旱作马铃薯氮素的吸收、积累和分配规律

马铃薯植株体内氮素浓度的高低与其生长势的强弱密切相关,本研究结果表明,叶片、地上茎、块茎中氮素浓度的变化幅度分别为2%～5%、1%～4%、1%～3%;成熟期氮素在叶片、地上茎、块茎中的分配率分别为30%左右、10%～15%、50%～60%。马铃薯对氮素的吸收速率在整个生育期间呈单峰曲线变化,峰值出现在块茎快速增长期(出苗后51d左右),最高吸收速率平均可达99 96mg/(株·d),每生产500kg块茎需吸收氮素3 02kg。     

马铃薯磷素的吸收、积累和分配规律

磷元素在马铃薯植株体内的流动性较大,磷营养水平与块茎膨大密切相关,块茎是磷素的最终贮存库。在块茎增长初期,叶片、地上茎和块茎中的磷素浓度均为一生中的最高值,此时是马铃薯对磷需求最多的时期,块茎形成后,则大量的磷(P2O5)向块茎转移。马铃薯对磷素(P2O5)吸收速率较低。在整个生育期内吸收速率呈单峰曲线变化,峰值出现在块茎增长期。     

马铃薯钾素的吸收、积累和分配规律

马铃薯各器官中钾素(K2O)浓度始终以茎秆中最高,表明作为运输器官的地上茎需要更多的钾离子。马铃薯对钾素(K2O)的吸收速率呈双峰曲线变化,峰值分别出现在块茎增长初期和淀粉积累期,且以淀粉积累期的吸收速率为最高,这与块茎的生育代谢规律一致。降低密度、增施氮、磷、钾肥可提高各器官中钾的含量和钾的积累量,尤其是增施磷肥。马铃薯钾素(K2O)积累量在淀粉积累期达到峰值,在块茎形成期以前,叶片中钾素(K2O)的分配率最高;块茎形成后,地上茎中的K2O的分配率始终高于叶片,这有利于保持地上茎的高效运输、直立与抗性;块茎形成后,K2O的分配率逐渐增加,对于块茎体积的增长和淀粉的积累具有重要意义。     

冬种马铃薯的氮素吸收、积累、分配特征研究

在田间条件下,通过布置氮磷钾肥料基追分配试验,探讨了冬种马铃薯对氮素的吸收、积累和分配规律.结果表明:马铃薯叶片、茎的氮素含量在齐苗后15 d左右出现小高峰,后逐渐递减;块茎氮素浓度随着生长发育进程整体上呈现递减的趋势.马铃薯各器官氮素含量总体表现为叶片＞茎＞块茎.2009～2010年,每生产1 000kg块茎需吸收氮素(N)2.62 kg; 2010～2011年,每生产1 000kg块茎需吸收氮素(N)4.14 kg.叶片中氮素吸收量在齐苗后25 d达到高峰,用于叶绿体和光合系统的建成,此后,氮素对叶片的吸收量逐渐下降.茎中氮素吸收量在齐苗后35 d达到高峰,然后随着生育进程逐渐下降.块茎对氮素的吸收在齐苗后55 d达到高峰,大量的氮素转移到块茎中,用于块茎的建成.     

旱作马铃薯钾素的吸收、积累和分配规律

马铃薯各器官钾素浓度随生长发育进程均呈现递减变化,且地上茎中钾素浓度始终高于叶片和块茎,而块茎和叶片的钾素浓度差异较小。钾素(K2O)的吸收速率呈单峰曲线变化,在种植密度适宜、氮磷钾适量配施下,最高吸收速率可达130 81mg/(株·d),峰值出现在出苗后47d左右;钾素(K2O)积累量随生长发育进程呈三次曲线变化,在优化栽培条件下,每生产500kg块茎需吸收钾素(K2O)4 49kg;成熟期钾素在叶片、地上茎、块茎中的分配率分别为10%～20%、10%～20%、60%～70%。     

