Selection of Greenhouse Zucchini Varieties and High-Quality,High-Yield and High-Efficiency Cultivation Techniques

[Objectives]To select zucchini varieties suitable for cultivation in Zibo City and test its high-yield cultivation techniques.[Methods]Six zucchini varieties were introduced,and their commercial quality and yield were determined.[Results]The yield of Shengfeier,Xiuyu 170 and Xihulu 309 increased by 11.4%,6.9%and 4.6%,respectively compared with S68(control),and zucchini was straight,looked pleasing to the eye,and had strong disease resistance.[Conclusions]The zucchini varieties were selected and the high-quality,high-yield and high-efficiency cultivation techniques were integrated.

Deciphering the morpho–physiological traits for high yield potential in nitrogen efficient varieties(NEVs):A japonica rice case study

The use of nitrogen(N)-efficient rice(Oryza sativa L.) varieties could reduce excessive N input without sacrificing yields. However, the plant traits associated with N-efficient rice varieties have not been fully defined or comprehensively explored. Here, three japonica N-efficient varieties(NEVs) and three japonica N-inefficient varieties(NIVs) of rice were grown in a paddy field under N omission(0 N, 0 kg N ha^(-1)) and normal N(NN, 180 or 200 kg N ha^(-1)) treatments. Results showed that NEVs exhibited higher grain yield and nitrogen use efficiency(NUE) than NIVs under both treatments, due to improved sink size and filled-grains percentage in the former which had higher root oxidation activity and greater root dry weight, root length and root diameter at panicle initiation(PI), as well as higher spikelet-leaf ratio and more productive tillers during the grain-filling stage. Compared with NIVs, NEVs also exhibited enhanced N translocation and dry matter accumulation after heading and improved flag leaf morpho-physiological traits, including greater leaf thickness and specific leaf weight and higher contents of ribulose^(-1),5-bisphosphate carboxylase/oxygenase, chlorophyll, nitrogen, and soluble sugars, leading to better photosynthetic performance. Additionally, NEVs had a better canopy structure, as reflected by a higher ratio of the extinction coefficient for effective leaf N to the light extinction coefficient, leading to enhanced canopy photosynthesis and dry matter accumulation. These improved agronomic and physiological traits were positively and significantly correlated with grain yield and internal NUE, which could be used to select and breed N-efficient rice varieties.

Effect of nitrogen fertilizer on the uptake and utilization of potassium by various rice varieties in purple soil

Nitrogen and potassium are important nutrientelements for rice.Besides supplied by the or- ganic manure,potassium nutrition of ricecomes dominantly from purple soils in Sichuanbasin.Potassium exists abundantly in mineralforms in the purple soils.Availability of soilpotassium for crop depends on the potassiumforms,the uptake ability of crops,and fertiliz-er practices.A pot culture experiment wasconducted to study the kinetics of potassiumuptake in the purple soil(total N 22.64g·kg,total K 24.36g·kg,available N 102.6mg·kg,available K 140.6mg·kg,acidsoluble K 936.0mg·kg,and pH 6.8).Ma-terials used were three Fhybrid rices,Eryou

Comparison of yield performance between direct-seeded and transplanted double-season rice using ultrashort-duration varieties in central China

Labor scarcity requires double-season rice to be planted by direct seeding as an alternative to transplanting. Only ultrashort-duration varieties can be used in direct-seeded, double-season rice(DSD) in central China where thermal time is limited. Whether ultrashort-duration varieties grown in DSD can be as productive and efficient in nitrogen(N) use as transplanted double-season rice(TPD) remains unclear. Field experiments were conducted in Hubei province, central China with two establishment methods(DSD,TPD) and three N rates in the early and late seasons of 2017 and 2018. Nitrogen treatments included zero-N control(N0), total N rate of 60 kg N ha;with equal splits at basal, midtillering, and panicle initiation(N1), and weekly N application at 15 kg ha;from seeding/transplanting to heading(N2). Both early-and late-season rice under DSD matured within 95 days, on average 9 days shorter than rice under TPD. The grain yield of DSD was comparable to or higher than that of TDP in both seasons, although the daily yield was significantly higher under DSD than under TDP. Before heading, DSD had higher leaf area,stem number, intercepted radiation, and radiation use efficiency than TPD, which compensated for the negative effect of short growth duration on biomass production. Total dry weight and harvest index under DSD were comparable to or higher than those under TDP. In general, the recovery efficiency of fertilizer-N under DSD was higher than that under TPD, but the reverse was true for physiological N use efficiency. Thus, there was no significant difference in agronomic N use efficiency between DSD and TPD. These results suggested that DSD with ultrashort-duration varieties is a promising alternative to TPD in central China for maintaining high grain yield and N fertilizer use efficiency with less labor input.

