Effects of Continuous Nitrogen Application on Grain Yield and Nitrogen Uptake and Utilization in Winter Wheat-Summer Maize Rotation System

[Objective] This study aimed to achieve high yield and stable yield of win- ter wheat-summer maize rotation system and provide basis for rational application of nitrogen fertilizer. [Method] Effects of continuous nitrogen application on grain yield, economic profit, nitrogen uptake and utilization efficiency, and soil inorganic nitrogen accumulation in winter wheat-summer maize rotation system were investigated. [Re- sult] Nitrogen application could significantly increase the y（eld of the winter wheat- summer maize rotation system, which increased by 17.76%-30.32% and 22.24%- 46.63% in two rotation cycles, respectively. The yield of the winter wheat-summer maize rotation system was the maximum in two rotation cycles with nitrogen appli- cation amount of 660.0 kg/hm2, which reached respectively 23 391.19 and 23 444.35 kg/hm2, the yield and economic benefit were the highest, the nitrogen fertilizer use efficiency was 22.2% and 30.7%, the agronomic efficiency was 8.3 and 11.3 kg/kg. However, the nitrogen fertilizer use efficiency and agronomic efficiency between ni- trogen application amount of 540.0 and 660.0 kg/hm2 showed no significant differ- ence. After two rotation cycles, inorganic nitrogen accumulation in 0-40 cm soil with nitrogen application amount of 540.0 kg/hm2 was almost equal to that before experi- ment. [Conclusion] Under the experimental conditions, comprehensively considering the grain yield, economic profit, nitrogen fertilizer efficiency and soil inorganic nitro- gen balance, the optimal nitrogen application amount was 625.3-660.0 kg/hm2 in high-yield winter wheat-summer maize rotation system.

Fate of ^(15)N-Labeled Urea Under a Winter Wheat-Summer Maize Rotation on the North China Plain

A field experiment was conducted to investigate the fate of ^15N-labeled urea and its residual effect under the winter wheat （Triticum aestivum L.） and summer maize （Zea mays L.） rotation system on the North China Plain. Compared to a conventional application rate of 360 kg N ha^-1 （N360）, a reduced rate of 120 kg N ha^-1 （N120） led to a significant increase （P 〈 0.05） in wheat yield and no significant differences were found for maize. However, in the 0-100 cm soil profile at harvest, compared with N360, N120 led to significant decreases （P 〈 0.05） of percent residual N and percent unaccounted-for N, which possibly reflected losses from the managed system. Of the residual fertilizer N in the soil profile, 25.6%-44.7% and 20.7%-38.2% for N120 and N360, respectively, were in the organic N pool, whereas 0.3%-3.0% and 11.2%-24.4%, correspondingly, were in the nitrate pool, indicating a higher potential for leaching loss associated with application at the conventional rate. Recovery of residual N in the soil profile by succeeding crops was less than 7.5% of the applied N. For N120, total soil N balance was negative; however, there was still considerable mineral N （NH4^＋-N and NO3^--N） in the soil profile after harvest. Therefore, N120 could be considered ngronomically acceptable in the short run, but for long-term sustainability, the N rate should be recommended based on a soil mineral N test and a plant tissue nitrate test to maintain the soil fertility.

Experimental Study on No-tillage Cultivation of Flowering Chinese Cabbage in Rice Winter Fallow Fields

The research made comparisons on no-tillage cultivation and ploughing cultivations of Flowering Chinese cabbage on one-season paddy fields and explored the effects of no-tillage cultivation of Flowering Chinese cabbage on survival rate, insect damages, production cost, yield and benefits of plants. The results indicated that no-tillage cultivation reduced the injured rate of Flowering Chinese cabbage by cutworms, and production cost, but crop yield and output value declined as well. Specifically, yield in the treatment as per no-tillage cultivation lowered by 10.3% and 11.9% compared with the treatments by machine-based ploughing and manual ploughing, and the production interests declined by 11.9% and 11.1%, accordingly.

