不同密度·揭膜时间和施氮量对免耕油菜生育动态的影响(英文)

[Objective] This study was to understend the optimized combination of planting density, duration of disclosing plastic film and nitrogen fertilization under no-tillage cultivation. [Method] Quadratic polynomial regression and saturated D-optimal design were employed to investigate the effects of planting density, duration of disclosing plastic film and nitrogen fertilization on the dynamics growth of rapeseed under no-tillage cultivation. [Result] Within the experimental range, the growth dynamics of no-tillage cultivated rapeseed assumed a rise-fall tend. For the effects to the growth dynamics of no-tillage cultivated rapeseed, nitrogen application amount was higher than planting density and duration of disclosing plastic film. The interaction effect between planting density and duration of disclosing plastic film was higher than that between nitrogen application amount and planting density, and between nitrogen application amount and duration of disclosing plastic film. [Conclusion] The optimized combination of these factors for dynamic growth of rapeseed under no-tillage cultivation was determined to be: planting density of per hectare 154 925 individuals, duration of disclosing plastic film of 110 d, nitrogen application amount of 315 kg/hm2.     

不同施氮量对杂交油菜鲜干重净增量的影响(英文)

[Objective]The aim of the research was to provide reference for reasonable application of nitrogen fertilizer for high yield cultivation of hybrid rape cultivar Youyan 9 and Youyan 10.[Method] The net increment changes of individual plant fresh weight and dry matter weight of Youyan 9 and Youyan 10 with different nitrogen application treatments were studied.[Result]The differences among average fresh weight increments of individual plant and average dry matter weight increment of individual plant with different treatments reached 0.01 extremely significant level. Fresh weight increment and dry matter weight net increment of individual plant declined gradually with the increase of nitrogen application. In growth course,fresh weight net increment of individual plant increased firstly then decreased and the maximum was in beginning flowering stage,besides that dry matter net increment increased gradually and the maximum was in mature period.The correlations among fresh net increment,dry matter weight net increment and yield net increment were positive or extremely positive.[Conclusion]Under experimental condition,when nitrogen application was 225 kg/hm2,hybrid rape Yanyou 9 and Yanyou 10 with low erucic,low glucosinolate could obtain high yield.     

Effect of Different Nitrogen Application Amount on the Net Increment of Fresh Dry Weight in Hybrid Rape

[Objective]The aim of the research was to provide reference for reasonable application of nitrogen fertilizer for high yield cultivation of hybrid rape cultivar Youyan 9 and Youyan 10.[Method] The net increment changes of individual plant fresh weight and dry matter weight of Youyan 9 and Youyan 10 with different nitrogen application treatments were studied.[Result]The differences among average fresh weight increments of individual plant and average dry matter weight increment of individual plant with different treatments reached 0.01 extremely significant level. Fresh weight increment and dry matter weight net increment of individual plant declined gradually with the increase of nitrogen application. In growth course,fresh weight net increment of individual plant increased firstly then decreased and the maximum was in beginning flowering stage,besides that dry matter net increment increased gradually and the maximum was in mature period.The correlations among fresh net increment,dry matter weight net increment and yield net increment were positive or extremely positive.[Conclusion]Under experimental condition,when nitrogen application was 225 kg/hm2,hybrid rape Yanyou 9 and Yanyou 10 with low erucic,low glucosinolate could obtain high yield.     

