前氮后移对水稻产量形成和农田氮素流失的影响

基于太湖地区稻田养分流失主要集中在水稻生育前期的特点,以超级稻武运粳29号为供试材料,通过田间小区试验,基肥采用机械深施,在施氮量300 kg/hm2水平下,设计4个氮肥运筹比例,基肥：分蘖肥：穗肥的比例分别为5：2：3 (O1);4：2：4 (O2);3：2：5 (O3);2：2：6 (O4),研究氮肥后移对水稻产量构成和农田地表径流氮素流失量的影响。结果表明,从产量构成因素来看,前氮后移的O4处理较常规氮肥运筹的O2处理水稻有效穗数和每穗粒数均显著下降,但是其结实率和千粒重均明显增加;最终前氮后移的O4处理水稻产量略有下降,但处理间的差异不显著。水稻季农田共发生地表径流6次,径流水总量为3 567.0 m3/hm2。农田地表径流总氮流失量随着前氮后移比例的增加而减少,O4处理较O2处理地表径流总氮流失量下降了12.02%,处理间的差异均达到显著水平。同时,前氮后移能够降低稻田地表径流总氮流失率和水稻氮素偏流失率。     

农田施用水葫芦对水稻钾素吸收利用的影响

以粳稻品种‘运2645’为供试材料,设计农田施用水葫芦（将晒干水葫芦按4500 kg/hm2农田施用）、不施用水葫芦处理和施N量为120 kg/hm2（LN）、240 kg/hm2（NN）处理,研究其对水稻不同生育时期K素含量、K素吸收、K素分配和K素利用效率的影响。结果表明：（1）农田施用水葫芦使水稻不同生育时期植株含K率显著提高,增加幅度从够苗期逐渐下降,到抽穗后又逐渐增加;使各生育时期吸K量显著提高;（2）农田施用水葫芦对水稻不同生育时期K素在茎鞘、叶片中分配比例多无显著影响,使成熟期K素在穗中分配比例显著降低;（3）农田施用水葫芦使水稻不同生育时期K素干物质生产效率均显著或极显著降低,使K素籽粒效率和K素收获指数均显著降低;（4）增施N肥,使水稻不同生育时期的植株K素含量和吸K量均得到极显著的增加,使K素干物质生产效率和K素籽粒生产效率均显著或极显著下降;（5）水葫芦 × N对稻株K素吸收利用多无显著互作效应。农田施用水葫芦使水稻植株含K率、K素吸收量显著提高,使K素干物质生产效率和K素籽粒生产效率显著降低。     

播期对复播玉米生育期及产量的影响

北疆准噶尔盆地南缘西部地区麦收后，热量资源是复播玉米成功的关键。试验表明：播期和播种方式对全生育期天数有一定影响，并且播期与播种方式对复播玉米千粒重呈显著相关。随播期推迟收获籽粒千粒重降低，而覆膜栽培籽粒千粒重则高于露地栽培。     

播期对华北平原雨养夏玉米产量形成与资源利用效率的影响

以京农科728（JNK728）和郑单958（ZD958）为材料,设置6月6日（SD1）、6月11日（SD2）、6月16日（SD3）、6月20日（SD4）和6月26日（SD5）5个播期,研究播期对雨养夏玉米产量形成及资源利用效率的影响。结果表明,随播期推迟,雨养夏玉米灌浆期和总生育期逐渐延长;2个品种平均叶面积指数（LAI）和干物质积累总量（DM）均呈先升高后降低的趋势,在SD2和SD3播期吐丝期LAI最高,SD2吐丝期DM显著高于SD1、SD4和SD5处理,SD2和SD3处理收获期DM显著高于SD4和SD5处理。随播期的推迟,雨养夏玉米穗粒数和行粒数先升高后降低,穗行数逐渐减少,千粒重逐渐升高,2个品种平均产量在SD2和SD3最高,分别为9.84×10³和9.51×10³kg/hm²,SD5最低,仅为8.04×10³kg/hm²,SD5比SD1~SD4产量分别降低9.53%、22.44%、18.36%和15.00%;JNK728比ZD958增产9.19%。灌浆期和全生育期内温度和光辐射量与穗粒数呈显著正相关,但抑制了籽粒灌浆,与千粒重呈负相关,因此雨养夏玉米产量随灌浆期和全生育期内温度升高和光辐射量增加而提高。SD1~SD4光能和降水生产效率比SD5分别提高4.9%~17.6%和13.6%~26.8%,SD2~SD5积温生产效率比SD1提高2.8%~13.3%。综上所述,播期可调控雨养夏玉米的生长发育进程、LAI、干物质积累与分配以及产量,提高资源利用效率,华北平原雨养夏玉米选用抗旱性强品种（JNK728）在6月11日-15日播种,产量可以突破9.5×10³kg/hm²。     