Effect of Paclobutrazol plus Ethephon Treatment on Endogenous Hormones and Carbon and Nitrogen Nutrients in Litchi Variety ‘Feizixiao'

[Objective] This study aimed to investigate the effect of spraying the mixture of paclobutrazol and ethephon on the endogenous hormones and carbon and nitrogen nutrients in litchi variety ＇Feizixiao＇.[Method] [Result] The results showed that foliar spraying of the mixture of paclobutrazol and ethephon could effectively inhibit litchi variety ＇Feizixiao＇ to produce winter shoots,promote the flower bud differentiation and improve flower formation rate; meanwhile,this treatment could also increase the contents of ABA and ZR,and the ratios of ABA/IAA,ABA/GA3,ZR/IAA,ZR/GA3,and decrease the contents of IAA and GA3; additionally,it could increase the contents of soluble sugar,starch and total nitrogen,and raise C/N ratio,thus improving the flower formation rate.[Conclusion] Foliar spraying of the mixture of paclobutrazol and ethephon is an effective pathway for solving warmth damage to litchi.

Varietal Difference in Leaf Nitrogen Content and Leaf Area and Their Effects to Ripening Rate During Mature Period of japonica Rice

Employing the pot experiment of the complete random block design with 6 replications,four varieties of japonica rice (Fujisaka 5,Honenwase,Akitakomachi and Taichung 65) were used to study the varietal differences in leaf nitrogen content(LNC) and leaf area during mature period,their relation and effects to the ripening rate.The results showed that(1) thee were varietal differences in LNC at the heading stage and the LNC decrease rate during the matue period,the high LNC at the heading stage was related to the rapid LNC decrease.(2) There were two phases of the leaf area changing process during the mature period,first was the stable,and second was the decreased phase.There was varietal difference in the critical time of phase 1 and phase 2.The hign leaf area in the phase 1 was in relation to the rapid leaf area decrease in the phase 2.It was not found that there was relation between the leaf quality and quantity.(3)It wa unfavorable to the ripening rate for the high leaf area at the heading stage and the rapid decrease of the leaf area during the mature period.(4)It was put forward that the super high yield rice variety should possess the not very high leaf area and high LNC at the heading stage,slow senescence in the leaf area during the mature period.

Differing responses of root morphology and physiology to nitrogen application rates and their relationships with grain yield in rice