免耕条件下川香优9838氮磷钾吸收规律与氮肥合理施用(英文)

The aim of the study is to investigate the absorption laws of nitrogen,phosphorus,and potassium,and proper nitrogen application in Chuanxiangyou 9838 under no-tillage cultivation. Five nitrogen application treatments were designed to analyze the absorption laws of N,P and K,and to discuss the effects of different N fertilizer application amounts on yield and yield composition factors of Chuanxiangyou 9838. The results showed that gross nutrient absorption in Chuanxiangyou 9838 was greatly varied at different developmental stages under rice-rape rotation with no-tillage. The maximum N absorption in Chuanxiangyou 9838 appeared at jointing stage followed by heading stage,thirdly the tillering stage; the P absorption in Chuanxiangyou 9838 presented the consecutively slight increase during seedling stage and mature stage; the K absorption in Chuanxiangyou 9838 was mainly conducted from jointing stage to heading stage,during which K absorption accounts for 73.4% of the total absorption in whole developmental stage. Consequently,N fertilizer should be applied earlier (before jointing stage),P fertilizer is suitable as base fertilizer and application of K fertilizer should be preferably conducted at early-middle period. When the yield reached 11 t/hm2,the optimal N application amount in Chuanxiangyou 9838 was about 165 kg/hm2.     

Study on Absorption Law of Nitrogen,Phosphorus and Potassium and Proper Nitrogen Application in Chuanxiangyou 9838 under No-tillage Cultivation

The aim of the study is to investigate the absorption laws of nitrogen,phosphorus,and potassium,and proper nitrogen application in Chuanxiangyou 9838 under no-tillage cultivation. Five nitrogen application treatments were designed to analyze the absorption laws of N,P and K,and to discuss the effects of different N fertilizer application amounts on yield and yield composition factors of Chuanxiangyou 9838. The results showed that gross nutrient absorption in Chuanxiangyou 9838 was greatly varied at different developmental stages under rice-rape rotation with no-tillage. The maximum N absorption in Chuanxiangyou 9838 appeared at jointing stage followed by heading stage,thirdly the tillering stage; the P absorption in Chuanxiangyou 9838 presented the consecutively slight increase during seedling stage and mature stage; the K absorption in Chuanxiangyou 9838 was mainly conducted from jointing stage to heading stage,during which K absorption accounts for 73.4% of the total absorption in whole developmental stage. Consequently,N fertilizer should be applied earlier (before jointing stage),P fertilizer is suitable as base fertilizer and application of K fertilizer should be preferably conducted at early-middle period. When the yield reached 11 t/hm2,the optimal N application amount in Chuanxiangyou 9838 was about 165 kg/hm2.     

Effects of seedling age on the growth stage and yield formation of hydroponically grown long-mat rice seedlings

Understanding the characteristics of rice productivity is of great importance for achieving high yield formation. However, such traits have not yet been studied for different ages of hydroponically grown long-mat rice seedlings(HLMS), which constitutes a new method of seedling cultivation. Field experiments were conducted to evaluate the effects of seedling age on the growth stage, photosynthesis characteristics, dry matter production, and yield of HLMS. A conventional japonica rice cultivar(Wuyunjing 24) and an indica hybrid rice cultivar(6 Liangyou 9368) were used as test materials. The results showed that the whole phase was shortened by 13–15 days for young seedlings(13-day-old) compared with old seedlings(27-day-old), which occurred because the growth process accelerated with the transplantation of young seedlings. As seedling age increased, the dry matter weight of stems of individual plants and of the population increased at the transplanting stage but decreased at the maturity stage(MS). Compared with that of 27-day-old seedlings, the average ratio of panicle weight to total plant dry weight of 13-day-old seedlings during a 2-year period increased by 3.71% for Wuyunjing 24 and by 3.78% for 6 Liangyou 9368 at the MS. Moreover, as seedling age increased, the leaf area index and photosynthetic potential decreased for both cultivars, and the photosynthetic rate markedly decreased at the heading stage(HS). With the exception of that of Wuyunjing 24 from the jointing stage to the HS in 2014, the crop growth rate was higher for young seedlings than for old seedlings. Grain yield significantly decreased with seedling age, but no significant difference was detected between the 13-and 20-day-old seedlings for either cultivar. Therefore, equilibrious and high biological yield formation, vigorous growth in the late stages, and high photosynthetic production capacity are important characteristics and causes of the efficient and sustainable output of photosynthetic systems and for achieving high yield formation in young transplanted seedlings(13–20-day-old).     

