Slow-controlled release fertilizers are experiencing a popularity in rice cultivation due to their effectiveness in yield and quality with low environmental costs. However, the underlying mechanism by which these fertilizers regulate grain quality remains inadequately understood. This study investigated the effects of five fertilizer management practices on rice yield and quality in a two-year field experiment: CK, conventional fertilization, and four applications of slow-controlled release fertilizer (UF, urea formaldehyde; SCU, sulfur-coated urea; PCU, polymer-coated urea; BBF, controlled-release bulk blending fertilizer). In 2020 and 2021, the yields of UF and SCU groups showed significant decreases when compared to conventional fertilization, accompanied by a decline in nutritional quality. Additionally, PCU group exhibited poorer cooking and eating qualities. However, BBF group achieved increases in both yield (10.8 t hm and 11.0 t hm) and grain quality reaching the level of CK group. The adequate nitrogen supply in PCU group during the grain-filling stage led to a greater capacity for the accumulation of proteins and amino acids in the PCU group compared to starch accumulation. Intriguingly, BBF group showed better carbon-nitrogen metabolism than that of PCU group. The optimal nitrogen supply present in BBF group suitable boosted the synthesis of amino acids involved in the glycolysis/ tricarboxylic acid cycle, thereby effectively coordinating carbon-nitrogen metabolism. The application of the new slow-controlled release fertilizer, BBF, is advantageous in regulating the carbon flow in the carbon-nitrogen metabolism to enhance rice quality.© 2024. The Author(s).

The use of controlled-release urea (CRU) has become one of best management practices for increasing crop yield and improving nitrogen (N) use efficiency (NUE). However, the effects of CRU on direct-seeded rice are not well understood while direct-seeding has gradually replaced transplanting due to increasing labor cost and lack of irrigation water. The objective of this two-year field experiment was to compare the effects of the CRU at four rates (120, 180, 240 and 360 kg N ha, CRU1, CRU2, CRU3 and CRU4, respectively) with a conventional urea fertilizer (360 kg N ha; U) and a control (no N fertilizer applied; CK) on yield, biomass, NUE of direct-seeded rice and soil nutrients. The results indicated that the successive release rates of N from CRU corresponded well to the N requirements of rice. The use of CRU3 and CRU4 increased rice grain yields by 20.8 and 28.7%, respectively, compared with U. In addition, the NUEs were improved by all CRU treatments compared to the U treatment. Concentrations of NO-N and NH-N in the soil were increased, especially during the later growth stages of the rice, and the leaching of N was reduced with CRU treatments. In conclusion, applying CRU on direct-seeded rice increased the crops yields and NUE, increased nitrogen availability at the late growth stages, and reduced N leaching.Copyright © 2018 Elsevier Ltd. All rights reserved.

Rapid hydrolysis of urea results in further fertilization frequency and excessive nitrogen (N) input. A modified urea, dimethylolurea (DMU), was synthesized in this study. The structure of the sample was characterized by Fourier transform infrared and nuclear magnetic resonance analysis, manifesting the formation of DMU. N release investigation confirmed that DMU enabling provided a gradual N supply. The N leaching experiment indicated that increasing the applied DMU significantly reduced the NH-N, NO-N, and total N leaching, compared with urea application alone. The application effect on maize and wheat was evaluated. The results revealed that singly applied DMU with 100% or 80% N input, irrespective of the amount, promoted crop yield and agronomic characteristic and N use efficiency (NUE) of maize and wheat, beyond urea with two split applications at the recommended rate. Thus, the potential availability of DMU was proven; this could be widely used in agricultural fields as a slow-release fertilizer.

<div style="line-height: 150%">This experiment explored the effects of single application of seven types of slow- and controlled-release fertilizers on rice yield and various population characteristics.&nbsp; Based on a study of the nitrogen (N) release characteristics of these fertilizers, pot experiments were conducted in 2018 and 2019 with split fertilization (CK, urea applied split equally at basal and panicle initiation stages, respectively) as control, which assessed the effects on SPAD value, yield and yield components, dynamic changes of rice tillers and dry matter accumulation.&nbsp; The results showed that the N release characteristics of different types of slow- and controlled-release fertilizers were significantly different.&nbsp; Polymer-coated urea (PCU) showed a controlled-release mode and provided sustained release throughout the whole growth stages.&nbsp; Sulfur-coated urea (SCU) exhibited a slow-release mode, providing insufficient release at the middle and late stages.&nbsp; Urease inhibitor urea (AHA) and urea-formaldehyde (UF) yielded a rapid-release mode, with an explosive N release at the early stage and no release at the middle and late stages.&nbsp; These results showed that PCU delayed the peak seedling stage.&nbsp; Compared with CK, dry matter accumulation and SPAD showed no significant differences, and due to the continuous release of N throughout the growth stages, rice yield, spikelets per panicle, seed setting rate, and 1 000-grain weight were all increased.&nbsp; Owing to the lack of N supply at the late stage and the low number of spikelets, SCU led to a reduction of rice yield, which is nevertheless not statistically significant.&nbsp; AHA and UF were susceptible to environmental factors and had varying effects on rice yield.&nbsp; The results of this experiment indicated that given a fixed amount of N applied in a pot, the stronger the N supply capacity and the longer the effective duration time of the fertilizer, the higher the dry matter accumulation at the late growth stage, and the higher the rice yield.</div>