Divergent responses of tiller and grain yield to fertilization and fallow precipitation:Insights from a 28-year long-term experiment in a semiarid winter wheat system

Tillering is an important phenological stage,which is strongly related to the yield in spike components and final grain yield during winter wheat growth.Precipitation during the fallow season(fallow precipitation)influences tillering in winter wheat on the semi-arid Chinese Loess Plateau.However,little work has been done regarding tiller number changes under various types of fertilization and amounts of fallow precipitation on a long-term scale.Effects of fallow precipitation and fertilization on tiller were investigated in a winter wheat(Triticum aestivum L.)system in a 28-year field study(1990 to 2017)in a semiarid agro-ecosystem.Tiller number,spike number and grain yield were measured in four fertilization conditions:control without fertilizer(CK);mineral nitrogen fertilizer alone(N);mineral phosphorus fertilizer alone(P);mineral nitrogen and phosphorus fertilizer together(NP).Based on the long-term annual fallow precipitation,dry years(mean annual fallow precipitation)were distinguished.Phosphorus fertilization alone significantly increased the mean annual tiller number(23%),and the increase in tiller number was higher in wet years(29%)than in the dry years(17%).However,nitrogen fertilization alone had little effect on mean tiller number,while nitrogen and phosphorus together significantly increased mean annual tiller number(30%),mean tiller number in wet years(45%)and mean tiller number in dry years(17%).Tiller number was significantly and positively correlated with fallow precipitation in dry years for all fertilizer treatments,whereas it was weakly and either positively or negatively correlated with fallow precipitation in wet years depending on the treatment.This study found positive correlations between tiller number and fallow precipitation in the CK and NP treatments,and it found negative correlations between tiller number and fallow precipitation in the treatments with nitrogen fertilization alone or phosphorous fertilization alone in wet years.Understanding the impacts of fallow precipitation and fertilization on tiller development shed light on ways to improve crop production in rain-fed agricultural regions.

夏闲季不同耕作措施对旱地麦田土壤养分含量和酶活性的影响

为明确夏闲季不同耕作措施对旱地麦田土壤理化特性和酶活性的影响,基于2018年开始设置在黄土高原与黄淮海平原交汇处典型旱作区洛宁县小界乡的夏闲季定位耕作管理大区试验,2020—2022年研究了传统翻耕(CT)、一次深翻(DT)、免耕覆盖(NTM)、深松覆盖(STM)和深松垄沟覆盖(SRFM)5种夏闲季耕作措施对旱地麦田土壤三相比、养分含量和酶活性的影响。结果表明,优化夏闲季耕作措施可改善旱地麦田土壤三相比,提高土壤养分含量和酶活性,总体以SRFM效果最好。与CT相比,STM和SRFM的三相比R值显著降低4.7%~28.2%和10.9%~33.7%,DT、STM和SRFM在0~40 cm土层土壤全氮含量分别提高2.8%~11.2%、11.7%~21.4%和15.6%~30.6%,有效磷含量分别提高6.9%~39.5%、7.4%~68.8%和13.6%~80.3%,速效钾含量分别提高5.2%~19.7%、9.6%~25.8%和13.8%~35.0%;土壤蔗糖酶活性分别提高7.8%~21.5%、17.1%~75.9%和27.9%~99.1%,脲酶活性分别提高7.6%~97.0%、12.8%~165.5%和23.5%~194.9%,过氧化氢酶活性分别提高5.5%~15.2%、16.3%~26.7%和20.8%~50.3%,增幅多达到显著水平且表现为SRFM>STM>DT,NTM可显著提高0~10 cm土层但降低20~40 cm土层土壤养分含量和酶活性。综合来看,夏闲季深松垄沟并结合秸秆覆盖的措施可改善土壤三相比,提高土壤养分含量和酶活性,是利于提高旱地麦田土壤质量的耕作措施。

夏闲期耕作下旱地土壤有机碳库与温度和含水量季节变化及关系研究

为明确夏闲期耕作下土壤有机碳(SOC)库与温度和含水量的季节变化及其相互关系,设置夏闲期免耕、翻耕和深松3种耕作处理,分析了黄土高原旱地麦田SOC和易氧化有机碳(POxC)含量的季节变化、土壤含水量和温度的季节变化、以及碳库与温度和含水量变化的关系。结果表明,在冬小麦生育期内,随着生育进程的推进,翻耕和深松处理0~5和5~10 cm土层SOC含量呈先升高后降低的变化趋势,而POxC含量呈“降低—升高—再降低”的变化趋势;土壤质量含水量变化均呈“增加—降低—再增加”的变化趋势,而土壤温度呈先降低后升高的变化趋势。回归分析发现,5~10 cm土层土壤质量含水量与SOC含量呈线性关系(P<0.05),与POxC含量呈二次多项式关系(P<0.05),尤其与免耕和深松处理相比,翻耕处理拟合效果更佳。此外,0~5和5~10 cm土层土壤温度变化与SOC含量无显著相关性,而日最高温度、日平均温度和日最低温度与POxC含量呈显著负相关。综上所述,不同夏闲期耕作下旱地麦田0~10 cm土层POxC含量季节变化与土壤质量含水量和温度变化密切相关,而SOC含量变化对土壤温度变化的敏感性较弱。本研究结果为旱地麦田碳库管理提供了理论依据。