Does nitrogen application rate affect the moisture content of corn grains?

Nitrogen fertilizer application is an important measure to obtain high and stable corn yield, and the moisture content of corn grains is an important factor affecting the quality of mechanical grain harvesting. In this study, four different nitrogen fertilizer treatments from 0 to 450 kg ha~(–1) pure nitrogen were set for a planting density of 12.0×10~4 plants ha~(–1) in 2017 and 2018, and 18 different nitrogen fertilizer treatments from 0 to 765 kg ha~(–1) pure nitrogen were set for planting densities of 7.5×10~4 and 12.0×10~4 plants ha~(–1) in 2019, to investigate the effect of nitrogen application rate on the moisture content of corn grains. Under each treatment, the growth of corn, leaf area index(LAI) of green leaves, grain moisture content, and grain dehydration rate were measured. The results showed that, as nitrogen application increased from 0 to 765 kg ha~(–1), the silking stage was delayed by about 1 day, the maturity stage was delayed by about 1–2 days, and the number of physiologically mature green leaves and LAI increased. At and after physiological maturity, the extreme difference in grain moisture content between different nitrogen application rates was 1.9–4.0%. As the amount of nitrogen application increased, the corn grain dehydration rate after physiological maturity decreased, but it did not reach statistical significance between nitrogen application rate and grain dehydration rate. No significant correlation was observed between LAI at physiological maturity and grain dehydration rate after physiological maturity. In short, nitrogen application affected the grain moisture content of corn at and after physiological maturity, however, the difference in grain moisture content among different nitrogen application rates was small. These results suggest that the effect of nitrogen application on the moisture content of corn grains should not be considered in agricultural production.     

Postponed and reduced basal nitrogen application improves nitrogen use efficiency and plant growth of winter wheat

Excessive nitrogen(N) fertilization with a high basal N ratio in wheat can result in lower N use efficiency(NUE) and has led to environmental problems in the Yangtze River Basin, China. However, wheat requires less N fertilizer at seedling growth stage, and its basal N fertilizer utilization efficiency is relatively low; therefore, reducing the N application rate at the seedling stage and postponing the N fertilization period may be effective for reducing N application and increasing wheat yield and NUE. A 4-year field experiment was conducted with two cultivars under four N rates(240 kg N ha–1(N240), 180 kg N ha–1(N180), 150 kg N ha–1(N150), and 0 kg N ha–1(N0)) and three basal N application stages(seeding(L0), fourleaf stage(L4), and six-leaf stage(L6)) to investigate the effects of reducing the basal N application rate and postponing the basal N fertilization period on grain yield, NUE, and N balance in a soil-wheat system. There was no significant difference in grain yield between the N180 L4 and N240 L0(control) treatments, and the maximum N recovery efficiency and N agronomy efficiency were observed in the N180 L4 treatment. Grain yield and NUE were the highest in the L4 treatment. The leaf area index, flag leaf photosynthesis rate, flag leaf nitrate reductase and glutamine synthase activities, dry matter accumulation, and N uptake post-jointing under N180 L4 did not differ significantly from those under N240 L0. Reduced N application decreased the inorganic N content in the 0–60-cm soil layer, and the inorganic N content of the L6 treatment was higher than those of the L0 and L4 treatments at the same N level. Surplus N was low under the reduced N rates and delayed basal N application treatments. Therefore, postponing and reducing basal N fertilization could maintain a high yield and improve NUE by improving the photosynthetic production capacity, promoting N uptake and assimilation, and reducing surplus N in soil-wheat systems.     

