMS2，玉米2行，大豆2行）3种种植方式和3种施肥水平不施氮（N0）、减量施氮200 kg/hm（N1）、常量施氮300 kg/hm（N2）对玉米生长、产量以及土壤硝态氮含量的影响。结果表明，IMS1下，N2玉米叶面积较N0显著提高6.30%。间作和N1处理对玉米产量无显著影响，但显著提高了玉米和大豆总产量。N1较N2的氮肥农学效率显著提高。土壤硝态氮随玉米不同生育期的变化而变化，在成熟期达到最低值。与N2相比，N1土壤硝态氮无显著变化，未对土壤养分产生负面影响并能满足作物对氮素的需求，保持高产。总体来看，玉米大豆间作模式下减量施氮有利于节肥和提高间作体系总产量。     

Grain yield,nitrogen use efficiency and tillage intensity in wheat as affected by precision nutrient management

ABSTRACT

The present studies were conducted to evaluate the effect of different nutrient management practices under two tillage options in wheat. The experiments were laid out in split-plot design with a combination of two varieties (WH 1105 and HD 2967) and two tillage options (Conventional and No tillage) in the main plot and six precision nutrient management practices [absolute control, site-specific nutrient management with Nutrient Expert for wheat (SSNM-NE)(170 kg nitrogen (N)/ha), SSNM NE+GreenSeeker (GS)(153/158 N kg/ha), N₁₂₀ (120 kg N/ha) before irrigation, N₁₂₀ after irrigation and N Rich (180 kg N/ha)] in subplot replicated thrice. The grain yield and quality characters in no tillage (NT) and conventional tillage (CT) were similar but agronomic efficiency was higher in NT. Both the varieties (WH 1105 and HD 2967) gave similar grain yield and quality. Wheat variety WH 1105 recorded significantly higher sodium dodecyl sulfate sedimentation (SDS) and gluten index. The treatment SSNM NE+GS had resulted in 107.1% higher grain yield than no nitrogen control but similar to enriched N plot (180 kg N/ha). The grain protein, SDS and gluten index in need-based nutrient management (SSNM+GS) treatment were found to be similar as recorded in SSNM-NE (170 kgN/ha) and N enriched plot (180 kg N ha^?1). The agronomic efficiency and recovery efficiency in SSNM+GS were also better than SSNM NE.     

科尔沁草甸湿地土壤碳氮剖面分布及生长季动态特征

采用定位观测的试验方法,于2016年5-10月及2017年8月对科尔沁草甸湿地0~100 cm土层土壤有机碳、全氮剖面分布及生长季动态特征进行了实验分析,旨在为科尔沁草甸湿地保护提供科学指导并为干旱半干旱地区湿地土壤碳氮储量估算提供借鉴。结果表明:1)科尔沁草甸湿地土壤有机碳、全氮含量整体随土层深度下降,0~20 cm土层间下降显著,20 cm以下趋于相对稳定,范围分别为11.9~23.5 g·kg^-1和0.66~1.50 g·kg^-1。2)各土层土壤碳氮含量月间差异显著(全氮40~60 cm土层除外),变化幅度随土层深度先减小后增大;土壤碳氮密度(100 cm)生长季变化大于年际变化,有机碳密度全生长季呈上升趋势,范围为15.44~20.82 kg·m^-2,全氮密度生长初期明显下降,之后趋于相对稳定,范围为1.01~1.16 kg·m^-2。3)土壤有机碳含量与全氮含量呈极显著正相关;植被和水文是影响其分布、变化的关键因子。科尔沁草甸湿地生长季土壤有机碳、全氮密度变化较大,且表现为潜在的碳汇和氮源,但年际间碳汇潜力未充分发挥,本研究建议禁牧力度应加大并增加氮肥投入以提高科尔沁草甸湿地生态系统功能。     

氮肥、密度对寒地超级稻‘龙粳31’产量的互作效应研究

试验采用单因子和二次正交旋转组合设计,探讨氮肥密度互作对寒地超级稻‘龙粳31’产量、干物质重及产量构成的影响情况。结果表明:产量与氮肥、密度均呈显著的二次曲线关系,同时氮肥密度对产量互作效应明显,中等施氮量和较高密度互作更易获得高产。互作效应下氮肥取135.0 kg/hm2、密度取34.6穴/m2时,产量最高达9948.17 kg/hm2。高氮肥高密度配合,齐穗期干物质重最重,但此时产量却显著下降。高氮肥和高密度配合更容易获得较多穗数;但中等施氮量和较低的密度配合更易获得大穗;氮肥密度与千粒重不存在互作效应。因此科学合理的氮肥、密度相互配合,从而构建合理的群体结构,获得适宜的齐穗期干物质重,才能发挥超级稻的产量潜力。     

Carbohydrate and crude protein fractions in perennial ryegrass as affected by defoliation frequency and nitrogen application rate

The objective of this study was to evaluate the effects of defoliation frequency (either at two‐ or three‐leaf stage) and nitrogen (N) application rate (0, 75, 150, 300, 450 kg N ha^?1 year^?1) on herbage carbohydrate and crude protein (CP) fractions, and the water‐soluble carbohydrate‐to‐protein ratio (WSC:CP) in perennial ryegrass swards. Crude protein fractions were analysed according to the Cornell carbohydrate and protein system. Carbohydrate fractions were analysed by ultra‐high‐performance liquid chromatography. Sward defoliation at two‐leaf stage increased the total CP, reduced the buffer‐soluble CP fractions and decreased carbohydrate fractions of herbage (P < 0·001). The effect of defoliation frequency was less marked during early spring and autumn (P < 0·001) than for the rest of the seasons. An increase in N application rate was negatively associated with WSC, fructans and neutral detergent fibre (P < 0·001), and positively associated with CP and nitrate (N‐NO₃) contents of herbage. Nitrogen application rate did not affect CP fractions of herbage (P > 0·05). The fluctuations in CP and WSC contents of herbage resulted in lower WSC:CP ratios during early spring and autumn (0·45:1 and 0·75:1 respectively) than in late spring (1·11:1). The herbage WSC:CP ratio was greater (P < 0·001) at the three‐leaf than the two‐leaf defoliation stage and declined as the N application increased in all seasons (P < 0·001). The results of this study indicate that CP and carbohydrate fractions of herbage can be manipulated by sward defoliation frequency and N application rate. The magnitude of these effects, however, may vary with the season.     

水分与氮素及其互作对水稻产量和水肥利用效率的影响研究进展

了解水分、氮素及其互作对水稻产量与水、氮利用效率的影响,对协同提高水稻产量与水氮利用效率有重要意义。本文概述了水稻节水灌溉技术、氮肥利用效率与氮肥施用技术、水分与氮素对水稻产量及水氮利用效率的耦合效应、作物-土壤关系及水氮调控机制等方面取得的进展;讨论了存在的问题,这些问题包括:高产水稻作物与土壤的水氮互作效应尚不明确;高产水稻水氮耦合与高效利用的分子机理不清楚;协同提高水稻产量与水氮利用效率的调控途径尚未掌握。针对这些问题,建议今后重点研究:高产水稻作物与土壤的水氮互作效应及其机制;水氮互作调控水稻吸收利用水分和氮素的生理与分子机理;协同提高水稻产量和水氮利用效率的调控途径与关键技术。