提高谷子水分利用效率的研究

采用不同品种、播种期、植物生长调节剂,实施地膜覆盖和综合栽培技术体系试验证明,品种基石型、播种期和施肥对谷子水分利用影响的作用较在植物生长调节剂和地膜也有较好作用。提高谷子水分利用效率应以选用水分利用效率应以选用水分利用高的良种,适期播种,科学施肥和选用生长调节剂为中心集成的综合栽培技术体系。试验证明,防秕增粒高产栽培体系能提高水分利用效率２６．５％～３６．９％,分带种同效栽培体系能提高水分利用３     

谷子不同栽培模式对土壤水温环境及水分利用效率的影响

通过大田试验研究了山西中部地区谷子不同栽培模式(覆膜穴播、精量条播、传统穴播)对土壤水温环境、谷子叶片及群体水分利用率的影响。结果表明:覆膜穴播处理与不覆膜的精量条播和传统穴播处理相比,全生育期土壤平均含水量分别增加1.59%和1.84%,土壤平均积温增加182.3℃,为谷子生长提供了良好的土壤环境条件。覆膜穴播与2个不覆膜处理相比,显著提高了谷子各生育阶段的叶片水平水分利用效率(WUEl)和群体水平水分利用效率(WUEc),促进了谷子的生长发育,产量显著增加。精量条播处理与传统穴播处理相比,在部分生育期的WUEl、群体WUEc、部分生长指标及产量上有着更好的表现。不同栽培模式之间的水分利用差异,WUEl提高的主要原因是净光合速率的显著增加,而WUEc提高的主要原因则是产量的显著增加。综合试验研究结果,可以确定覆膜穴播是山西中部地区谷子最适宜的高产高效栽培模式,而在不使用地膜覆盖的条件下,则应当优先选择精量条播栽培模式。     

施肥对春谷子生长发育及水分利用效率的影响

试验研究不同施肥水平对半湿润偏旱区春谷子生长发育和水分利用效率的影响结果表明,春谷子株高、单位面积穗数和千粒重对施肥量的变化均有响应,一定施肥水平内随施肥量的增加,春谷子株高、单位面积穗数和千粒重均有所增加。施肥导致春谷子地2m土体土壤蓄水量下降,且随施肥量的增加而降幅增大;施肥使春谷子水分利用效率增加11.56%~16.24%。但当施肥量超过一定水平时,增加施肥量反而使春谷子产量和水分利用效率下降。     

覆黑地膜对旱作玉米根区土壤温湿度和光合特性的影响

明确雨养旱地地膜覆盖春玉米高产与水分高效利用的土壤环境条件,及其对玉米光合特性的作用,对延缓玉米衰老、提高玉米光合能力和促进玉米增产具有重要意义。以陕单609为材料,2012和2013年开展黑色地膜覆盖、白色地膜覆盖和裸地栽培试验,研究黑色地膜对玉米根区土壤水温环境、玉米叶片光合特性、产量和水分利用效率的影响。结果表明,黑色地膜较普通白色地膜和裸地栽培,能显著改善玉米根区土壤温湿条件,提高玉米叶片光合能力。黑色地膜覆盖下,玉米叶片衰老时间明显推迟,衰老速度显著下降,成熟期叶片叶绿素含量较普通白色地膜提高11.7%(P0.05),较裸地提高45.5%(P0.05)。与普通白色地膜和裸地栽培相比,黑色地膜覆盖提高了吐丝后玉米叶片光合速率、蒸腾速率、叶片水分利用效率、PSII电子传递速率、量子产量(灌浆期除外)和光化学猝灭系数。黑色地膜覆盖下玉米千粒质量、产量和水分利用效率显著增加,千粒质量较普通白色地膜和裸地栽培分别增加5.0%和14.9%(P0.05);产量分别提高10.4%和22.1%(P0.05);水分利用效率分别提高10.4%和25.3%(P0.05)。在雨养旱作地区,玉米采用黑色地膜覆盖具有延缓后期叶片衰老和促进增产的效果。     

不同覆盖方式对绿豆水分利用效率的影响

绿豆是陕北旱区特色经济作物和主要农作物之一,探索适合地区特色的绿豆高产抗旱栽培技术对完善该区小杂粮栽培模式和提高区域农业水平意义重大。通过田间试验,设置垄膜覆盖、双沟覆膜、全膜覆盖、秸秆覆盖和露地5种处理,分析了不同覆盖方式对绿豆土壤温度、耗水量、水分利用效率、生长和经济性状以及产量的影响。结果表明,地膜覆盖对陕北地区绿豆增产效果极为显著,秸秆覆盖可提高水分利用效率,但同时降低地温,增产作用不明显。3种地膜覆盖方式中,又以垄膜覆盖方式提高水分利用效率和增加绿豆产量的效果最好,且操作简单,在陕北地区绿豆抗旱栽培中应优先考虑。     