减量施肥对冬小麦休闲期农田杂草物种多样性及生态化学计量特征的影响

【目的】分析减量施肥对冬小麦休闲期农田杂草物种多样性及生态化学计量特征的影响,旨在为化肥农药“双减”政策产生的生态环境效应科学评价提供参考。【方法】以陕西杨凌曹新庄试验地冬小麦肥料试验为基础,设置不施肥(CK)、减量施肥(氮(N)、磷(P_(2)O_(5))用量分别为165和122 kg/hm^(2))和常规施肥(N、P_(2)O_(5)用量分别为220和160 kg/hm^(2))3个处理,测定不同处理小麦产量及夏季休闲期农田杂草的生物量、株高、盖度、多度、频度、丰富度,以及藜、狗尾草和马唐的有机碳、全氮、全磷含量,计算植物多样性指标及生态化学计量比(C/N、C/P、N/P),研究减量施肥对农田杂草物种多样性及生态化学计量特征的影响。【结果】与对照相比,减量施肥和常规施肥处理均对冬小麦休闲期农田杂草的生物量、株高、盖度、多度、频度有明显影响,冬小麦籽粒产量和杂草生物量增加;施肥处理藜和地锦草的株高和生物量均显著增加,其他农田杂草的株高和生物量总体降低。与对照相比,施肥处理苋的有机碳含量以及藜、狗尾草、马唐和葎草的全氮含量均显著增加,藜、马唐全磷含量显著降低。相较于常规施肥,减量施肥处理狗尾草全磷含量显著降低。与对照相比,减量施肥和常规施肥处理藜、狗尾草和马唐氮磷比和碳磷比总体显著增加,碳氮比显著降低。相对于常规施肥处理,减量施肥处理缓解了藜和马唐氮磷比的增加幅度。与对照相比,施肥处理的Shannon-Wiener多样性指数、Simpson多样性指数和Margalef丰富度指数均显著降低;与减量施肥处理相比,常规施肥处理Pielou均匀度指数与丰富度显著降低。植物β多样性指数表明,常规施肥对小区植物多样性的影响最大。【结论】减量施肥和常规施肥处理冬小麦休闲期农田杂草的物种多样性均明显降低,但减量施肥处理缓解了常规施肥对农田杂草生物多样性和生态化学计量特征的影响。

填闲作物对烤烟生长和温室气体排放的影响

为了解填闲作物对烤烟生长和温室气体排放的影响,本研究以潮土烟田为研究对象,在冬季休闲期分别种植光叶紫花苕(Vicia villosa var.glabrescens)、小黑麦(×Triticale Wittmack)和油菜(Brassica napus),地上部分饲用,残茬还田,分析各处理间填闲作物及烤烟生物学产量、土壤CO_(2)和N_(2)O排放的差异。结果表明:(1)3种填闲作物处理烤烟总生物量和烟叶产量均显著高于对照,其中光叶紫花苕最高、油菜次之;(2)光叶紫花苕-烤烟、小黑麦-烤烟和油菜-烤烟土壤CO_(2)排放量分别略高于、显著高于和显著低于对照,土壤N_(2)O排放量均显著低于对照,其中油菜-烤烟差异最大;(3)烟田土壤CO_(2)的全球增温潜势远大于N_(2)O,光叶紫花苕、小黑麦和油菜处理土壤的全球增温潜势分别是对照的106.1%、116.2%和78.1%。综上所述,黄淮烟区潮土烟田油菜-烤烟种植模式既能提高烤烟收益又可降低烟田土壤的全球增温潜势,光叶紫花苕-烤烟在不显著提高烟田土壤全球增温潜势的同时可更大幅度提高烤烟收益,因此,可因地制宜发展油菜-烤烟或光叶紫花苕-烤烟等种植模式。