Root morphology and physiology influence aboveground growth and yield formation in rice.However,root morphological and physiological differences among rice varieties with differing nitrogen(N)sensitivities and their relationship with grain yield are still unclear.In this study,rice varieties differing in N sensitivity over many years of experiments were used.A field experiment with multiple N rates(0,90,180,270,and 360 kg ha^(-1))was conducted to elucidate the effects of N application on root morphology,root physiology,and grain yield.A pot experiment with root excision and exogenous application of 6-benzyladenine(6-BA)at heading stage was used to further verify the above effects.The findings revealed that(1)under the same N application rate,N-insensitive varieties(NIV)had relatively large root biomass(root dry weight,length,and number).Grain yield was associated with root biomass in NIV.The oxidation activity and zeatin(Z)+zeatin riboside(ZR)contents in roots obviously and positively correlated with grain yield in N-sensitive varieties(NSV),and accounted for its higher grain yield than that of NIV at lower N application rates(90 and 180 kg ha^(-1)).(2)The root dry weight required for equal grain yield of NIV was greater than that of NSV.Excision of 1/10 and 1/8 of roots at heading stage had no discernible effect on the yield of Liangyoupeijiu(NIV),and it significantly reduced yield by 11.5%and 21.3%in Tianyouhuazhan(NSV),respectively,compared to the treatment without root excision.The decrease of filled kernels and grain weight after root excision was the primary cause for the yield reduction.Root excision and exogenous 6-BA application after root excision had little influence on the root activity of NIV.The oxidation activity and Z+ZR contents in roots of NSV decreased under root excision,and the increase in the proportion of excised roots aggravated these effects.The application of exogenous 6-BA increased the root activity of NSV and increased filled kernels and grain weight,thereby reducing yield loss after root excision.Thus,the root biomass of NIV was large,and there may be a phenomenon of"root growth redundancy."Vigorous root activity was an essential feature of NSV.Selecting rice varieties with high root activity or increasing root activity by cultivation measures could lead to higher grain yield under lower N application rates.

Growth, Yield and Nitrogen Use Efficiency of New Rice Variety under Variable Nitrogen Rates

Globally, the current important concern is to minimize nitrogen use in crop culture under climate change condition. The experiment was conducted at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh during the rainy season of 2014 to assess growth, yield and nitrogen use efficiency of a new rice variety. The new rice variety (BUdhan 1) was treated with six levels of nitrogenous fertilizer in a randomized complete block design replicated three times. The nitrogen levels 0, 20, 40, 60, 80 and 100 kg N ha-1 constituted the treatment variables. Results revealed that growth of the new rice variety favored at higher levels of applied nitrogen although it flattened at 80 and 100 kg N -1. Preanthesis assimilates reserves contributed to sustaining the yield of the variety which indicated that current photosynthesis was insufficient to support the present yield level. The assimilate remobilization varied from 109.21 to 232.93 g·m-2 between the nitrogen levels where the maximum amount of remobilization was observed at 60 kg N -1. The highest grain yield (5.36 t·-1) was found when the variety was fertilized with 60 kg N -1. Application of 60 kg N -1 also showed the highest nitrogen use efficiency (344.50 kg grain/kg N applied) of the variety. We concluded that application of the intermediate level of nitrogen was economical and environment-friendly for the cultivation of new rice variety.

Effect of Increased Nitrogen Application Rates and Environment on Protein, Oil, Fatty Acids, and Minerals in Sesame (<i>Sesamum indicum</i>) Seed Grown under Mississippi Delta Conditions

Information on the effect of nitrogen fertilizer rates and environment on sesame seed composition and nutrition is scarce. The objective of this research was to investigate the effects of nitrogen fertilizer application rates on sesame seed yield, protein, oil, fatty acids, and mineral nutrition. A two-year (2014, 2015) field experiment was conducted. Nitrogen fertilizer (urea ammonium nitrate) solution (UAN, 32% N) was applied by side dressing to four sesame varieties (S-34, S-35, S-38, S-39) at rates of 44.7, 67.2, 89.6 and 112.0 kg·ha-1. Rate of 44.7 kg·ha-1 was used as control since this rate is traditionally recommended in the region. Increasing nitrogen application rates resulted in higher protein and oleic acid contents in two varieties in 2014, and in all varieties in 2015. Increased protein and oleic acid were accompanied by lower total oil and linoleic acid. Increased nitrogen application also resulted in higher seed N, S, B, Cu, Fe, and Zn in 2014 in S-34 and S-35, but either a decline or no clear change was observed in seed levels of these nutrients in S-38 and S-39. In 2015, increased nitrogen application resulted in significantly higher seed N in all varieties, and higher S, B, Cu, Fe, and Zn in some varieties. A significant positive correlation was observed between nitrogen application rate and yield, and with seed levels of protein, oleic, acid, N, B, Cu, Fe, and Zn. A significant negative correlation was observed between nitrogen application rate and seed oil and linoleic acid. Thus, increased nitrogen fertilizer application resulted in higher seed protein, oleic acid, and some mineral nutrients, but lower oil and linoleic acid. However, this effect depended on variety and environmental conditions. Because higher protein and oleic acid are desirable traits for sesame seed nutritional value and oil stability, regional breeders should select sesame varieties for efficient fertilizer response.