氮肥施用时期对马铃薯氮素积累与分配的影响

以马铃薯克新13号脱毒种薯为材料,在相同氮肥用量下,设置不同生育时期施氮的田间小区试验,通过测定主要生育期植株各器官干物重和含氮量,研究施氮时期对马铃薯不同器官氮素积累、分配及块茎产量和质量的影响。结果表明,马铃薯在营养生长期的吸氮素量仅为全生育期的1/3,块茎形成中期达到马铃薯的吸氮高峰期,块茎增长后期至成熟期块茎中的氮素主要来自营养器官的二次分配。与N 150 kg/hm2全部做基肥相比,将1/3的氮在块茎增长初期追施可使商品薯产量提高25%(P<0.05),达到30.01 t/hm2。氮肥利用率达到44%(P<0.05)。适宜氮肥用量下,基肥和追肥的合理分配是获得马铃薯高产优质的重要条件,基肥氮不足,氮肥集中在苗后施用,则易导致植株贪青。试验在肥力中等的土壤种植马铃薯,150 kg/hm2氮素用量条件下,将2/3的氮作基肥施用,1/3的氮在块茎增长初期追施,较有利于养分在块茎中的分配,同时也能获得最高的块茎产量。     

马铃薯器官生长发育与产量形成的研究

马铃薯叶面积、叶干重以及块茎干物重和块茎体积的变化动态均符合三次曲线变化 ,地上茎干重、茎粗、株高符合S型曲线变化 ,其中 ,叶干重的峰值早于叶面积的峰值 ,块茎体积的增长则在出苗后 5 5～ 70d内最快。马铃薯地上茎的生长主要是伸长与充实 ,但伸长较充实缓慢、持续时间更长。匍匐茎与块茎的形成是马铃薯产量形成的前提条件 ,二者的建成与植株其它器官的生长发育密切相关 :匍匐茎和块茎的形成与叶片和地上茎形成时期并进 ,所以 ,马铃薯块茎的建成与地上营养器官的生长发育存在着光合产物的竞争 ,但地上部器官的建成依然是产量形成的物质基础。     

马铃薯硫素吸收规律的初步研究

通过田间试验和室内测定分析,研究了马铃薯硫素吸收规律。结果表明:马铃薯全生育期内各器官含硫量始终以叶片最高,茎秆其次,块茎最低;全株硫的累积吸收量随生育进程的推进呈二次曲线变化,在淀粉积累期硫素累积量达到最大值;块茎形成至块茎增长期是马铃薯一生中硫素吸收速率最快、吸收数量最多的时期;生育期间硫素在马铃薯各器官的分配随着生长中心的转移,发生相应的变化,块茎增长期之前叶片中分配最多,其次为茎秆,块茎中最少,之后则是块茎中最多,茎秆其次,叶片中最少;硫在叶片中的分配率随生育进程逐渐降低,块茎中硫的分配率则为直线增长,茎秆中硫的分配率变化表现为单峰曲线,峰值出现在块茎形成期。本试验产量水平下,每生产500kg块茎需要吸收硫0.13kg。     

施氮量对马铃薯氮素积累分配及利用率的影响

合理的施肥技术是提高马铃薯产量的主要措施之一。氮肥在马铃薯增产中作用巨大,但是氮肥的不合理施用通常造成马铃薯产量降低、品质下降、氮肥利用率降低。为合理施用氮肥,提高马铃薯产量和氮肥利用率,以鲜食品种‘东农09-33069’为试验材料,研究不同氮肥施用量对马铃薯氮素积累分配规律及其利用率的影响。结果表明,马铃薯植株氮含量、氮素积累量随施氮量的增加而升高。随生育期的推移,马铃薯植株氮素积累量呈先增加后降低的趋势,氮素在茎和叶片中分配比例逐渐降低,块茎中氮素分配比例逐渐升高至成熟期的57%~78%。当施氮量超过10 kg/667m2时,块茎中氮素积累量增加不明显,块茎氮素分配比例不再增加。马铃薯产量在施氮量13.3 kg/667m2时达到最大值,氮素吸收利用率、偏生产力、氮肥农学利用率和氮肥生理利用率在施氮量3.3 kg/667m2时取得最大值。     

旱作马铃薯磷素的吸收、积累和分配规律

磷元素在植株体内的流动性较大,磷营养水平与块茎膨大密切相关,块茎是磷素的最终贮存库。叶片、地上茎、块茎中磷素浓度的变化幅度分别为0 28%～0 51%、0 26%～0 58%、0 33%～0 49%,成熟期磷素在叶片、地上茎、块茎中的分配率分别为15%～20%、10%～15%、70%～75%。马铃薯对磷素的吸收速率在整个生育期间呈单峰曲线变化,峰值出现在块茎快速增长期(出苗后50d左右),最高吸收速率可达19 2mg/(株·d),每生产500kg块茎需吸收磷素0 80kg。     

