Effects of Interaction between Density and Nitrogen Rate on Growth and Yield of No-tilling and Direct Sowing Rapeseed in Chengdu Plain

[Objective] The aim was to explore the optimal density and nitrogen rate of no-tilling and direct sowing rapeseeds in Chengdu plain. [Methods] Effects of in- teraction between density and nitrogen rate on the growth and yield of direct sowing rapeseed under no-tillage condition were investigated with Chuanyou 58 as materials and a split-plot experiment adopted. [Results] In Chengdu Plain, the yields of rape- seed changed from increasing to decreasing with increase of density and nitrogen rate. Both of density and nitrogen rate had significant effects on growth and yield of rapeseed and the latter overweighed in the effect. In addition, interaction of the two had negative effects on rapeseed yield. The yield of rapeseeds achieved the highest at 3 395.25 kg/hm^2 with interaction of density at 30.00×10^4 plant/hm^2 and nitrogen rate at 180.00 kg/hm^2; the theoretical maximal yield was 3 403.41 kg/hm^2 with interaction of density at 40.80×10^4 plants/hm^2 and nitrogen rate at 198.90 kg/hm^2. [Conclusion] In Chengdu Plain, the optimal density and nitrogen rate are 30.00×10^4-45.00×10^4 plant/hm^2 and 180.00-198.90 kg/hm^2, respectively.

The Development and Application of 2BDQ-8 Rice Direct Sowing Machine

[Objective] The aim was to introduce the development and application of 2BDQ-8 rice direct sowing machine and provide a theoretical basis for rice mechanization production. [Method] 2BDQ-8 rice direct sowing machine was used for the promotion test in field of several cities and counties in Jiangsu Province,and artificial rice planting and mechanization rice planting were compared to explore the production and economic situation. [Result] 2BDQ-8 rice direct sowing machine had advantages such as high efficiency and low cost,the rice direct sowing machine saved about 30% compared to the artificial rice planting and mechanization rice planting,and the overall efficiency was significant. [Conclusion] 2BDQ-8 rice sowing machine was a production technology that had low cost and high efficiency,which should be widely applied.

Effects of Direct Sowing under Mulch-Based Cropping System (DMC) on Cotton and Maize Yield and Chemical Characteristics of Ferruginous Soil (Lixisoil) in the South Sudan Area of Burkina Faso

To better understand the effects of direct sowing under mulch-based cropping system (DMC) in Burkina Faso’s cotton production systems, randomized blocks of Fisher experimental design were implemented at Farako-Ba research station from 2010 to 2019. The study was conducted on lixisoil to evaluate DMC effects on biomass production, crops yields and soil chemical properties in a maize and cotton rotation system associated with cover crop. Conventional tillage and direct seeding without cover crop were compared to DMC under B. ruziziensis (GERM. & EVRARD), DMC under B. ruziziensis + M. cochinchinensis mulch and DMC under C. juncea (L.) mulch used in association with maize. Biomass production, crop yields and soil chemistry were evaluated. Results showed that over 10 years, no-till with or without a cover crop provided cotton seed and maize yields that were statistically equivalent to the tillage commonly practiced by farmers. Cover crop has allowed increasing the biomass production compared to Conventional Tillage and Direct Seeding. Maize yield has not varied significantly with the cover crop. After 10 years of maize and cotton rotation, the improvement raised from +27% to +38% for organic matter and from +15% to +29% for nitrogen with DMC including legumes such as M. cochinchinensis and C. juncea compared to Conventional Tillage on 0 - 5 cm depth. No significant differences were found on soil pH like P2O5 and K2O content. Although DMC with C. juncea used as cover crop did not provide the best biomass production, it contributes to increase nitrogen and organic matter and presents better mineral balances in 10 years of rotation. The 5 - 10 cm and 10 - 20 cm were little influenced by DMC systems.