Influence of Nitrogen-Potassium Fertilizers on the Growth and the Productivity Parameters of Plantain Banana PITA 3, FHIA 21 and CORNE 1

This study was undertaken to measure the impact of fertilizers (nitrogen-potassium) on the growth and the development of plantain banana. Different doses of fertilizers (T2, T3, T4, T5 and T6) were applied to two hybrid varieties (PITA 3 and FHIA 21) and a traditional variety (CORNE 1) on an experimental split plot plan with a planting density of 2500 plants per hectare. Results showed that fertilizers improve parameters of plantain than control (T1). T6 with high potassium content (240 kg·ha−1 N and 987 kg·ha−1 K) improved the growth (35.72 ± 0.95 cm·month−1) and the widening (9.56 ± 0.17 cm·month−1) of PITA 3, and performed FHIA 21 agronomic parameters by reducing the length of the production cycle and increased the length of fruits. T2 treatment improved FHIA 21 agronomic and yield parameters. Also, the weight of CORNE 1 regimens (9.00 ± 0.67 kg) and fruits (296.59 ± 4.50 g), the length (33.37 ± 0.31 cm) and the circumference (14.73 ± 0.31 cm) increased with T2. T4 induced shorter production cycle of PITA 3 (390.40 ± 0.67 cm·month−1), improved PITA3 regimens weight (10.33 ± 0.44 kg) and the number of hands by regimen (6.00 ± 0.00) of FHIA 21. T3 with weak nitrogen content (120 kg·ha−1 N and 658 kg·ha−1 K) improved the characteristics of PITA 3 fruits notably, the weight (176.09 ± 2.96 g) and the circumference (13.87 ± 0.89 cm). T5 (240 kg·ha−1 N and 329 kg·ha−1 K) performed CORNE 1 trees number of sheets (3.85 ± 0.16). CORNE 1 cycle production with T6 treatment was 137.80 days longer than those of T2 treatment (483 ± 3.50 days). In conclusion, with T2 and T6, growth parameters were globally improved in FHIA 21 by the regimen largest and the higher number of fingers, and productivity parameters were improved in CORNE 1 by the heaviest, the longest and the thickest of the fruits.

Nitrogen Metabolism and Curing Characteristics of Flue-cured Tobacco Variety NC71

[Objectives]To explore the growth characteristics,nitrogen metabolism and curing characteristics of the new variety NC71 in strongly aromatic tobacco leaves production area.[Methods]With Yunyan 87 as the control and NC71 as the experimental material,the experiment was carried out in Nanyang tobacco area for two consecutive years to study the growth characteristics of tobacco plants,the activity of key enzymes in nitrogen metabolism,the content of secondary metabolites,and the differences of tobacco-related water content,PPO enzyme activity and total phenol content.[Results]NC71 plants had lower height,better appearance quality and lower nicotine,total sugar and chlorine content.NC71 high nitrogen treatment and Yunyan 87 medium nitrogen treatment had similar key enzyme activity of nitrogen metabolism,content of secondary metabolites;Yunyan 87 and NC71 were easy to cure and resistant to curing.[Conclusions]This study provides a reference for measuring the appropriate nitrogen application rate and optimizing the curing process from the activities of the key enzymes NR and GS in nitrogen metabolism at the mature stage of the variety.

