Factors Affecting Yield and Yield Components of Main and Ratoon Rice: A Review

Rice ratooning refers to the production of second crop from the stubble after the harvest of main crop.Main and ratoon rice growth and development are affected by different factors.These factors include varieties selection,water management,fertilizer management,stubble height,plant protection practices and external environmental factors such as temperature and light.In this review,we discussed the different factors affecting the yield and yield components of main and ratoon rice.Among these factors the most important and first one is varietal selection.Varieties should be selected according to the requirement of specific area and prefer varieties resistant to insects/pests and diseases.Sufficient amount of water and fertilizer should be supplied.Stubble height of 10-20 cm will resulted in high production of ratoon rice.Too low or too high temperature and light would reduce the grain yield and quality of rice.Optimal temperature is useful for higher yield.It was concluded that by keeping the management practices more efficiently,the yield of main rice as well as ratoon rice could be increased.There is a need of more studies focusing on improvement of the quality of ratoon rice.     

中国再生稻的产量差及影响因素

【目的】阐明再生稻的产量差及影响因素,为揭示其生产潜力和制定高产高效栽培措施提供科学依据。【方法】从中国知网和Web of Science两个数据库,分别以“再生稻产量、品种、施肥、种植密度、留桩高度、种植方式和收割方式”和“ratoon rice,variety,fertilizer and China”为关键词检索,共收集目标文献119篇。总结再生稻头季、再生季和两季总的产量潜力和产量差,通过分析品种、施肥、种植密度、留桩高度、种植方式和收割方式对再生稻产量的影响,阐明再生稻产量差的影响因素及缩小产量差的途径。【结果】当前我国再生稻头季、再生季和两季总的产量潜力分别为11.65、6.90和17.10 t·hm ^-2,总样本平均产量仅分别实现了产量潜力的71%、53%和68%。籼稻和杂交稻的再生稻产量分别比粳稻和常规稻增产24%—19%和18%—8%;头季的最优施肥量约为N 168 kg·hm ^-2,P₂O₅ 123 kg·hm ^-2,K₂O 124 kg·hm ^-2;再生季的最优施肥量约为N 145 kg·hm ^-2,P₂O₅ 50 kg·hm ^-2,K₂O 200 kg·hm ^-2。再生稻头季的适宜种植密度为22.4—29.1万穴/hm ²;适宜留桩高度为40—50 cm;手栽种植利于再生季产量的提高因而总产量也最大;人工收割比机械收割的再生季产量高12%,虽然机种机收会减少产量,但差异不显著。【结论】我国再生稻头季、再生季及两季总产量的增产潜力分别为3.38、3.27和5.41 t·hm ^-2。合适的品种、肥料管理、种植密度、留桩高度、种植和收割方式可以缩小产量差,其中品种以籼稻和杂交稻为主;优化施肥量可以使头季和再生季分别增产9%和22%,优化种植密度则分别增产8%和17%;适宜的留桩高度为40—50 cm;机种机收更符合轻简化现代农业的需求。     

不同品种和栽培条件对再生稻产量及其构成因素的影响

探索不同品种和不同栽培因素综合对再生稻产量及其构成因素的影响,为提高再生稻产量水平的最优栽培模式提供理论依据,采用L_9(3~4)正交设计原理,研究不同品种、不同留桩高度、不同促芽肥施用量3个因素对再生稻头季、再生季及年产量及其产量构成因素的综合影响。结果表明:无论对头季、再生季还是年产量,品种、留桩高度和促芽肥施用量三因素的最优组合为两优616、留桩高度为10cm、促芽肥为140kg·hm-2,可获得高产;对再生稻年产量的影响顺序为:品种留桩高度促芽肥,品种对产量起最主要的作用;对头季稻产量的影响顺序为品种促芽肥留桩高度,最主要的影响是品种;在再生季,对有效穗和穗粒数的影响程度顺序为品种留桩高度促芽肥,而对千粒重和结实率的影响程度为品种促芽肥留桩高度。综合来看,在本试验范围内,品种两优616、留桩高度10cm、促芽肥140kg·hm-2的组合有利于再生稻获得高产。     