马铃薯氮素营养状况的SPAD仪诊断

以马铃薯品种克新1号为材料,研究了叶片SPAD值、叶片全氮含量、叶绿素含量以及块茎产量随供氮水平的变化规律及相互关系,旨在为使用叶绿素仪进行马铃薯无损伤氮素诊断和推荐施肥奠定基础。研究结果表明,从马铃薯苗期到块茎淀粉积累各个生育阶段叶片的SPAD测定值均与马铃薯叶片含氮量呈显著正相关关系。除苗期外,块茎形成期、块茎膨大期、淀粉积累期的马铃薯叶片含氮量和叶片SPAD值随土壤施氮量的变化均表现为线形加平台的模式。因此马铃薯块茎形成期后叶片的SPAD读数可揭示马铃薯的氮素营养状况。统计分析结果还表明,叶片SPAD值与块茎相对产量呈线形加平台的数量关系模式,据此确定了应用叶绿素仪SPAD-502进行马铃薯推荐施肥的SPAD临界值为块茎形成期47.3、块茎膨大期45.1、淀粉积累期40.2。     

Leaf Positions of Potato Suitable for Determination of Nitrogen Content with a SPAD Meter

Abstract

Hand-held SPAD meter can be used to evaluate the leaf nitrogen status of potato. For practical use, it is necessary to select a proper compound leaf, a proper leaflet within compound leaf and position of leaflet suitable for measurement. Therefore, field experiments were conducted in northern China in 2009 and 2010. The SPAD values, plant growth, N uptake of potato plants at tuber initiation and tuber bulking stages under different N supply levels, and final tuber yields were examined. The criteria for determining the most suitable leaf, leaflet and position within a leaflet are that the SPAD values show less variation at a given N supply level, and show a more sensitive response to different nitrogen levels. Our results showed that the coefficients of variance of SPAD values ranged from 8.7 to 25.9% with a leaf N concentration range of 2.1 to 3.8 gN 100 g-¹ at tuber initiation stage, and 7.2 to 21.6% with leaf N concentration range of 0.96 to 1.26gN 100 g-¹ at the tuber bulking stage. The SPAD values of the 4th compound leaf from apex were more stable and more sensitive to the nitrogen level than those of other leaves, suggesting that the 4th compound leaf is suitable for estimating the leaf N status using a SPAD meter. Within a compound leaf, the SPAD value of the top leaflet was more sensitivethan the other leaflets to nitrogen supply, whereas it was less stable, making it difficult to chose the leaflet for measurement. However, the top leaflet emerges and expands much earlier than the side leaflets, and should be better for SPAD value measurement. The SPAD measurements at the top point of the top leaflet of the 4th leaf demonstrated both less variation and higher sensitivity to nitrogen supply. Therefore, we conclude that the top point of the top leaflet of the 4th compound leaf is the best position for potato N status diagnosis using a SPAD meter.     

农田土壤Nmin对马铃薯块茎形成的影响

为明确农田土壤矿质氮(Nmin)含量对马铃薯块茎形成的影响,在内蒙古阴山北麓马铃薯主产区大田条件下,利用主栽马铃薯品种‘克新1号’,通过设置不同供氮水平,研究了薯田土壤Nmin含量对块茎形成的时间、数量以及重量的影响。结果表明:土壤Nmin含量在18⁵0 mg/kg范围内时均可形成块茎,且在18.6450 mg/kg范围内时均可形成块茎,且在18.64¹9.94 mg/kg可较早形成块茎,超过50.57 mg/kg时,不形成块茎;较高的土壤Nmin含量会降低块茎形成的数量,在内蒙古阴山北麓地区,马铃薯出苗39 d以后,块茎数量不再增加;虽土壤Nmin含量的增加推迟了块茎的形成时间,但较高的土壤Nmin有利于马铃薯生育后期单株块茎重量的增加。     