氮磷肥配施促进半干旱区沟垄集雨种植谷子节水增产

沟垄集雨种植是西北旱作农田广泛运用的高效节水栽培模式,为优化施肥配置,进一步提升其增产效能,该研究在沟垄集雨和平作2种种植模式下分别设置不施肥、低量（N 93 kg/hm2+ P2O548 kg/hm2）、中量（N 186 kg/hm2+ P2O596 kg/hm2）和高量（N 279 kg/hm2+ P2O5144 kg/hm2）共4个施肥量水平,对宁南旱区连续4 a（2012—2015年）施肥梯度处理下谷子产量及水肥利用效率进行了研究。结果表明,沟垄集雨种植较平作可有效降低土壤水分蒸发,谷子全生育期总耗水量减少了18.3~26.8 mm;同一施肥水平下,沟垄集雨种植在2012、2013年（丰水）呈减产趋势,在2014、2015年（平水）显著增产,较平作增加了穗粒数和收获指数,提高了谷子的水肥利用效率。在各降雨年份下,随施肥量的加大,沟垄集雨种植下谷子干物质积累量、产量和水分利用效率均呈增加趋势,当超过中肥后增幅不显著,肥料农学利用效率呈下降趋势,经济收益在中肥下达到最大。综合产量和经济效益分析,中肥是半干旱区谷子沟垄集雨种植模式的适宜施肥量,较平作种植在平水年型下可增产7.6%,水分利用效率和肥料农学利用效率分别提高了14.9%和9.9%。     

施肥和秸秆覆盖对旱地作物水分利用效率的影响

１９９２～１９９５年,在陕西省合阳旱地进行了施肥和秸秆覆盖对冬小麦、春向日葵水分利用效率影响试验。结果表明,在一定的施肥范围内,肥水表现为互促协同效应,作物的水分利用效率随着施肥量的增加而提高,试验条件下,冬小麦水分利用效率增加１４．９％～５７．５％。秸秆覆盖能抑制土壤蒸发,增强作物蒸腾,从而提高作物水分利用效率,在旱地推广合理施肥和秸秆覆盖技术是提高作物产量的有效途径。     

覆膜和密度对宁南旱地马铃薯产量及水分利用效率的影响

以庄薯3号为供试材料,采用大田试验,研究覆膜对不同栽培密度条件下土壤储水量、马铃薯产量构成、产量以及水分利用效率的影响。结果表明:地膜覆盖可明显提高0—40,40—100 cm土壤储水量,提高了马铃薯块茎产量（25.2%）和水分利用效率（28.0%）;不论覆膜与否,适宜的马铃薯密度可提高马铃薯产量和水分利用效率,趋势为6.0万株/hm² > 7.5万株/hm² > 4.5万株/hm²,但地膜覆盖优于裸地。因此,在宁南旱地马铃薯覆膜栽培条件下密度为6.0万株/hm²时,能有效减少土壤水分消耗,同时实现马铃薯高产。     

旱地谷子平膜穴播高产栽培技术

谷子在榆林南部黄土高原丘陵沟壑区及西南部梁状低山丘陵等旱作地区广泛种植。为了给干旱地区谷子生产提供支撑,提高谷子产量和效益。在榆林旱作农业区通过开展平膜穴播谷子高产栽培试验,从选地整地、施肥、品种选择、种子处理、播种、田间管理、病虫草鸟害防治和适时收获等方面总结提出了榆林旱作区谷子高产栽培技术。     

不同栽培方式对马铃薯田间土壤温湿度及产量的影响

为了研究地膜覆盖和绿肥对提高我国西南高寒山区春播马铃薯田间耕层土壤温度和水分的影响,通过2009－2010年设置地膜覆盖和绿肥的不同处理,研究其对马铃薯田间土壤耕层温度、水分及产量的影响。结果表明：与传统栽培方式相比,播种后至封行前,地膜覆盖且施绿肥栽培方式和地膜覆盖栽培方式耕层土壤（0～20?cm）日平均温度提高3.6℃和2.9℃。地膜覆盖且施绿肥栽培方式、施绿肥栽培方式和地膜覆盖栽培方式田间土壤（0～21?cm）平均含水率提高了12.93%、6.3%和10.88%;封行后,地膜覆盖且施绿肥栽培方式和地膜覆盖栽培方式田间土壤平均含水率低6.35%和6.4%。地膜覆盖且施绿肥栽培方式和施绿肥栽培方式马铃薯的块茎产量增加25.6%和2.3%。因此,地膜覆盖且施绿肥栽培方式能显著地提高苗期耕层土壤温度、含水率和马铃薯的块茎产量。     