目的 探明不同类型水稻品种产量和氮素吸收利用对FACE(大气CO₂浓度增高)响应的差异。方法 以常规粳稻、杂交籼稻、常规籼稻共6个品种为供试材料,研究FACE对不同类型水稻产量、氮素吸收利用的影响。结果 1）FACE处理极显著提高了水稻产量,平均增加24.17%, 常规籼稻增幅最大,FACE和对照均以杂交籼稻最高;2）FACE处理显著增加了单位面积穗数,常规粳稻增幅最大,并显著增加了杂交籼稻和常规籼稻每穗粒数;3）FACE处理显著提高了成熟期吸氮量和氮素籽粒生产效率,成熟期吸氮量平均增加21.23%,杂交籼稻增幅最大, FACE和对照均以常规籼稻最高;氮素籽粒生产效率平均增加7.33%,杂交籼稻增幅最大,FACE和对照均以杂交籼稻最高。成熟期吸氮量对产量促进作用略大于成熟期氮素籽粒生产效率;4）FACE处理降低了植株含氮率,成熟期平均下降0.105个百分点,常规粳稻降幅最大。FACE处理极显著提高植株干物质量,成熟期平均增加23.95%,常规籼稻增幅最大;FACE处理显著提高常规籼稻和杂交籼稻成熟期单穗吸氮量,分别增加10.79%、13.93%,但常规粳稻下降了9.60%;FACE处理显著提高了成熟期群体吸氮强度,平均增加22.29%,杂交籼稻增幅最大。FACE处理对水稻全生育期天数无显著影响;FACE处理显著提高茎鞘、叶片、穗各器官吸氮量,叶片增幅最大,平均增加51.86%,杂交籼稻增幅最大;FACE处理显著提高了不同生育阶段吸氮量,抽穗-成熟阶段增幅最大,平均增加108.90%,杂交籼稻增幅最大;5）植株干物质量、单穗吸氮量、吸氮强度、穗吸氮量、抽穗-成熟阶段吸氮量对成熟期总吸氮量的促进作用分别大于植株含氮率、单位面积穗数、生育天数、茎鞘叶吸氮量、移栽-分蘖和分蘖-抽穗阶段吸氮量;6）FACE处理显著提高了氮肥偏生产力,降低了每百千克籽粒需氮量,前者平均增加24.16%,常规籼稻增加最多;后者平均降低4.7%,常规籼稻降幅最大。结论 FACE处理可显著提高水稻产量和氮素吸收利用效率,但品种间差异较大。

为提高肥料利用率，追求水稻增产效益，本试验以籼粳杂交水稻品种‘甬优12’为材料，探究不同类型缓释肥对‘甬优12’产量以及群体结构的影响。结果表明：汉枫缓释肥对‘甬优12’有明显增产效应，较配方肥增产2.7%~3.5%；六国网缓释肥和丰筑缓释肥无明显增产效应。汉枫缓释肥处理下的水稻成穗率和每穗粒数均高于其他处理，弥补了有效穗数较低的不足。各生育期内的叶面积指数和干物质量均以汉枫缓释肥处理最高。综合产量以及群体特征的表现，汉枫缓释肥的经济效益优于六国网缓释肥和丰筑缓释肥，可为‘甬优12’的因种施肥提供依据。

Plants can assimilate inorganic nitrogen (N) sources to organic N such as amino acids. N is the most important of the mineral nutrients required by plants and its metabolism is tightly coordinated with carbon (C) metabolism in the fundamental processes that permit plant growth. Increased understanding of N regulation may provide important insights for plant growth and improvement of quality of crops and vegetables because N as well as C metabolism are fundamental components of plant life. Metabolomics is a global biochemical approach useful to study N metabolism because metabolites not only reflect the ultimate phenotypes (traits), but can mediate transcript levels as well as protein levels directly and/or indirectly under different N conditions. This review outlines analytical and bioinformatic techniques particularly used to perform metabolomics for studying N metabolism in higher plants. Examples are used to illustrate the application of metabolomic techniques to the model plants Arabidopsis and rice, as well as other crops and vegetables.