Border effects of the main and ratoon crops in the rice ratooning system

The border effect (BE) is widely observed in crop field experiments, and it has been extensively studied in many crops.  However, only limited attention has been paid to the BE of ratoon rice.  We conducted field experiments on ratoon rice in Qichun County, Hubei Province, Central China in 2018 and 2019 to compare the BE in the main and ratoon crops, and to quantify the contribution of BE in the main crop to that in the ratoon crop.  The BE of two hybrid varieties was measured for the outermost, second outermost, and third outermost rows in each plot of both crops.  To determine the contribution of BE between the two crops, portions of hills in the outermost and second outermost rows were uprooted during the harvest of the main crop so that the second and third outermost rows then became the outermost rows in the ratoon crop.  Overall, the BE on grain yield was greater in the main crop than in the ratoon crop.  In the main crop, the BE on grain yield was 98.3% in the outermost row, which was explained by the BE on panicles m^–2, spikelets/panicle, spikelets m^–2, and total dry weight.  In the ratoon crop, the BE on grain yield was reduced to 60.9 and 27.6% with and without the contribution of the BE in the main crop, respectively.  Consequently, 55.1% of the BE on grain yield in the ratoon crop was contributed from the main crop.  High stubble dry weight and non-structural carbohydrate (NSC) accumulation at the harvest of the main crop were responsible for the contribution of BE in the main crop to that in the ratoon crop.  Our results suggest that increases in stubble dry weight and NSC accumulation at the harvest of the main crop could be important strategies for developing high-yielding cropping practices in the rice ratooning system.     

Optimal management of nitrogen fertilizer in the main rice crop and its carrying-over effect on ratoon rice under mechanized cultivation in Southeast China

This study attempted to clarify the carrying-over effect of different nitrogen treatments applied to the main crop on the crop population growth and yield formation of ratoon rice under mechanized cultivation in Southeast China.  Based on the constant total nitrogen application amounts (225.00 kg ha^–1) in the main crop, an experiment with different ratios of basal and topdressing nitrogen fertilizer (the ratio of basal fertilizer:primary tillering fertilizer:secondary tillering fertilizer:booting fertilizer at 3:1:2:4 (N1), 3:2:1:4 (N2), 3:3:0:4 (N3), and 4:3:0:3 (N4), respectively, and a control without nitrogen treatment (N0)) was set up across two consecutive years in field using hybrid rice variety Yongyou 1540 as the test materials.  The results showed that the total tiller number and effective tillering percentage increased in the main crop under the N1 treatment, more nitrogen fertilizer applied in late growth stage of the main crop, and its effective tillering percentage of the main crop was the highest at up to 70.18%, which was 9.15% higher than that of conventional fertilization treatment (N4), more nitrogen fertilizer applied in early growth stage of the main crop.  The same tendency was observed in leaf area index (LAI) value of the main crop and its subsequent ratoon rice, which were 16.52 and 29.87% higher, respectively, in the N1 treatment than that in the N4 treatment at the full heading stage.  The same was true in the case of the transport rates of stem and sheath dry mater and the canopy light interception rates in both the main and its ratoon crops.  The transport rate of stem and sheath in main crop rice under N1 treatment increased by 50.57% compared with N4 treatment.  The canopy light interception rate of N1 treatment increased by 5.07% compared with N4 treatment at the full heading stage of the ratoon crop.  Therefore, the total actual yield was the highest in the main and its ratoon crops under N1 treatment, averaging 17 351.23 kg ha^–1 in two-year trials, which was 23.00% higher than that in the conventional fertilization treatment (N4).  The results showed that appropriate nitrogen treatment was able to produce a good crop stand in the main crop, which was essential for producing a good ratoon crop population and high yield especially under mechanized cultivation with low stubble height of the main crop.  The study suggested that shifting the proper nitrogen application amounts to the late growth stage of the main crop, such as N1 treatment, not only had a higher productive effect on ensuring the yield of the main crop, but also had a positive effect on the axillary bud sprouts from the stubbles for ratoon rice, resulting in an increased percentage of productive panicles and achieving the goal of one planting with two good harvests under the conditions of our study.     