Nutrient deficiency limits population development,yield formation,and nutrient uptake of direct sown winter oilseed rape

Direct-sowing establishment method has great significance in improving winter oilseed rape（Brassica napus L.） production and guaranteeing edible oil security in China. However, nutrient responses on direct sown winter oilseed rape（DOR） performance and population development dynamic are still not well understood. Therefore, five on-farm experiments were conducted in the reaches of the Yangtze River（RYR） to determine the effects of nitrogen（N）, phosphorus（P）, and potassium（K） deficiencies on population density, dry matter production, nutrient uptake, seed yield, and yield components of DOR plants. Four fertilization treatments included the balanced NPK application treatment（NPK, 180 kg N, 39.3 kg P, 100 kg K, and 1.8 kg borax ha–1） and three nutrient deficiency treatments based on the NPK treatment, i.e., –N, –P, and –K. The results indicated that DOR population density declined gradually throughout the growing season, especially at over-wintering and pod-development stages. Nutrient deficiency decreased nutrient concentration in DOR plants, limited dry matter production and nutrient uptake, and thereby exacerbated density reduction during plants growth. The poor individual growth and reduced population density together decreased seed yield in the nutrient deficiency treatment. Averaged across all the experiments, seed yield reduced 61% by N deficiency, 38.3% by P deficiency, and 14.4% by K deficiency. The negative effects of nutrient deficiency on DOR performances followed the order of –N–P–K, and the effects were various among different nutrient deficiencies. Although N deficiency improved DOR emergence, but it seriously limited dry matter production and nutrient uptake, which in turn led to substantial plants death and therefore resulted in a very low harvested density. The P deficiency significantly reduced initial density, limited plants growth, and exacerbated density reduction. The K deficiency mainly decreased individual growth and yield, but did not affect density dynamic. Our results highlighted the importance of balanced NPK application in DOR production, suggesting that management strategy of these nutrients should be comprehensively considered with an aim to build an appropriate population structure with balanced plant density and individual growth.

基于四行精密播种的玉米直播机设计与试验

为了解决播种玉米种子精度低的问题,设计了一款基于四行精密播种的玉米直播机,可实现玉米种子快速、精准播种。试验表明:该玉米直播机移动性能好、播种速度快、种植深度和每穴种子数量更加准确,封土情况也大幅改善,符合设计需求,具有较高的可靠性和可行性。

化肥优化减施对麦茬旱直播稻强、弱势粒食味与营养品质的影响

以常规施肥处理(F0,施N 350 kg/hm^(2)、P_(2)O_(5)135 kg/hm^(2)、K_(2)O 135 kg/hm^(2))为对照,研究不同化肥优化减施处理(F1:施N 280 kg/hm^(2)、P_(2)O_(5)108 kg/hm^(2)、K_(2)O 135 kg/hm^(2);F2:施N 210 kg/hm^(2)、P_(2)O_(5)81 kg/hm^(2)、K_(2)O 135 kg/hm^(2);F3:施N 140 kg/hm^(2)、P_(2)O_(5)54 kg/hm^(2)、K_(2)O 135 kg/hm^(2))对麦茬旱直播稻强、弱势粒食味与营养品质的影响,以期为直播稻优质高产施肥管理提供参考。结果表明,各化肥优化减施处理总体上均显著提高了直播稻强、弱势粒崩解值和峰值黏度,改善了食味品质,F1、F2、F3处理强势粒的崩解值分别比F0处理显著提高8.35%、7.65%、9.78%,F1、F3处理弱势粒的崩解值分别比F0处理显著提高13.25%、11.13%。各化肥优化减施处理总体上均显著降低了强、弱势粒中组氨酸、脯氨酸及锰含量,总体上均显著提高了强、弱势粒中酪氨酸、精氨酸、赖氨酸含量和弱势粒中铜、锌含量,另外,F1处理还显著提高弱势粒中铁含量,F2处理显著提高强势粒中铁、铜含量及强、弱势粒中钙含量。与F0处理相比,F1、F2、F3处理强势粒的酪氨酸含量分别显著提高100.28%、44.76%、41.08%,弱势粒的酪氨酸含量分别显著提高85.21%、61.64%、22.47%;F1、F2、F3处理强势粒的赖氨酸含量分别显著提高28.87%、27.32%、70.62%,F1和F3处理弱势粒的赖氨酸含量分别显著提高27.23%、39.44%;F1、F2、F3处理强势粒的精氨酸含量分别显著提高6.54%、11.84%、2.18%,弱势粒的精氨酸含量分别显著提高32.83%、33.59%、23.02%。与F0处理相比,F1处理弱势粒铁含量显著提高27.16%,F1、F2、F3处理弱势粒锌含量分别显著提高18.86%、6.56%、3.39%,F1、F2、F3处理弱势粒铜含量分别显著提高2.49%、2.95%、3.11%。综上,化肥优化减施在提高强、弱势粒食味品质的同时,可以改善营养品质,总体上以F1处理最优。