With the rapid development of modern agriculture, high-quality rice production and consumption has become the current urgent demand for the development of rice production. In this paper, the effects of late-stage nitrogen fertilizer application on rice quality were studied under the same genetic background. Wx near-isogenic lines were used as test materials to study the starch composition, amylopectin structure and cooking quality of rice.Results showed that rice amylose content and gel consistency significantly differed when different Wx genes were tranformed into waxy rice. The law of apparent amylose content in rice is Wx> Wx> Wx> wx at the same nitrogen level, while the trend of gel consistency was opposite to that of apparent amylose content, presenting obvious characteristics of Indica and Japonica varieties. As the amount of fertilizer application increased, apparent amylose content increased, gel consistency decreased, breakdown and peak viscosities dropped and setback viscosity and peak time increased. Moreover, the cooking quality of rice significantly decreased with the use of nitrogen fertilizer, especially under low-level nitrogen fertilizer application. Amylopectin structure varied significantly in different genotypes of the Wx gene, and the degree of branching was as follows: wx > Wx> Wx> Wx. This result indicated that the closer to Indica rice, the fewer short chains of amylopectin. Starch crystallinity and swelling potential were negatively correlated with amylose content but significantly positively correlated with amylopectin branching degree, decreasing with the increase of late-stage nitrogen fertilization.Late-stage nitrogen fertilization reduced the cooking quality of rice by increasing amylose content and reducing amylopectin branching degree, which decreased starch crystallinity and aggravated pasting properties. Obviously, controlling late nitrogen application is essential to optimize rice quality. © 2017 Society of Chemical Industry.© 2017 Society of Chemical Industry.

研究旨在探讨滨海盐碱地缓释肥与无机肥配施情况下,氮素在各时期的用量分配对水稻生育期、生长特性、产量及食味品质的影响。以中粳中晚熟水稻品种‘南粳9108’为试验材料,在3‰~6‰土壤盐分条件下,设计了5种施肥方式,在生育期的关键节点测定水稻的根系指标、叶面积指数、各部位干物质积累,并比较各施肥处理水稻的生长指标和食味品质。结果表明,配施缓释肥与无机肥且减少氮素用量20%的T3处理组,水稻的生殖生长期占全生育期的比例较全氮量施肥且施用无机肥的T1处理组缩短0.25%,营养生长期占全生育期的比例增长0.23%,全生育期减少2天。水稻的总根系长度、叶面积指数、单位叶面积干物质积累、单位面积茎鞘干物质及产量总体趋势为T3>T1>T2>T4>T5。稻米中蛋白质含量与食味值呈现负相关性,蛋白质含量越高,食味值越低;稻米中直链淀粉含量与食味值之间呈现负相关,直链淀粉含量越高,食味值越低。氮肥用量的提高显著降低了稻米的食味品质,不施用氮素的T5处理组食味值最高,配施缓释肥与无机肥处理土壤肥效增强,但稻米的食味值也最低。缓释肥与无机肥配施,减少氮素用量20%,且穗肥不追施任何氮素处理时,水稻的生长指标、稻米的食味值显著的提高。

为探究缓控释氮肥对机插杂交籼稻稻米品质的影响,本试验以杂交籼稻F 优498为材料,采用随机区组大田试验设计,研究不同氮肥处理对机插稻碾米品质、外观品质及淀粉快速粘度分析(RVA)谱特征值的影响。结果表明,氮肥处理对稻穗不同部位籽粒品质特性影响显著,与普通尿素常规施肥(T1)相比,普通尿素优化施肥(T2)使上部稻米的精米率和中部的崩解值分别提高2.38%和9.32%;掺混缓控释肥基肥一次施肥(T3)和树脂尿素基肥一次施肥(T4)使下部稻米的整精米率分别提高4.35%和5.15%;掺混缓控释肥与普通尿素配施(T6)的各穗部稻米的整精米率较高,同时降低了中上部稻米的消减值和糊化温度。各氮肥处理间,缓控释氮肥基肥一次施肥(T3、T4、T5)、T2和T6较好地提高了稻米碾米品质和外观品质。与T1相比,T3、T4和T5使精米率分别提高2.88%、3.86%和3.24%,T2和T6使整精米率分别提高2.74%和2.61%。峰值黏度表现为CK>T2>T1>T6>T3>T5>T4,崩解值表现为CK>T1>T6>T2>T5>T4>T3,消减值表现为T3>T5>T4>T6>T2>T1>CK,CK、T1、T2和T6的蒸煮食味品质较好。普通尿素按基肥∶分蘖肥∶促花肥∶保花肥=3∶2∶3∶2的优化施肥方式(T2)和掺混缓释肥N 135 kg·hm^-2作为基肥,尿素N 45 kg·hm^-2作为分蘖肥的配施(T6)能较好的协调碾米品质、外观品质及淀粉RVA谱特性三者的关系,是实现优质的有效措施。本研究为缓控释氮肥在杂交籼稻优质生产上的应用提供了理论参考。