杂交中稻及其再生稻高产栽培关键技术

阐述了杂交中稻及其再生稻的高产栽培关键技术,包括适时播种、合理密植、科学施肥管水和再生稻施好促芽肥及发苗肥、保留适当稻桩高度等内容,以指导杂交中稻及其再生稻的高产栽培管理。     

隆两优华占高产高效再生稻栽培技术研究

2015~2016年在湖南永州对隆两优华占再生稻进行了喷施"九二○"、增施促芽肥、机收时稻田土壤水分含量、留桩高度对比等试验,试验结果表明:隆两优华占两季总产量最高,生育期适中,再生力强,抗逆性较强,是一个综合性状优良的再生稻品种;蓄留再生稻在前季稻齐穗后约15 d和再生稻破口期喷施"九二○"可明显提高产量;在肥力上等的田块增施促芽肥尿素10~12.5 kg/667m~2,在肥力中等和差的田块增施促芽肥尿素15 kg/667m~2,可显著提高再生稻产量;头季稻机械收割蓄留的再生稻产量低于人工收割蓄留的;蓄留再生稻以头季稻始穗后约18 d排水晒田再机械收割最适宜;机械收割留桩高度以25~30 cm为宜。     

留桩高度对再生稻生长发育及产量的影响

以汕优63、明恢63为试材,设10、20、40 cm3个留桩高度处理,研究了不同留桩高度对再生稻生长发育及产量的影响。结果表明,高留桩使再生稻生育期缩短,而株高、穗长、再生率和产量均增加;反之,低留桩使再生稻生育期延长,而株高、穗长、再生率和产量均下降。再生稻以“多穗取胜”,为保证再生稻获得高产,供试品种留桩高度应在30-40 cm,以确保再生季在9月中旬“寒露风”来临前安全齐穗,提高有效穗数。     

High quality and high efficiency fertilization of rice

正Rice (Oryza sativa L.), one essential staple cereal, feeds over 60%of the world’s population (FAO 2020). As the global population grows, improving rice yield becomes an effective strategy to achieve food security (Deng et al. 2019).The use of chemical fertilizer, especially N fertilizer,has historically played a critical role in the growth of rice yield (Zhang et al. 2015; Wood et al. 2020). However,     

刈割处理对再生稻头季全株生物量、青贮品质和再生季产量的影响

为研究再生稻齐穗后刈割时间和留桩高度对再生稻头季生物量、青贮品质和再生季产量的影响,在湖南省益阳市大通湖区选取湘两优900和甬优4149为供试材料,设置刈割时间分别为齐穗后10（P10）、15（P15）、20（P20）、25（P25）和30 d（P30）;留桩高度分别为10（H10）、20（H20）和30 cm（H30）,研究不同处理下再生稻头季生物量、青贮品质和再生季产量的变化。结果表明,再生稻头季全株生物量随刈割时间的推迟呈现出逐渐增加的趋势,P25和P30处理的全株生物量显著高于P10和P20处理,V-score评分均在80分以上,且感官品质优良,发酵品质良好,相对饲用价值较高;留桩高度H10和H20处理头季的全株生物量显著高于H30处理,V-score评分均在80分以上,且感官品质优良,发酵品质良好,相对饲用价值较高;再生季产量随刈割时间的推迟呈现下降趋势,P10和P15 处理再生季的产量显著高于P20和P30处理;留桩高度H20和H30处理再生季的产量显著高于留桩高度H10处理。综上所述,以收获全株青贮饲料为主要目的时,头季宜采取齐穗后25~30 d、10~20 cm留桩高度的刈割处理,此时,生物量高,感官品质、发酵品质和营养品质较好;以收获再生季稻谷为主要目的时,头季宜采用齐穗后10~15 d、留桩20~30 cm的刈割处理,再生季产量较高。     