基于粮食安全视角的南方冬季耕地资源利用潜力空间布局及优化——以鄱阳湖平原为例

研究目的:基于新一轮千亿斤粮食产能提升行动的背景,分析冬季耕地资源利用现状,模拟其兼并作物类型和种植窗口的利用潜力空间布局,评估对区域粮食的增产效应,并探究空间优化方案。研究方法:EcoCrop模型、全球农业生态区划(GAEZ)模型、文献归纳法等。研究结果:(1)鄱阳湖平原近30年冬季作物种植面积比例平均为50%左右,以2007年为突变年份呈显著减小趋势。(2)冬季耕地资源对提高耕地利用效率和提升粮食产量均具有较大潜力。研究区97%耕地适合冬种,完全利用可实现约440万~490万t的产量提升,同时促使水稻增产约42.2万t。(3)冬种作物在不同种植窗口下的分布和产量均存在空间差异,可细化作物种植时空分异性的布局特征,实现协同高适宜性和高产量的空间优化。研究结论:本文提出的兼并作物类型和种植窗口的冬季耕地资源利用潜力空间布局和优化方案,对实际农业生产更具指导价值,可为区域耕地集约化管理和利用、种植结构优化和调整提供路径选择和决策建议。

Effects of Reduced Nitrogen Fertilization and Biochar Application on CO_2 and N_2O Emissions from a Summer Maize-Winter Wheat Rotation Field in North China

This experiment was conducted in Xinxiang, Henan from June 2013 to June 2014. Total four treatments were designed including farmers ’ common practice （F, 250 kg/hm^2）, 80% F （LF, 200 kg/hm^2）, 80% F＋biochar （LFC） and no fertilizer （CK） to measure the dynamic emissions of CO2 and N2O from a summer maize-winter wheat field by static chamber-gas chromatography method. The results showed that the soil CO2 emission was 21.8-1 022.7 mg/（m^2·h）, and was mainly influenced by soil temperature and moisture content. During the growth of summer maize, the soil CO2 emission was more significantly affected by soil moisture con-tent; and in winter wheat growing season, it was more significantly affected by soil temperature in the top 5 cm. The LF and LFC treatments significantly reduced the soil cumulative CO2 emission, especial y during the growth of winter wheat. Fertiliza-tion and irrigation were the main factors influencing the soil N2O emission. The soil N2O emission during the fertilization period accounted for 73.9%-74.5% and 40.5%-43.6% of the soil cumulative N2O emission during the summer maize-and winter wheat-growing season, respectively. The peak of emission fluxes was determined by fertilization amount, while the occurrence time of emission peak and emission re-duction effect were influenced by irrigation. The LF treatment reduced the soil cu-mulative N2O emission by 15.7%-16.8% and 18.1%-18.5% during the growth period of summer maize and winter wheat, respectively. Reduced nitrogen fertilization is an effective way for reducing N2O emission in intensive high-yielding farmland. Under a suitable nitrogen level （200 kg/hm^2）, the application of biochar showed no significant effect on the soil N2O emission in a short term. The N2O emission factors of the L and LF treatments were 0.60% and 0.56%, respectively. ln the intensive high-yield-ing farmland of North China, reducing the nitrogen application amount is an appro-priate measure to mitigate greenhouse gas emissions without crop yield loss.

湿地公园水稻田冬季水鸟分布及其栖息地特征

稻田是我国人工湿地的重要组成部分。为探究冬季稻田管理模式对湿地水鸟多样性保护及栖息生境改善的重要意义,2017年12月至2018年2月及2018年11月,采用样带法对天福国家湿地公园冬季休耕蓄水区和传统稻田的水鸟种群进行调查,对比水鸟种群及栖息地特征。结果表明:1)冬季休耕蓄水区记录4目7科25种水鸟,鸻鹬类占36%,鹭类占28%,雁鸭类占24%;传统稻田湿地共3目5科10种,其中鸻鹬类和鹭类分别占30%,无雁鸭类水鸟。2)冬季蓄水区水鸟多样性及物种丰富度较高,水鸟优势种群数量明显增多,Shannon-Wiener多样性指数(1.64)高于传统稻田(1.50),水鸟均匀度指数(0.84)低于传统稻田(1.37),相似性系数为0.51。3)冬季休耕蓄水区的水面面积、水位、食物、植被覆盖度是影响水鸟种数增多的重要因子,营巢地、停歇点也是影响冬季水鸟栖息的因素。因此,冬季稻田休耕蓄水管理的实施能够对生物多样性保护与提升发挥积极作用。