施氮水平对不同切花菊品种生长及氮素累积和分配的影响

[目的]针对当前菊花生产中氮肥使用过量、氮效率低下和不同氮素营养特性菊花品种氮素吸收及分配规律不明等问题,本文研究不同施氮水平对不同切花菊生长、氮效率及氮素累积和分配的影响,以明确不同切花菊品种对氮素吸收利用特性,为切花菊的高效生产提供理论依据。[方法]以9个不同家系的切花菊品种为材料,测定了高氮(每株800 mg)、正常氮(每株400 mg)和低氮水平(每株50 mg)下,9个切花菊品种全生育期生长指标、氮效率指标和各部位氮素累积量。[结果]9个切花菊品种的株高、茎粗、叶干重、茎干重、根干重、总根长、一级分枝数、着花数等生长指标和根氮累积量、叶氮累积量、植株氮累积量等氮累积量指标均随氮水平的增加而增加,氮效率指标随氮水平的增加而降低;正常氮水平下,9个菊花品种的花干重、冠幅、花径和花氮累积量最高,花期最早。不同氮水平下,‘南农丽黄’在茎粗、各部位生物量、平均根直径、根体积、冠幅、花径、氮吸收效率、农艺氮效率、植株氮累积量和花氮累积量指标上显著高于其他品种(P<0.05);‘南农雪峰’和‘南农紫峰’的株高、茎粗、各部位生物量、冠幅、花径、氮吸收效率、农艺氮效率和植株氮累积量较其他品种低。苗期和生殖生长期间,9个菊花品种植株中叶氮累积量最高,茎次之,根最低;盛花期时,植株中叶和茎氮累积量比例显著下降,花器官的氮累积量显著高于其他器官。不同氮水平下,9个菊花品种的植株氮累积量与花干重、冠幅、花径、一级分枝数、着花数、花期呈显著正相关(0.39≤r≤0.83),花氮累积量与花干重、花期呈显著正相关(0.53≤r≤0.89)。[结论]高氮水平促进了菊花的营养生长,抑制了菊花的氮效率和品质形成,菊花的全生育期生长规律和氮素累积分配规律一致,植株氮累积量和花氮累积量对菊花开花品质的形成具关键作用。

江苏粳稻育成品种氮响应相关性状位点分析

【目的】江苏省是水稻氮肥施用量较高的区域,且水稻品种选育历史悠久,种质来源广泛;为了鉴定江苏水稻品种的氮响应相关性状以及氮响应相关基因,筛选氮高效品系,最终降低氮肥用量。【方法】利用76份不同地区、不同选育时间育成的江苏粳稻品种为试验材料,利用GATK4等软件获取群体变异信息,并用Admixture软件分析群体结构,以三个不同氮肥处理水平,调查成熟期氮响应相关性状并分析氮响应相关位点。【结果】筛选到了华粳5号和宁粳5号等氮钝感品种;利用关联分析,发现了已知或已报道的氮相关基因(OsAMT1.2,OsNRT2.4和Fd-GOGAT1等)邻近位点;进一步分析了位点的优异变异和携带优异位点的品种。【结论】鉴定了江苏育成粳稻品种的氮响应差异和携带的优异位点,可为选育不同氮响应品种提供参考。

黄淮北部不同冬小麦品种(系)产量和氮素利用效率差异

为了研究黄淮北部不同冬小麦品种(系)类型的产量与氮素利用、转运和积累的差异,在2021—2022年,2022—2023年分别对黄淮北部麦区29,26个供试冬小麦品种(系)的产量性状和氮素利用效率进行了调查和分析。通过聚类分析,将小麦分成高产型、中高产型、中产型和低产型4种类型。分别在开花期和成熟期对小麦的茎、叶、穗和籽粒(成熟期)进行氮含量测定,分析氮素利用特性相关参数与产量之间的关系。结果表明,2021—2023年高产型、中高产型、中产型和低产型品种(系)间的平均产量差异显著,其中,高产型品种的公顷穗数显著高于其他3种类型。在开花期,各器官的氮积累量和分配率大小表现为茎鞘>叶片>穗;在成熟期,各器官的氮积累量大小表现为籽粒>茎鞘>穗>叶片。不同品种小麦花后氮素积累量、花前氮素转运量及其对籽粒的贡献率均以高产型品种(系)较高,且花前氮素转运量及其对籽粒的贡献率大于花后氮素积累量及其对籽粒的贡献率。氮素利用效率、氮素收获指数、开花期氮素积累量和成熟期氮素积累量与小麦籽粒产量呈显著正相关。因此,可通过不同品种的氮素吸收转运规律及分配特点进行水肥管理,或者选育氮素利用效率高的小麦品种,以实现小麦高产、高效生产。