Management of rice straw with relay cropping of Chinese milk vetch improved double-rice cropping system production in southern China

Improved utilization of rice(Oryza sativa L.) straw and Chinese milk vetch(Astragalus sinicus L., vetch) has positive effects on rice production. So far, few studies have investigated the productivity of vetch under different residue management practices in double-rice cropping system. The effects of rice straw on the growth and nutrient accumulation of vetch across seven years(2011–2017) and the subsequent effects of rice straw and vetch on two succeeding rice crops in a vetch–rice–rice cropping system, with the vetch established by relay cropping, were examined. The seven-year double-rice experiment consisted of the following treatments:(1) 100% chemical fertilizer(F-F100);(2) only vetch without chemical fertilizer(M-Con);(3) 80% chemical fertilizer plus vetch plus a low-cutting height(low-retained stubble) with the removal of straw(M-F80);(4) 80% chemical fertilizer plus vetch plus a low-cutting height with the retention of straw(M-F80-LR);(5) 80% chemical fertilizer plus vetch plus a high-cutting height(high-retained stubble) with the retention of straw(M-F80-HR); and(6) no fertilizer(F-Con). The yields of the two rice crops after vetch were not affected by either the cutting height of stubble with retention of straw or by the management of straw(retention vs. removal) with low-cutting height of stubble. The yields of the two rice crops after vetch were significantly higher for M-F80-HR than for M-F80-LR, but the relative contributions of the high-cutting height and straw retention to the higher rice yield could not be determined in this study. The yield stability of the double-rice grain in M-F80-HR was also increased, as determined by a sustainable yield index. Significant increases in vetch biomass and nutrient uptake were observed in the fertilized treatments during the rice season compared with the unfertilized treatments. In M-F80-HR plots, improvements in the growing environment of the vetch by conserving soil water content were associated with the highest vetch biomass, nutrient uptake, and yield stability of vetch biomass. These increased nutrient inputs partially replaced the demand for chemical fertilizer and stimulated the rice yields. It can be concluded that retaining higher-cutting stubble residues with straw retention could be the best straw management practice for increasing the vetch biomass and nutrient use efficiency, thereby allowing utilization of high-cutting height with retention of straw and vetch to improve the stability of rice productivity in a double-rice cropping system.     

头季稻收割前施促芽肥对再生稻出苗及产量的影响试验

为充分利用一季中稻地区的光温资源,提高复种指数,增产增收,以超级稻中浙优1号为材料,进行了头季稻收割前不同时期施用促芽肥对再生稻出苗及产量的影响试验。结果表明,在头季稻收割前8～12 d施促芽肥（尿素,225 kg/ha）对再生稻出苗及产量有一定的促进作用,以收割前12 d施用促芽肥出苗最快,生育期长（69 d）,有效穗数300.9万穗/ha、每穗总粒数84.13粒、每穗实粒数71.83粒、结实率85.38%和产量5208.89 kg/ha等性状均最高,可在一季中稻区推广应用。     

Effects of nitrogen management on the ratoon crop yield and head rice yield in South USA