冬闲盐碱地绿肥种植对淡水淋盐土壤及淋溶液碳氮影响

为探讨绿肥种植对盐碱地淡水淋盐下土壤及淋溶液碳氮含量的影响,于2021年10月至2022年5月设置冬闲(T1)、冬牧70黑麦(T2)和油菜(T3)3个处理进行大田试验,测定土壤及淋溶液有机碳(SOC)、硝态氮(NO_(3)^(-)-N)、铵态氮(NH_(4)^(+)-N)空间分布情况。结果表明,T1、T2、T3处理0~30 cm土层中土壤有机碳分别由淋盐前的6.20,6.58,7.24 g/kg增加到淋盐后的6.48,7.39,8.06 g/kg,增幅分别为4.41%,12.20%,11.23%。淋盐前后0~60 cm土层中T1处理土壤硝态氮含量显著高于T2和T3,淡水淋盐后,0~30 cm土层各处理分别降低42.42%,3.85%,10.84%;60~90 cm土层中减少了1.38%,7.96%,18.11%。淋盐前各土层土壤铵态氮含量不同处理之间无显著差异,淋盐后各土层土壤铵态氮含量均以T2含量最高。综上,淋盐灌溉后,相较于淋盐前各处理不同土层土壤有机碳均呈增加趋势,而土壤氮素则呈明显降低趋势,通过对土壤及淋溶液氮素含量分析发现,淋盐灌溉造成的氮素淋失主要以硝态氮为主。相较于冬闲田,种植油菜绿肥对土壤氮素提高有明显效果,而种植冬牧70绿肥对减少土壤氮素淋失具有最佳效果。

绿肥油菜栽培技术

种植绿肥油菜,不仅可以稳定并扩大绿肥种植面积,提高冬闲田的利用率,也有利于改良土壤、减少病虫害、提升后茬作物产量和品质。本文从绿肥油菜的种植优势、栽培要点及推广应用成效方面总结了绿肥油菜栽培技术,经过两年实践,初步形成了适应当地气候条件的“适宜品种+配套技术+冬闲茬口”土壤有机质提升方案,并进行大面积推广。研究成果为绿肥油菜种植提供参考。

南方双季稻区冬闲期绿肥对田间养分固持和减排的影响

【目的】探究南方双季稻区冬闲期不同绿肥品种混播对稻田氮磷钾养分固持减排效果,为有效降低冬闲期稻田中养分的流失,改善农业生态环境提供参考依据。【方法】2019—2020年,采用田间小区试验,设计紫云英、油菜、黑麦草和肥田萝卜等常见绿肥单播或混播8个绿肥处理,以自然生草为对照处理,监测双季稻区冬闲期间水体氮磷钾养分流失量,测定绿肥总生物量和植株体中总碳氮磷钾含量以及土壤中养分含量。【结果】冬闲期种植绿肥的处理中稻田氮磷钾养分固持和减排效果明显优于对照处理,种植绿肥处理水体中总氮、总磷和总钾流失量较对照处理降幅分别为27.7%~47.6%、14.3%~65.5%和9.8%~93.6%,其中种植黑麦草的处理中总氮磷钾流失量显著低于其他处理(P<0.05,下同);种植绿肥处理的植株总生物量较对照处理增加46.9%~378.7%,植株体中总碳、总氮、总磷和总钾含量较对照处理分别增加67.9%~377.1%、55.4%~2613.6%、68.0%~557.8%和100.0%~664.5%,其中种植紫云英的处理中总碳氮磷钾含量显著高于其他处理;相比对照处理,冬闲期种植绿肥处理中土壤活性有机质含量、缓效钾含量和阳离子交换量分别增加21.3%~29.8%、1.6%~5.7%和1.3%~8.2%,土壤有效磷和速效钾含量分别降低2.3%~17.0%和3.7%~30.1%。【结论】南方双季稻区冬闲期种植绿肥对田间养分固持减排效果显著,其中紫云英和黑麦草混播(紫云英∶黑麦草=4∶6)处理对降低水体总磷钾流失量、提高植株体中总碳磷钾固持量的效果最佳。