播期和密度对精量穴直播水稻产量和抗倒伏性的影响

为探究渝西地区播期与密度互作对精量穴直播水稻产量和抗倒伏的影响,以渝香优8133和泰优粤禾丝苗为试验材料,设置2个播期(B1:3月29日、B2:5月25日)和5个播种密度(D1:每1 hm^(2)1.50×10^(5)穴、D2:每1 hm^(2)1.95×10^(5)穴、D3:每1 hm^(2)2.40×10^(5)穴、D4:每1 hm^(2)2.85×10^(5)穴、D5:每1 hm^(2)3.30×10^(5)穴),分析茎秆力学、茎秆形态及器官干物质积累与茎秆抗倒伏性和产量的关系。结果表明,与早播处理(B1)相比,迟播处理(B2)可显著提高精量穴直播水稻产量水平;同时,B2播期处理较高的叶面积指数(LAI)和有效穗数导致茎秆倒伏指数显著提高。随着播种密度增加,2个水稻品种的产量均呈先增加后降低趋势,B1播期下D3处理产量最高,B2播期下D4处理产量最高,但与D3处理差异不显著;而倒伏指数呈持续增加趋势,2个水稻品种趋势一致。与D1处理相比,B1和B2播期的D2、D3处理倒伏指数增幅较小,D4、D5处理显著升高,以渝香优8133表现明显。在B1和B2播期下,D2、D3处理的单株茎鞘干重、基部节间茎粗、壁厚及茎鞘充实度与D1处理相当,而D4、D5处理大幅降低。综合分析认为,在B1和B2播期下,D3处理是精量穴直播水稻产量、抗倒伏协同较好的适宜播种密度。

播种量对滨海稻区水稻机械旱直播产量、米质及经济效益的影响

为了完善滨海稻区水稻机械旱直播稻高产栽培技术体系,保证产量米质同时尽量降低农业成本、降低劳动强度,提高农业生产效率、经济效益,为直播稻未来在滨海稻区发展提供理论依据。采用田间对比试验方法,研究了不同播种量对滨海稻区水稻机械旱直播产量、米质及经济效益的影响,探索滨海稻区水稻机械旱直播最佳播种量。结果表明,播种量为97.5 kg/hm^(2)机械旱直播产量最高,加工品质较好,但稻米营养品质及食味值略低于播种量为120 kg/hm^(2);水稻机械旱直播比机插秧分别减产2.13 t/hm^(2)、1.76 t/hm^(2)、2.05 t/hm^(2),但效益比机插秧分别增加了0.144万元/hm^(2)、0.218万元/hm^(2)、0.118万元/hm^(2),处理2比处理1、3分别增加0.074万元/hm^(2)、0.100万元/hm^(2)。