Ratoon rice cropping is an important component of the rice cropping system in Texas and south Louisiana, USA, and expanded to Asian countries in 1970. Two field studies were conducted with widely planted rice(Oryza sativa L.) cultivars at Eagle Lake, Texas, USA to determine the effects of nitrogen(N) management in main(first) crop(MC) and ratoon(second) crop(RC) on RC yield. In 2012 and 2013, one cultivar(Presidio) was adopted to determine the effects of RC N management on ratoon yield and head rice yield. In 2016 and 2017, CL153, CL163 and CL272 in addition to Presidio were adopted to examine the effect of MC N management on ratoon yield and head rice yield. N applied at preflood after MC harvest considerably improved RC yield. Application of 99 kg N ha–1 at preflood after MC harvest was practically adequate for RC regrowth, development and approaching the yield potential for Presidio. RC could produce quite high average grain yields of 5.90 to 6.53 t ha–1 in 2012 and 2013, respectively. Main crop N rate only significantly affected MC yield; however, given N applied of 99 kg ha–1 at preflood after MC harvest, ratoon yield was not significantly affected by MC N rate. Neither the main nor ratoon crop N management had a significant effect on RC head rice yield. Considerable RC head rice yields(55–65%) were observed in all of the four cultivars and 4 years except for CL272 in 2016. These results indicat that without very high N fertilizer application, rice ratoon crop could produce a considerable grain yield and an expectative head rice yield. Rice ratooning could be a practical way to increase rice yields with the minimal input in south Texas and regions with a similar climate.     

杂交水稻不同留桩高度对再生稻产量的影响

[目的]确定合适的留桩高度,以便指导再生稻的生产。[方法]采用目前生产上推广的3个中稻品种(深两优5814、两优6326、新两优223),开展50、35和15 cm 3种不同留桩高度试验,分析再生穗的出苗速度、生育期、农艺性状、经济性状和产量等性状的变化规律。[结果]50、35 cm留桩高度处理再生穗的出苗速度、生育期、农艺性状、经济性状和产量等性状都优于15 cm低留桩高度处理。[结论]该研究进一步印证生产实践中留桩高度分别为50、35 cm为农民所接受。     

全履带式再生稻收割机行走底盘碾压率的模拟与分析

为减少全履带式再生稻收割机收获再生稻头季时行走底盘对留桩的碾压率(履带碾压面积与收割面积的比值),以利于提高再生季水稻产量、并改善再生季稻米品质,基于履带式车辆设计理论,以割幅Z、轨距B、履带接地长度L、履带宽度b、转向半径R0、底盘中心轴线与割台割刀纵向距离X为影响因素,建立了全履带式再生稻收割机行走底盘结构模型及其田间直行转弯碾压模型,以种植行距i,株距c,穴径br的水稻为对象,对上述各参数对碾压率的影响规律进行了分析,结果表明,其他参数相同条件下,直行时,碾压率δ1随割幅Z与履带宽度b的比值增加而减小;转弯时,全履带式再生稻收割机碾压率δ2随转向角度θ增大而减小,随转向半径R0的增大而减小;碾压率不受底盘中心轴线与割台割刀纵向距离X的影响;轨距B以及割幅Z与轨距B之差为行距和株距的公倍数时有利于减少碾压率;在相同接地比压条件下,割幅Z增加有利于减少碾压率。为减少碾压率,全履带式再生稻收割机结构设计时,在满足接地比压前提下,应减少履带宽度b和接地长度L,增大割幅Z,轨距B取行距和株距的公倍数,割幅Z与轨距B之差为行距和株距的最小公倍数,采用回转式行走路径;结合田块形状与面积,优先选用较大转向半径R0;在农艺上,建议水稻种植行距与株距有整数倍关系。     

影响水稻再生力QTLs位点与再生稻筛选体系研究进展

挖掘水稻产量潜力是水稻研究最重要的方向之一。再生稻是一种利用水稻头季收割后稻桩上存活的腋芽，在适宜的光照、温度、养分等条件下萌发成蘖，进而抽穗成熟的水稻，在节约大量人力物力的同时能够保证水稻产量与双季稻基本持平，对于稳定国家粮食安全具有重要意义。本文综述了已报道的水稻再生力相关QTLs位点，发现水稻再生力相关的QTLs位点贡献率偏低，相关研究不深入，与生产联系不紧密；总结了水稻再生力评价标准的现状，发现前期头季稻的SPAD衰减指数、中期再生稻的再生芽出鞘率以及收获后期的日产量和热量利用率是评价水稻品种再生力的重要指标，可用于筛选强再生力的水稻品种；概括了留桩高度对再生稻产量和品质的影响。提出再生稻的培育应聚焦优质、高产、抗病等水稻重要性状及强再生力相关性状，利用多组学分析挖掘新基因及其优异自然变异，开发功能分子标记，利用全基因组关联分析与分子模块育种技术相结合开展强再生力水稻种质资源精准鉴定、新基因发掘、种质创新、新品种选育研究。     