长期不同施肥对黄壤单季稻冬闲田春季杂草群落的影响

为探讨长期不同施肥模式下杂草群落变化及其与土壤养分相关性,依托一项连续24年长期施肥试验,采用田间调查法,对不平衡施肥[氮磷肥(NP)、磷钾肥(PK)、氮钾肥(NK)]、常量化肥(NPK)、单施有机肥(M)、1/2有机肥替代化肥(1/2MNP)、不施肥(CK)模式下黄壤单季稻冬闲田春季杂草群落变化及其与土壤养分相关性进行研究。结果表明,长期不同施肥模式下春季杂草密度、生物量、群落多样性等均发生变化。M处理下土壤养分均较高,杂草群落总密度1208.44株·m^(-2)、总生物量1071.24 g·m^(-2),均为最高,与CK处理相比,春季杂草总密度增加37.74%、总生物量增加179.58%,说明单施有机肥可提升土壤养分,促进春季杂草生长。不同处理对杂草群落影响存在差异:M处理下棒头草(Polypogon fugax)等未发生;长期施用无机化肥处理早熟禾(Poa annua)发生密度(0~4.89株·m^(-2))较低;缺磷处理下日本看麦娘(Alopecurus japonicus)发生密度(36.00株·m^(-2))最低。同时,缺氮导致杂草群落多样性指数增加、优势度指数降低,群落结构相对复杂;缺磷则反之。研究表明,全氮、碱解氮和全磷是影响杂草密度的关键因子,生产上可通过合理施肥控制田间杂草发生,稳定土壤肥力及物种多样性,促进农业生态系统发挥出最大生态效应。

南方冬闲田绿肥鲜食两用蚕豆产业发展策略及建议

绿肥鲜食两用蚕豆作为粮、饲、菜、肥兼用的经济作物,是随着农业产业结构调整及农业供给侧结构性改革而产生的产业新类型。充分利用冬闲田种植绿肥鲜食两用蚕豆,不仅可以解决冬闲田闲置而造成的土地浪费问题,还能促进农民增收和农业可持续发展,符合现代农业的发展要求。研究从冬闲田的利用现状、绿肥鲜食两用蚕豆种植模式及效益、两用蚕豆发展需求3个方面梳理冬闲田形成的原因,思考进一步利用绿肥鲜食两用蚕豆在冬闲田周年种植的模式。提出建议:筛选适宜于南方种植的品种,研发配套适宜于南方的栽培技术和绿色标准化生产技术,优化周年高效种植模式和构建种养循环新模式,创新优化冷链物流技术和速冻加工技术,探索鲜食蚕豆修复重金属污染效果。为解决南方冬闲田大量闲置的问题及绿肥鲜食两用蚕豆的进一步推广应用提供参考。

乌蒙山冷凉山区饲用燕麦农艺性状与营养品质评价

为高效利用乌蒙山区丰富的冬闲田资源,对17份饲用燕麦(Avena sativa L.)开展了农艺性状与营养成分的比较试验。结果显示,平均生育期为194~226 d,出苗-拔节期时长超过生育期50%;农艺性状变异系数多数高于10%,产量(28.42%)和有效分蘖(30.52%)最高。不同品种粗蛋白(Crude protein,CP)和酸性洗涤纤维(Acid detergent fiber,ADF)含量差异显著(P<0.05),分别为8.33%~10.13%和25.32%~30.15%;中性洗涤纤维(Neurtral detergent fiber,NDF)含量为50.51%~57.58%,品种差异不显著;相对饲喂价值(Relative feed value,RFV)为106.57~133.83,品种间差异显著(P<0.05)。‘永久444’ADF含量显著高于其他品种(P<0.05),爱沃RFV显著高于其他品种(P<0.05);各指标间存在密切相关关系,穗粒数与产量正相关(P<0.05),生育期与CP正相关(P<0.05);铃铛数、NDF、有效分蘖、CP、产量、茎粗可作为优良品种鉴定主要参考指标。综合显示,‘伽利略’、‘黄燕麦’表现最好,推荐为当地主推品种。