氮锌配施对不同锌效率玉米品种植株矿质元素累积、分配的影响

以锌高效玉米品种郑单958和锌不敏感品种隆平638为试验材料,设置90 kg/hm^(2)(LN)、180kg/hm^(2)(MN)、225 kg/hm^(2)(HN)3个施氮量和不喷施锌肥(F0)、拔节期和大口期1∶1喷锌4.5 kg/hm^(2)(F1)2个喷锌处理,分析氮锌配施对不同锌效率玉米品种植株矿质元素含量、累积量、分配和籽粒产量的影响,为玉米生产上氮锌合理配施提供依据。结果表明,玉米籽粒中铜、锌含量以MN处理最高,分别为1.82、16.23 mg/kg。F1处理能够提高籽粒中氮、锌含量和锌有效性。植株中氮、磷、钾累积量以MNF1处理隆平638最高,籽粒中铜和锌、锰和铁累积量分别以LNF1、HNF1处理郑单958最高。籽粒中氮、磷、铜的占比以隆平638 HNF1处理最高,籽粒中锌占比以郑单958 HNF0和LNF0处理较高。HN处理籽粒产量最高,平均为10.31 t/hm^(2),其次是MN处理,LN处理最低。2个品种籽粒磷含量与锰含量均呈极显著正相关,隆平638籽粒钾含量与铁、锌含量均呈显著正相关,与铜含量呈显著负相关。总体来看,施氮量180 kg/hm^(2)配合拔节期和大口期1∶1叶面喷施锌肥能够提高玉米籽粒中锌生物有效性和矿质元素累积量,促进玉米籽粒产量和矿质元素营养同步提高,可在大田中进行推广应用。

增温及其应对措施对小麦光合特性和酶活性的影响

于2022—2023年小麦生长季在南京信息工程大学农业气象试验站进行大田试验,以当地常规耕种方式为对照(CK),设置3种应对增温措施,分别为选择耐高温品种(CV,‘淮麦33’)、添加生物炭(BC,20 t·hm^(-2))、增施氮肥(NF,总施氮量增加50 kg·hm^(-2)),采用开放式增温系统将小麦整个生育期的气温提高1.5℃,测定不同措施下小麦旗叶叶面积、叶绿素含量、光合、酶活性的变化以及植株的生物量和产量。结果表明,全生育期增温使冬小麦旗叶丙二醛(MDA)含量升高、过氧化物酶(POD)和过氧化氢酶(CAT)活性增强,但增温对小麦旗叶叶面积、SPAD值、光合特性、超氧化物歧化酶(SOD)活性的影响存在生育期差异。增温条件下,添加生物炭和增施氮肥处理孕穗期小麦MDA含量、POD活性、CAT活性分别降低12.50%和21.22%、15.65%和12.91%、19.75%和14.33%,SOD活性分别升高455.75%和395.58%;开花期小麦SOD活性分别下降9.89%和31.89%,CAT活性分别升高20.94%和17.12%,最终产量分别显著增加50.29%和23.45%。改变品种处理的小麦旗叶叶面积、SPAD值、净光合速率和产量无显著变化。因此,应对未来可能的增温环境,添加生物炭和增施氮肥可能是较为有效的措施。

新疆冬小麦耐低氮品种筛选与评价

【目的】探索建立新疆冬小麦氮素品种筛选评价指标,在生产上筛选推荐耐低氮品种,为新疆冬小麦耐低氮品种选育提供方法和材料依据。【方法】于2018~2019年度分别对新疆成功培育的21份冬小麦品种应用“饿氮法”进行耐低氮种质筛选,并应用隶属函数、主成分分析以及聚类分析等方法,对参试冬小麦品种耐低氮程度进行了评估。【结果】两年度连续测试结果表明,在不施氮肥和正常施氮的对比下,株高、蛋白含量均得到不同程度影响,其中蛋白含量敏感度为最高;主成分分析提出3个主要成分,平均贡献率依次为39.63%、19.22%、18.21%,累积贡献率达到了77.06%。【结论】低氮胁迫对冬小麦的产量与相关性状有较大影响,并根据冬小麦种质资源间耐氮程度的不同,结合以上分析方法,能准确评估新疆冬小麦种质资源耐低氮情况。