水稻施用生长调节剂对产量和结实率的影响

通过水稻生态旱育秧施用生长调节剂对穗期抗寒性的影响。试验结果表明:水稻生态旱育秧始穗期喷施6-苄氨基嘌呤生长调节剂比喷施清水提前齐穗和灌浆3d,提高结实率3.7%和4.5%,增加千粒重0.7g,减少了秋风阴雨对水稻开花、授粉的影响,对提高水稻单产在一定程度上能起到关键性作用。     

施用钙肥对盐碱地花生开花期后土壤水分、盐分和速效养分运移的影响

为探索黄河三角洲盐碱土区花生高产高效栽培技术、提高出苗和建苗率,田间条件下,设置Ca-0 (CK、 0 kg/hm_² CaO)、Ca-1(180 kg/hm_² CaO)和Ca-2(360 kg/hm_² CaO)试验,研究盐碱土花生开花期后0-100 cm剖面土壤水分、盐分和速效氮磷养分含量随花生生育进程的动态变化。研究结果表明,施用钙肥可明显降低0-60 cm土层含盐量, 80 cm以下土层含盐量明显增加,对0-40 cm土层含水量影响不大,但明显提高开花后60-80 cm土层土壤含水量,且较高钙肥用量可降低60-100 cm土层含水量。施用钙肥可明显提高开花期后0-60 cm土层水解性氮和速效磷含量,明显降低土壤水解性氮的淋溶强度,尤以Ca-2处理表现明显。黄河三角洲盐碱土区,土壤水解性氮含量匮乏,速效磷含量虽然较充足,但由于盐碱胁迫、团粒结构缺乏、土壤板结严重等因素制约,不利于花生根系对养分的吸收,使土壤磷效率难以发挥,基施钙肥可有效提高0-60 cm土层水解性氮和速效磷含量,降低水解性氮的淋溶强度,使其土壤肥力有效发挥。     

利用播期研究气候变化对玉米产量的影响

为明确气候变化对玉米产量的影响,对相对气象产量与各发育期干燥度K的相关性进行了分析,结果显示玉米各发育阶段干燥度K对产量影响的程度由重至轻依次为:抽雄—乳熟>拔节—抽雄>出苗—拔节>乳熟—成熟,分析表明抽雄—乳熟期的干燥度K对产量的影响最大,综合全生育期的干燥度K对产量影响的相关系数得出,I上升0.1,玉米气象产量下降800kg/hm^2左右。     

播期对鲜食玉米产量与经济效益的影响

为了探讨不同播期对鲜食玉米产量及经济效益的影响,选取鲜食玉米品种SD902作为试验对象,研究在春播和夏播不同播期处理下鲜食玉米的产量、穗部性状变化及对经济效益的影响。根据相关性分析可知,整穗鲜重与各穗部性状都呈极显著相关性,其中籽粒鲜重与整穗鲜重的相关性最强且呈正相关,秃尖长与整穗鲜重呈负相关;随着播期延迟,春播鲜食玉米产量呈上升趋势,夏播则呈下降趋势。根据2022年鲜食玉米的实际产投比可知,春播的整体经济效益呈负增长,而夏播鲜食玉米市场价格增高且无需机耕和起垄覆膜,整体经济效益较高。对于种植地来说,1年2季有利于解决亏损问题,实现高产和经济效益最大化。     