Biochar particle size and Rhizobia strains effect on the uptake and efficiency of nitrogen in lentils

Abstract

Biochar has attained significant attention as a beneficial soil amendment amongst growers and researchers. However, the impact of particle size of biochar is yet to be investigated. Here in the present study, we studied three particle sizes (<2?mm, 2–5?mm, and >5?mm) of biochar and two rhizobia strains (Rhizobium leguminoserum (RL) and Rhizogold (RG)) for their effect on the uptake and efficiency of nitrogen (N) in lentils. The two years experiment followed a randomized complete block design with split plot arrangement replicated three times. The data revealed that grain N, straw N, N uptake, N recovery efficiency (NRE), and N agronomic efficiency (NAE) were maximum with biochar smallest size (<2?mm). However, the N physiological efficiency, number of branches and plant height decreased with reduced particle size. Furthermore, the smallest particle size showed more number of pod plant^?1. Biofertilizer strain (RL and RG) significantly increased the straw N but not the grain N. Both strains showed increased NRE and NAE, however, the RL demonstrated 7% more grain N than the RG. Both strains (RL and RG) demonstrated 16% and 20% increase in number of branches plant^?1, 62% and 48% in plant height and 2% and 5% in root length, respectively. The RL strain improved the number of branches plant^?1 at the lowest (<2?mm) and medium size (2–5?mm) particles size but both RL and RG strains demonstrated increased plant height under the maximum particle size. These results indicated that a mere increase in surface area with decreasing biochar particle size may not serve for enhancing biofertilizer strains performance since reducing particle size may immobilize the starter N applied. However, reducing particle size effect on N cycling into soil plant system was favorable.     

Nutrient accumulation and nutritional efficiencies of cashew genotypes

Efficient cashew plants in relation to nutrition may represent gains in growth and production, especially in low fertility soils. This study aimed to determine the accumulation, the uptake, transport, and utilization efficiencies in different cashew genotypes. Twelve genotypes were evaluated, 10 of the dwarf type, a common type, and a hybrid. The seedlings were grown in plastic pots filled out with organic substrate. Sixty days after sowing, the plants were collected for the determination of dry matter and macro and micronutrients concentrations. Nutrient accumulation in cashew follows the descending order: N?>?K > P?>?Mg?>?Ca?>?S > Fe?>?Mn?>?Cu?>?B > Zn. Overall, for all nutrients, plants from BRS 274 had the high accumulation and utilization efficiency; the CCP 06 and CCP 76 in uptake; and the CCP 76 and BRS 189 in transport.     

Corn Yield and Nitrogen- and Water-Use under No-Tillage Rotations

Increased crop diversity and length of rotation may improve corn (Zea mays L.) yield and water- and nitrogen-use efficiency (WUE and NUE). The objectives of this study were to determine effects of crop rotation on corn yield, water use, and nitrogen (N) use. No-tillage (NT) crop rotations were started in 1997 on a Barnes clay loam (fine-loamy, mixed, superactive, frigid Calcic Hapludoll) near Brookings, S.D. Rotations were continuous corn (CC), corn–soybean [Glycine max (L.) Merr.] (CS), a 3-year rotation of corn–soybean–oat/pea (Avena sativa L. and Pisum sativum L.) hay (CSH), a 3-year rotation of corn–soybean–spring wheat (Triticum aestivum L.) (CSW), and a 5-year rotation of corn–soybean–oat/pea hay companion seeded with alfalfa (Medicago sativa L.)–alfalfa–alfalfa (CSHAA). Fertilizer N was applied to corn on all rotations at planting (16 kg N ha^?1) and side-dressed (64 kg N ha^?1). Average corn grain yields (1998–2007) were greatest under CSW (7.38 Mg ha^?1) and least under CC (4.66 Mg ha^?1). Yields were not different among CSH, CSW, and CSHAA rotations. Water-use efficiency of rotation was ordered as CSW > CSH > CSHAA > CS > CC. Nitrogen-use efficiency was greatest under CSW and least under CC. There were no differences in yield advantage (YA) among crop rotations during years with plentiful early-season rainfall (May 1–July 31). In years with low spring rainfall, YA was greatest under CSW (54%) and least under CSHAA (33%). Corn yields under extended rotations (CSH, CSW, and CSHAA) were greater than under CC and CS, but lack of rainfall may result in reduced yields under CSHAA.     