肥密措施对水直播稻苗期杂草发生及产量的影响

为明确水分管理方式、施氮量和用种量对水直播稻生长发育特性、产量和苗期稻田杂草发生的影响,于2021年以卓两优1126为试验材料,采用再裂区试验设计,在湖南省浏阳市开展大田试验。以水分管理方式为主区,施氮量为副区,播种量为再副区。水分管理(播种至3叶1心期)设淹水(W1)和湿润(W2)2个处理;施氮量设0 kg/hm^(2)(N0)、150 kg/hm^(2)(N1)和195 kg/hm^(2)(N2)3个处理;播种量设15.0 kg/hm^(2)(D1)、22.5 kg/hm^(2)(D2)和30.0 kg/hm^(2)(D3)3个处理。结果表明,不同水分管理方式间苗期稻田杂草总数差异极显著,而不同施氮量和用种量处理间杂草总数差异不显著。W1处理水稻平均产量为8.5 t/hm^(2),显著高于W2处理;N1和N2处理间水稻平均产量差异不显著,但均显著高于N0处理;水稻产量随着用种量的增加而增加,但不同用种量处理间差异不显著。综上,水稻淹水直播条件下,施氮量为150 kg/hm^(2),播种量为15.0 kg/hm^(2),并于3叶1心期除草1次,可在减少除草剂用量的同时实现水稻增产。

洋葱小鳞茎大小及播种方向对其品质及产量的影响

以洋葱小鳞茎作为材料,采用田间试验的方法,设计5~6、4 mm和3 mm 3种小鳞茎大小,鳞茎根部向下和鳞茎水平放置2种播种方向,研究了不同小鳞茎横径大小及鳞茎根部不同播种方向对洋葱鳞茎性状、品质及产量的影响,以期获得最适宜的小鳞茎横径标准。结果表明:T1处理的综合评价最高,发芽率95.06%、株高57.90 cm、假茎粗11.47 mm、叶片数7.93片、SPAD值52.07、果形指数0.91、单果质量311.33 g、2.68 m^(2)小区产量18.96 kg、干物质含量6.33%、可溶性固形物含量15.00%、可溶性糖含量1.63%、丙酮酸含量8.71 mg·(100g)-1FW、维生素C含量11.99 mg·(100g)-1FW。将6种处理的各项指标进行主成分分析并进行综合评价,综合评价值由高到低为T1>T2>T3>T4>T5>T6。综上所述,5~6 mm鳞茎根部向下(T1)处理的综合表现良好,排名第一,洋葱的生长、品质及产量达到最优。

鄂中地区油菜专用肥施用效果

为明确油菜(Brassica napus L.)专用肥对鄂中地区直播油菜产量的提升效果,于2019—2021年在湖北省沙洋县开展了连续2年的田间试验,设置了不施肥、常规施肥、宜施壮专用肥和洋丰专用肥4个施肥处理,考察各处理下成熟期油菜产量、地上部生物量、地上部养分含量、地上部养分积累量以及肥料偏生产力等的差异。结果表明,与不施肥对照相比,常规施肥和专用肥处理均能显著提高油菜子产量;与常规施肥相比,专用肥处理总养分投入减少了41.3%,而两者油菜子产量无明显差异。施肥显著增加了油菜地上部生物量,促进了油菜地上部对养分的吸收。油菜专用肥处理显著提高了肥料偏生产力,与常规施肥处理相比,宜施壮专用肥和洋丰专用肥处理平均肥料偏生产力在2019—2020年、2020—2021年分别提高了80.6%和68.2%。综上所述,油菜专用肥在保障油菜高产稳产的同时,提高了肥料利用率。