不同播期玉米覆膜直播对产量的影响

玉米覆膜直播省工,增加土壤温度,保蓄水分,增加玉米抗旱能力。通过不同播期试验得出,在福泉市4月4日播种获得的产量最高。     

杂交粳稻亲本产量性状优异配合力的标记基因型筛选

提高杂交粳稻竞争优势的关键是改良其恢复系产量性状的配合力。为使之更富成效,选用115个SSR引物扩增6个粳稻BT型不育系和12个恢复系的标记基因型,并按NCII遗传设计配制72个F1组合,分析18个亲本的单株日产量、单株有效穗数、每穗总粒数、每穗实粒数、千粒重5个性状的配合力,结合亲本SSR分子标记数据和性状配合力数据筛选了5个性状优异配合力的标记基因型。结果发现20个SSR标记基因型与亲本产量及其构成性状配合力显著相关。其中8个与亲本单个性状配合力相关;6个同时与亲本2个性状配合力相关;4个同时与亲本3个性状配合力相关;2个同时与亲本4个性状配合力相关。同时与多个性状配合力相关的标记基因型,对各性状的作用方向有正有负。RM152-165/170是单株日产量和单株有效穗数优异配合力效应最大的标记基因型,可使F1的相应性状值增加20.6%和12.7%。优异配合力的标记基因型可直接用于粳稻恢复系配合力的分子标记辅助改良。     

影响籼稻品种产量水平的主要根系性状

2001和2002年，在群体水培条件下分别以国内外不同年代育成的籼稻代表品种（品系）88个和122个为供试材料，抽穗期测定12个有关根系形态性状和根系活力，成熟期测定产量、冠根比等，采用组内最小平方和的动态聚类方法对供试籼稻品种的产量进行聚类，研究不同产量类型籼稻品种根系有关性状的差异以及影响籼稻品种产量水平的主     

施用河道污泥对水稻氮素吸收利用的影响

为了探索污染河道污泥农业资源化利用的有效途径,本研究以河道污泥为研究对象,设计施N量为120、240 kg/hm2 2 个水平,研究河道污泥农田施用对不同生育时期水稻氮素含量、氮素吸收、氮素分配和氮素利用效率的影响。结果表明：（1）施用河道污泥使不同生育时期水稻植株含氮率显著提高,使各生育时期氮素累积量显著提高;（2）使水稻抽穗后氮素在茎鞘中的分配比例显著提高,使水稻抽穗后氮素在叶片和穗中的分配比例明显下降;（3）使不同生育时期水稻氮素干物质生产效率以及氮素籽粒效率均显著或极显著降低,但对水稻氮素收获指数影响不显著;（4）河道污泥×N的互作效应对稻株氮素吸收利用无显著影响。施用河道污泥使水稻植株含氮率、氮素累积量显著增加,而水稻氮素干物质生产效率和氮素籽粒效率则显著降低。     

降解地膜与控释肥对再生稻生长及产量的影响

为了探索更加清洁高效的水稻覆膜栽培技术,采用小区试验的方法,研究可降解地膜代替常规地膜、一次性施用不同用量的控释氮肥,与"中稻+再生稻"的最佳结合技术。结果表明:覆膜后降解地膜与普通非降解地膜覆对再生稻两季产量影响差异不显著。控释肥一次性基施以150 kg N/hm2处理头季稻产量最高,225 kg N/hm2处理"中稻+再生稻"两季总产最高。因此,水稻覆膜技术与可降解地膜、控释肥以及再生稻技术结合后,是一项清洁、高产、高效的水稻栽培新技术。     

Effect of Integration of Fertilizer and Green Manure Nitrogen on Yield Attributes, Nitrogen Uptake and Yield of Lowland Rice (Oryza sativa L.)

Field experiments were conducted at Tamil Nadu Rice Research Institute, Aduthurai, India, during the wet seasons of 1992 and 1993 to study the effect of full and partial substitution of fertiliser N with green manure N (Sesbania rostrata) on nitrogen uptake, yield attributes and yield of rice. The experiment consisted of eight treatments with two levels of N (100 and 200 kg ha⁻¹) and three sources of N application viz., fertilizer, integrated (1:1 fertilizer and green manure N) and green manure N compared to the recommended practice (150 kg fertilizer plus 6.25 t ha⁻¹ (72 kg N) green manure) and a no N control. Nitrogen application markedly increased the N uptake. Combined use of the two N sources at 200 and 222 kg N ha⁻¹ and of single fertilizer N at 200 kg N ha⁻¹ recorded the maximum N uptake, increased the yield attributes such as number of panicles per unit area, weight per panicle, number of total and filled grains per panicle and test weight. At 200 kg N ha⁻¹ full substitution of N by green manure reduced the grain yield but only partial substitution of N by green manure resulted in almost similar yield as single fertilizer N. Thus 200 kg N ha⁻¹ applied in equal proportions of fertilizer and green manure N can be recommended for medium duration rice cultivars.     