西南山区冬闲田功能型燕麦品种潜力挖掘评价

为筛选出适宜西南山区冬闲田推广种植的功能型燕麦品种,本研究选取15份燕麦品种针对燕麦蛋白质、脂肪、淀粉、葡聚糖和氨基酸含量5个营养品质开展系统分析,采用灰色关联度分析法和聚类分析法进行综合评价,研究结果与联合国粮食及农业组织/世界卫生组织(FAO/WHO)等相关指标对比分析,深挖适用于不同功能型燕麦加工产品的品种资源潜力。结果表明:15个燕麦品种当中定莜5号的综合营养价值表现最好,较适宜大面积推广种植。定莜4号的蛋白质含量最高(170.2 g·kg^(-1)),可作为燕麦乳、能量棒等高蛋白燕麦加工食品的原材料;定莜1号脂肪含量最高(64.8 g·kg^(-1)),可作为燕麦片、燕麦饼干等高饱腹食品的加工原料,满足减肥人群的饮食需求;定莜10号淀粉含量最低(388.1 g·kg^(-1)),可作为燕麦米、燕麦片等低血糖生成指数(GI)的燕麦加工食品的原料,满足消费者对于低GI食品的需求;香燕13号β-葡聚糖含量最高(4.33%),可作为保健品等保健型食品的加工原料,满足中老年人对于功能型食品的需求。与FAO/WHO中蛋白的必需氨基酸含量、全鸡蛋蛋白相比,研究品种中定莜5号必需氨基酸含量为67.04 g·kg^(-1),相对FAO/WHO提高幅度为72.7%,综合表现占据了非常大的优势,利用冬闲田种植燕麦,营养品质优良,市场应用前景非常广泛。研究结果对未来西南山区冬闲田资源的有效利用与燕麦加工行业的功能型品种选育及燕麦产品的生产制造提供重要的理论依据与数据支撑。

南疆休作期棉田墒情调控及播种前适宜灌水阈值研究

针对南疆冬季休作期棉田无雪层覆盖及农用水资源匮乏现象,当地多选择冬春灌调控棉田的播前墒情,已有研究表明在休作期春灌滴灌对盐分的淋洗和墒情调控情况较好。对比研究冬灌漫灌、不同灌溉定额冬灌滴灌及冬灌滴灌+干播湿出3种调控措施灌水前后水盐的特征变化,探寻不同墒情调控措施对棉田播前土壤墒情的影响以及在播种前后找出适宜的灌水阈值,为后期实施干播技术提供墒情保障。对比其他调控措施,高定额冬灌滴灌的调控措施播前40~60cm土层墒情较为稳定且土壤水分分布更均匀;在用水量较少的状况下,播后测得冬灌滴灌+干播湿出措施中灌溉定额为(600+225)m^(3)/hm^(2)与灌溉定额为1200m^(3)/hm^(2)的冬灌滴灌措施的土壤含水率差异性不大且前者平均含水率要稍高;冬灌滴灌+干播湿出措施中灌溉定额为(1200+225)m^(3)/hm^(2)的土壤含水率对比冬灌漫灌措施更平稳均衡。冬灌调控后土壤平均含盐量明显减低,冬灌滴灌灌溉定额越高盐分淋洗越彻底。冬灌滴灌+干播湿出的调控措施与冬灌滴灌措施对比,0~40cm土层的平均含盐量差异显著,且各土层波动不大,对比其他措施淋洗和压制土壤盐分效果较好。综上冬灌滴灌+干播湿出调控措施在节水的基础上各土层平均含水率较高,其土壤盐分和水分环境更适宜棉花萌芽,进而影响到棉花的保苗以及后续生长。

施用冬闲杂草对免耕水稻产量及生长特性的影响

以Y两优1号为材料,在湖南省浏阳市永安镇坪头村开展大田试验,研究不同施氮量(N0,0 kg/hm^(2);N150,150 kg/hm^(2);N225,225 kg/hm^(2))下施用冬闲杂草(折合干物质量W0,0 kg/hm^(2);W1,5000 kg/hm^(2))对免耕水稻产量及生长生理特性的影响。结果表明,N0和N150水平下,与未施用冬闲杂草处理(W0)相比,施用冬闲杂草(W1)分别提高水稻产量28.8%和4.2%,增产的原因是有效穗数、每穗粒数、总颖花量和千粒重提高;N225水平下,W1处理降低水稻产量5.9%。N0和N150水平下,与W0处理相比,W1处理大幅度提高免耕水稻后期叶面积指数、干物质积累量、辐射利用率、净光合速率和SPAD值的同时,还提升了水稻叶茎鞘转运能力和收获指数;N225水平下,W1处理显著增加水稻的无效分蘖,降低成穗率,同时叶茎鞘转运能力降低,最终降低了水稻的每穗粒数、总颖花量和结实率。综上,在低氮(0~150 kg/hm^(2))水平下,施用冬闲杂草有利于提高免耕水稻产量,在高氮(225 kg/hm^(2))水平下,施用冬闲杂草反而会降低产量。