不同播种量对直播山地油菜农艺性状和产量的影响

为在低纬度高原山区综合评价并推广直播油菜最适宜的播种量和种植密度,研究不同播种量对早熟杂交油菜品种‘黔油早2号’产量及经济性状等的影响。结果表明:(1)‘黔油早2号’油菜生育期、成株率、株高、一次分枝数、主花序荚数、主花序长、单株有效荚数、每角粒数等性状均随着播种量的增加呈下降趋势,油菜倒伏率、分枝高随着播种量的增加呈增加趋势;(2)不同播种量的油菜产量构成因子有较大差异,单位面积有效荚数、千粒重、产量随着播量增加呈现先增后减的趋势;(3)‘黔油早2号’在10月中上旬播种,播种量为200 g/667m^(2)时,油菜生长势较强,单位面积有效角果数最高,产量也最高,可达220.99 kg/667m^(2)。本研究通过对早熟油菜品种生育期、倒伏性、冻害、一致性、株高、主花序长、产量构成因子、产量等全性状对比分析,进一步明确了不同种植密度下直播油菜主要性状的变化趋势,明确了低纬度高海拔山区‘黔油早2号’直播的最佳种植密度,该研究结果对于山地生产条件下科学评价和推荐直播油菜最佳种植密度具有现实意义。

Effects of Key Agricultural Measures of Mechanized Direct Seeding Technology on Rapeseed Yield in Chengdu Plain

Mechanized direct sowing of rapeseed is a labor-saving and highly-efficient culture technique. In order to explore high-yield cultivation techniques suitable for Chengdu Plain, effects of several key agronomic measures＇, such as sowing date, density and N fertilizers, on development and yield formation were studied by strip and split plot experiment of three factors. The research showed that optimal condi- tions for direct seeding technology can be achieved provided with scientific sowing date, density and appropriate N fertilizers, and the research showed that rapeseed yield reached the peak at 320 g/m2, when sowing date was on September 3th, sow- ing density was 30 plant/m2, and nitrogen fertilizer was 27 g/m2.

宣粳糯7号选育及作麦茬稻种植的高产栽培技术

本文分析了宣粳糯7号的选育过程及其特征特性,并从机插秧和直播两种栽培模式总结其作为麦茬稻的高产栽培技术。选育方面宣粳糯7号是以宣粳糯1号为母本,粳糯86120-5为父本经过系统选育而成的早熟晚粳糯稻品种,具有耐迟播、抗逆性强和适应性广等品种特性,适宜机插秧和直播作麦茬稻种植。作麦茬稻高产栽培技术原则是在有足够的有效穗数基础上,促壮秆、成大穗和增粒重,配合病虫草害防治。具体措施包括适时适量播种、科学肥水管理、综合防治病虫草害和适时收获等,机插秧还要求匀栽密植、插足基本苗。目的在于为该品种的推广种植提供参考。

不同种植方式对木地肤成活率及产量的影响

为筛选出适宜木地肤的种植方式,设置撒播、裸根苗移栽和穴盘苗移栽3个处理,研究其对木地肤成活率、冠幅、分枝数、株高、生长速率、产量和幼苗密度的影响。结果表明:3种种植方式中,穴盘苗移栽的成活率、单株鲜草产量、单株干草产量、单株种子产量和幼苗密度均取得最高值,分别为60.40%、206.10 g、125.72 g、50.81 g、203.67株/m^(2);冠幅、分枝数也最高。说明穴盘苗移栽是木地肤最佳种植方式,更有利于建植群落,可优先选择。

封杀结合技术对直播稻田杂草防治效果

直播稻田杂草种类多、密度大、出草持续时间长、危害重。随着规模化种植面积不断扩大,田间管理比较粗放,导致土壤封闭除草效果不理想。由于长期大面积使用苄嘧磺隆、氰氟草酯、五氟磺草胺等除草剂,杂草抗药性问题日趋突出,“一封一杀”技术难以有效控制杂草为害,严重影响粮食生产,需要探索直播稻田杂草防除新技术。为此,该研究进行土壤封闭与茎叶处理相结合的直播稻田杂草防治试验。结果表明,药后20 d各处理对耳叶水苋、日照飘拂草、异型莎草以及总草的防治效果均达90%以上。