为探究缓控释复合肥在籼粳杂交稻生产上的应用效果,[方法]在田间小区试验条件下研究对比不同量的缓控释复合肥和常规施肥对水稻“甬优12”产量、品质和经济效益的影响。试验设置5个施肥处理：不施肥(CK)、常规施肥(RF)、100%缓控释复合肥(100% CRF)、80%缓控释复合肥(80% CRF)和60%缓控释复合肥(60% CRF)。[结果]整体而言,100% CRF对水稻产量、经济性状指标、稻米品质指标和经济效益的提高最好,例如,增加水稻的精整米率和碱消值,降低垩白粒率和粗蛋白含量；80% CRF对水稻指标的影响与RF相近；而60% CRF处理的水稻产量、株高、有效穗和经济效益均明显低于RF。[结论]研究结果表明,在一定范围内,施氮量仍然是限制水稻产量和影响水稻品质指标最重要的元素,因而今后在研制和推广缓控释复合肥时应着重考虑其氮素水平。

【目的】淀粉是稻米的主要成分，其构成及理化特性基本决定了稻米食味表现。探讨优良食味稻米的淀粉构成特征，并解析结实期氮素水平的作用效应，对优良食味水稻品种的调优栽培具有重要意义。【方法】以稻米食味有明显差异的水稻品种金香玉1号、武育粳3号、武密粳和淮稻5号为试验材料，设置结实期不同氮素水平处理，分析稻米淀粉理化特性与食味品质的关系及其对氮素水平的响应。【结果】稻米的食味值表现为金香玉1号>武育粳3号>武密粳>淮稻5号，不同氮素水平下表现一致。优良食味稻米的直链淀粉和蛋白质含量均较低；淀粉RVA谱崩解值较高，消减值较低，淀粉易于糊化；溶解度、膨胀势和淀粉颗粒形态较优，淀粉相对结晶度较高；短支链淀粉占比较高。随着结实期氮素水平的提高，稻米的食味值显著下降，直链淀粉含量有所降低，蛋白质含量显著增加，胶稠度变短，最高黏度和崩解值下降，消减值上升；淀粉的颗粒形态劣化；淀粉的糊化焓、相对结晶度和支链淀粉分支中的B2、B3链含量上升，溶解度、膨胀势、A链和B1链含量下降。稻米理化特性和食味值对氮素的响应存在明显的品种间差异，优良食味品种的食味品质较为稳定，对氮素的敏感度小于普通食味稻米。【结论】优良食味稻米的直链淀粉和蛋白质含量较低，直链淀粉含量、蒸煮特性和淀粉颗粒形态特征较优，淀粉结晶特性较好，短支链含量较多。结实期较高的氮素水平提高了支链淀粉长支链占比，增加了淀粉糊化所需能量，降低了淀粉溶解度和膨胀势，对稻米蒸煮食味品质有明显的劣化作用。

利用低谷蛋白含量（low glutelin content， LGC）粳稻品种W1721与大面积应用的杂交粳稻恢复系轮回422构建了重组自交系群体。根据种子总蛋白质的SDSPAGE带型，推断各单株LGC位点的基因型。在排除脂肪的影响下，比较了基因型LGCLGC（谷蛋白含量较醇溶蛋白低）与基因型lgclgc（谷蛋白含量较醇溶蛋白高）在RVA谱特征值上的差异，以及同一基因型内总蛋白质含量与淀粉RVA谱特征值的关系。结果表明基因型LGCLGC的崩解值和回复值的平均值分别显著和极显著大于基因型lgclgc；LGC对崩解值和回复值的相对加性效应分别为3.91%和4.45%，贡献率分别为4.81%和12.81%。LGCLGC型的稻米，总蛋白质含量与崩解值和消减值分别存在显著的负线性回归和正线性回归关系，贡献率分别为9.86%和11.48%；lgclgc型的稻米，总蛋白质含量与消减值和回复值都存在极显著的负线性回归关系，贡献率分别为1341%和27.88%。结合前人研究认为，稻米食味品质受谷蛋白相对于醇溶蛋白的含量以及总蛋白质含量的影响；而总蛋白质含量对食味品质的影响因谷蛋白相对于醇溶蛋白的含量的不同而异。因此，育种工作中应当把谷蛋白相对于醇溶蛋白的含量以及总蛋白质含量同时作为选择指标。