Water usage by potato plants at different stages of growth

Three groups of single-halm potato plants were tested for water usage at different stages of growth under growth chamber, greenhouse and field conditions by conducting 24-hour uptake studies at weekly intervals. Although the water usage was higher and more variable in the greenhouse and field than in the growth chamber because of varying environmental conditions during the 24-hour test periods, similar patterns were obtained. From emergence, the potato plant appeared to have four growth stages based on morphological development and water use. The young plant stage from emergence to tuber initiation is characterized by rapid growth, high transpiration rate per unit of plant material (essentially foliage), transpiration significantly correlated with the amount of foliage and a higher percentage of moisture being retained in the plant. The second stage is essentially a short transition stage of tuber initiation where top growth continues, transpiration levels off and a lower percentage of moisture is retained in the plant. The third stage is the tuber bulking stage where transpiration and water use remain relatively static because of non-expanding top growth and a lower percentage of moisture being retained in the plant during the bulking process. The final stage of senescence and tuber ripening is characterized by a marked reduction in water use primarily because of lower transpiration and loss of functioning foliage.     

施用硫酸钾对马铃薯生物性状的影响

钾素对马铃薯的生长发育、结薯、薯块膨大和干物质的积累具有十分重要的作用。凉山州马铃薯主产区土壤普遍缺钾少磷,试验选用马铃薯品种凉薯97,研究在凉山州不同地区不同海拔高度施用硫酸钾对马铃薯生物性状的影响,结果表明:马铃薯施用一定量的硫酸钾能适当延长生育期、显著增产、增加薯块干物质和淀粉含量。667 m2施用硫酸钾15 kg的平均全生育期比对照增加2 d;667 m2施用硫酸钾10 kg的平均产量最高,达到1 819 kg,较对照高28.26%,差异达极显著水平;施用硫酸钾对提高干物质、淀粉含量有一定的作用,综合考虑产量、品质、效益等因素,667 m2硫酸钾施用量以5.0～10.0 kg为宜。     

Potato Stolon and Tuber Growth Influenced by Nitrogen Form

Abstract

Potato tuber initiation and its growth are key processes determining tuber yield, which are closely related to stolon growth, and are influenced by many factors including N nutrition. We investigated the influences of different forms of nitrogen (N) on stolon and tuber growth in sand culture with a nitrification inhibitor during 2010 – 2011, and using two potato cultivars. Plants supplied with NO₃-N (N as nitrate, NO₃^-) produced more and thicker stolons than those supplied with NH₄-N (N as ammonium, NH₄⁺) at tuber initiation stage. In the plants fed NO₃-N, the stolon tips swelled or formed tubers earlier and produced more tubers than in those fed with NH₄-N. However, no significant difference was observed among N forms in terms of tuber yield at harvest, this may have been because of the shoot growth rate at tuber initiation stage was lower in the plants fed NO₃-N. During the tuber bulking stage, the difference in shoot DWs among N forms began to decrease, and the shoot DW of plants fed NO₃-N was even heavier than those fed NH₄-N in some cases. The influence of N form on potato plant growth may therefore vary with the potato growth stage.     

The effect of short periods of shading at different stages of growth on the development of tuber number and yield

Summary Shading potato plants at the beginning of tuber initiation for a period of 12 days reduced the rate of tuber formation and growth; but after the shades were removed tuber formation continued to give more tubers and the shaded plants eventually produced 30% more tubers than the unshaded, with similar yield. Shading for 12 days during the early stages of rapid tuber bulking had no effect on tuber number or survival, though bulking rate was temporarily reduced, leading to a reduction in final yield. These number results indicate that tuber number can be influenced by the weather during the period of tuber initiation.     

马铃薯对氮、磷、钾的吸收及分配规律研究进展

马铃薯的生长发育受到很多因素的影响,特别是养分的供应以及马铃薯对养分的吸收、利用,对其块茎的形成、膨大及淀粉积累的影响尤为显著。氮、磷、钾在马铃薯生长发育中需要量大,必须加以补充,才能满足其正常生长需求。生产上不合理的施肥,导致马铃薯产量不高、品质较差及生产成本增高。通过分析马铃薯不同生育阶段、不同器官吸收养分的特征和分配规律,从而探索马铃薯生产中最佳的氮、磷、钾施肥组合,这对于丰富马铃薯栽培生理理论和指导生产中氮、磷、钾肥合理配施均具有重要的现实意义。