直播栽培对双季早稻生育期、抗倒伏能力及产量效益的影响

【目的】探究直播栽培方式对不同类型水稻品种生育期、抗倒伏能力、产量和经济效益的影响,以期为机械化直播稻的应用推广提供理论基础。【方法】2020年和2021年早稻,以广西生产上推广面积较大的常规稻品种桂育9号、桂育11号、桂野丰、广粮香2号和杂交稻Y两优1号等5个品种为供试材料,以人工移栽为对照,进行大田精量直播。试验采用裂区设计,以栽培模式为主区,品种为副区,设置3个重复。记录各生育周期,测定主茎形态、基部茎秆特征以及抗折力、弯曲力度和倒伏指数等抗倒伏指标,成熟期测定产量及其构成因素,并计算成本和经济效益。【结果】（1）直播稻的生育期缩短2—6 d,主要表现在播种到幼穗分化期之间;（2）直播稻的抗倒伏能力低于移栽稻,其株高、重心高度与穗干重均较低,第二节间的茎粗、壁厚、鲜重和干重亦较低,茎秆长度则高于移栽稻,这是导致直播水稻抗倒伏能力弱的主要原因;（3）在产量表现方面,除Y两优1号外,其余4个水稻品种的产量表现为直播稻低于移栽稻。生育期相对短的品种,直播稻的产量明显低于移栽稻,而生育期较长的品种,产量差异不显著,在产量构成因素中,每穗粒数增加和结实率的提高是直播稻增产的主要因素;（4）...     

优质稻保优栽培技术的研究进展（综述）

综述了温、光等环境因子和肥、水、病、虫等栽培因子对优质水稻品质形成的影响。阐述了在栽培中如何通过合理安排播种期、运筹肥水、防治病虫害等措施保持优质稻的优质特性。     

百色市主要农作物土地生产潜力研究

[目的]探讨百色市主要农作物的土地生产潜力估算方法,为提高百色市主要农作物的土地生产潜力提供参考.[方法]用农业生态区域法估算主要农作物的光温生产潜力;在光温生产潜力的基础上用水分订正系数进行修订,估算出主要农作物的气候生产潜力;在气候生产潜力基础上用土地质量系数进行修订,估算出主要农作物的土地生产潜力.[结果]百色市主要农作物光温、气候和土地生产潜力均以水稻最高,其余依次为玉米、大豆和红薯.4种作物土地生产潜力分别为：5466.0、5074.4、2414.3和1190.5 kg/ha.[结论]百色市主要农作物的土地生产潜力较低,为提高百色市主要农作物的土地生产潜力,应优化农作物品种结构,引进高产优质的农作物品种,提高土壤肥力,加强水肥管理和以农田水利为重点的农业基础设施建设等.     

道县中稻-再生稻高产栽培模式研究初报

以Y两优9918和晶两优华占2个水稻品种为试验材料,研究了不同水稻品种进行中稻-再生稻高产栽培时头季稻、再生稻的生育期、产量和经济效益的变化。结果表明:在中稻-再生稻高产栽培模式下,2个水稻品种水稻生育期均无明显差异;头季稻产量以Y两优9918较高,达545.88 kg/667m~2;再生季水稻产量以晶两优华占较高,达254.53 kg/667m~2。两季水稻,以Y两优9918的经济效益较高,为910.37元/667m~2。总的来说,选择Y两优9918水稻品种开展中稻-再生稻栽培模式能获得较高的经济效益,具有一定的应用前景。