Effects of Mg on C and N Metabolism of Soybean at Different Nitrogen Supplying Levels

A pot experiment was conducted to study the effects of magnesium on carbon and nitrogen metabolism of soybean at different nitrogen supplying levels. The results showed that the effects of magnesium at low nitrogen rate on N content, soluble protein, soluble sugar contents were not alike at different growth stage, although nodule dry weights raised, the yield and protein content of seeds decreased, however, the oil content was improved. The application of magnesium at medium and high nitrogen supplying levels promoted the uptake of N effectively, increased the soluble protein and soluble sugar contents, but the nodule dry weights of application magnesium at medium nitrogen supplying level decreased and the yield increased only a little despite the improved quality. Application of magnesium at high nitrogen supplying level raised nodule dry weights and soybean yield significantly, the quality of seeds was also improved.     

Effects of nitrogen application rate and hill density on rice yield and nitrogen utilization in sodic saline–alkaline paddy fields

Soil salinity and alkalinity can inhibit crop growth and reduce yield,and this has become a global environmental concern.Combined changes in nitrogen (N) application and hill density can improve rice yields in sodic saline–alkaline paddy fields and protect the environment.We investigated the interactive effects of N application rate and hill density on rice yield and N accumulation,translocation and utilization in two field experiments during 2018 and 2019 in sodic saline–alkaline paddy fields.Five N application rates (0 (control),90,120,150,and 180 kg N ha~(-1) (N0–N4),respectively) and three hill densities(achieved by altering the distance between hills,in rows spaced 30 cm apart:16.5 cm (D1),13.3 cm (D2) and 10 cm (D3))were utilized in a split-plot design with three replicates.Nitrogen application rate and hill density significantly affected grain yield.The mathematical model of quadratic saturated D-optimal design showed that with an N application rate in the range of 0–180 kg N ha~(-1),the highest yield was obtained at 142.61 kg N ha~(-1) which matched with a planting density of 33.3×10~4 ha~(-1).Higher grain yield was mainly attributed to the increase in panicles m~(–2).Nitrogen application rate and hill density significantly affected N accumulation in the aboveground parts of rice plants and showed a highly significant positive correlation with grain yield at maturity.From full heading to maturity,the average N loss rate of the aboveground parts of rice plants in N4 was 70.21% higher than that of N3.This is one of the reasons why the yield of N4 treatment is lower than that of the N3 treatment.Nitrogen accumulation rates in the aboveground parts under treatment N3 (150 kg N ha~(-1)) were 81.68 and 106.07% higher in 2018 and 2019,respectively,than those in the control.The N translocation and N translocation contribution rates increased with the increase in the N application rate and hill density,whereas N productivity of dry matter and grain first increased and then decreased with the increase in N application rate and hill density.Agronomic N-use efficiency decreased with an increase in N application rate,whereas hill density did not significantly affect it.Nitrogen productivity of dry matter and grain,and agronomic N-use efficiency,were negatively correlated with grain yield.Thus,rice yield in sodic saline–alkaline paddy fields can be improved by combined changes in the N application rate and hill density to promote aboveground N accumulation.Our study provides novel evidence regarding optimal N application rates and hill densities for sodic saline–alkaline rice paddies.     

施氮量、密度和苗龄对稻田免耕油菜苗期干物质积累的影响

[目的]寻求稻田免耕栽培条件下油菜适宜的施氮量、密度和苗龄。[方法]运用三因素二次回归饱和D-最优设计310方案,研究施氮量、密度和苗龄对稻田免耕油菜苗期干物质积累的影响。[结果]稻田免耕油菜苗期干物质含量随着施氮量、密度、苗龄的增加,呈现先升后降的抛物线。其中施氮量的变化量对干物质积累的影响大于密度和苗龄;施氮量与密度互作效应大于施氮量与苗龄和密度与苗龄的互作效应。[结论]综合考虑,施氮量在195 kg/hm2、密度在93 000株/hm2、苗龄在33 d时,免耕油菜苗期干物质含量达到最高（4 768.215 kg/hm2）。     