华北寒旱区马铃薯的氮效率评价及筛选

为筛选氮高效马铃薯品种,提高冀西北地区氮肥利用效率,本试验以15个马铃薯品种为供试材料,设置大田条件下不施氮与施氮两种处理,从马铃薯块茎产量、氮浓度、氮吸收量、氮生物学效率、氮肥农学效率、氮肥偏生产力、氮肥表观利用率等方面进行氮效率评价;并采用隶属函数对各马铃薯品种进行综合氮效率评价及筛选。结果表明,品种与施氮水平均会影响马铃薯产量,在不施氮处理下大西洋的产量最高,干重为10645.70 kg/667 m^(2);施氮处理下丽薯产量的增幅最大,为23.38%。15个马铃薯品种在施氮肥产量、氮吸收量、氮肥农学效率、氮肥偏生产力及氮肥表观利用率等氮效率性状评价下存在宽幅变异,变异系数为7%~64%。施氮与不施氮条件下,马铃薯氮浓度与产量均无显著相关关系,氮肥表观利用率与氮肥农学效率呈显著正相关。隶属函数分析表明,马铃薯品种大西洋、冀张薯8号、北方002、丽薯的综合氮效率较高,可利用于生产或氮高效种质资源。

甜菜品种间氮效率差异及其对产质量的影响

【目的】研究不同类型甜菜品种氮素吸收利用差异及其与产质量的关系,以期为生产上氮肥精准施用奠定基础。【方法】采用大田试验方法,以丰产型(‘HI1003’)、标准型(‘IM1162’和‘SX1511’)和高糖型(‘KWS1197’)甜菜品种为试验材料,设置N_(0)(0 kg/hm^(2))、N_(75)(75 kg/hm^(2))和N_(225)(225 kg/hm^(2))施氮处理,测定甜菜不同生育时期干物质量分配、根冠比、氮积累与分配、氮效率和产质量指标。【结果】(1)甜菜生育期氮素吸收利用特征呈单峰曲线变化趋势,在8月9日达到高峰;(2)8月份块根及糖分增长期,N_(0)和N_(75)处理下,丰产和高糖型品种地上部干物质分配较标准型品种增加4.57%~36.77%,标准型品种根冠比变化幅度低于高糖和丰产型品种;(3)N_(75)处理下,高糖型品种收获期氮肥利用率最高,较标准型品种‘SX1511’和‘IM1162’分别增加58.44%和71.26%;N_(225)处理下,氮肥利用率和产量是丰产型品种最高,其产量较标准型品种‘IM1162’和‘SX1511’分别增加10.31%和14.06%。【结论】块根及糖分增长期是氮素调控产质量的关键时期,在该时期进行氮素调控,在发挥品种氮素吸收利用最大效率的同时可实现丰产或高含糖的目标。

青贮玉米应用现状以及其栽培措施研究进展

青贮玉米营养丰富、适口性好,是畜牧业发展中重要的饲草作物。近年来,随着我国畜牧业的迅速发展和“粮改饲”政策的不断推进,我国青贮玉米产业发展迅速,产量和品质均得到很大提升。青贮玉米种植面积有限,且品种多为传统品种。如何在有限的资源条件下提高青贮玉米产量和品质,是目前青贮玉米产业亟待解决的问题。目前,对于青贮玉米的栽培措施已开展了许多深入的研究,文章综述了青贮玉米的发展现状和近年来青贮玉米高产优质栽培的研究成果,主要包括品种选择、种植方式、种植密度、氮肥施用和收获时期等栽培措施对青贮玉米产量和品质的影响,以及青贮玉米与动物生产应用相关的研究,旨在为青贮玉米优质生产提供重要参考。