Yield of F1, F2 and F3 hybrids of rice (Oryza sativa L.)

Summary Yield and yield components of F₁ hybrids were studied in three experiments at 30×30 cm spacings and in one experiment at 15×15 cm spacings. In the 30×30 cm experiments, 10 of the 41 hybrids tested significantly outyielded their high parents. However, only 2 hybrids significantly outyielded the best cultivar: one hybrid yielded 23 % and the other 16 % more than their respective check cultivars. The four hybrids in the 15×15 cm experiment yielded only 59 to 92% as much as their high parents.In areas where rice is transplanted at relatively wide spacings, the observed levels of F₁ heterosis in selected hybrids may be sufficient to warrant production of hybrid rice, if enough hybrid seed can be produced. For direct-seeding at the high rates normal in the USA, the relatively small levels of heterosis and the difficulties of hybrid seed production preclude use of F₁ hybrid rice cultivars at present.None of 19 bulk F₂ and F₃ hybrids in two experiments yielded significantly more than its high parent. Similarly, none of the 12 mixtures included in one experiment yielded significantly more than its high parent. On the basis of yield alone, using bulk F₂ or F₃ or simple mixture populations is not merited.Contribution from the Western Region, Agricultural Research Service, U.S. Department of Agriculture, and the Department of Agronomy and Range Science, University of California, Davis, California 95616.     

Physiological Analysis of Growth, Yield Development and Grain Quality of Some Deep-water Rice (Oryza sativa L.) Cultivars

A field experiment was conducted with 10 deep‐water rice varieties (nine traditional and one improved), viz. Amona, Maguri, Rangoli, Kakua, Panikakua, Deoribao, Moimonsingia, Duatkalam, Dalbao and PJNB‐96‐10, to study their physiological performance, grain‐quality characters and yield. Among the cultivars, significant variations were recorded in plant height, root length, number of internode, tiller number, number of ear‐bearing tillers, panicle length, panicle weight, number of spikelets per panicle and filled grain percentage. The highest number of spikelets per panicle (199), filled grain percentage (95 %) and grain yield (4.32 t ha^?1) were recorded in Maguribao. The highest grain length was recorded in PNJB‐96‐10 (9.5 mm), whereas highest grain thickness was observed in Duatkalam (2.8 mm). Glutelin was the most dominant fraction of protein in all the tested cultivars. Maguribao showed the highest glutelin content (26.7 mg g^?1 dry weight), whereas Panikakua showed the highest amylose (24.45 %) and crude fat (4.64 %) content. Differences were also recorded among cultivars in fibre, ash and iron content in grain. Maguribao was found to have superior physiological traits for growth and hence may be considered for inclusion in deep‐water rice breeding programmes.     

水稻突变体的创制

为功能基因组学研究提供较好的基础材料,利用0.75%甲基磺酸乙酯溶液和γ射线双重诱变处理‘晋恢21’M1、‘中花11’、LR001种子进行研究。结果表明,经过M2筛选,获得716份叶、茎、穗、粒等性状变异的突变体,突变频率较高,达1.79%,还获得一些如不分蘖、多分蘖、白化苗、mini-plant、稀粒、花器官等极具研究价值的突变类型。双重诱变可以获得各种类型的突变体,所有的突变类型在3种材料中均有出现,说明该技术可为功能基因组研究提供大量的实物材料。     

Effect of Zinc and Iron Supply on Production Potential of Rice (Oryza sativa L.)

A field experiment was performed to study the effect of zinc and iron supply on grain yield in four promising varieties of rice ( Oryza sativa L.) viz. IR-20, Jaya, Pusa 2–21, and IET-1444. Three doses of ZnSO₄ or FeSO₄ (0, 20 or 40 kg ha⁻¹) along with all possible combinations were investigated. The varietal differences were significant in grain yield ha⁻¹. The grain yield increased with the dose of zinc and Jaya but not significantly in IR-20. The increase in grain yield was more significant and dose dependent in IET-1444 than in Jaya in response to iron application.