不同播种密度和施肥量对江淮稻田免耕直播油菜产量形成及农艺性状的影响

[目的]为探明江淮地区稻-油两熟制度下油菜免耕直播高产栽培技术。[方法]以核油56为材料,采用田间裂区试验,比较3种施氮水平（Tn）和4种播种密度（Tm）对江淮稻田免耕机开沟直播栽培油菜的产量构成、农艺形状以及生物学产量、秸秆系数等的影响。[结果]在较低密度和中等密度条件下,增施氮肥有利于生物学产量和经济产量的提高。[结论]江淮稻田油菜直播适宜的施氮量为180kg/hm2,适宜的播种密度为3.0kg/hm2;免耕直播油菜的秸秆系数随施氮量增加而增加,随播种密度增加而降低,平均在0.76～0.78。     

留苗密度对直播油菜产量及机械收获的影响

[目的]找出最佳直播播量及大田留苗密度处理,为实现大面积机收推广提供科学依据。[方法]对直播油菜设置4种播量及留苗密度处理,调查各处理产量构成、实产、抗逆性(如菌核病、抗倒性)、开花结荚历期。[结果]随着播量的增加,油菜个体生长发育受到影响,有效降低了油菜株高,提高了油菜第1分枝节位,利于油菜分枝向上集中、油菜株型的塑造和机械化收割,但播量增加,限制了油菜个体的发育,使油菜分枝数减少,有效角果数、每角粒数变少,千粒重下降,不利于油菜产量增加。[结论]在安徽沿江地区,油菜直播量为3 750 g/hm~2、大田留苗密度约37.5万/hm~2的处理,比较适合油菜机械化收割。     

不同施氮量对免耕移栽杂交水稻干物质积累与运转的影响

[目的]研究施氮量对免耕移栽杂交水稻干物质积累与运转的影响。[方法]以超级杂交水稻黔南优2058为试材,设5种施氮量处理进行免耕移栽的稻作试验。[结果]随着氮肥施用量的增加,水稻生育中、后期的干物质积累量均有增加的趋势,在最高分蘖期和孕穗期茎干物质减少,叶干物质逐渐增加;在齐穗期茎、叶干物质逐渐减少,穗干物质比例和穗／茎叶逐渐增加;成熟期的情况与齐穗期相反。在75～225kg／hm^2施氮量范围内,随着施氮量的增加,茎鞘物质输出率、茎鞘物质转换率、抽穗后茎叶干物质表观输出量和输出率、每穗总粒数、结实率和千粒重逐渐下降,而有效穗数逐渐升高。[结论]随着施氮量的增加,水稻产量以抛物线形式增加,施氮量为284．0kg／hm^2,可获得最高产量。     

施氮量对迟播油菜生长及氮素吸收的影响(英文)

[目的]分析氮肥对不同冬油菜品种越冬期营养生长和氮素吸收的影响。[方法]连续两年(2009-2011)田间试验,以早熟品种中油116和中晚熟品种中油杂12号为材料,设5种氮肥用量(0,90,180,270,360kg/hm2)。在越冬期对油菜干重,根系和地上部氮含量及比例,叶片硝酸还原酶活性进行测定,并对籽粒产量进行考查。[结果]中油116在施氮量从0增加到180kg/hm2时,地上部干重迅速增加;而在施氮量从180kg/hm2增加到360kg/hm2时,地上部干重缓慢增加。中油杂12号的地上部干重随施氮量的增加呈单峰曲线变化,在270kg/hm2时达到最大值。当施氮量从90kg/hm2到180kg/hm2时,地上部和根中的氮含量及比例均迅速增加,并且中油杂12号根中的氮含量及比例高于中油116。两个品种的硝酸还原酶活性在施氮量从90kg/hm2到180kg/hm2时增加最为明显。[结论]合理施用氮肥能够显著增加不同熟期油菜品种越冬期的干重及氮素吸收,并提高油菜产量。     

Effect of Nitrogen Fertilizer on the Accumulation and Distribution of Dry Matter in Broomcorn Millet