Assessment of nitrogen uptake and utilization in drought tolerant and Striga resistant tropical maize varieties

Maize (Zea mays L.) is an important food crop in the Guinea savannas of Nigeria. Despite its high production potential, drought, Striga hermonthica parasitsim, and poor soil fertility particularly nitrogen deficiency limit maize production in the savannas. Breeders at IITA have developed drought- and Striga-tolerant cultivars for testing, dissemination, and deployment in the region. Information on the response of these cultivars to N fertilization is, however, not available. This study evaluated grain yield, total N uptake (TNU), N uptake (NUPE), N utilization (NUTE), and N use efficiency (NUE) of selected maize cultivars along with a widely grown improved maize cultivar at two locations in the Guinea savannas of northern Nigeria. Maize grain yield increased with N application. The average grain yield of the maize cultivars was 76% higher at 30, 156% higher at 60, and 203% higher at 120 kg N ha^?1 than at 0 kg N ha^?1. This suggests that N is a limiting nutrient in the Nigerian savannas. Five drought-tolerant cultivars produced consistently higher yields when N was added at all levels. These cultivars had either high NUPE or NUTE confirming earlier reports that high N uptake or NUTE improves maize grain yield. The study also confirms earlier reports that maize cultivars that are selected for tolerance to drought are also efficient in uptake and use of N fertilizer. This means that these cultivars can be grown with application of less N fertilizer thereby reducing investment on fertilizers and reduction in environmental pollution.     

玉米自交系苗期磷营养特性评价

利用一元线性回归模型对9种基因型玉米自交系在6叶龄苗期的磷(P)营养特性进行了评价。以幼苗的全株或地上部生物量(mg/plant)分别与培养介质对其供磷量(P.mg)建立线性模型,其回归系数作为全株或地上部磷效率的指标;以幼苗的全株或地上部生物量分别与相应的全株或地上部磷含量(P.mg/plant)建立线性模型,其回归系数作为全株或地上部磷利用效率的指标;以幼苗全株磷含量与培养介质对其供磷量建立线性模型的回归系数作为幼苗磷吸收效率的指标。结果表明,9种玉米基因型的磷效率,磷利用效率和磷吸收效率的平均值分别为53.95(全株)和42.61(地上部)、131.84(全株)和124.45(地上部)、0.41。自交系04419的磷效率比平均值约高出45%(全株)和59%(地上部),属于磷效率高效型;而自交系04065和04088的磷效率分别比平均值约低43%、38%(全株)和55%、51%(地上部),属于磷效率低效型;其余自交系的磷效率介于两者之间,为磷效率中间型。玉米自交系苗期的磷效率与磷吸收效率呈显著正相关,与磷利用效率关系不明显;磷吸收效率可作为苗期磷效率预筛选的生理指标。     

Effect of nitrogen application on growth and yield of pumpkin

Evaluation of any crop response to different nitrogen amounts is important for determining the amount that can be considered as optimum from economical and environmental point of view. This study was conducted to (1) evaluate the growth and yield of pumpkin (Cucurbita pepo L.) under different nitrogen rates and (2) determine the nitrogen use efficiency (NUE) of pumpkin in two growing seasons (2013 and 2014). In both growing seasons, nitrogen fertilizer (at three rates including 50, 150, and 250 kg ha^?1) was band-dressed on the planted side of each furrow, coinciding with 4–6 leaves stage and flowering. Crop performance over 2 years was evaluated by measuring shoot dry matter, crop growth rate (CGR), leaf area index (LAI), leaf area duration (LAD), intercepted PAR (PAR_i), radiation use efficiency (RUE), shoot nitrogen uptake, water use efficiency (WUE), NUE, and fruit and seed yield. The results showed that in both growing seasons, the highest growth and yield of pumpkin were obtained by applying 250 kg N ha^?1 (using urea fertilizer containing 46% nitrogen). Increased nitrogen rate from 50 to 250 kg ha^?1 resulted in 87.3%, 27.0%, 62.1%, 87.5%, and 84.5% increase in shoot dry weight, RUE, WUE, fruit yield, and seed yield of pumpkin, respectively, across both growing seasons. However, higher application nitrogen rate decreased the NUE of pumpkin, i.e., the NUE decreased by 62.5% when the nitrogen rate increased from 50 to 250 kg ha^?1. The effect of nitrogen applied in 2014 growing season on growth and yield of pumpkin was higher than that in 2013 growing season, which might be due to more suitable weather condition. In conclusion, the nitrogen rate of 250 kg ha^?1 produced the highest amount of fruit and seed yield in pumpkin.     