Experimental Study on Working Performance of Rice Rope Direct Seeding Machine

Structure and sowing principles of rice rope direct seeding machine are introduced. In order to test the machine＇ s working performance, such as compacting effect, sowing depth, influence of sowing device to rice rope, etc., field experiments were conducted. It is concluded that mean slip ratio of compacting wheel 1 is 4.44%, wheel 2 is 5.58%, wheel 3 is 7.81%, and wheel 4 is 6.96%; mean depth of planting is 29.72 mm, and mean variability coefficient of planting depth is 6.39%. Maximum variability coefficient of planting depth is 8.40%. Rice rope＇s snapping is closely related with the machine＇s speed and guide thread wheel by sowing device orthogonal experiments. Test results show that the machine has a rational design, safe work and meets to the requirements of planting. This study has laid the foundation for further studying the project.

遵义市酒用高粱品种红缨子的适宜直播期及其气候风险

【目的】探明遵义市酒用高粱品种红缨子的适宜直播期及其气候风险,以降低或避免酒用高粱播种期受低温气象灾害的影响。【方法】基于遵义市13个(县市、区)和毕节市金沙县国家气象观测台站1961—2020年逐日气象资料,分析酒用高粱安全直播期的时空变化特征。【结果】近60年遵义市高粱主产区安全直播始期呈提前趋势,提前速率为0.086 d/a。根据Mann-Kendel法突变统计检验,高粱安全直播始期呈平稳-推迟-提前趋势,安全直播始期的UF趋势在1995年上升至最高点,2000年初发生突变。在赤水河谷海拔600 m以下地区,酒用高粱常年最早安全直播始期在3月中旬;在遵义市西部和北部海拔600~900 m地区常年最早安全直播始期在3月下旬,海拔900~1100 m地区在4月上旬。【结论】在气候变暖背景下遵义市酒用高粱直播始期呈提前趋势,在安全播期内,避开春季强降温情况,适当提前播种期可避开后期干旱、秋绵雨影响,以利于稳产高产。

耐直播粳稻种质资源筛选及其适宜种植密度研究

为筛选适合河南省稻区种植的耐直播粳稻种质,对2000份粳稻种质资源进行大田直播,分析出苗能力、始穗期、株高和产量等性状,初筛耐直播种质,然后通过考种进一步筛选耐直播高产种质,再通过始穗期、产量及其相关性状比较进一步筛选耐直播高产种质,并研究种植密度[80 kg/hm^(2)(T1)、100 kg/hm^(2)(T2)、120 kg/hm^(2)(T3)和140 kg/hm^(2)(T4)]对其产量及其构成因素的影响,确定适宜种植密度及最终的耐直播高产种质。结果表明,2000份粳稻种质中,出苗能力分级为1级的种质8份(0.40%)、3级85份(4.25%)、5级1762份(88.10%)、7级102份(5.10%)、9级43份(2.15%),平均出苗能力分级为5.09,不同地理来源种质平均出苗能力分级在4.82~5.46。随种质地理来源纬度降低,始穗期延迟。黑龙江省、吉林省、内蒙古自治区、新疆维吾尔自治区和宁夏回族自治区等地来源种质始穗期一般在8月15日之前,平均播始历期分别为47.5 d、54.9 d、54.8 d、57.8 d和59.7 d;辽宁省、日本和韩国、北京市和河北省来源种质始穗期一般在8月20—25日,平均播始历期分别为65.8 d、66.4 d、68.9 d和68.1 d;来自山东省、河南省、江苏省和云南省的种质大多数不能正常抽穗,占比48.33%~79.04%,能抽穗的种质始穗期大多在8月25日之后,平均播始历期分别为72.0 d、78.2 d、77.8 d和75.2 d。田间初步筛选出苗能力分级不低于7级,始穗期8月15日—9月4日,株高115 cm以下,无倒伏现象,无稻瘟病、纹枯病等,丰产性较好的种质194份。测产考种筛选出结实率高于80%、产量较高的耐直播种质150份。150份种质的出苗能力分级以5级为主,其中3级3份(2.0%),5级135份(90.0%),7级12份(8.0%);始穗期介于8月21日—9月4日;来源于辽宁省、河北省、山东省、河南省和江苏省5省,种质份数分别为116份(77.3%)、11份(7.3%)、7份(4.7%)、7份(4.7%)和9份(6.0%);辽宁省来源种质平均产量最高,达9286.5 kg/hm^(2),河北省、山东省、河南省和江苏省来源种质平均产量分别为6390.0 kg/hm^(2)、7053.0 kg/hm^(2)、6432.0 kg/hm^(2)和7054.5 kg/hm^(2)。鉴于150份耐直播种质中,辽宁省来源种质产量性状表现突出,从辽宁省来源耐直播种质中筛选株高不超过110 cm、始穗期8月20—30日、产量较高的种质76份,并对其进行适宜种植密度研究,发现随种植密度增加,基本苗数、穗数显著增加;T3、T4处理总颖花数显著高于T1、T2处理;T1、T2、T3、T4处理产量分别为7621.20、7735.35、8003.25、7961.10 kg/hm^(2),T3和T4处理产量显著高于T1和T2处理,T3处理产量最高。在T3处理下从76份种质中筛选出耐直播高产种质14份,其中较对照郑旱10号增产的种质9份,分别是辽星13、辽粳9号、营9207、丹粳12、锦稻105、辽星15、美锋1号、辽盐糯10号、祥丰00-93,分别较对照增产17.72%、7.75%、6.61%、6.15%、3.46%、3.16%、1.87%、1.27%、0.93%,这些种质可用于河南省及邻近地区粳稻耐直播育种,其中辽星13产量达11018.0 kg/hm^(2),表现高产,可直接应用。