[Objective] To understand the effect of nitrogen application on dry matter accumulation and allocation dynamics in broomcorn millet. [Method] The accumulation and distribution of dry matter were studied using cultivars Jin Shu 7 and Huang Mizi at different levels of nitrogen fertilizer at the jointing stage. [Result] The results showed that increasing N application led to the increase of green leaf area and the delay of leaf senescence, which was beneficial to the accumulation of dry matter.Appropriate nitrogen application(90 kg/hm2) could coordinate the translocation rate of dry matter among different plant parts, thereby enhancing the yield of broomcorn millet; among different organs, the contribution rate of stem to kernel was greater than that of leaf to kernel; there was obvious correlation between dry matter and yield. For Jin Shu 7, leaf area and dry weight of spike showed significant negative correlation with yield. [Conclusion] The formation of grain yield of broomcorn millet involved the accumulation and allocation of dry matter, the appropriate amount of nitrogen application(90 kg/hm2) could improve the rates of translocation and contribution of dry matter, thereby promoting the yield of broomcorn millet.     

秧龄和播量对水稻机插秧苗素质及产量的影响

[目的]研究秧龄和播量对水稻机插秧苗素质及产量的影响。[方法]以优质粳稻品种南粳46为材料,研究不同秧龄和播量对水稻机插秧苗苗高、叶龄、成苗率、成苗数、素质、茎蘖动态、产量及其构成因素的影响。[结果]秧龄和播量对机插秧苗素质及产量有显著影响。其中,20 d秧龄和80 g/盘播种量时机插秧苗素质最好,实测产量最高,达10 263.45 kg/hm~2。[结论]该试验为进一步完善机插育秧技术,加快水稻种植机械化发展提供理论依据。     

移栽密度与施氮量对油菜生长发育和产量的影响

以华杂油9号为材料,研究了不同移栽密度与施氮量对油菜生长发育、植株生物学特性、产量构成因素和产量的影响。研究结果表明:在15～45万株/hm2的移栽密度下,移栽密度对油菜生育期无明显影响,前期施用氮肥能促进油菜苗期的生长发育。在相同的施氮条件,各处理油菜植株的单株叶干重、茎干重、叶面积均随着种植密度的增加而降低。各处理油菜产量均显著高于对照,其产量大小顺序为T4>T5>T6>T3>T1>T2,分别比对照增加175.90%、168.83%、180.97%、222.55%、220.54%和203.29%。试验条件下油菜获得高产的适宜施氮量为180.0 kg/hm2、移栽密度15万株/hm2。     

水稻秸秆还田下油菜免耕生产力保持技术研究

[目的]研究江淮地区稻油二熟制水稻秸秆还田后的油菜免耕生产力保持技术。[方法]通过选择油菜种植品种,调控播种密度、运筹肥料等栽培技术开展研究。[结果]水稻秸秆还田下油菜免耕直播,选择分枝数少的品种便于油菜机械收割;相同施肥条件下,棉油11号15.0万棵/hm2处理比24.0万棵/hm2处理的有效分枝数多38.96%,播种密度为24.0万棵/hm2时,理论产量比15.0万棵/hm2处理高81.41%,实际产量高47.44%。在油菜播种密度为24.0万棵/hm2情况下,不同施氮量对油菜植株的单株角果数、每角粒数均有影响,以施氮量210 kg/hm2理论产量最高,达3 671.70 kg/hm2。[结论]适当调控油菜直播密度和氮肥施用量有利于油菜生长,适当密植能提高油菜产量,同时便于油菜机械收割。     

不同施氮量对杂交油菜鲜干重净增量的影响

以“三高两低”杂交油菜油研9号和油研10号为材料，进行不同施氮量对单株鲜重净增量、单株干物重净增量影响的研究，探讨不同施氮量间施氮量净增量相同（75kg／hm^2），而单株鲜重净增量、单株干物重净增量的变化。