Wheat Yield Differences between Two Cropping Systems in Permanent Raised-Beds as Affected by Components of Nitrogen Use Efficiency

Permanent raised-bed is an alternative planting system for wheat (Triticum aestivum L.) in rain-fed areas. However, this system in monoculture conditions produces lower yields compared with wheat in rotation. Our objective was to estimate these yield differences as affected by nitrogen (N) use efficiency (NUE). Wheat in monoculture and in rotation with maize (Zea mays L.) was evaluated for eight years (2002–2009) with four N rates (0, 40, 80 or 120 kg ha^?1). Yield response to N in monoculture was consistently lower than for wheat in rotation. Yield reduction in monoculture at low and high N rate was 81 and 99% attributed to NUE out of which 70 and 82% was due to the uptake efficiency (UPE) and 30 and 19% to the utilization efficiency (UTE), respectively. Total N uptake proved to be the parameter that needs to be improved to enhance wheat yield in monoculture.

Abbreviations: NUE: nitrogen use efficiency; UPE: uptake efficiency; UTE: utilization efficiency; Ns: nitrogen supply; NDVI: normalized difference vegetation index     

农作物N素利用效率基因型差异及其机理

不同农作物N素利用效率基因型差异主要与N素吸收效率和生理利用效率有关。根系N的吸收动力学、根系形态、吸收时间是影响N素吸收效率的重要因素;N素生理利用效率与N的同化、转运及光合作用、C转运效率等生理过程有关。分析农作物N素利用效率基因型差异机理对提高N肥利用效率,降低N肥损失,充分发挥N肥在农业生产中的作用,降低农业生产成本和保护生态环境,促进农业可持续发展具有重要意义。     

不同年代棉花品种磷效率比较

提高磷肥利用率是当今农田磷养分资源管理面临的重要难题,作物品种改良是提高磷利用率的有效途径之一。为明确新疆不同年代棉花品种(系)磷效率的差异,采用单因素随机区组设计,通过大田试验,以新疆1950s—2013年不同年代的22个棉花品种(系)为材料,研究了不同年代培育的棉花品种(系)在苗期、蕾期、花铃期和吐絮期的磷吸收、利用效率特征,并采用模糊数学隶属函数和聚类分析方法,对不同棉花品种(系)磷效率的高低进行了综合评价。结果表明:不同棉花品种(系)磷吸收效率、利用效率、磷由茎叶向籽粒的转移效率(再转移效率)存在差异。吐絮期磷吸收效率为164.26～395.75 mg·株~(-1),变异系数为3.3%;磷利用效率为0.25～0.40 g·mg~(-1),变异系数为67.7%;磷再转移效率为16.0%～58.1%,变异系数为11.1%。以每20年为一个时期,划分了3个品种更替阶段,棉花磷利用效率在3个阶段没有发生明显改变,始终维持在0.30～0.32 g·mg~(-1);磷吸收效率由225.5 mg·株~(-1)增加到286.3 mg·株~(-1),提高了27.0%;磷由根系向地上部的转移效率(转移效率)没有发生明显改变,始终维持在93.9%～94.9%;磷再转移效率由26.8%增加到38.3%;磷经济利用效率由20.6 mg·mg~(-1)增加到30.4 mg·mg~(-1)。相关性分析表明:不同棉花品种(系)生物量与磷吸收效率呈显著正相关,而与磷利用效率无显著的相关性;皮棉产量与磷吸收效率、转移效率、再转移效率、经济利用效率呈极显著正相关,而与磷利用效率相关性不明显。对22个棉花品种(系)吐絮期生物量、皮棉产量、磷吸收利用效率及转移效率和经济利用效率等性状指标的综合评价和聚类分析,将22个品种(系)分为磷高效型、中效型、低效型和极低效型4组,‘新陆早50号’‘新陆早57号’‘军棉1号’为磷高效型品种。与磷低效组相比,磷高效组的品种具有较高的生物量和产量。以上结果表明,新疆棉花高产育种过程提高了磷素吸收、再转移和经济利用效率。     

氮肥对水稻氮素吸收及利用效率的影响

选用超级稻品种沈农265和传统品种辽粳294为试材,比较氮肥对两品种氮素吸收及利用效率的影响。结果表明,氮肥施用量高时,沈农265氮素农学效率、生理效率等指标高于辽粳294,氮肥用量低时则相反,说明高氮肥条件有利于沈农265潜力的发挥;同样肥力水平下,沈农265每100 kg子粒所需氮量少,说明其氮素向子粒转化、运输能力强于辽粳294。