播深和播量对宁夏地区直播稻幼苗素质和产量的影响

为探究播深和播量对宁夏地区直播稻幼苗生长发育和产量的影响,以宁夏水稻主栽品种富源4号为试验材料,采用二因素裂区设计,设置4种播深:1、2、3和4 cm,4个播量:112.5、187.5、262.5和337.5 kg·hm^(-2),研究不同播深和播量对直播稻幼苗素质及其产量的影响。结果表明,播深×播量对水稻出苗率的影响存在显著的互作效应,其中播深1~2 cm、播量112.5~187.5 kg·hm^(-2)四种组合较其他组合的出苗率明显增加;幼苗素质中苗高、茎基宽、充实度和壮秧指数4个指标均在播深2 cm、播量262.5 kg·hm^(-2)组合中优于其他组合;发根力在播深2~3 cm、播量187.5 kg·hm^(-2)两种组合中优于其他组合;幼苗整齐度在播深3 cm、播量262.5 kg·hm^(-2)组合中优于其他组合。在幼苗素质指标中,播深×播量对充实度和壮秧指数的影响均存在极显著的互作效应。对于根系生理指标,根系活力、根系总吸收面积和根系活跃吸收面积在播深2 cm、播量187.5~262.5 kg·hm^(-2)和播深3 cm、播量187.5 kg·hm^(-2)三种组合中优于其他组合,且播深×播量对上述3个指标的影响均存在极显著互作效应。进一步通过隶属函数结合权重分析法对不同播深和播量组合下的12个幼苗素质相关指标进行综合评价(D值),筛选到播深2~3 cm、播量187.5~262.5 kg·hm^(-2)四种较优组合。产量分析结果表明,播深3 cm、播量187.5~262.5 kg·hm^(-2)两种组合较其他组合增产明显,增产率达到4.29%~17.10%。综上,适宜播深和播量组合(播深3 cm、播量187.5~262.5 kg·hm^(-2))通过提高发根力、幼苗整齐度和根系吸收面积等幼苗素质指标促进了直播稻幼苗的生长,改善了直播稻群体质量,从而增加了直播稻产量。本研究结果为宁夏地区水稻覆土直播栽培技术的构建奠定了理论基础。